From e59310adf5eebce108f78b6c47bb330aae2e1666 Mon Sep 17 00:00:00 2001 From: Seiji Aguchi Date: Fri, 11 Jan 2013 18:10:05 +0000 Subject: efi_pstore: Avoid deadlock in non-blocking paths [Issue] There is a scenario which efi_pstore may hang up: - cpuA grabs efivars->lock - cpuB panics and calls smp_send_stop - smp_send_stop sends IRQ to cpuA - after 1 second, cpuB gives up on cpuA and sends an NMI instead - cpuA is now in an NMI handler while still holding efivars->lock - cpuB is deadlocked This case may happen if a firmware has a bug and cpuA is stuck talking with it. [Solution] This patch changes a spin_lock to a spin_trylock in non-blocking paths. and if the spin_lock has already taken by another cpu, it returns without accessing to a firmware to avoid the deadlock. Signed-off-by: Seiji Aguchi Acked-by: Don Zickus Signed-off-by: Tony Luck --- drivers/firmware/efivars.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 7b1c37497c9a..ef5070d86f88 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1209,7 +1209,16 @@ static int efi_pstore_write(enum pstore_type_id type, u64 storage_space, remaining_space, max_variable_size; efi_status_t status = EFI_NOT_FOUND; - spin_lock(&efivars->lock); + if (pstore_cannot_block_path(reason)) { + /* + * If the lock is taken by another cpu in non-blocking path, + * this driver returns without entering firmware to avoid + * hanging up. + */ + if (!spin_trylock(&efivars->lock)) + return -EBUSY; + } else + spin_lock(&efivars->lock); /* * Check if there is a space enough to log. -- cgit From 81fa4e581d9283f7992a0d8c534bb141eb840a14 Mon Sep 17 00:00:00 2001 From: Seiji Aguchi Date: Tue, 12 Feb 2013 12:59:07 -0800 Subject: efivars: Disable external interrupt while holding efivars->lock [Problem] There is a scenario which efi_pstore fails to log messages in a panic case. - CPUA holds an efi_var->lock in either efivarfs parts or efi_pstore with interrupt enabled. - CPUB panics and sends IPI to CPUA in smp_send_stop(). - CPUA stops with holding the lock. - CPUB kicks efi_pstore_write() via kmsg_dump(KSMG_DUMP_PANIC) but it returns without logging messages. [Patch Description] This patch disables an external interruption while holding efivars->lock as follows. In efi_pstore_write() and get_var_data(), spin_lock/spin_unlock is replaced by spin_lock_irqsave/spin_unlock_irqrestore because they may be called in an interrupt context. In other functions, they are replaced by spin_lock_irq/spin_unlock_irq. because they are all called from a process context. By applying this patch, we can avoid the problem above with a following senario. - CPUA holds an efi_var->lock with interrupt disabled. - CPUB panics and sends IPI to CPUA in smp_send_stop(). - CPUA receives the IPI after releasing the lock because it is disabling interrupt while holding the lock. - CPUB waits for one sec until CPUA releases the lock. - CPUB kicks efi_pstore_write() via kmsg_dump(KSMG_DUMP_PANIC) And it can hold the lock successfully. Signed-off-by: Seiji Aguchi Acked-by: Mike Waychison Acked-by: Matt Fleming Signed-off-by: Tony Luck --- drivers/firmware/efivars.c | 86 ++++++++++++++++++++++++---------------------- 1 file changed, 44 insertions(+), 42 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index ef5070d86f88..a64fb7bda365 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -405,10 +405,11 @@ static efi_status_t get_var_data(struct efivars *efivars, struct efi_variable *var) { efi_status_t status; + unsigned long flags; - spin_lock(&efivars->lock); + spin_lock_irqsave(&efivars->lock, flags); status = get_var_data_locked(efivars, var); - spin_unlock(&efivars->lock); + spin_unlock_irqrestore(&efivars->lock, flags); if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n", @@ -537,14 +538,14 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) return -EINVAL; } - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); status = efivars->ops->set_variable(new_var->VariableName, &new_var->VendorGuid, new_var->Attributes, new_var->DataSize, new_var->Data); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", @@ -713,7 +714,7 @@ static ssize_t efivarfs_file_write(struct file *file, * amounts of memory. Pick a default size of 64K if * QueryVariableInfo() isn't supported by the firmware. */ - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); if (!efivars->ops->query_variable_info) status = EFI_UNSUPPORTED; @@ -723,7 +724,7 @@ static ssize_t efivarfs_file_write(struct file *file, &remaining_size, &max_size); } - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); if (status != EFI_SUCCESS) { if (status != EFI_UNSUPPORTED) @@ -754,7 +755,7 @@ static ssize_t efivarfs_file_write(struct file *file, * set_variable call, and removal of the variable from the efivars * list (in the case of an authenticated delete). */ - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); status = efivars->ops->set_variable(var->var.VariableName, &var->var.VendorGuid, @@ -762,7 +763,7 @@ static ssize_t efivarfs_file_write(struct file *file, data); if (status != EFI_SUCCESS) { - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); kfree(data); return efi_status_to_err(status); @@ -783,20 +784,20 @@ static ssize_t efivarfs_file_write(struct file *file, NULL); if (status == EFI_BUFFER_TOO_SMALL) { - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); mutex_lock(&inode->i_mutex); i_size_write(inode, newdatasize + sizeof(attributes)); mutex_unlock(&inode->i_mutex); } else if (status == EFI_NOT_FOUND) { list_del(&var->list); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); efivar_unregister(var); drop_nlink(inode); dput(file->f_dentry); } else { - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); pr_warn("efivarfs: inconsistent EFI variable implementation? " "status = %lx\n", status); } @@ -818,11 +819,11 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, void *data; ssize_t size = 0; - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, &attributes, &datasize, NULL); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); if (status != EFI_BUFFER_TOO_SMALL) return efi_status_to_err(status); @@ -832,12 +833,12 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, if (!data) return -ENOMEM; - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, &attributes, &datasize, (data + sizeof(attributes))); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); if (status != EFI_SUCCESS) { size = efi_status_to_err(status); @@ -965,9 +966,9 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, goto out; kobject_uevent(&var->kobj, KOBJ_ADD); - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); list_add(&var->list, &efivars->list); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); d_instantiate(dentry, inode); dget(dentry); out: @@ -984,7 +985,7 @@ static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) struct efivars *efivars = var->efivars; efi_status_t status; - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); status = efivars->ops->set_variable(var->var.VariableName, &var->var.VendorGuid, @@ -992,14 +993,14 @@ static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) if (status == EFI_SUCCESS || status == EFI_NOT_FOUND) { list_del(&var->list); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); efivar_unregister(var); drop_nlink(dir); dput(dentry); return 0; } - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); return -EINVAL; }; @@ -1065,13 +1066,13 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) /* copied by the above to local storage in the dentry. */ kfree(name); - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); efivars->ops->get_variable(entry->var.VariableName, &entry->var.VendorGuid, &entry->var.Attributes, &size, NULL); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); mutex_lock(&inode->i_mutex); inode->i_private = entry; @@ -1122,7 +1123,7 @@ static int efi_pstore_open(struct pstore_info *psi) { struct efivars *efivars = psi->data; - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); efivars->walk_entry = list_first_entry(&efivars->list, struct efivar_entry, list); return 0; @@ -1132,7 +1133,7 @@ static int efi_pstore_close(struct pstore_info *psi) { struct efivars *efivars = psi->data; - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); return 0; } @@ -1208,6 +1209,7 @@ static int efi_pstore_write(enum pstore_type_id type, int i, ret = 0; u64 storage_space, remaining_space, max_variable_size; efi_status_t status = EFI_NOT_FOUND; + unsigned long flags; if (pstore_cannot_block_path(reason)) { /* @@ -1215,10 +1217,10 @@ static int efi_pstore_write(enum pstore_type_id type, * this driver returns without entering firmware to avoid * hanging up. */ - if (!spin_trylock(&efivars->lock)) + if (!spin_trylock_irqsave(&efivars->lock, flags)) return -EBUSY; } else - spin_lock(&efivars->lock); + spin_lock_irqsave(&efivars->lock, flags); /* * Check if there is a space enough to log. @@ -1230,7 +1232,7 @@ static int efi_pstore_write(enum pstore_type_id type, &remaining_space, &max_variable_size); if (status || remaining_space < size + DUMP_NAME_LEN * 2) { - spin_unlock(&efivars->lock); + spin_unlock_irqrestore(&efivars->lock, flags); *id = part; return -ENOSPC; } @@ -1244,7 +1246,7 @@ static int efi_pstore_write(enum pstore_type_id type, efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES, size, psi->buf); - spin_unlock(&efivars->lock); + spin_unlock_irqrestore(&efivars->lock, flags); if (size) ret = efivar_create_sysfs_entry(efivars, @@ -1271,7 +1273,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count, time.tv_sec); - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = name[i]; @@ -1315,7 +1317,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, if (found) list_del(&found->list); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); if (found) efivar_unregister(found); @@ -1385,7 +1387,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj, return -EINVAL; } - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); /* * Does this variable already exist? @@ -1403,7 +1405,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj, } } if (found) { - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); return -EINVAL; } @@ -1417,10 +1419,10 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj, if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", status); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); return -EIO; } - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); /* Create the entry in sysfs. Locking is not required here */ status = efivar_create_sysfs_entry(efivars, @@ -1448,7 +1450,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, if (!capable(CAP_SYS_ADMIN)) return -EACCES; - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); /* * Does this variable already exist? @@ -1466,7 +1468,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, } } if (!found) { - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); return -EINVAL; } /* force the Attributes/DataSize to 0 to ensure deletion */ @@ -1482,12 +1484,12 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", status); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); return -EIO; } list_del(&search_efivar->list); /* We need to release this lock before unregistering. */ - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); efivar_unregister(search_efivar); /* It's dead Jim.... */ @@ -1602,9 +1604,9 @@ efivar_create_sysfs_entry(struct efivars *efivars, kfree(short_name); short_name = NULL; - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); list_add(&new_efivar->list, &efivars->list); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); return 0; } @@ -1673,9 +1675,9 @@ void unregister_efivars(struct efivars *efivars) struct efivar_entry *entry, *n; list_for_each_entry_safe(entry, n, &efivars->list, list) { - spin_lock(&efivars->lock); + spin_lock_irq(&efivars->lock); list_del(&entry->list); - spin_unlock(&efivars->lock); + spin_unlock_irq(&efivars->lock); efivar_unregister(entry); } if (efivars->new_var) -- cgit From a93bc0c6e07ed9bac44700280e65e2945d864fd4 Mon Sep 17 00:00:00 2001 From: Seiji Aguchi Date: Tue, 12 Feb 2013 13:04:41 -0800 Subject: efi_pstore: Introducing workqueue updating sysfs [Problem] efi_pstore creates sysfs entries, which enable users to access to NVRAM, in a write callback. If a kernel panic happens in an interrupt context, it may fail because it could sleep due to dynamic memory allocations during creating sysfs entries. [Patch Description] This patch removes sysfs operations from a write callback by introducing a workqueue updating sysfs entries which is scheduled after the write callback is called. Also, the workqueue is kicked in a just oops case. A system will go down in other cases such as panic, clean shutdown and emergency restart. And we don't need to create sysfs entries because there is no chance for users to access to them. efi_pstore will be robust against a kernel panic in an interrupt context with this patch. Signed-off-by: Seiji Aguchi Acked-by: Matt Fleming Signed-off-by: Tony Luck --- drivers/firmware/efivars.c | 85 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 80 insertions(+), 5 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index a64fb7bda365..69225115304d 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -158,6 +158,13 @@ efivar_create_sysfs_entry(struct efivars *efivars, efi_char16_t *variable_name, efi_guid_t *vendor_guid); +/* + * Prototype for workqueue functions updating sysfs entry + */ + +static void efivar_update_sysfs_entries(struct work_struct *); +static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries); + /* Return the number of unicode characters in data */ static unsigned long utf16_strnlen(efi_char16_t *s, size_t maxlength) @@ -1248,11 +1255,8 @@ static int efi_pstore_write(enum pstore_type_id type, spin_unlock_irqrestore(&efivars->lock, flags); - if (size) - ret = efivar_create_sysfs_entry(efivars, - utf16_strsize(efi_name, - DUMP_NAME_LEN * 2), - efi_name, &vendor); + if (reason == KMSG_DUMP_OOPS) + schedule_work(&efivar_work); *id = part; return ret; @@ -1496,6 +1500,75 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, return count; } +static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) +{ + struct efivar_entry *entry, *n; + struct efivars *efivars = &__efivars; + unsigned long strsize1, strsize2; + bool found = false; + + strsize1 = utf16_strsize(variable_name, 1024); + list_for_each_entry_safe(entry, n, &efivars->list, list) { + strsize2 = utf16_strsize(entry->var.VariableName, 1024); + if (strsize1 == strsize2 && + !memcmp(variable_name, &(entry->var.VariableName), + strsize2) && + !efi_guidcmp(entry->var.VendorGuid, + *vendor)) { + found = true; + break; + } + } + return found; +} + +static void efivar_update_sysfs_entries(struct work_struct *work) +{ + struct efivars *efivars = &__efivars; + efi_guid_t vendor; + efi_char16_t *variable_name; + unsigned long variable_name_size = 1024; + efi_status_t status = EFI_NOT_FOUND; + bool found; + + /* Add new sysfs entries */ + while (1) { + variable_name = kzalloc(variable_name_size, GFP_KERNEL); + if (!variable_name) { + pr_err("efivars: Memory allocation failed.\n"); + return; + } + + spin_lock_irq(&efivars->lock); + found = false; + while (1) { + variable_name_size = 1024; + status = efivars->ops->get_next_variable( + &variable_name_size, + variable_name, + &vendor); + if (status != EFI_SUCCESS) { + break; + } else { + if (!variable_is_present(variable_name, + &vendor)) { + found = true; + break; + } + } + } + spin_unlock_irq(&efivars->lock); + + if (!found) { + kfree(variable_name); + break; + } else + efivar_create_sysfs_entry(efivars, + variable_name_size, + variable_name, &vendor); + } +} + /* * Let's not leave out systab information that snuck into * the efivars driver @@ -1833,6 +1906,8 @@ err_put: static void __exit efivars_exit(void) { + cancel_work_sync(&efivar_work); + if (efi_enabled) { unregister_efivars(&__efivars); kobject_put(efi_kobj); -- cgit From 46c66c4b7ba0f9bb3e2ae3a3cfd40cd3472c8f80 Mon Sep 17 00:00:00 2001 From: Yasuaki Ishimatsu Date: Fri, 22 Feb 2013 16:32:56 -0800 Subject: memory-hotplug: remove /sys/firmware/memmap/X sysfs When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type} sysfs files are created. But there is no code to remove these files. This patch implements the function to remove them. We cannot free firmware_map_entry which is allocated by bootmem because there is no way to do so when the system is up. But we can at least remember the address of that memory and reuse the storage when the memory is added next time. This patch also introduces a new list map_entries_bootmem to link the map entries allocated by bootmem when they are removed, and a lock to protect it. And these entries will be reused when the memory is hot-added again. The idea is suggestted by Andrew Morton. NOTE: It is unsafe to return an entry pointer and release the map_entries_lock. So we should not hold the map_entries_lock separately in firmware_map_find_entry() and firmware_map_remove_entry(). Hold the map_entries_lock across find and remove /sys/firmware/memmap/X operation. And also, users of these two functions need to be careful to hold the lock when using these two functions. [tangchen@cn.fujitsu.com: Hold spinlock across find|remove /sys operation] [tangchen@cn.fujitsu.com: fix the wrong comments of map_entries] [tangchen@cn.fujitsu.com: reuse the storage of /sys/firmware/memmap/X/ allocated by bootmem] [tangchen@cn.fujitsu.com: fix section mismatch problem] [tangchen@cn.fujitsu.com: fix the doc format in drivers/firmware/memmap.c] Signed-off-by: Wen Congyang Signed-off-by: Yasuaki Ishimatsu Signed-off-by: Tang Chen Reviewed-by: Kamezawa Hiroyuki Cc: KOSAKI Motohiro Cc: Jiang Liu Cc: Jianguo Wu Cc: Lai Jiangshan Cc: Tang Chen Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Julian Calaby Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/firmware/memmap.c | 196 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 183 insertions(+), 13 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c index 90723e65b081..0b5b5f619c75 100644 --- a/drivers/firmware/memmap.c +++ b/drivers/firmware/memmap.c @@ -21,6 +21,7 @@ #include #include #include +#include /* * Data types ------------------------------------------------------------------ @@ -52,6 +53,9 @@ static ssize_t start_show(struct firmware_map_entry *entry, char *buf); static ssize_t end_show(struct firmware_map_entry *entry, char *buf); static ssize_t type_show(struct firmware_map_entry *entry, char *buf); +static struct firmware_map_entry * __meminit +firmware_map_find_entry(u64 start, u64 end, const char *type); + /* * Static data ----------------------------------------------------------------- */ @@ -79,7 +83,52 @@ static const struct sysfs_ops memmap_attr_ops = { .show = memmap_attr_show, }; -static struct kobj_type memmap_ktype = { +/* Firmware memory map entries. */ +static LIST_HEAD(map_entries); +static DEFINE_SPINLOCK(map_entries_lock); + +/* + * For memory hotplug, there is no way to free memory map entries allocated + * by boot mem after the system is up. So when we hot-remove memory whose + * map entry is allocated by bootmem, we need to remember the storage and + * reuse it when the memory is hot-added again. + */ +static LIST_HEAD(map_entries_bootmem); +static DEFINE_SPINLOCK(map_entries_bootmem_lock); + + +static inline struct firmware_map_entry * +to_memmap_entry(struct kobject *kobj) +{ + return container_of(kobj, struct firmware_map_entry, kobj); +} + +static void __meminit release_firmware_map_entry(struct kobject *kobj) +{ + struct firmware_map_entry *entry = to_memmap_entry(kobj); + + if (PageReserved(virt_to_page(entry))) { + /* + * Remember the storage allocated by bootmem, and reuse it when + * the memory is hot-added again. The entry will be added to + * map_entries_bootmem here, and deleted from &map_entries in + * firmware_map_remove_entry(). + */ + if (firmware_map_find_entry(entry->start, entry->end, + entry->type)) { + spin_lock(&map_entries_bootmem_lock); + list_add(&entry->list, &map_entries_bootmem); + spin_unlock(&map_entries_bootmem_lock); + } + + return; + } + + kfree(entry); +} + +static struct kobj_type __refdata memmap_ktype = { + .release = release_firmware_map_entry, .sysfs_ops = &memmap_attr_ops, .default_attrs = def_attrs, }; @@ -88,13 +137,6 @@ static struct kobj_type memmap_ktype = { * Registration functions ------------------------------------------------------ */ -/* - * Firmware memory map entries. No locking is needed because the - * firmware_map_add() and firmware_map_add_early() functions are called - * in firmware initialisation code in one single thread of execution. - */ -static LIST_HEAD(map_entries); - /** * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. * @start: Start of the memory range. @@ -118,11 +160,25 @@ static int firmware_map_add_entry(u64 start, u64 end, INIT_LIST_HEAD(&entry->list); kobject_init(&entry->kobj, &memmap_ktype); + spin_lock(&map_entries_lock); list_add_tail(&entry->list, &map_entries); + spin_unlock(&map_entries_lock); return 0; } +/** + * firmware_map_remove_entry() - Does the real work to remove a firmware + * memmap entry. + * @entry: removed entry. + * + * The caller must hold map_entries_lock, and release it properly. + **/ +static inline void firmware_map_remove_entry(struct firmware_map_entry *entry) +{ + list_del(&entry->list); +} + /* * Add memmap entry on sysfs */ @@ -144,6 +200,78 @@ static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry) return 0; } +/* + * Remove memmap entry on sysfs + */ +static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry) +{ + kobject_put(&entry->kobj); +} + +/* + * firmware_map_find_entry_in_list() - Search memmap entry in a given list. + * @start: Start of the memory range. + * @end: End of the memory range (exclusive). + * @type: Type of the memory range. + * @list: In which to find the entry. + * + * This function is to find the memmap entey of a given memory range in a + * given list. The caller must hold map_entries_lock, and must not release + * the lock until the processing of the returned entry has completed. + * + * Return: Pointer to the entry to be found on success, or NULL on failure. + */ +static struct firmware_map_entry * __meminit +firmware_map_find_entry_in_list(u64 start, u64 end, const char *type, + struct list_head *list) +{ + struct firmware_map_entry *entry; + + list_for_each_entry(entry, list, list) + if ((entry->start == start) && (entry->end == end) && + (!strcmp(entry->type, type))) { + return entry; + } + + return NULL; +} + +/* + * firmware_map_find_entry() - Search memmap entry in map_entries. + * @start: Start of the memory range. + * @end: End of the memory range (exclusive). + * @type: Type of the memory range. + * + * This function is to find the memmap entey of a given memory range. + * The caller must hold map_entries_lock, and must not release the lock + * until the processing of the returned entry has completed. + * + * Return: Pointer to the entry to be found on success, or NULL on failure. + */ +static struct firmware_map_entry * __meminit +firmware_map_find_entry(u64 start, u64 end, const char *type) +{ + return firmware_map_find_entry_in_list(start, end, type, &map_entries); +} + +/* + * firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem. + * @start: Start of the memory range. + * @end: End of the memory range (exclusive). + * @type: Type of the memory range. + * + * This function is similar to firmware_map_find_entry except that it find the + * given entry in map_entries_bootmem. + * + * Return: Pointer to the entry to be found on success, or NULL on failure. + */ +static struct firmware_map_entry * __meminit +firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type) +{ + return firmware_map_find_entry_in_list(start, end, type, + &map_entries_bootmem); +} + /** * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do * memory hotplug. @@ -161,9 +289,19 @@ int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type) { struct firmware_map_entry *entry; - entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); - if (!entry) - return -ENOMEM; + entry = firmware_map_find_entry_bootmem(start, end, type); + if (!entry) { + entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); + if (!entry) + return -ENOMEM; + } else { + /* Reuse storage allocated by bootmem. */ + spin_lock(&map_entries_bootmem_lock); + list_del(&entry->list); + spin_unlock(&map_entries_bootmem_lock); + + memset(entry, 0, sizeof(*entry)); + } firmware_map_add_entry(start, end, type, entry); /* create the memmap entry */ @@ -196,6 +334,36 @@ int __init firmware_map_add_early(u64 start, u64 end, const char *type) return firmware_map_add_entry(start, end, type, entry); } +/** + * firmware_map_remove() - remove a firmware mapping entry + * @start: Start of the memory range. + * @end: End of the memory range. + * @type: Type of the memory range. + * + * removes a firmware mapping entry. + * + * Returns 0 on success, or -EINVAL if no entry. + **/ +int __meminit firmware_map_remove(u64 start, u64 end, const char *type) +{ + struct firmware_map_entry *entry; + + spin_lock(&map_entries_lock); + entry = firmware_map_find_entry(start, end - 1, type); + if (!entry) { + spin_unlock(&map_entries_lock); + return -EINVAL; + } + + firmware_map_remove_entry(entry); + spin_unlock(&map_entries_lock); + + /* remove the memmap entry */ + remove_sysfs_fw_map_entry(entry); + + return 0; +} + /* * Sysfs functions ------------------------------------------------------------- */ @@ -217,8 +385,10 @@ static ssize_t type_show(struct firmware_map_entry *entry, char *buf) return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); } -#define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) -#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) +static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr) +{ + return container_of(attr, struct memmap_attribute, attr); +} static ssize_t memmap_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) -- cgit From 7f78e0351394052e1a6293e175825eb5c7869507 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sat, 2 Mar 2013 19:39:14 -0800 Subject: fs: Limit sys_mount to only request filesystem modules. Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn Acked-by: Kees Cook Reported-by: Kees Cook Signed-off-by: "Eric W. Biederman" --- drivers/firmware/efivars.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 7320bf891706..3edade07b249 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1234,6 +1234,7 @@ static struct file_system_type efivarfs_type = { .mount = efivarfs_mount, .kill_sb = efivarfs_kill_sb, }; +MODULE_ALIAS_FS("efivarfs"); /* * Handle negative dentry. -- cgit From 68d929862e29a8b52a7f2f2f86a0600423b093cd Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Sat, 2 Mar 2013 19:40:17 -0500 Subject: efi: be more paranoid about available space when creating variables UEFI variables are typically stored in flash. For various reasons, avaiable space is typically not reclaimed immediately upon the deletion of a variable - instead, the system will garbage collect during initialisation after a reboot. Some systems appear to handle this garbage collection extremely poorly, failing if more than 50% of the system flash is in use. This can result in the machine refusing to boot. The safest thing to do for the moment is to forbid writes if they'd end up using more than half of the storage space. We can make this more finegrained later if we come up with a method for identifying the broken machines. Signed-off-by: Matthew Garrett Cc: Josh Boyer Cc: Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 106 +++++++++++++++++++++++++++++++++------------ 1 file changed, 79 insertions(+), 27 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 7320bf891706..0d504971ed4c 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -426,6 +426,44 @@ get_var_data(struct efivars *efivars, struct efi_variable *var) return status; } +static efi_status_t +check_var_size_locked(struct efivars *efivars, u32 attributes, + unsigned long size) +{ + u64 storage_size, remaining_size, max_size; + efi_status_t status; + const struct efivar_operations *fops = efivars->ops; + + if (!efivars->ops->query_variable_info) + return EFI_UNSUPPORTED; + + status = fops->query_variable_info(attributes, &storage_size, + &remaining_size, &max_size); + + if (status != EFI_SUCCESS) + return status; + + if (!storage_size || size > remaining_size || size > max_size || + (remaining_size - size) < (storage_size / 2)) + return EFI_OUT_OF_RESOURCES; + + return status; +} + + +static efi_status_t +check_var_size(struct efivars *efivars, u32 attributes, unsigned long size) +{ + efi_status_t status; + unsigned long flags; + + spin_lock_irqsave(&efivars->lock, flags); + status = check_var_size_locked(efivars, attributes, size); + spin_unlock_irqrestore(&efivars->lock, flags); + + return status; +} + static ssize_t efivar_guid_read(struct efivar_entry *entry, char *buf) { @@ -547,11 +585,16 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) } spin_lock_irq(&efivars->lock); - status = efivars->ops->set_variable(new_var->VariableName, - &new_var->VendorGuid, - new_var->Attributes, - new_var->DataSize, - new_var->Data); + + status = check_var_size_locked(efivars, new_var->Attributes, + new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); + + if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) + status = efivars->ops->set_variable(new_var->VariableName, + &new_var->VendorGuid, + new_var->Attributes, + new_var->DataSize, + new_var->Data); spin_unlock_irq(&efivars->lock); @@ -702,8 +745,7 @@ static ssize_t efivarfs_file_write(struct file *file, u32 attributes; struct inode *inode = file->f_mapping->host; unsigned long datasize = count - sizeof(attributes); - unsigned long newdatasize; - u64 storage_size, remaining_size, max_size; + unsigned long newdatasize, varsize; ssize_t bytes = 0; if (count < sizeof(attributes)) @@ -722,28 +764,18 @@ static ssize_t efivarfs_file_write(struct file *file, * amounts of memory. Pick a default size of 64K if * QueryVariableInfo() isn't supported by the firmware. */ - spin_lock_irq(&efivars->lock); - if (!efivars->ops->query_variable_info) - status = EFI_UNSUPPORTED; - else { - const struct efivar_operations *fops = efivars->ops; - status = fops->query_variable_info(attributes, &storage_size, - &remaining_size, &max_size); - } - - spin_unlock_irq(&efivars->lock); + varsize = datasize + utf16_strsize(var->var.VariableName, 1024); + status = check_var_size(efivars, attributes, varsize); if (status != EFI_SUCCESS) { if (status != EFI_UNSUPPORTED) return efi_status_to_err(status); - remaining_size = 65536; + if (datasize > 65536) + return -ENOSPC; } - if (datasize > remaining_size) - return -ENOSPC; - data = kmalloc(datasize, GFP_KERNEL); if (!data) return -ENOMEM; @@ -765,6 +797,19 @@ static ssize_t efivarfs_file_write(struct file *file, */ spin_lock_irq(&efivars->lock); + /* + * Ensure that the available space hasn't shrunk below the safe level + */ + + status = check_var_size_locked(efivars, attributes, varsize); + + if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED) { + spin_unlock_irq(&efivars->lock); + kfree(data); + + return efi_status_to_err(status); + } + status = efivars->ops->set_variable(var->var.VariableName, &var->var.VendorGuid, attributes, datasize, @@ -1345,7 +1390,6 @@ static int efi_pstore_write(enum pstore_type_id type, efi_guid_t vendor = LINUX_EFI_CRASH_GUID; struct efivars *efivars = psi->data; int i, ret = 0; - u64 storage_space, remaining_space, max_variable_size; efi_status_t status = EFI_NOT_FOUND; unsigned long flags; @@ -1365,11 +1409,11 @@ static int efi_pstore_write(enum pstore_type_id type, * size: a size of logging data * DUMP_NAME_LEN * 2: a maximum size of variable name */ - status = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES, - &storage_space, - &remaining_space, - &max_variable_size); - if (status || remaining_space < size + DUMP_NAME_LEN * 2) { + + status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES, + size + DUMP_NAME_LEN * 2); + + if (status) { spin_unlock_irqrestore(&efivars->lock, flags); *id = part; return -ENOSPC; @@ -1544,6 +1588,14 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj, return -EINVAL; } + status = check_var_size_locked(efivars, new_var->Attributes, + new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); + + if (status && status != EFI_UNSUPPORTED) { + spin_unlock_irq(&efivars->lock); + return efi_status_to_err(status); + } + /* now *really* create the variable via EFI */ status = efivars->ops->set_variable(new_var->VariableName, &new_var->VendorGuid, -- cgit From 123abd76edf56c02a76b46d3d673897177ef067b Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Tue, 5 Mar 2013 07:40:16 +0000 Subject: efivars: efivarfs_valid_name() should handle pstore syntax Stricter validation was introduced with commit da27a24383b2b ("efivarfs: guid part of filenames are case-insensitive") and commit 47f531e8ba3b ("efivarfs: Validate filenames much more aggressively"), which is necessary for the guid portion of efivarfs filenames, but we don't need to be so strict with the first part, the variable name. The UEFI specification doesn't impose any constraints on variable names other than they be a NULL-terminated string. The above commits caused a regression that resulted in users seeing the following message, $ sudo mount -v /sys/firmware/efi/efivars mount: Cannot allocate memory whenever pstore EFI variables were present in the variable store, since their variable names failed to pass the following check, /* GUID should be right after the first '-' */ if (s - 1 != strchr(str, '-')) as a typical pstore filename is of the form, dump-type0-10-1-. The fix is trivial since the guid portion of the filename is GUID_LEN bytes, we can use (len - GUID_LEN) to ensure the '-' character is where we expect it to be. (The bogus ENOMEM error value will be fixed in a separate patch.) Reported-by: Joseph Yasi Tested-by: Joseph Yasi Reported-by: Lingzhu Xiang Cc: Josh Boyer Cc: Jeremy Kerr Cc: Matthew Garrett Cc: # v3.8 Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 0d504971ed4c..1b9a6e17e3dc 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -974,8 +974,8 @@ static bool efivarfs_valid_name(const char *str, int len) if (len < GUID_LEN + 2) return false; - /* GUID should be right after the first '-' */ - if (s - 1 != strchr(str, '-')) + /* GUID must be preceded by a '-' */ + if (*(s - 1) != '-') return false; /* -- cgit From feff5dc4f98330d8152b521acc2e18c16712e6c8 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Tue, 5 Mar 2013 12:46:30 +0000 Subject: efivarfs: return accurate error code in efivarfs_fill_super() Joseph was hitting a failure case when mounting efivarfs which resulted in an incorrect error message, $ sudo mount -v /sys/firmware/efi/efivars mount: Cannot allocate memory triggered when efivarfs_valid_name() returned -EINVAL. Make sure we pass accurate return values up the stack if efivarfs_fill_super() fails to build inodes for EFI variables. Reported-by: Joseph Yasi Reported-by: Lingzhu Xiang Cc: Josh Boyer Cc: Jeremy Kerr Cc: Matthew Garrett Cc: # v3.8 Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 1b9a6e17e3dc..bea32d1ef7d5 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1163,15 +1163,22 @@ static struct dentry_operations efivarfs_d_ops = { static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name) { + struct dentry *d; struct qstr q; + int err; q.name = name; q.len = strlen(name); - if (efivarfs_d_hash(NULL, NULL, &q)) - return NULL; + err = efivarfs_d_hash(NULL, NULL, &q); + if (err) + return ERR_PTR(err); + + d = d_alloc(parent, &q); + if (d) + return d; - return d_alloc(parent, &q); + return ERR_PTR(-ENOMEM); } static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) @@ -1181,6 +1188,7 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) struct efivar_entry *entry, *n; struct efivars *efivars = &__efivars; char *name; + int err = -ENOMEM; efivarfs_sb = sb; @@ -1231,8 +1239,10 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) goto fail_name; dentry = efivarfs_alloc_dentry(root, name); - if (!dentry) + if (IS_ERR(dentry)) { + err = PTR_ERR(dentry); goto fail_inode; + } /* copied by the above to local storage in the dentry. */ kfree(name); @@ -1259,7 +1269,7 @@ fail_inode: fail_name: kfree(name); fail: - return -ENOMEM; + return err; } static struct dentry *efivarfs_mount(struct file_system_type *fs_type, -- cgit From a40e7cf8f06b4e322ba902e4e9f6a6b0c2daa907 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Fri, 8 Mar 2013 12:43:32 -0800 Subject: dmi_scan: fix missing check for _DMI_ signature in smbios_present() Commit 9f9c9cbb6057 ("drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists") hoisted the check for "_DMI_" into dmi_scan_machine(), which means that we don't bother to check for "_DMI_" at offset 16 in an SMBIOS entry. smbios_present() may also call dmi_present() for an address where we found "_SM_", if it failed further validation. Check for "_DMI_" in smbios_present() before calling dmi_present(). [akpm@linux-foundation.org: fix build] Signed-off-by: Ben Hutchings Reported-by: Tim McGrath Tested-by: Tim Mcgrath Cc: Zhenzhong Duan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/firmware/dmi_scan.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 982f1f5f5742..4cd392dbf115 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -442,7 +442,6 @@ static int __init dmi_present(const char __iomem *p) static int __init smbios_present(const char __iomem *p) { u8 buf[32]; - int offset = 0; memcpy_fromio(buf, p, 32); if ((buf[5] < 32) && dmi_checksum(buf, buf[5])) { @@ -461,9 +460,9 @@ static int __init smbios_present(const char __iomem *p) dmi_ver = 0x0206; break; } - offset = 16; + return memcmp(p + 16, "_DMI_", 5) || dmi_present(p + 16); } - return dmi_present(buf + offset); + return 1; } void __init dmi_scan_machine(void) -- cgit From ed9dc8ce7a1c8115dba9483a9b51df8b63a2e0ef Mon Sep 17 00:00:00 2001 From: Seth Forshee Date: Thu, 7 Mar 2013 11:40:17 -0600 Subject: efivars: Allow disabling use as a pstore backend Add a new option, CONFIG_EFI_VARS_PSTORE, which can be set to N to avoid using efivars as a backend to pstore, as some users may want to compile out the code completely. Set the default to Y to maintain backwards compatability, since this feature has always been enabled until now. Signed-off-by: Seth Forshee Cc: Josh Boyer Cc: Matthew Garrett Cc: Seiji Aguchi Cc: Tony Luck Cc: Signed-off-by: Matt Fleming --- drivers/firmware/Kconfig | 9 +++++++ drivers/firmware/efivars.c | 64 +++++++++++++++------------------------------- 2 files changed, 29 insertions(+), 44 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index 9b00072a020f..898023d8e486 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -53,6 +53,15 @@ config EFI_VARS Subsequent efibootmgr releases may be found at: +config EFI_VARS_PSTORE + bool "Register efivars backend for pstore" + depends on EFI_VARS && PSTORE + default y + help + Say Y here to enable use efivars as a backend to pstore. This + will allow writing console messages, crash dumps, or anything + else supported by pstore to EFI variables. + config EFI_PCDP bool "Console device selection via EFI PCDP or HCDP table" depends on ACPI && EFI && IA64 diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index fe62aa392239..37b6f247399e 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1309,9 +1309,7 @@ static const struct inode_operations efivarfs_dir_inode_operations = { .create = efivarfs_create, }; -static struct pstore_info efi_pstore_info; - -#ifdef CONFIG_PSTORE +#ifdef CONFIG_EFI_VARS_PSTORE static int efi_pstore_open(struct pstore_info *psi) { @@ -1514,38 +1512,6 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, return 0; } -#else -static int efi_pstore_open(struct pstore_info *psi) -{ - return 0; -} - -static int efi_pstore_close(struct pstore_info *psi) -{ - return 0; -} - -static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, int *count, - struct timespec *timespec, - char **buf, struct pstore_info *psi) -{ - return -1; -} - -static int efi_pstore_write(enum pstore_type_id type, - enum kmsg_dump_reason reason, u64 *id, - unsigned int part, int count, size_t size, - struct pstore_info *psi) -{ - return 0; -} - -static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, - struct timespec time, struct pstore_info *psi) -{ - return 0; -} -#endif static struct pstore_info efi_pstore_info = { .owner = THIS_MODULE, @@ -1557,6 +1523,24 @@ static struct pstore_info efi_pstore_info = { .erase = efi_pstore_erase, }; +static void efivar_pstore_register(struct efivars *efivars) +{ + efivars->efi_pstore_info = efi_pstore_info; + efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); + if (efivars->efi_pstore_info.buf) { + efivars->efi_pstore_info.bufsize = 1024; + efivars->efi_pstore_info.data = efivars; + spin_lock_init(&efivars->efi_pstore_info.buf_lock); + pstore_register(&efivars->efi_pstore_info); + } +} +#else +static void efivar_pstore_register(struct efivars *efivars) +{ + return; +} +#endif + static ssize_t efivar_create(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) @@ -2025,15 +2009,7 @@ int register_efivars(struct efivars *efivars, if (error) unregister_efivars(efivars); - efivars->efi_pstore_info = efi_pstore_info; - - efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); - if (efivars->efi_pstore_info.buf) { - efivars->efi_pstore_info.bufsize = 1024; - efivars->efi_pstore_info.data = efivars; - spin_lock_init(&efivars->efi_pstore_info.buf_lock); - pstore_register(&efivars->efi_pstore_info); - } + efivar_pstore_register(efivars); register_filesystem(&efivarfs_type); -- cgit From ec0971ba5372a4dfa753f232449d23a8fd98490e Mon Sep 17 00:00:00 2001 From: Seth Forshee Date: Mon, 11 Mar 2013 16:17:50 -0500 Subject: efivars: Add module parameter to disable use as a pstore backend We know that with some firmware implementations writing too much data to UEFI variables can lead to bricking machines. Recent changes attempt to address this issue, but for some it may still be prudent to avoid writing large amounts of data until the solution has been proven on a wide variety of hardware. Crash dumps or other data from pstore can potentially be a large data source. Add a pstore_module parameter to efivars to allow disabling its use as a backend for pstore. Also add a config option, CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE, to allow setting the default value of this paramter to true (i.e. disabled by default). Signed-off-by: Seth Forshee Cc: Josh Boyer Cc: Matthew Garrett Cc: Seiji Aguchi Cc: Tony Luck Cc: Signed-off-by: Matt Fleming --- drivers/firmware/Kconfig | 9 +++++++++ drivers/firmware/efivars.c | 8 +++++++- 2 files changed, 16 insertions(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index 898023d8e486..42c759a4d047 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -62,6 +62,15 @@ config EFI_VARS_PSTORE will allow writing console messages, crash dumps, or anything else supported by pstore to EFI variables. +config EFI_VARS_PSTORE_DEFAULT_DISABLE + bool "Disable using efivars as a pstore backend by default" + depends on EFI_VARS_PSTORE + default n + help + Saying Y here will disable the use of efivars as a storage + backend for pstore by default. This setting can be overridden + using the efivars module's pstore_disable parameter. + config EFI_PCDP bool "Console device selection via EFI PCDP or HCDP table" depends on ACPI && EFI && IA64 diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 37b6f247399e..6607daf5a08d 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -103,6 +103,11 @@ MODULE_VERSION(EFIVARS_VERSION); */ #define GUID_LEN 36 +static bool efivars_pstore_disable = + IS_ENABLED(EFI_VARS_PSTORE_DEFAULT_DISABLE); + +module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); + /* * The maximum size of VariableName + Data = 1024 * Therefore, it's reasonable to save that much @@ -2009,7 +2014,8 @@ int register_efivars(struct efivars *efivars, if (error) unregister_efivars(efivars); - efivar_pstore_register(efivars); + if (!efivars_pstore_disable) + efivar_pstore_register(efivars); register_filesystem(&efivarfs_type); -- cgit From ec50bd32f1672d38ddce10fb1841cbfda89cfe9a Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 1 Mar 2013 14:49:12 +0000 Subject: efivars: explicitly calculate length of VariableName It's not wise to assume VariableNameSize represents the length of VariableName, as not all firmware updates VariableNameSize in the same way (some don't update it at all if EFI_SUCCESS is returned). There are even implementations out there that update VariableNameSize with values that are both larger than the string returned in VariableName and smaller than the buffer passed to GetNextVariableName(), which resulted in the following bug report from Michael Schroeder, > On HP z220 system (firmware version 1.54), some EFI variables are > incorrectly named : > > ls -d /sys/firmware/efi/vars/*8be4d* | grep -v -- -8be returns > /sys/firmware/efi/vars/dbxDefault-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > /sys/firmware/efi/vars/KEKDefault-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > /sys/firmware/efi/vars/SecureBoot-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > /sys/firmware/efi/vars/SetupMode-Information8be4df61-93ca-11d2-aa0d-00e098032b8c The issue here is that because we blindly use VariableNameSize without verifying its value, we can potentially read garbage values from the buffer containing VariableName if VariableNameSize is larger than the length of VariableName. Since VariableName is a string, we can calculate its size by searching for the terminating NULL character. Reported-by: Frederic Crozat Cc: Matthew Garrett Cc: Josh Boyer Cc: Michael Schroeder Cc: Lee, Chun-Yi Cc: Lingzhu Xiang Cc: Seiji Aguchi Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 6607daf5a08d..1e9d9b9d7a12 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1705,6 +1705,31 @@ static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) return found; } +/* + * Returns the size of variable_name, in bytes, including the + * terminating NULL character, or variable_name_size if no NULL + * character is found among the first variable_name_size bytes. + */ +static unsigned long var_name_strnsize(efi_char16_t *variable_name, + unsigned long variable_name_size) +{ + unsigned long len; + efi_char16_t c; + + /* + * The variable name is, by definition, a NULL-terminated + * string, so make absolutely sure that variable_name_size is + * the value we expect it to be. If not, return the real size. + */ + for (len = 2; len <= variable_name_size; len += sizeof(c)) { + c = variable_name[(len / sizeof(c)) - 1]; + if (!c) + break; + } + + return min(len, variable_name_size); +} + static void efivar_update_sysfs_entries(struct work_struct *work) { struct efivars *efivars = &__efivars; @@ -1745,10 +1770,13 @@ static void efivar_update_sysfs_entries(struct work_struct *work) if (!found) { kfree(variable_name); break; - } else + } else { + variable_name_size = var_name_strnsize(variable_name, + variable_name_size); efivar_create_sysfs_entry(efivars, variable_name_size, variable_name, &vendor); + } } } @@ -1995,6 +2023,8 @@ int register_efivars(struct efivars *efivars, &vendor_guid); switch (status) { case EFI_SUCCESS: + variable_name_size = var_name_strnsize(variable_name, + variable_name_size); efivar_create_sysfs_entry(efivars, variable_name_size, variable_name, -- cgit From e971318bbed610e28bb3fde9d548e6aaf0a6b02e Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Thu, 7 Mar 2013 11:59:14 +0000 Subject: efivars: Handle duplicate names from get_next_variable() Some firmware exhibits a bug where the same VariableName and VendorGuid values are returned on multiple invocations of GetNextVariableName(). See, https://bugzilla.kernel.org/show_bug.cgi?id=47631 As a consequence of such a bug, Andre reports hitting the following WARN_ON() in the sysfs code after updating the BIOS on his, "Gigabyte Technology Co., Ltd. To be filled by O.E.M./Z77X-UD3H, BIOS F19e 11/21/2012)" machine, [ 0.581554] EFI Variables Facility v0.08 2004-May-17 [ 0.584914] ------------[ cut here ]------------ [ 0.585639] WARNING: at /home/andre/linux/fs/sysfs/dir.c:536 sysfs_add_one+0xd4/0x100() [ 0.586381] Hardware name: To be filled by O.E.M. [ 0.587123] sysfs: cannot create duplicate filename '/firmware/efi/vars/SbAslBufferPtrVar-01f33c25-764d-43ea-aeea-6b5a41f3f3e8' [ 0.588694] Modules linked in: [ 0.589484] Pid: 1, comm: swapper/0 Not tainted 3.8.0+ #7 [ 0.590280] Call Trace: [ 0.591066] [] ? sysfs_add_one+0xd4/0x100 [ 0.591861] [] warn_slowpath_common+0x7f/0xc0 [ 0.592650] [] warn_slowpath_fmt+0x4c/0x50 [ 0.593429] [] ? strlcat+0x65/0x80 [ 0.594203] [] sysfs_add_one+0xd4/0x100 [ 0.594979] [] create_dir+0x78/0xd0 [ 0.595753] [] sysfs_create_dir+0x86/0xe0 [ 0.596532] [] kobject_add_internal+0x9c/0x220 [ 0.597310] [] kobject_init_and_add+0x67/0x90 [ 0.598083] [] ? efivar_create_sysfs_entry+0x61/0x1c0 [ 0.598859] [] efivar_create_sysfs_entry+0x11b/0x1c0 [ 0.599631] [] register_efivars+0xde/0x420 [ 0.600395] [] ? edd_init+0x2f5/0x2f5 [ 0.601150] [] efivars_init+0xb8/0x104 [ 0.601903] [] do_one_initcall+0x12a/0x180 [ 0.602659] [] kernel_init_freeable+0x13e/0x1c6 [ 0.603418] [] ? loglevel+0x31/0x31 [ 0.604183] [] ? rest_init+0x80/0x80 [ 0.604936] [] kernel_init+0xe/0xf0 [ 0.605681] [] ret_from_fork+0x7c/0xb0 [ 0.606414] [] ? rest_init+0x80/0x80 [ 0.607143] ---[ end trace 1609741ab737eb29 ]--- There's not much we can do to work around and keep traversing the variable list once we hit this firmware bug. Our only solution is to terminate the loop because, as Lingzhu reports, some machines get stuck when they encounter duplicate names, > I had an IBM System x3100 M4 and x3850 X5 on which kernel would > get stuck in infinite loop creating duplicate sysfs files because, > for some reason, there are several duplicate boot entries in nvram > getting GetNextVariableName into a circle of iteration (with > period > 2). Also disable the workqueue, as efivar_update_sysfs_entries() uses GetNextVariableName() to figure out which variables have been created since the last iteration. That algorithm isn't going to work if GetNextVariableName() returns duplicates. Note that we don't disable EFI variable creation completely on the affected machines, it's just that any pstore dump-* files won't appear in sysfs until the next boot. Reported-by: Andre Heider Reported-by: Lingzhu Xiang Tested-by: Lingzhu Xiang Cc: Seiji Aguchi Cc: Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 48 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 1e9d9b9d7a12..d64661fda4fd 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -170,6 +170,7 @@ efivar_create_sysfs_entry(struct efivars *efivars, static void efivar_update_sysfs_entries(struct work_struct *); static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries); +static bool efivar_wq_enabled = true; /* Return the number of unicode characters in data */ static unsigned long @@ -1444,7 +1445,7 @@ static int efi_pstore_write(enum pstore_type_id type, spin_unlock_irqrestore(&efivars->lock, flags); - if (reason == KMSG_DUMP_OOPS) + if (reason == KMSG_DUMP_OOPS && efivar_wq_enabled) schedule_work(&efivar_work); *id = part; @@ -1975,6 +1976,35 @@ void unregister_efivars(struct efivars *efivars) } EXPORT_SYMBOL_GPL(unregister_efivars); +/* + * Print a warning when duplicate EFI variables are encountered and + * disable the sysfs workqueue since the firmware is buggy. + */ +static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, + unsigned long len16) +{ + size_t i, len8 = len16 / sizeof(efi_char16_t); + char *s8; + + /* + * Disable the workqueue since the algorithm it uses for + * detecting new variables won't work with this buggy + * implementation of GetNextVariableName(). + */ + efivar_wq_enabled = false; + + s8 = kzalloc(len8, GFP_KERNEL); + if (!s8) + return; + + for (i = 0; i < len8; i++) + s8[i] = s16[i]; + + printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n", + s8, vendor_guid); + kfree(s8); +} + int register_efivars(struct efivars *efivars, const struct efivar_operations *ops, struct kobject *parent_kobj) @@ -2025,6 +2055,22 @@ int register_efivars(struct efivars *efivars, case EFI_SUCCESS: variable_name_size = var_name_strnsize(variable_name, variable_name_size); + + /* + * Some firmware implementations return the + * same variable name on multiple calls to + * get_next_variable(). Terminate the loop + * immediately as there is no guarantee that + * we'll ever see a different variable name, + * and may end up looping here forever. + */ + if (variable_is_present(variable_name, &vendor_guid)) { + dup_variable_bug(variable_name, &vendor_guid, + variable_name_size); + status = EFI_NOT_FOUND; + break; + } + efivar_create_sysfs_entry(efivars, variable_name_size, variable_name, -- cgit From ca0ba26fbbd2d81c43085df49ce0abfe34535a90 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Fri, 22 Mar 2013 19:56:51 +0000 Subject: efivars: Fix check for CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE The 'CONFIG_' prefix is not implicit in IS_ENABLED(). Signed-off-by: Ben Hutchings Cc: Seth Forshee Cc: Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d64661fda4fd..7acafb80fd4c 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -104,7 +104,7 @@ MODULE_VERSION(EFIVARS_VERSION); #define GUID_LEN 36 static bool efivars_pstore_disable = - IS_ENABLED(EFI_VARS_PSTORE_DEFAULT_DISABLE); + IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE); module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); -- cgit From d5abc7c1050ab2b9556a4bf21626cd74e83cd086 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Sun, 3 Feb 2013 19:53:46 +0000 Subject: efi: move utf16 string functions to efi.h There are currently two implementations of the utf16 string functions. Somewhat confusingly, they've got different names. Centralise the functions in efi.h. Reviewed-by: Tom Gundersen Tested-by: Tom Gundersen Reviewed-by: Mike Waychison Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 17 ----------------- drivers/firmware/google/gsmi.c | 19 ++++--------------- 2 files changed, 4 insertions(+), 32 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 7acafb80fd4c..34c8783a2aa8 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -172,23 +172,6 @@ static void efivar_update_sysfs_entries(struct work_struct *); static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries); static bool efivar_wq_enabled = true; -/* Return the number of unicode characters in data */ -static unsigned long -utf16_strnlen(efi_char16_t *s, size_t maxlength) -{ - unsigned long length = 0; - - while (*s++ != 0 && length < maxlength) - length++; - return length; -} - -static inline unsigned long -utf16_strlen(efi_char16_t *s) -{ - return utf16_strnlen(s, ~0UL); -} - /* * Return the number of bytes is the length of this string * Note: this is NOT the same as the number of unicode characters diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c index 91ddf0f7a1b9..c409a7577afc 100644 --- a/drivers/firmware/google/gsmi.c +++ b/drivers/firmware/google/gsmi.c @@ -288,17 +288,6 @@ static int gsmi_exec(u8 func, u8 sub) return rc; } -/* Return the number of unicode characters in data */ -static size_t -utf16_strlen(efi_char16_t *data, unsigned long maxlength) -{ - unsigned long length = 0; - - while (*data++ != 0 && length < maxlength) - length++; - return length; -} - static efi_status_t gsmi_get_variable(efi_char16_t *name, efi_guid_t *vendor, u32 *attr, unsigned long *data_size, @@ -311,7 +300,7 @@ static efi_status_t gsmi_get_variable(efi_char16_t *name, }; efi_status_t ret = EFI_SUCCESS; unsigned long flags; - size_t name_len = utf16_strlen(name, GSMI_BUF_SIZE / 2); + size_t name_len = utf16_strnlen(name, GSMI_BUF_SIZE / 2); int rc; if (name_len >= GSMI_BUF_SIZE / 2) @@ -380,7 +369,7 @@ static efi_status_t gsmi_get_next_variable(unsigned long *name_size, return EFI_BAD_BUFFER_SIZE; /* Let's make sure the thing is at least null-terminated */ - if (utf16_strlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2) + if (utf16_strnlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2) return EFI_INVALID_PARAMETER; spin_lock_irqsave(&gsmi_dev.lock, flags); @@ -408,7 +397,7 @@ static efi_status_t gsmi_get_next_variable(unsigned long *name_size, /* Copy the name back */ memcpy(name, gsmi_dev.name_buf->start, GSMI_BUF_SIZE); - *name_size = utf16_strlen(name, GSMI_BUF_SIZE / 2) * 2; + *name_size = utf16_strnlen(name, GSMI_BUF_SIZE / 2) * 2; /* copy guid to return buffer */ memcpy(vendor, ¶m.guid, sizeof(param.guid)); @@ -434,7 +423,7 @@ static efi_status_t gsmi_set_variable(efi_char16_t *name, EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, }; - size_t name_len = utf16_strlen(name, GSMI_BUF_SIZE / 2); + size_t name_len = utf16_strnlen(name, GSMI_BUF_SIZE / 2); efi_status_t ret = EFI_SUCCESS; int rc; unsigned long flags; -- cgit From 4423d779af2a8f1fbd01aeca5c56522efce7262f Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Sat, 2 Feb 2013 15:22:24 +0000 Subject: efivars: Keep a private global pointer to efivars Some machines have an EFI variable interface that does not conform to the UEFI specification, e.g. CONFIG_GOOGLE_SMI. Add the necessary code so that it's only possible to use one implementation of EFI variable operations at runtime. This allows us to keep a single (file-scope) global pointer 'struct efivars', which simplifies access. This will hopefully dissuade developers from accessing the generic operations struct directly in the future, as was done in the efivarfs and pstore code, thereby allowing future code to work with both the generic efivar ops and the google SMI ops. This may seem like a step backwards in terms of modularity, but we don't need to track more than one 'struct efivars' at one time. There is no synchronisation done between multiple EFI variable operations, and according to Mike no one is using both the generic EFI var ops and CONFIG_GOOGLE_SMI simultaneously, though a single kernel build _does_ need to able to support both. It also helps to clearly highlight which functions form the core of the efivars interface - those that require access to __efivars. Reviewed-by: Tom Gundersen Tested-by: Tom Gundersen Acked-by: Mike Waychison Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 80 ++++++++++++++++++++++++++-------------------- 1 file changed, 46 insertions(+), 34 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 34c8783a2aa8..eab4ec41c523 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -125,7 +125,6 @@ struct efi_variable { } __attribute__((packed)); struct efivar_entry { - struct efivars *efivars; struct efi_variable var; struct list_head list; struct kobject kobj; @@ -137,8 +136,8 @@ struct efivar_attribute { ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); }; -static struct efivars __efivars; -static struct efivar_operations ops; +/* Private pointer to registered efivars */ +static struct efivars *__efivars; #define PSTORE_EFI_ATTRIBUTES \ (EFI_VARIABLE_NON_VOLATILE | \ @@ -479,7 +478,7 @@ efivar_attr_read(struct efivar_entry *entry, char *buf) if (!entry || !buf) return -EINVAL; - status = get_var_data(entry->efivars, var); + status = get_var_data(__efivars, var); if (status != EFI_SUCCESS) return -EIO; @@ -513,7 +512,7 @@ efivar_size_read(struct efivar_entry *entry, char *buf) if (!entry || !buf) return -EINVAL; - status = get_var_data(entry->efivars, var); + status = get_var_data(__efivars, var); if (status != EFI_SUCCESS) return -EIO; @@ -530,7 +529,7 @@ efivar_data_read(struct efivar_entry *entry, char *buf) if (!entry || !buf) return -EINVAL; - status = get_var_data(entry->efivars, var); + status = get_var_data(__efivars, var); if (status != EFI_SUCCESS) return -EIO; @@ -545,7 +544,7 @@ static ssize_t efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) { struct efi_variable *new_var, *var = &entry->var; - struct efivars *efivars = entry->efivars; + struct efivars *efivars = __efivars; efi_status_t status = EFI_NOT_FOUND; if (count != sizeof(struct efi_variable)) @@ -606,7 +605,7 @@ efivar_show_raw(struct efivar_entry *entry, char *buf) if (!entry || !buf) return 0; - status = get_var_data(entry->efivars, var); + status = get_var_data(__efivars, var); if (status != EFI_SUCCESS) return -EIO; @@ -728,7 +727,7 @@ static ssize_t efivarfs_file_write(struct file *file, const char __user *userbuf, size_t count, loff_t *ppos) { struct efivar_entry *var = file->private_data; - struct efivars *efivars; + struct efivars *efivars = __efivars; efi_status_t status; void *data; u32 attributes; @@ -746,8 +745,6 @@ static ssize_t efivarfs_file_write(struct file *file, if (attributes & ~(EFI_VARIABLE_MASK)) return -EINVAL; - efivars = var->efivars; - /* * Ensure that the user can't allocate arbitrarily large * amounts of memory. Pick a default size of 64K if @@ -855,7 +852,7 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, size_t count, loff_t *ppos) { struct efivar_entry *var = file->private_data; - struct efivars *efivars = var->efivars; + struct efivars *efivars = __efivars; efi_status_t status; unsigned long datasize = 0; u32 attributes; @@ -1009,7 +1006,7 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { struct inode *inode; - struct efivars *efivars = &__efivars; + struct efivars *efivars = __efivars; struct efivar_entry *var; int namelen, i = 0, err = 0; @@ -1038,7 +1035,6 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, var->var.VariableName[i] = '\0'; inode->i_private = var; - var->efivars = efivars; var->kobj.kset = efivars->kset; err = kobject_init_and_add(&var->kobj, &efivar_ktype, NULL, "%s", @@ -1063,7 +1059,7 @@ out: static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) { struct efivar_entry *var = dentry->d_inode->i_private; - struct efivars *efivars = var->efivars; + struct efivars *efivars = __efivars; efi_status_t status; spin_lock_irq(&efivars->lock); @@ -1175,7 +1171,7 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) struct inode *inode = NULL; struct dentry *root; struct efivar_entry *entry, *n; - struct efivars *efivars = &__efivars; + struct efivars *efivars = __efivars; char *name; int err = -ENOMEM; @@ -1302,7 +1298,7 @@ static const struct inode_operations efivarfs_dir_inode_operations = { static int efi_pstore_open(struct pstore_info *psi) { - struct efivars *efivars = psi->data; + struct efivars *efivars = __efivars; spin_lock_irq(&efivars->lock); efivars->walk_entry = list_first_entry(&efivars->list, @@ -1312,7 +1308,7 @@ static int efi_pstore_open(struct pstore_info *psi) static int efi_pstore_close(struct pstore_info *psi) { - struct efivars *efivars = psi->data; + struct efivars *efivars = __efivars; spin_unlock_irq(&efivars->lock); return 0; @@ -1323,7 +1319,7 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, char **buf, struct pstore_info *psi) { efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - struct efivars *efivars = psi->data; + struct efivars *efivars = __efivars; char name[DUMP_NAME_LEN]; int i; int cnt; @@ -1386,7 +1382,7 @@ static int efi_pstore_write(enum pstore_type_id type, char name[DUMP_NAME_LEN]; efi_char16_t efi_name[DUMP_NAME_LEN]; efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - struct efivars *efivars = psi->data; + struct efivars *efivars = __efivars; int i, ret = 0; efi_status_t status = EFI_NOT_FOUND; unsigned long flags; @@ -1443,7 +1439,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, char name_old[DUMP_NAME_LEN]; efi_char16_t efi_name_old[DUMP_NAME_LEN]; efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - struct efivars *efivars = psi->data; + struct efivars *efivars = __efivars; struct efivar_entry *entry, *found = NULL; int i; @@ -1535,7 +1531,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj, char *buf, loff_t pos, size_t count) { struct efi_variable *new_var = (struct efi_variable *)buf; - struct efivars *efivars = bin_attr->private; + struct efivars *efivars = __efivars; struct efivar_entry *search_efivar, *n; unsigned long strsize1, strsize2; efi_status_t status = EFI_NOT_FOUND; @@ -1612,7 +1608,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, char *buf, loff_t pos, size_t count) { struct efi_variable *del_var = (struct efi_variable *)buf; - struct efivars *efivars = bin_attr->private; + struct efivars *efivars = __efivars; struct efivar_entry *search_efivar, *n; unsigned long strsize1, strsize2; efi_status_t status = EFI_NOT_FOUND; @@ -1670,7 +1666,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) { struct efivar_entry *entry, *n; - struct efivars *efivars = &__efivars; + struct efivars *efivars = __efivars; unsigned long strsize1, strsize2; bool found = false; @@ -1716,7 +1712,7 @@ static unsigned long var_name_strnsize(efi_char16_t *variable_name, static void efivar_update_sysfs_entries(struct work_struct *work) { - struct efivars *efivars = &__efivars; + struct efivars *efivars = __efivars; efi_guid_t vendor; efi_char16_t *variable_name; unsigned long variable_name_size = 1024; @@ -1843,7 +1839,6 @@ efivar_create_sysfs_entry(struct efivars *efivars, return 1; } - new_efivar->efivars = efivars; memcpy(new_efivar->var.VariableName, variable_name, variable_name_size); memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t)); @@ -1942,6 +1937,8 @@ void unregister_efivars(struct efivars *efivars) { struct efivar_entry *entry, *n; + __efivars = NULL; + list_for_each_entry_safe(entry, n, &efivars->list, list) { spin_lock_irq(&efivars->lock); list_del(&entry->list); @@ -1998,6 +1995,8 @@ int register_efivars(struct efivars *efivars, unsigned long variable_name_size = 1024; int error = 0; + __efivars = efivars; + variable_name = kzalloc(variable_name_size, GFP_KERNEL); if (!variable_name) { printk(KERN_ERR "efivars: Memory allocation failed.\n"); @@ -2085,6 +2084,24 @@ out: } EXPORT_SYMBOL_GPL(register_efivars); +static struct efivars generic_efivars; +static struct efivar_operations generic_ops; + +static int generic_ops_register(void) +{ + generic_ops.get_variable = efi.get_variable; + generic_ops.set_variable = efi.set_variable; + generic_ops.get_next_variable = efi.get_next_variable; + generic_ops.query_variable_info = efi.query_variable_info; + + return register_efivars(&generic_efivars, &generic_ops, efi_kobj); +} + +static void generic_ops_unregister(void) +{ + unregister_efivars(&generic_efivars); +} + /* * For now we register the efi subsystem with the firmware subsystem * and the vars subsystem with the efi subsystem. In the future, it @@ -2111,12 +2128,7 @@ efivars_init(void) return -ENOMEM; } - ops.get_variable = efi.get_variable; - ops.set_variable = efi.set_variable; - ops.get_next_variable = efi.get_next_variable; - ops.query_variable_info = efi.query_variable_info; - - error = register_efivars(&__efivars, &ops, efi_kobj); + error = generic_ops_register(); if (error) goto err_put; @@ -2132,7 +2144,7 @@ efivars_init(void) return 0; err_unregister: - unregister_efivars(&__efivars); + generic_ops_unregister(); err_put: kobject_put(efi_kobj); return error; @@ -2144,7 +2156,7 @@ efivars_exit(void) cancel_work_sync(&efivar_work); if (efi_enabled(EFI_RUNTIME_SERVICES)) { - unregister_efivars(&__efivars); + generic_ops_unregister(); kobject_put(efi_kobj); } } -- cgit From e14ab23dde12b80db4c94b684a2e485b72b16af3 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Sun, 3 Feb 2013 20:16:40 +0000 Subject: efivars: efivar_entry API There isn't really a formal interface for dealing with EFI variables or struct efivar_entry. Historically, this has led to various bits of code directly accessing the generic EFI variable ops, which inherently ties it to specific EFI variable operations instead of indirectly using whatever ops were registered with register_efivars(). This lead to the efivarfs code only working with the generic EFI variable ops and not CONFIG_GOOGLE_SMI. Encapsulate everything that needs to access '__efivars' inside an efivar_entry_* API and use the new API in the pstore, sysfs and efivarfs code. Much of the efivars code had to be rewritten to use this new API. For instance, it is now up to the users of the API to build the initial list of EFI variables in their efivar_init() callback function. The variable list needs to be passed to efivar_init() which allows us to keep work arounds for things like implementation bugs in GetNextVariable() in a central location. Allowing users of the API to use a callback function to build the list greatly benefits the efivarfs code which needs to allocate inodes and dentries for every variable. It previously did this in a racy way because the code ran without holding the variable spinlock. Both the sysfs and efivarfs code maintain their own lists which means the two interfaces can be running simultaneously without interference, though it should be noted that because no synchronisation is performed it is very easy to create inconsistencies. efibootmgr doesn't currently use efivarfs and users are likely to also require the old sysfs interface, so it makes sense to allow both to be built. Reviewed-by: Tom Gundersen Tested-by: Tom Gundersen Cc: Seiji Aguchi Cc: Matthew Garrett Cc: Jeremy Kerr Cc: Tony Luck Cc: Mike Waychison Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 1819 ++++++++++++++++++++++++---------------- drivers/firmware/google/gsmi.c | 11 +- 2 files changed, 1107 insertions(+), 723 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index eab4ec41c523..82fd145ead3b 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -97,39 +97,14 @@ MODULE_VERSION(EFIVARS_VERSION); #define DUMP_NAME_LEN 52 -/* - * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee")) - * not including trailing NUL - */ -#define GUID_LEN 36 +static LIST_HEAD(efivarfs_list); +static LIST_HEAD(efivar_sysfs_list); static bool efivars_pstore_disable = IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE); module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); -/* - * The maximum size of VariableName + Data = 1024 - * Therefore, it's reasonable to save that much - * space in each part of the structure, - * and we use a page for reading/writing. - */ - -struct efi_variable { - efi_char16_t VariableName[1024/sizeof(efi_char16_t)]; - efi_guid_t VendorGuid; - unsigned long DataSize; - __u8 Data[1024]; - efi_status_t Status; - __u32 Attributes; -} __attribute__((packed)); - -struct efivar_entry { - struct efi_variable var; - struct list_head list; - struct kobject kobj; -}; - struct efivar_attribute { struct attribute attr; ssize_t (*show) (struct efivar_entry *entry, char *buf); @@ -144,6 +119,11 @@ static struct efivars *__efivars; EFI_VARIABLE_BOOTSERVICE_ACCESS | \ EFI_VARIABLE_RUNTIME_ACCESS) +static struct kset *efivars_kset; + +static struct bin_attribute *efivars_new_var; +static struct bin_attribute *efivars_del_var; + #define EFIVAR_ATTR(_name, _mode, _show, _store) \ struct efivar_attribute efivar_attr_##_name = { \ .attr = {.name = __stringify(_name), .mode = _mode}, \ @@ -158,10 +138,7 @@ struct efivar_attribute efivar_attr_##_name = { \ * Prototype for sysfs creation function */ static int -efivar_create_sysfs_entry(struct efivars *efivars, - unsigned long variable_name_size, - efi_char16_t *variable_name, - efi_guid_t *vendor_guid); +efivar_create_sysfs_entry(struct efivar_entry *new_var); /* * Prototype for workqueue functions updating sysfs entry @@ -346,8 +323,8 @@ static const struct variable_validate variable_validate[] = { { "", NULL }, }; -static bool -validate_var(struct efi_variable *var, u8 *data, unsigned long len) +bool +efivar_validate(struct efi_variable *var, u8 *data, unsigned long len) { int i; u16 *unicode_name = var->VariableName; @@ -382,47 +359,16 @@ validate_var(struct efi_variable *var, u8 *data, unsigned long len) return true; } +EXPORT_SYMBOL_GPL(efivar_validate); static efi_status_t -get_var_data_locked(struct efivars *efivars, struct efi_variable *var) -{ - efi_status_t status; - - var->DataSize = 1024; - status = efivars->ops->get_variable(var->VariableName, - &var->VendorGuid, - &var->Attributes, - &var->DataSize, - var->Data); - return status; -} - -static efi_status_t -get_var_data(struct efivars *efivars, struct efi_variable *var) -{ - efi_status_t status; - unsigned long flags; - - spin_lock_irqsave(&efivars->lock, flags); - status = get_var_data_locked(efivars, var); - spin_unlock_irqrestore(&efivars->lock, flags); - - if (status != EFI_SUCCESS) { - printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n", - status); - } - return status; -} - -static efi_status_t -check_var_size_locked(struct efivars *efivars, u32 attributes, - unsigned long size) +check_var_size(u32 attributes, unsigned long size) { u64 storage_size, remaining_size, max_size; efi_status_t status; - const struct efivar_operations *fops = efivars->ops; + const struct efivar_operations *fops = __efivars->ops; - if (!efivars->ops->query_variable_info) + if (!fops->query_variable_info) return EFI_UNSUPPORTED; status = fops->query_variable_info(attributes, &storage_size, @@ -438,20 +384,6 @@ check_var_size_locked(struct efivars *efivars, u32 attributes, return status; } - -static efi_status_t -check_var_size(struct efivars *efivars, u32 attributes, unsigned long size) -{ - efi_status_t status; - unsigned long flags; - - spin_lock_irqsave(&efivars->lock, flags); - status = check_var_size_locked(efivars, attributes, size); - spin_unlock_irqrestore(&efivars->lock, flags); - - return status; -} - static ssize_t efivar_guid_read(struct efivar_entry *entry, char *buf) { @@ -473,13 +405,12 @@ efivar_attr_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; char *str = buf; - efi_status_t status; if (!entry || !buf) return -EINVAL; - status = get_var_data(__efivars, var); - if (status != EFI_SUCCESS) + var->DataSize = 1024; + if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) return -EIO; if (var->Attributes & EFI_VARIABLE_NON_VOLATILE) @@ -507,13 +438,12 @@ efivar_size_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; char *str = buf; - efi_status_t status; if (!entry || !buf) return -EINVAL; - status = get_var_data(__efivars, var); - if (status != EFI_SUCCESS) + var->DataSize = 1024; + if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) return -EIO; str += sprintf(str, "0x%lx\n", var->DataSize); @@ -524,13 +454,12 @@ static ssize_t efivar_data_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; - efi_status_t status; if (!entry || !buf) return -EINVAL; - status = get_var_data(__efivars, var); - if (status != EFI_SUCCESS) + var->DataSize = 1024; + if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) return -EIO; memcpy(buf, var->Data, var->DataSize); @@ -544,8 +473,7 @@ static ssize_t efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) { struct efi_variable *new_var, *var = &entry->var; - struct efivars *efivars = __efivars; - efi_status_t status = EFI_NOT_FOUND; + int err; if (count != sizeof(struct efi_variable)) return -EINVAL; @@ -567,32 +495,20 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) } if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || - validate_var(new_var, new_var->Data, new_var->DataSize) == false) { + efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) { printk(KERN_ERR "efivars: Malformed variable content\n"); return -EINVAL; } - spin_lock_irq(&efivars->lock); - - status = check_var_size_locked(efivars, new_var->Attributes, - new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); - - if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) - status = efivars->ops->set_variable(new_var->VariableName, - &new_var->VendorGuid, - new_var->Attributes, - new_var->DataSize, - new_var->Data); - - spin_unlock_irq(&efivars->lock); + memcpy(&entry->var, new_var, count); - if (status != EFI_SUCCESS) { - printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", - status); + err = efivar_entry_set(entry, new_var->Attributes, + new_var->DataSize, new_var->Data, false); + if (err) { + printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err); return -EIO; } - memcpy(&entry->var, new_var, count); return count; } @@ -600,16 +516,17 @@ static ssize_t efivar_show_raw(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; - efi_status_t status; if (!entry || !buf) return 0; - status = get_var_data(__efivars, var); - if (status != EFI_SUCCESS) + var->DataSize = 1024; + if (efivar_entry_get(entry, &entry->var.Attributes, + &entry->var.DataSize, entry->var.Data)) return -EIO; memcpy(buf, var, sizeof(*var)); + return sizeof(*var); } @@ -698,6 +615,9 @@ static int efi_status_to_err(efi_status_t status) int err; switch (status) { + case EFI_SUCCESS: + err = 0; + break; case EFI_INVALID_PARAMETER: err = -EINVAL; break; @@ -714,7 +634,7 @@ static int efi_status_to_err(efi_status_t status) err = -EACCES; break; case EFI_NOT_FOUND: - err = -EIO; + err = -ENOENT; break; default: err = -EINVAL; @@ -727,14 +647,12 @@ static ssize_t efivarfs_file_write(struct file *file, const char __user *userbuf, size_t count, loff_t *ppos) { struct efivar_entry *var = file->private_data; - struct efivars *efivars = __efivars; - efi_status_t status; void *data; u32 attributes; struct inode *inode = file->f_mapping->host; unsigned long datasize = count - sizeof(attributes); - unsigned long newdatasize, varsize; ssize_t bytes = 0; + bool set = false; if (count < sizeof(attributes)) return -EINVAL; @@ -745,23 +663,6 @@ static ssize_t efivarfs_file_write(struct file *file, if (attributes & ~(EFI_VARIABLE_MASK)) return -EINVAL; - /* - * Ensure that the user can't allocate arbitrarily large - * amounts of memory. Pick a default size of 64K if - * QueryVariableInfo() isn't supported by the firmware. - */ - - varsize = datasize + utf16_strsize(var->var.VariableName, 1024); - status = check_var_size(efivars, attributes, varsize); - - if (status != EFI_SUCCESS) { - if (status != EFI_UNSUPPORTED) - return efi_status_to_err(status); - - if (datasize > 65536) - return -ENOSPC; - } - data = kmalloc(datasize, GFP_KERNEL); if (!data) return -ENOMEM; @@ -771,76 +672,24 @@ static ssize_t efivarfs_file_write(struct file *file, goto out; } - if (validate_var(&var->var, data, datasize) == false) { - bytes = -EINVAL; + bytes = efivar_entry_set_get_size(var, attributes, &datasize, + data, &set); + if (!set && bytes) goto out; - } - - /* - * The lock here protects the get_variable call, the conditional - * set_variable call, and removal of the variable from the efivars - * list (in the case of an authenticated delete). - */ - spin_lock_irq(&efivars->lock); - - /* - * Ensure that the available space hasn't shrunk below the safe level - */ - - status = check_var_size_locked(efivars, attributes, varsize); - - if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED) { - spin_unlock_irq(&efivars->lock); - kfree(data); - - return efi_status_to_err(status); - } - - status = efivars->ops->set_variable(var->var.VariableName, - &var->var.VendorGuid, - attributes, datasize, - data); - - if (status != EFI_SUCCESS) { - spin_unlock_irq(&efivars->lock); - kfree(data); - - return efi_status_to_err(status); - } - - bytes = count; - /* - * Writing to the variable may have caused a change in size (which - * could either be an append or an overwrite), or the variable to be - * deleted. Perform a GetVariable() so we can tell what actually - * happened. - */ - newdatasize = 0; - status = efivars->ops->get_variable(var->var.VariableName, - &var->var.VendorGuid, - NULL, &newdatasize, - NULL); - - if (status == EFI_BUFFER_TOO_SMALL) { - spin_unlock_irq(&efivars->lock); + if (!bytes) { mutex_lock(&inode->i_mutex); - i_size_write(inode, newdatasize + sizeof(attributes)); + i_size_write(inode, datasize + sizeof(attributes)); mutex_unlock(&inode->i_mutex); - - } else if (status == EFI_NOT_FOUND) { - list_del(&var->list); - spin_unlock_irq(&efivars->lock); - efivar_unregister(var); + } else if (bytes == -ENOENT) { drop_nlink(inode); d_delete(file->f_dentry); dput(file->f_dentry); - - } else { - spin_unlock_irq(&efivars->lock); + } else pr_warn("efivarfs: inconsistent EFI variable implementation? " - "status = %lx\n", status); - } + "status=%zu\n", bytes); + + bytes = count; out: kfree(data); @@ -852,38 +701,25 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, size_t count, loff_t *ppos) { struct efivar_entry *var = file->private_data; - struct efivars *efivars = __efivars; - efi_status_t status; unsigned long datasize = 0; u32 attributes; void *data; ssize_t size = 0; + int err; - spin_lock_irq(&efivars->lock); - status = efivars->ops->get_variable(var->var.VariableName, - &var->var.VendorGuid, - &attributes, &datasize, NULL); - spin_unlock_irq(&efivars->lock); - - if (status != EFI_BUFFER_TOO_SMALL) - return efi_status_to_err(status); + err = efivar_entry_size(var, &datasize); + if (err) + return err; data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL); if (!data) return -ENOMEM; - spin_lock_irq(&efivars->lock); - status = efivars->ops->get_variable(var->var.VariableName, - &var->var.VendorGuid, - &attributes, &datasize, - (data + sizeof(attributes))); - spin_unlock_irq(&efivars->lock); - - if (status != EFI_SUCCESS) { - size = efi_status_to_err(status); + size = efivar_entry_get(var, &attributes, &datasize, + data + sizeof(attributes)); + if (size) goto out_free; - } memcpy(data, &attributes, sizeof(attributes)); size = simple_read_from_buffer(userbuf, count, ppos, @@ -947,17 +783,17 @@ static struct inode *efivarfs_get_inode(struct super_block *sb, */ static bool efivarfs_valid_name(const char *str, int len) { - static const char dashes[GUID_LEN] = { + static const char dashes[EFI_VARIABLE_GUID_LEN] = { [8] = 1, [13] = 1, [18] = 1, [23] = 1 }; - const char *s = str + len - GUID_LEN; + const char *s = str + len - EFI_VARIABLE_GUID_LEN; int i; /* * We need a GUID, plus at least one letter for the variable name, * plus the '-' separator */ - if (len < GUID_LEN + 2) + if (len < EFI_VARIABLE_GUID_LEN + 2) return false; /* GUID must be preceded by a '-' */ @@ -969,7 +805,7 @@ static bool efivarfs_valid_name(const char *str, int len) * * 12345678-1234-1234-1234-123456789abc */ - for (i = 0; i < GUID_LEN; i++) { + for (i = 0; i < EFI_VARIABLE_GUID_LEN; i++) { if (dashes[i]) { if (*s++ != '-') return false; @@ -1006,7 +842,6 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { struct inode *inode; - struct efivars *efivars = __efivars; struct efivar_entry *var; int namelen, i = 0, err = 0; @@ -1024,7 +859,7 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, } /* length of the variable name itself: remove GUID and separator */ - namelen = dentry->d_name.len - GUID_LEN - 1; + namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1; efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1, &var->var.VendorGuid); @@ -1035,17 +870,8 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, var->var.VariableName[i] = '\0'; inode->i_private = var; - var->kobj.kset = efivars->kset; - - err = kobject_init_and_add(&var->kobj, &efivar_ktype, NULL, "%s", - dentry->d_name.name); - if (err) - goto out; - kobject_uevent(&var->kobj, KOBJ_ADD); - spin_lock_irq(&efivars->lock); - list_add(&var->list, &efivars->list); - spin_unlock_irq(&efivars->lock); + efivar_entry_add(var, &efivarfs_list); d_instantiate(dentry, inode); dget(dentry); out: @@ -1059,26 +885,13 @@ out: static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) { struct efivar_entry *var = dentry->d_inode->i_private; - struct efivars *efivars = __efivars; - efi_status_t status; - - spin_lock_irq(&efivars->lock); - status = efivars->ops->set_variable(var->var.VariableName, - &var->var.VendorGuid, - 0, 0, NULL); - - if (status == EFI_SUCCESS || status == EFI_NOT_FOUND) { - list_del(&var->list); - spin_unlock_irq(&efivars->lock); - efivar_unregister(var); - drop_nlink(dentry->d_inode); - dput(dentry); - return 0; - } + if (efivar_entry_delete(var)) + return -EINVAL; - spin_unlock_irq(&efivars->lock); - return -EINVAL; + drop_nlink(dentry->d_inode); + dput(dentry); + return 0; }; /* @@ -1097,7 +910,7 @@ static int efivarfs_d_compare(const struct dentry *parent, const struct inode *p unsigned int len, const char *str, const struct qstr *name) { - int guid = len - GUID_LEN; + int guid = len - EFI_VARIABLE_GUID_LEN; if (name->len != len) return 1; @@ -1107,7 +920,7 @@ static int efivarfs_d_compare(const struct dentry *parent, const struct inode *p return 1; /* Case-insensitive compare for the GUID */ - return strncasecmp(name->name + guid, str + guid, GUID_LEN); + return strncasecmp(name->name + guid, str + guid, EFI_VARIABLE_GUID_LEN); } static int efivarfs_d_hash(const struct dentry *dentry, @@ -1120,7 +933,7 @@ static int efivarfs_d_hash(const struct dentry *dentry, if (!efivarfs_valid_name(s, len)) return -EINVAL; - while (len-- > GUID_LEN) + while (len-- > EFI_VARIABLE_GUID_LEN) hash = partial_name_hash(*s++, hash); /* GUID is case-insensitive. */ @@ -1166,15 +979,87 @@ static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name) return ERR_PTR(-ENOMEM); } -static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) +static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor, + unsigned long name_size, void *data) { + struct super_block *sb = (struct super_block *)data; + struct efivar_entry *entry; struct inode *inode = NULL; - struct dentry *root; - struct efivar_entry *entry, *n; - struct efivars *efivars = __efivars; + struct dentry *dentry, *root = sb->s_root; + unsigned long size = 0; char *name; + int len, i; int err = -ENOMEM; + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return err; + + memcpy(entry->var.VariableName, name16, name_size); + memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); + + len = utf16_strlen(entry->var.VariableName); + + /* name, plus '-', plus GUID, plus NUL*/ + name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL); + if (!name) + goto fail; + + for (i = 0; i < len; i++) + name[i] = entry->var.VariableName[i] & 0xFF; + + name[len] = '-'; + + efi_guid_unparse(&entry->var.VendorGuid, name + len + 1); + + name[len + EFI_VARIABLE_GUID_LEN+1] = '\0'; + + inode = efivarfs_get_inode(sb, root->d_inode, S_IFREG | 0644, 0); + if (!inode) + goto fail_name; + + dentry = efivarfs_alloc_dentry(root, name); + if (IS_ERR(dentry)) { + err = PTR_ERR(dentry); + goto fail_inode; + } + + /* copied by the above to local storage in the dentry. */ + kfree(name); + + efivar_entry_size(entry, &size); + efivar_entry_add(entry, &efivarfs_list); + + mutex_lock(&inode->i_mutex); + inode->i_private = entry; + i_size_write(inode, size + sizeof(entry->var.Attributes)); + mutex_unlock(&inode->i_mutex); + d_add(dentry, inode); + + return 0; + +fail_inode: + iput(inode); +fail_name: + kfree(name); +fail: + kfree(entry); + return err; +} + +static int efivarfs_destroy(struct efivar_entry *entry, void *data) +{ + efivar_entry_remove(entry); + kfree(entry); + return 0; +} + +static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) +{ + struct inode *inode = NULL; + struct dentry *root; + int err; + efivarfs_sb = sb; sb->s_maxbytes = MAX_LFS_FILESIZE; @@ -1195,65 +1080,13 @@ static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) if (!root) return -ENOMEM; - list_for_each_entry_safe(entry, n, &efivars->list, list) { - struct dentry *dentry, *root = efivarfs_sb->s_root; - unsigned long size = 0; - int len, i; - - inode = NULL; - - len = utf16_strlen(entry->var.VariableName); - - /* name, plus '-', plus GUID, plus NUL*/ - name = kmalloc(len + 1 + GUID_LEN + 1, GFP_ATOMIC); - if (!name) - goto fail; - - for (i = 0; i < len; i++) - name[i] = entry->var.VariableName[i] & 0xFF; - - name[len] = '-'; - - efi_guid_unparse(&entry->var.VendorGuid, name + len + 1); - - name[len+GUID_LEN+1] = '\0'; - - inode = efivarfs_get_inode(efivarfs_sb, root->d_inode, - S_IFREG | 0644, 0); - if (!inode) - goto fail_name; - - dentry = efivarfs_alloc_dentry(root, name); - if (IS_ERR(dentry)) { - err = PTR_ERR(dentry); - goto fail_inode; - } - - /* copied by the above to local storage in the dentry. */ - kfree(name); - - spin_lock_irq(&efivars->lock); - efivars->ops->get_variable(entry->var.VariableName, - &entry->var.VendorGuid, - &entry->var.Attributes, - &size, - NULL); - spin_unlock_irq(&efivars->lock); - - mutex_lock(&inode->i_mutex); - inode->i_private = entry; - i_size_write(inode, size + sizeof(entry->var.Attributes)); - mutex_unlock(&inode->i_mutex); - d_add(dentry, inode); - } + INIT_LIST_HEAD(&efivarfs_list); - return 0; + err = efivar_init(efivarfs_callback, (void *)sb, false, + true, &efivarfs_list); + if (err) + __efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL); -fail_inode: - iput(inode); -fail_name: - kfree(name); -fail: return err; } @@ -1267,6 +1100,9 @@ static void efivarfs_kill_sb(struct super_block *sb) { kill_litter_super(sb); efivarfs_sb = NULL; + + /* Remove all entries and destroy */ + __efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL); } static struct file_system_type efivarfs_type = { @@ -1298,80 +1134,84 @@ static const struct inode_operations efivarfs_dir_inode_operations = { static int efi_pstore_open(struct pstore_info *psi) { - struct efivars *efivars = __efivars; - - spin_lock_irq(&efivars->lock); - efivars->walk_entry = list_first_entry(&efivars->list, - struct efivar_entry, list); + efivar_entry_iter_begin(); + psi->data = NULL; return 0; } static int efi_pstore_close(struct pstore_info *psi) { - struct efivars *efivars = __efivars; - - spin_unlock_irq(&efivars->lock); + efivar_entry_iter_end(); + psi->data = NULL; return 0; } -static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, - int *count, struct timespec *timespec, - char **buf, struct pstore_info *psi) +struct pstore_read_data { + u64 *id; + enum pstore_type_id *type; + int *count; + struct timespec *timespec; + char **buf; +}; + +static int efi_pstore_read_func(struct efivar_entry *entry, void *data) { efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - struct efivars *efivars = __efivars; + struct pstore_read_data *cb_data = data; char name[DUMP_NAME_LEN]; int i; int cnt; - unsigned int part, size; - unsigned long time; - - while (&efivars->walk_entry->list != &efivars->list) { - if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid, - vendor)) { - for (i = 0; i < DUMP_NAME_LEN; i++) { - name[i] = efivars->walk_entry->var.VariableName[i]; - } - if (sscanf(name, "dump-type%u-%u-%d-%lu", - type, &part, &cnt, &time) == 4) { - *id = part; - *count = cnt; - timespec->tv_sec = time; - timespec->tv_nsec = 0; - } else if (sscanf(name, "dump-type%u-%u-%lu", - type, &part, &time) == 3) { - /* - * Check if an old format, - * which doesn't support holding - * multiple logs, remains. - */ - *id = part; - *count = 0; - timespec->tv_sec = time; - timespec->tv_nsec = 0; - } else { - efivars->walk_entry = list_entry( - efivars->walk_entry->list.next, - struct efivar_entry, list); - continue; - } + unsigned int part; + unsigned long time, size; - get_var_data_locked(efivars, &efivars->walk_entry->var); - size = efivars->walk_entry->var.DataSize; - *buf = kmalloc(size, GFP_KERNEL); - if (*buf == NULL) - return -ENOMEM; - memcpy(*buf, efivars->walk_entry->var.Data, - size); - efivars->walk_entry = list_entry( - efivars->walk_entry->list.next, - struct efivar_entry, list); - return size; - } - efivars->walk_entry = list_entry(efivars->walk_entry->list.next, - struct efivar_entry, list); - } - return 0; + if (efi_guidcmp(entry->var.VendorGuid, vendor)) + return 0; + + for (i = 0; i < DUMP_NAME_LEN; i++) + name[i] = entry->var.VariableName[i]; + + if (sscanf(name, "dump-type%u-%u-%d-%lu", + cb_data->type, &part, &cnt, &time) == 4) { + *cb_data->id = part; + *cb_data->count = cnt; + cb_data->timespec->tv_sec = time; + cb_data->timespec->tv_nsec = 0; + } else if (sscanf(name, "dump-type%u-%u-%lu", + cb_data->type, &part, &time) == 3) { + /* + * Check if an old format, + * which doesn't support holding + * multiple logs, remains. + */ + *cb_data->id = part; + *cb_data->count = 0; + cb_data->timespec->tv_sec = time; + cb_data->timespec->tv_nsec = 0; + } else + return 0; + + __efivar_entry_size(entry, &size); + *cb_data->buf = kmalloc(size, GFP_KERNEL); + if (*cb_data->buf == NULL) + return -ENOMEM; + memcpy(*cb_data->buf, entry->var.Data, size); + return size; +} + +static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, + int *count, struct timespec *timespec, + char **buf, struct pstore_info *psi) +{ + struct pstore_read_data data; + + data.id = id; + data.type = type; + data.count = count; + data.timespec = timespec; + data.buf = buf; + + return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data, + (struct efivar_entry **)&psi->data); } static int efi_pstore_write(enum pstore_type_id type, @@ -1382,36 +1222,7 @@ static int efi_pstore_write(enum pstore_type_id type, char name[DUMP_NAME_LEN]; efi_char16_t efi_name[DUMP_NAME_LEN]; efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - struct efivars *efivars = __efivars; int i, ret = 0; - efi_status_t status = EFI_NOT_FOUND; - unsigned long flags; - - if (pstore_cannot_block_path(reason)) { - /* - * If the lock is taken by another cpu in non-blocking path, - * this driver returns without entering firmware to avoid - * hanging up. - */ - if (!spin_trylock_irqsave(&efivars->lock, flags)) - return -EBUSY; - } else - spin_lock_irqsave(&efivars->lock, flags); - - /* - * Check if there is a space enough to log. - * size: a size of logging data - * DUMP_NAME_LEN * 2: a maximum size of variable name - */ - - status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES, - size + DUMP_NAME_LEN * 2); - - if (status) { - spin_unlock_irqrestore(&efivars->lock, flags); - *id = part; - return -ENOSPC; - } sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, get_seconds()); @@ -1419,10 +1230,9 @@ static int efi_pstore_write(enum pstore_type_id type, for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = name[i]; - efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES, - size, psi->buf); - - spin_unlock_irqrestore(&efivars->lock, flags); + ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES, + !pstore_cannot_block_path(reason), + size, psi->buf); if (reason == KMSG_DUMP_OOPS && efivar_wq_enabled) schedule_work(&efivar_work); @@ -1431,69 +1241,79 @@ static int efi_pstore_write(enum pstore_type_id type, return ret; }; -static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, - struct timespec time, struct pstore_info *psi) +struct pstore_erase_data { + u64 id; + enum pstore_type_id type; + int count; + struct timespec time; + efi_char16_t *name; +}; + +/* + * Clean up an entry with the same name + */ +static int efi_pstore_erase_func(struct efivar_entry *entry, void *data) { - char name[DUMP_NAME_LEN]; - efi_char16_t efi_name[DUMP_NAME_LEN]; - char name_old[DUMP_NAME_LEN]; - efi_char16_t efi_name_old[DUMP_NAME_LEN]; + struct pstore_erase_data *ed = data; efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - struct efivars *efivars = __efivars; - struct efivar_entry *entry, *found = NULL; + efi_char16_t efi_name_old[DUMP_NAME_LEN]; + efi_char16_t *efi_name = ed->name; + unsigned long utf16_len = utf16_strlen(ed->name); + char name_old[DUMP_NAME_LEN]; int i; - sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count, - time.tv_sec); + if (efi_guidcmp(entry->var.VendorGuid, vendor)) + return 0; - spin_lock_irq(&efivars->lock); + if (utf16_strncmp(entry->var.VariableName, + efi_name, (size_t)utf16_len)) { + /* + * Check if an old format, which doesn't support + * holding multiple logs, remains. + */ + sprintf(name_old, "dump-type%u-%u-%lu", ed->type, + (unsigned int)ed->id, ed->time.tv_sec); - for (i = 0; i < DUMP_NAME_LEN; i++) - efi_name[i] = name[i]; + for (i = 0; i < DUMP_NAME_LEN; i++) + efi_name_old[i] = name_old[i]; - /* - * Clean up an entry with the same name - */ + if (utf16_strncmp(entry->var.VariableName, efi_name_old, + utf16_strlen(efi_name_old))) + return 0; + } - list_for_each_entry(entry, &efivars->list, list) { - get_var_data_locked(efivars, &entry->var); - - if (efi_guidcmp(entry->var.VendorGuid, vendor)) - continue; - if (utf16_strncmp(entry->var.VariableName, efi_name, - utf16_strlen(efi_name))) { - /* - * Check if an old format, - * which doesn't support holding - * multiple logs, remains. - */ - sprintf(name_old, "dump-type%u-%u-%lu", type, - (unsigned int)id, time.tv_sec); + /* found */ + __efivar_entry_delete(entry); + return 1; +} - for (i = 0; i < DUMP_NAME_LEN; i++) - efi_name_old[i] = name_old[i]; +static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, + struct timespec time, struct pstore_info *psi) +{ + struct pstore_erase_data edata; + struct efivar_entry *entry; + char name[DUMP_NAME_LEN]; + efi_char16_t efi_name[DUMP_NAME_LEN]; + int found, i; - if (utf16_strncmp(entry->var.VariableName, efi_name_old, - utf16_strlen(efi_name_old))) - continue; - } + sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count, + time.tv_sec); - /* found */ - found = entry; - efivars->ops->set_variable(entry->var.VariableName, - &entry->var.VendorGuid, - PSTORE_EFI_ATTRIBUTES, - 0, NULL); - break; - } + for (i = 0; i < DUMP_NAME_LEN; i++) + efi_name[i] = name[i]; - if (found) - list_del(&found->list); + edata.id = id; + edata.type = type; + edata.count = count; + edata.time = time; + edata.name = efi_name; - spin_unlock_irq(&efivars->lock); + efivar_entry_iter_begin(); + found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry); + efivar_entry_iter_end(); if (found) - efivar_unregister(found); + efivar_unregister(entry); return 0; } @@ -1508,19 +1328,17 @@ static struct pstore_info efi_pstore_info = { .erase = efi_pstore_erase, }; -static void efivar_pstore_register(struct efivars *efivars) +static void efivar_pstore_register(void) { - efivars->efi_pstore_info = efi_pstore_info; - efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); - if (efivars->efi_pstore_info.buf) { - efivars->efi_pstore_info.bufsize = 1024; - efivars->efi_pstore_info.data = efivars; - spin_lock_init(&efivars->efi_pstore_info.buf_lock); - pstore_register(&efivars->efi_pstore_info); + efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); + if (efi_pstore_info.buf) { + efi_pstore_info.bufsize = 1024; + spin_lock_init(&efi_pstore_info.buf_lock); + pstore_register(&efi_pstore_info); } } #else -static void efivar_pstore_register(struct efivars *efivars) +static void efivar_pstore_register(void) { return; } @@ -1531,76 +1349,41 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj, char *buf, loff_t pos, size_t count) { struct efi_variable *new_var = (struct efi_variable *)buf; - struct efivars *efivars = __efivars; - struct efivar_entry *search_efivar, *n; - unsigned long strsize1, strsize2; - efi_status_t status = EFI_NOT_FOUND; - int found = 0; + struct efivar_entry *new_entry; + int err; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || - validate_var(new_var, new_var->Data, new_var->DataSize) == false) { + efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) { printk(KERN_ERR "efivars: Malformed variable content\n"); return -EINVAL; } - spin_lock_irq(&efivars->lock); - - /* - * Does this variable already exist? - */ - list_for_each_entry_safe(search_efivar, n, &efivars->list, list) { - strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024); - strsize2 = utf16_strsize(new_var->VariableName, 1024); - if (strsize1 == strsize2 && - !memcmp(&(search_efivar->var.VariableName), - new_var->VariableName, strsize1) && - !efi_guidcmp(search_efivar->var.VendorGuid, - new_var->VendorGuid)) { - found = 1; - break; - } - } - if (found) { - spin_unlock_irq(&efivars->lock); - return -EINVAL; - } + new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL); + if (!new_entry) + return -ENOMEM; - status = check_var_size_locked(efivars, new_var->Attributes, - new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); + memcpy(&new_entry->var, new_var, sizeof(*new_var)); - if (status && status != EFI_UNSUPPORTED) { - spin_unlock_irq(&efivars->lock); - return efi_status_to_err(status); + err = efivar_entry_set(new_entry, new_var->Attributes, new_var->DataSize, + new_var->Data, &efivar_sysfs_list); + if (err) { + if (err == -EEXIST) + err = -EINVAL; + goto out; } - /* now *really* create the variable via EFI */ - status = efivars->ops->set_variable(new_var->VariableName, - &new_var->VendorGuid, - new_var->Attributes, - new_var->DataSize, - new_var->Data); - - if (status != EFI_SUCCESS) { - printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", - status); - spin_unlock_irq(&efivars->lock); - return -EIO; - } - spin_unlock_irq(&efivars->lock); - - /* Create the entry in sysfs. Locking is not required here */ - status = efivar_create_sysfs_entry(efivars, - utf16_strsize(new_var->VariableName, - 1024), - new_var->VariableName, - &new_var->VendorGuid); - if (status) { - printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n"); + if (efivar_create_sysfs_entry(new_entry)) { + printk(KERN_WARNING "efivars: failed to create sysfs entry.\n"); + kfree(new_entry); } return count; + +out: + kfree(new_entry); + return err; } static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, @@ -1608,70 +1391,40 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, char *buf, loff_t pos, size_t count) { struct efi_variable *del_var = (struct efi_variable *)buf; - struct efivars *efivars = __efivars; - struct efivar_entry *search_efivar, *n; - unsigned long strsize1, strsize2; - efi_status_t status = EFI_NOT_FOUND; - int found = 0; + struct efivar_entry *entry; + int err = 0; if (!capable(CAP_SYS_ADMIN)) return -EACCES; - spin_lock_irq(&efivars->lock); + efivar_entry_iter_begin(); + entry = efivar_entry_find(del_var->VariableName, del_var->VendorGuid, + &efivar_sysfs_list, true); + if (!entry) + err = -EINVAL; + else if (__efivar_entry_delete(entry)) + err = -EIO; - /* - * Does this variable already exist? - */ - list_for_each_entry_safe(search_efivar, n, &efivars->list, list) { - strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024); - strsize2 = utf16_strsize(del_var->VariableName, 1024); - if (strsize1 == strsize2 && - !memcmp(&(search_efivar->var.VariableName), - del_var->VariableName, strsize1) && - !efi_guidcmp(search_efivar->var.VendorGuid, - del_var->VendorGuid)) { - found = 1; - break; - } - } - if (!found) { - spin_unlock_irq(&efivars->lock); - return -EINVAL; - } - /* force the Attributes/DataSize to 0 to ensure deletion */ - del_var->Attributes = 0; - del_var->DataSize = 0; + efivar_entry_iter_end(); - status = efivars->ops->set_variable(del_var->VariableName, - &del_var->VendorGuid, - del_var->Attributes, - del_var->DataSize, - del_var->Data); + if (err) + return err; - if (status != EFI_SUCCESS) { - printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", - status); - spin_unlock_irq(&efivars->lock); - return -EIO; - } - list_del(&search_efivar->list); - /* We need to release this lock before unregistering. */ - spin_unlock_irq(&efivars->lock); - efivar_unregister(search_efivar); + efivar_unregister(entry); /* It's dead Jim.... */ return count; } -static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) +static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor, + struct list_head *head) { struct efivar_entry *entry, *n; - struct efivars *efivars = __efivars; unsigned long strsize1, strsize2; bool found = false; strsize1 = utf16_strsize(variable_name, 1024); - list_for_each_entry_safe(entry, n, &efivars->list, list) { + list_for_each_entry_safe(entry, n, head, list) { strsize2 = utf16_strsize(entry->var.VariableName, 1024); if (strsize1 == strsize2 && !memcmp(variable_name, &(entry->var.VariableName), @@ -1685,6 +1438,20 @@ static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) return found; } +static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor, + unsigned long name_size, void *data) +{ + struct efivar_entry *entry = data; + + if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false)) + return 0; + + memcpy(entry->var.VariableName, name, name_size); + memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); + + return 1; +} + /* * Returns the size of variable_name, in bytes, including the * terminating NULL character, or variable_name_size if no NULL @@ -1712,52 +1479,26 @@ static unsigned long var_name_strnsize(efi_char16_t *variable_name, static void efivar_update_sysfs_entries(struct work_struct *work) { - struct efivars *efivars = __efivars; - efi_guid_t vendor; - efi_char16_t *variable_name; - unsigned long variable_name_size = 1024; - efi_status_t status = EFI_NOT_FOUND; - bool found; + struct efivar_entry *entry; + int err; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return; /* Add new sysfs entries */ while (1) { - variable_name = kzalloc(variable_name_size, GFP_KERNEL); - if (!variable_name) { - pr_err("efivars: Memory allocation failed.\n"); - return; - } + memset(entry, 0, sizeof(*entry)); - spin_lock_irq(&efivars->lock); - found = false; - while (1) { - variable_name_size = 1024; - status = efivars->ops->get_next_variable( - &variable_name_size, - variable_name, - &vendor); - if (status != EFI_SUCCESS) { - break; - } else { - if (!variable_is_present(variable_name, - &vendor)) { - found = true; - break; - } - } - } - spin_unlock_irq(&efivars->lock); - - if (!found) { - kfree(variable_name); + err = efivar_init(efivar_update_sysfs_entry, entry, + true, false, &efivar_sysfs_list); + if (!err) break; - } else { - variable_name_size = var_name_strnsize(variable_name, - variable_name_size); - efivar_create_sysfs_entry(efivars, - variable_name_size, - variable_name, &vendor); - } + + efivar_create_sysfs_entry(entry); } + + kfree(entry); } /* @@ -1804,45 +1545,37 @@ static struct attribute_group efi_subsys_attr_group = { static struct kobject *efi_kobj; -/* - * efivar_create_sysfs_entry() - * Requires: - * variable_name_size = number of bytes required to hold - * variable_name (not counting the NULL - * character at the end. - * efivars->lock is not held on entry or exit. +/** + * efivar_create_sysfs_entry - create a new entry in sysfs + * @new_var: efivar entry to create + * * Returns 1 on failure, 0 on success */ static int -efivar_create_sysfs_entry(struct efivars *efivars, - unsigned long variable_name_size, - efi_char16_t *variable_name, - efi_guid_t *vendor_guid) +efivar_create_sysfs_entry(struct efivar_entry *new_var) { int i, short_name_size; char *short_name; - struct efivar_entry *new_efivar; + unsigned long variable_name_size; + efi_char16_t *variable_name; + + variable_name = new_var->var.VariableName; + variable_name_size = utf16_strlen(variable_name) * sizeof(efi_char16_t); /* * Length of the variable bytes in ASCII, plus the '-' separator, * plus the GUID, plus trailing NUL */ short_name_size = variable_name_size / sizeof(efi_char16_t) - + 1 + GUID_LEN + 1; + + 1 + EFI_VARIABLE_GUID_LEN + 1; short_name = kzalloc(short_name_size, GFP_KERNEL); - new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); - if (!short_name || !new_efivar) { + if (!short_name) { kfree(short_name); - kfree(new_efivar); return 1; } - memcpy(new_efivar->var.VariableName, variable_name, - variable_name_size); - memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t)); - /* Convert Unicode to normal chars (assume top bits are 0), ala UTF-8 */ for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) { @@ -1852,30 +1585,25 @@ efivar_create_sysfs_entry(struct efivars *efivars, private variables from another's. */ *(short_name + strlen(short_name)) = '-'; - efi_guid_unparse(vendor_guid, short_name + strlen(short_name)); + efi_guid_unparse(&new_var->var.VendorGuid, + short_name + strlen(short_name)); - new_efivar->kobj.kset = efivars->kset; - i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL, - "%s", short_name); - if (i) { - kfree(short_name); - kfree(new_efivar); - return 1; - } + new_var->kobj.kset = efivars_kset; - kobject_uevent(&new_efivar->kobj, KOBJ_ADD); + i = kobject_init_and_add(&new_var->kobj, &efivar_ktype, + NULL, "%s", short_name); kfree(short_name); - short_name = NULL; + if (i) + return 1; - spin_lock_irq(&efivars->lock); - list_add(&new_efivar->list, &efivars->list); - spin_unlock_irq(&efivars->lock); + kobject_uevent(&new_var->kobj, KOBJ_ADD); + efivar_entry_add(new_var, &efivar_sysfs_list); return 0; } static int -create_efivars_bin_attributes(struct efivars *efivars) +create_efivars_bin_attributes(void) { struct bin_attribute *attr; int error; @@ -1888,8 +1616,7 @@ create_efivars_bin_attributes(struct efivars *efivars) attr->attr.name = "new_var"; attr->attr.mode = 0200; attr->write = efivar_create; - attr->private = efivars; - efivars->new_var = attr; + efivars_new_var = attr; /* del_var */ attr = kzalloc(sizeof(*attr), GFP_KERNEL); @@ -1900,61 +1627,59 @@ create_efivars_bin_attributes(struct efivars *efivars) attr->attr.name = "del_var"; attr->attr.mode = 0200; attr->write = efivar_delete; - attr->private = efivars; - efivars->del_var = attr; + efivars_del_var = attr; - sysfs_bin_attr_init(efivars->new_var); - sysfs_bin_attr_init(efivars->del_var); + sysfs_bin_attr_init(efivars_new_var); + sysfs_bin_attr_init(efivars_del_var); /* Register */ - error = sysfs_create_bin_file(&efivars->kset->kobj, - efivars->new_var); + error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var); if (error) { printk(KERN_ERR "efivars: unable to create new_var sysfs file" " due to error %d\n", error); goto out_free; } - error = sysfs_create_bin_file(&efivars->kset->kobj, - efivars->del_var); + + error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var); if (error) { printk(KERN_ERR "efivars: unable to create del_var sysfs file" " due to error %d\n", error); - sysfs_remove_bin_file(&efivars->kset->kobj, - efivars->new_var); + sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); goto out_free; } return 0; out_free: - kfree(efivars->del_var); - efivars->del_var = NULL; - kfree(efivars->new_var); - efivars->new_var = NULL; + kfree(efivars_del_var); + efivars_del_var = NULL; + kfree(efivars_new_var); + efivars_new_var = NULL; return error; } -void unregister_efivars(struct efivars *efivars) +static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor, + unsigned long name_size, void *data) { - struct efivar_entry *entry, *n; + struct efivar_entry *entry; - __efivars = NULL; + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; - list_for_each_entry_safe(entry, n, &efivars->list, list) { - spin_lock_irq(&efivars->lock); - list_del(&entry->list); - spin_unlock_irq(&efivars->lock); - efivar_unregister(entry); - } - if (efivars->new_var) - sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var); - if (efivars->del_var) - sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var); - kfree(efivars->new_var); - kfree(efivars->del_var); - kobject_put(efivars->kobject); - kset_unregister(efivars->kset); + memcpy(entry->var.VariableName, name, name_size); + memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); + + efivar_create_sysfs_entry(entry); + + return 0; +} + +static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data) +{ + efivar_entry_remove(entry); + efivar_unregister(entry); + return 0; } -EXPORT_SYMBOL_GPL(unregister_efivars); /* * Print a warning when duplicate EFI variables are encountered and @@ -1985,43 +1710,91 @@ static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, kfree(s8); } -int register_efivars(struct efivars *efivars, - const struct efivar_operations *ops, - struct kobject *parent_kobj) +static struct kobject *efivars_kobj; + +void efivars_sysfs_exit(void) { - efi_status_t status = EFI_NOT_FOUND; - efi_guid_t vendor_guid; - efi_char16_t *variable_name; - unsigned long variable_name_size = 1024; - int error = 0; + /* Remove all entries and destroy */ + __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL, NULL); + + if (efivars_new_var) + sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); + if (efivars_del_var) + sysfs_remove_bin_file(&efivars_kset->kobj, efivars_del_var); + kfree(efivars_new_var); + kfree(efivars_del_var); + kobject_put(efivars_kobj); + kset_unregister(efivars_kset); +} - __efivars = efivars; +int efivars_sysfs_init(void) +{ + struct kobject *parent_kobj = efivars_kobject(); + int error = 0; - variable_name = kzalloc(variable_name_size, GFP_KERNEL); - if (!variable_name) { - printk(KERN_ERR "efivars: Memory allocation failed.\n"); - return -ENOMEM; - } + /* No efivars has been registered yet */ + if (!parent_kobj) + return 0; - spin_lock_init(&efivars->lock); - INIT_LIST_HEAD(&efivars->list); - efivars->ops = ops; + printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, + EFIVARS_DATE); - efivars->kset = kset_create_and_add("vars", NULL, parent_kobj); - if (!efivars->kset) { + efivars_kset = kset_create_and_add("vars", NULL, parent_kobj); + if (!efivars_kset) { printk(KERN_ERR "efivars: Subsystem registration failed.\n"); - error = -ENOMEM; - goto out; + return -ENOMEM; } - efivars->kobject = kobject_create_and_add("efivars", parent_kobj); - if (!efivars->kobject) { + efivars_kobj = kobject_create_and_add("efivars", parent_kobj); + if (!efivars_kobj) { pr_err("efivars: Subsystem registration failed.\n"); - error = -ENOMEM; - kset_unregister(efivars->kset); - goto out; + kset_unregister(efivars_kset); + return -ENOMEM; + } + + efivar_init(efivars_sysfs_callback, NULL, false, + true, &efivar_sysfs_list); + + error = create_efivars_bin_attributes(); + if (error) + efivars_sysfs_exit(); + + return error; +} +EXPORT_SYMBOL_GPL(efivars_sysfs_init); + +/** + * efivar_init - build the initial list of EFI variables + * @func: callback function to invoke for every variable + * @data: function-specific data to pass to @func + * @atomic: do we need to execute the @func-loop atomically? + * @duplicates: error if we encounter duplicates on @head? + * @head: initialised head of variable list + * + * Get every EFI variable from the firmware and invoke @func. @func + * should call efivar_entry_add() to build the list of variables. + * + * Returns 0 on success, or a kernel error code on failure. + */ +int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *), + void *data, bool atomic, bool duplicates, + struct list_head *head) +{ + const struct efivar_operations *ops = __efivars->ops; + unsigned long variable_name_size = 1024; + efi_char16_t *variable_name; + efi_status_t status; + efi_guid_t vendor_guid; + int err = 0; + + variable_name = kzalloc(variable_name_size, GFP_KERNEL); + if (!variable_name) { + printk(KERN_ERR "efivars: Memory allocation failed.\n"); + return -ENOMEM; } + spin_lock_irq(&__efivars->lock); + /* * Per EFI spec, the maximum storage allocated for both * the variable name and variable data is 1024 bytes. @@ -2035,6 +1808,9 @@ int register_efivars(struct efivars *efivars, &vendor_guid); switch (status) { case EFI_SUCCESS: + if (!atomic) + spin_unlock_irq(&__efivars->lock); + variable_name_size = var_name_strnsize(variable_name, variable_name_size); @@ -2046,17 +1822,24 @@ int register_efivars(struct efivars *efivars, * we'll ever see a different variable name, * and may end up looping here forever. */ - if (variable_is_present(variable_name, &vendor_guid)) { + if (duplicates && + variable_is_present(variable_name, &vendor_guid, head)) { dup_variable_bug(variable_name, &vendor_guid, variable_name_size); + if (!atomic) + spin_lock_irq(&__efivars->lock); + status = EFI_NOT_FOUND; break; } - efivar_create_sysfs_entry(efivars, - variable_name_size, - variable_name, - &vendor_guid); + err = func(variable_name, vendor_guid, variable_name_size, data); + if (err) + status = EFI_NOT_FOUND; + + if (!atomic) + spin_lock_irq(&__efivars->lock); + break; case EFI_NOT_FOUND: break; @@ -2066,40 +1849,637 @@ int register_efivars(struct efivars *efivars, status = EFI_NOT_FOUND; break; } + } while (status != EFI_NOT_FOUND); - error = create_efivars_bin_attributes(efivars); - if (error) - unregister_efivars(efivars); + spin_unlock_irq(&__efivars->lock); + + kfree(variable_name); + + return err; +} +EXPORT_SYMBOL_GPL(efivar_init); + +/** + * efivar_entry_add - add entry to variable list + * @entry: entry to add to list + * @head: list head + */ +void efivar_entry_add(struct efivar_entry *entry, struct list_head *head) +{ + spin_lock_irq(&__efivars->lock); + list_add(&entry->list, head); + spin_unlock_irq(&__efivars->lock); +} +EXPORT_SYMBOL_GPL(efivar_entry_add); + +/** + * efivar_entry_remove - remove entry from variable list + * @entry: entry to remove from list + */ +void efivar_entry_remove(struct efivar_entry *entry) +{ + spin_lock_irq(&__efivars->lock); + list_del(&entry->list); + spin_unlock_irq(&__efivars->lock); +} +EXPORT_SYMBOL_GPL(efivar_entry_remove); + +/* + * efivar_entry_list_del_unlock - remove entry from variable list + * @entry: entry to remove + * + * Remove @entry from the variable list and release the list lock. + * + * NOTE: slightly weird locking semantics here - we expect to be + * called with the efivars lock already held, and we release it before + * returning. This is because this function is usually called after + * set_variable() while the lock is still held. + */ +static void efivar_entry_list_del_unlock(struct efivar_entry *entry) +{ + WARN_ON(!spin_is_locked(&__efivars->lock)); + + list_del(&entry->list); + spin_unlock_irq(&__efivars->lock); +} + +/** + * __efivar_entry_delete - delete an EFI variable + * @entry: entry containing EFI variable to delete + * + * Delete the variable from the firmware and remove @entry from the + * variable list. It is the caller's responsibility to free @entry + * once we return. + * + * This function differs from efivar_entry_delete() because it is + * safe to be called from within a efivar_entry_iter_begin() and + * efivar_entry_iter_end() region, unlike efivar_entry_delete(). + * + * Returns 0 on success, or a converted EFI status code if + * set_variable() fails. If set_variable() fails the entry remains + * on the list. + */ +int __efivar_entry_delete(struct efivar_entry *entry) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + WARN_ON(!spin_is_locked(&__efivars->lock)); + + status = ops->set_variable(entry->var.VariableName, + &entry->var.VendorGuid, + 0, 0, NULL); + if (status) + return efi_status_to_err(status); + + list_del(&entry->list); + + return 0; +} +EXPORT_SYMBOL_GPL(__efivar_entry_delete); + +/** + * efivar_entry_delete - delete variable and remove entry from list + * @entry: entry containing variable to delete + * + * Delete the variable from the firmware and remove @entry from the + * variable list. It is the caller's responsibility to free @entry + * once we return. + * + * Returns 0 on success, or a converted EFI status code if + * set_variable() fails. + */ +int efivar_entry_delete(struct efivar_entry *entry) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + spin_lock_irq(&__efivars->lock); + status = ops->set_variable(entry->var.VariableName, + &entry->var.VendorGuid, + 0, 0, NULL); + if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) { + spin_unlock_irq(&__efivars->lock); + return efi_status_to_err(status); + } + + efivar_entry_list_del_unlock(entry); + return 0; +} +EXPORT_SYMBOL_GPL(efivar_entry_delete); + +/** + * efivar_entry_set - call set_variable() + * @entry: entry containing the EFI variable to write + * @attributes: variable attributes + * @size: size of @data buffer + * @data: buffer containing variable data + * @head: head of variable list + * + * Calls set_variable() for an EFI variable. If creating a new EFI + * variable, this function is usually followed by efivar_entry_add(). + * + * Before writing the variable, the remaining EFI variable storage + * space is checked to ensure there is enough room available. + * + * If @head is not NULL a lookup is performed to determine whether + * the entry is already on the list. + * + * Returns 0 on success, -EEXIST if a lookup is performed and the entry + * already exists on the list, or a converted EFI status code if + * set_variable() fails. + */ +int efivar_entry_set(struct efivar_entry *entry, u32 attributes, + unsigned long size, void *data, struct list_head *head) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + efi_char16_t *name = entry->var.VariableName; + efi_guid_t vendor = entry->var.VendorGuid; + + spin_lock_irq(&__efivars->lock); + + if (head && efivar_entry_find(name, vendor, head, false)) { + spin_unlock_irq(&__efivars->lock); + return -EEXIST; + } + + status = check_var_size(attributes, size + utf16_strsize(name, 1024)); + if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) + status = ops->set_variable(name, &vendor, + attributes, size, data); + + spin_unlock_irq(&__efivars->lock); + + return efi_status_to_err(status); +} +EXPORT_SYMBOL_GPL(efivar_entry_set); + +/** + * efivar_entry_set_safe - call set_variable() if enough space in firmware + * @name: buffer containing the variable name + * @vendor: variable vendor guid + * @attributes: variable attributes + * @block: can we block in this context? + * @size: size of @data buffer + * @data: buffer containing variable data + * + * Ensures there is enough free storage in the firmware for this variable, and + * if so, calls set_variable(). If creating a new EFI variable, this function + * is usually followed by efivar_entry_add(). + * + * Returns 0 on success, -ENOSPC if the firmware does not have enough + * space for set_variable() to succeed, or a converted EFI status code + * if set_variable() fails. + */ +int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, + bool block, unsigned long size, void *data) +{ + const struct efivar_operations *ops = __efivars->ops; + unsigned long flags; + efi_status_t status; + + if (!ops->query_variable_info) + return -ENOSYS; + + if (!block && !spin_trylock_irqsave(&__efivars->lock, flags)) + return -EBUSY; + else + spin_lock_irqsave(&__efivars->lock, flags); + + status = check_var_size(attributes, size + utf16_strsize(name, 1024)); + if (status != EFI_SUCCESS) { + spin_unlock_irqrestore(&__efivars->lock, flags); + return -ENOSPC; + } + + status = ops->set_variable(name, &vendor, attributes, size, data); + + spin_unlock_irqrestore(&__efivars->lock, flags); + + return efi_status_to_err(status); +} +EXPORT_SYMBOL_GPL(efivar_entry_set_safe); + +/** + * efivar_entry_find - search for an entry + * @name: the EFI variable name + * @guid: the EFI variable vendor's guid + * @head: head of the variable list + * @remove: should we remove the entry from the list? + * + * Search for an entry on the variable list that has the EFI variable + * name @name and vendor guid @guid. If an entry is found on the list + * and @remove is true, the entry is removed from the list. + * + * The caller MUST call efivar_entry_iter_begin() and + * efivar_entry_iter_end() before and after the invocation of this + * function, respectively. + * + * Returns the entry if found on the list, %NULL otherwise. + */ +struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, + struct list_head *head, bool remove) +{ + struct efivar_entry *entry, *n; + int strsize1, strsize2; + bool found = false; + + WARN_ON(!spin_is_locked(&__efivars->lock)); + + list_for_each_entry_safe(entry, n, head, list) { + strsize1 = utf16_strsize(name, 1024); + strsize2 = utf16_strsize(entry->var.VariableName, 1024); + if (strsize1 == strsize2 && + !memcmp(name, &(entry->var.VariableName), strsize1) && + !efi_guidcmp(guid, entry->var.VendorGuid)) { + found = true; + break; + } + } + + if (!found) + return NULL; + + if (remove) + list_del(&entry->list); + + return entry; +} +EXPORT_SYMBOL_GPL(efivar_entry_find); + +/** + * __efivar_entry_size - obtain the size of a variable + * @entry: entry for this variable + * @size: location to store the variable's size + * + * The caller MUST call efivar_entry_iter_begin() and + * efivar_entry_iter_end() before and after the invocation of this + * function, respectively. + */ +int __efivar_entry_size(struct efivar_entry *entry, unsigned long *size) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + WARN_ON(!spin_is_locked(&__efivars->lock)); + + *size = 0; + status = ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, NULL, size, NULL); + if (status != EFI_BUFFER_TOO_SMALL) + return efi_status_to_err(status); + + return 0; +} +EXPORT_SYMBOL_GPL(__efivar_entry_size); + +/** + * efivar_entry_size - obtain the size of a variable + * @entry: entry for this variable + * @size: location to store the variable's size + */ +int efivar_entry_size(struct efivar_entry *entry, unsigned long *size) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + *size = 0; + + spin_lock_irq(&__efivars->lock); + status = ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, NULL, size, NULL); + spin_unlock_irq(&__efivars->lock); + + if (status != EFI_BUFFER_TOO_SMALL) + return efi_status_to_err(status); + + return 0; +} +EXPORT_SYMBOL_GPL(efivar_entry_size); + +/** + * efivar_entry_get - call get_variable() + * @entry: read data for this variable + * @attributes: variable attributes + * @size: size of @data buffer + * @data: buffer to store variable data + */ +int efivar_entry_get(struct efivar_entry *entry, u32 *attributes, + unsigned long *size, void *data) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + spin_lock_irq(&__efivars->lock); + status = ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, + attributes, size, data); + spin_unlock_irq(&__efivars->lock); + + return efi_status_to_err(status); +} +EXPORT_SYMBOL_GPL(efivar_entry_get); + +/** + * efivar_entry_set_get_size - call set_variable() and get new size (atomic) + * @entry: entry containing variable to set and get + * @attributes: attributes of variable to be written + * @size: size of data buffer + * @data: buffer containing data to write + * @set: did the set_variable() call succeed? + * + * This is a pretty special (complex) function. See efivarfs_file_write(). + * + * Atomically call set_variable() for @entry and if the call is + * successful, return the new size of the variable from get_variable() + * in @size. The success of set_variable() is indicated by @set. + * + * Returns 0 on success, -EINVAL if the variable data is invalid, + * -ENOSPC if the firmware does not have enough available space, or a + * converted EFI status code if either of set_variable() or + * get_variable() fail. + * + * If the EFI variable does not exist when calling set_variable() + * (EFI_NOT_FOUND), @entry is removed from the variable list. + */ +int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes, + unsigned long *size, void *data, bool *set) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_char16_t *name = entry->var.VariableName; + efi_guid_t *vendor = &entry->var.VendorGuid; + efi_status_t status; + int err; + + *set = false; + + if (efivar_validate(&entry->var, data, *size) == false) + return -EINVAL; + + /* + * The lock here protects the get_variable call, the conditional + * set_variable call, and removal of the variable from the efivars + * list (in the case of an authenticated delete). + */ + spin_lock_irq(&__efivars->lock); + + /* + * Ensure that the available space hasn't shrunk below the safe level + */ + status = check_var_size(attributes, *size + utf16_strsize(name, 1024)); + if (status != EFI_SUCCESS) { + if (status != EFI_UNSUPPORTED) { + err = efi_status_to_err(status); + goto out; + } + + if (*size > 65536) { + err = -ENOSPC; + goto out; + } + } + + status = ops->set_variable(name, vendor, attributes, *size, data); + if (status != EFI_SUCCESS) { + err = efi_status_to_err(status); + goto out; + } + + *set = true; + + /* + * Writing to the variable may have caused a change in size (which + * could either be an append or an overwrite), or the variable to be + * deleted. Perform a GetVariable() so we can tell what actually + * happened. + */ + *size = 0; + status = ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, + NULL, size, NULL); + + if (status == EFI_NOT_FOUND) + efivar_entry_list_del_unlock(entry); + else + spin_unlock_irq(&__efivars->lock); + + if (status && status != EFI_BUFFER_TOO_SMALL) + return efi_status_to_err(status); + + return 0; + +out: + spin_unlock_irq(&__efivars->lock); + return err; + +} +EXPORT_SYMBOL_GPL(efivar_entry_set_get_size); + +/** + * efivar_entry_iter_begin - begin iterating the variable list + * + * Lock the variable list to prevent entry insertion and removal until + * efivar_entry_iter_end() is called. This function is usually used in + * conjunction with __efivar_entry_iter() or efivar_entry_iter(). + */ +void efivar_entry_iter_begin(void) +{ + spin_lock_irq(&__efivars->lock); +} +EXPORT_SYMBOL_GPL(efivar_entry_iter_begin); + +/** + * efivar_entry_iter_end - finish iterating the variable list + * + * Unlock the variable list and allow modifications to the list again. + */ +void efivar_entry_iter_end(void) +{ + spin_unlock_irq(&__efivars->lock); +} +EXPORT_SYMBOL_GPL(efivar_entry_iter_end); + +/** + * __efivar_entry_iter - iterate over variable list + * @func: callback function + * @head: head of the variable list + * @data: function-specific data to pass to callback + * @prev: entry to begin iterating from + * + * Iterate over the list of EFI variables and call @func with every + * entry on the list. It is safe for @func to remove entries in the + * list via efivar_entry_delete(). + * + * You MUST call efivar_enter_iter_begin() before this function, and + * efivar_entry_iter_end() afterwards. + * + * It is possible to begin iteration from an arbitrary entry within + * the list by passing @prev. @prev is updated on return to point to + * the last entry passed to @func. To begin iterating from the + * beginning of the list @prev must be %NULL. + * + * The restrictions for @func are the same as documented for + * efivar_entry_iter(). + */ +int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *), + struct list_head *head, void *data, + struct efivar_entry **prev) +{ + struct efivar_entry *entry, *n; + int err = 0; + + if (!prev || !*prev) { + list_for_each_entry_safe(entry, n, head, list) { + err = func(entry, data); + if (err) + break; + } + + if (prev) + *prev = entry; + + return err; + } + + + list_for_each_entry_safe_continue((*prev), n, head, list) { + err = func(*prev, data); + if (err) + break; + } + + return err; +} +EXPORT_SYMBOL_GPL(__efivar_entry_iter); + +/** + * efivar_entry_iter - iterate over variable list + * @func: callback function + * @head: head of variable list + * @data: function-specific data to pass to callback + * + * Iterate over the list of EFI variables and call @func with every + * entry on the list. It is safe for @func to remove entries in the + * list via efivar_entry_delete() while iterating. + * + * Some notes for the callback function: + * - a non-zero return value indicates an error and terminates the loop + * - @func is called from atomic context + */ +int efivar_entry_iter(int (*func)(struct efivar_entry *, void *), + struct list_head *head, void *data) +{ + int err = 0; + + efivar_entry_iter_begin(); + err = __efivar_entry_iter(func, head, data, NULL); + efivar_entry_iter_end(); + + return err; +} +EXPORT_SYMBOL_GPL(efivar_entry_iter); + +/** + * efivars_kobject - get the kobject for the registered efivars + * + * If efivars_register() has not been called we return NULL, + * otherwise return the kobject used at registration time. + */ +struct kobject *efivars_kobject(void) +{ + if (!__efivars) + return NULL; + + return __efivars->kobject; +} +EXPORT_SYMBOL_GPL(efivars_kobject); + +/** + * efivars_register - register an efivars + * @efivars: efivars to register + * @ops: efivars operations + * @kobject: @efivars-specific kobject + * + * Only a single efivars can be registered at any time. + */ +int efivars_register(struct efivars *efivars, + const struct efivar_operations *ops, + struct kobject *kobject) +{ + spin_lock_init(&efivars->lock); + efivars->ops = ops; + efivars->kobject = kobject; + + __efivars = efivars; if (!efivars_pstore_disable) - efivar_pstore_register(efivars); + efivar_pstore_register(); register_filesystem(&efivarfs_type); -out: - kfree(variable_name); + return 0; +} +EXPORT_SYMBOL_GPL(efivars_register); - return error; +/** + * efivars_unregister - unregister an efivars + * @efivars: efivars to unregister + * + * The caller must have already removed every entry from the list, + * failure to do so is an error. + */ +int efivars_unregister(struct efivars *efivars) +{ + int rv; + + if (!__efivars) { + printk(KERN_ERR "efivars not registered\n"); + rv = -EINVAL; + goto out; + } + + if (__efivars != efivars) { + rv = -EINVAL; + goto out; + } + + __efivars = NULL; + + rv = 0; +out: + return rv; } -EXPORT_SYMBOL_GPL(register_efivars); +EXPORT_SYMBOL_GPL(efivars_unregister); static struct efivars generic_efivars; static struct efivar_operations generic_ops; static int generic_ops_register(void) { + int error; + generic_ops.get_variable = efi.get_variable; generic_ops.set_variable = efi.set_variable; generic_ops.get_next_variable = efi.get_next_variable; generic_ops.query_variable_info = efi.query_variable_info; - return register_efivars(&generic_efivars, &generic_ops, efi_kobj); + error = efivars_register(&generic_efivars, &generic_ops, efi_kobj); + if (error) + return error; + + error = efivars_sysfs_init(); + if (error) + efivars_unregister(&generic_efivars); + + return error; } static void generic_ops_unregister(void) { - unregister_efivars(&generic_efivars); + efivars_sysfs_exit(); + efivars_unregister(&generic_efivars); } /* @@ -2113,15 +2493,12 @@ static void generic_ops_unregister(void) static int __init efivars_init(void) { - int error = 0; - - printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, - EFIVARS_DATE); + int error; if (!efi_enabled(EFI_RUNTIME_SERVICES)) return 0; - /* For now we'll register the efi directory at /sys/firmware/efi */ + /* Register the efi directory at /sys/firmware/efi */ efi_kobj = kobject_create_and_add("efi", firmware_kobj); if (!efi_kobj) { printk(KERN_ERR "efivars: Firmware registration failed.\n"); diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c index c409a7577afc..757b2d92d5b0 100644 --- a/drivers/firmware/google/gsmi.c +++ b/drivers/firmware/google/gsmi.c @@ -882,12 +882,19 @@ static __init int gsmi_init(void) goto out_remove_bin_file; } - ret = register_efivars(&efivars, &efivar_ops, gsmi_kobj); + ret = efivars_register(&efivars, &efivar_ops, gsmi_kobj); if (ret) { printk(KERN_INFO "gsmi: Failed to register efivars\n"); goto out_remove_sysfs_files; } + ret = efivars_sysfs_init(); + if (ret) { + printk(KERN_INFO "gsmi: Failed to create efivars files\n"); + efivars_unregister(&efivars); + goto out_remove_sysfs_files; + } + register_reboot_notifier(&gsmi_reboot_notifier); register_die_notifier(&gsmi_die_notifier); atomic_notifier_chain_register(&panic_notifier_list, @@ -919,7 +926,7 @@ static void __exit gsmi_exit(void) unregister_die_notifier(&gsmi_die_notifier); atomic_notifier_chain_unregister(&panic_notifier_list, &gsmi_panic_notifier); - unregister_efivars(&efivars); + efivars_unregister(&efivars); sysfs_remove_files(gsmi_kobj, gsmi_attrs); sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr); -- cgit From 048517722cde2595a7366d0c3c72b8b1ec142a9c Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 8 Feb 2013 15:48:51 +0000 Subject: efivars: Move pstore code into the new EFI directory efivars.c has grown far too large and needs to be divided up. Create a new directory and move the persistence storage code to efi-pstore.c now that it uses the new efivar API. This helps us to greatly reduce the size of efivars.c and paves the way for moving other code out of efivars.c. Note that because CONFIG_EFI_VARS can be built as a module efi-pstore must also include support for building as a module. Reviewed-by: Tom Gundersen Tested-by: Tom Gundersen Cc: Seiji Aguchi Cc: Anton Vorontsov Cc: Colin Cross Cc: Kees Cook Cc: Matthew Garrett Cc: Tony Luck Signed-off-by: Matt Fleming --- drivers/firmware/Kconfig | 36 +---- drivers/firmware/Makefile | 1 + drivers/firmware/efi/Kconfig | 39 ++++++ drivers/firmware/efi/Makefile | 4 + drivers/firmware/efi/efi-pstore.c | 244 +++++++++++++++++++++++++++++++++ drivers/firmware/efivars.c | 277 ++------------------------------------ 6 files changed, 301 insertions(+), 300 deletions(-) create mode 100644 drivers/firmware/efi/Kconfig create mode 100644 drivers/firmware/efi/Makefile create mode 100644 drivers/firmware/efi/efi-pstore.c (limited to 'drivers/firmware') diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index 42c759a4d047..93876302fb2e 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -36,41 +36,6 @@ config FIRMWARE_MEMMAP See also Documentation/ABI/testing/sysfs-firmware-memmap. -config EFI_VARS - tristate "EFI Variable Support via sysfs" - depends on EFI - default n - help - If you say Y here, you are able to get EFI (Extensible Firmware - Interface) variable information via sysfs. You may read, - write, create, and destroy EFI variables through this interface. - - Note that using this driver in concert with efibootmgr requires - at least test release version 0.5.0-test3 or later, which is - available from Matt Domsch's website located at: - - - Subsequent efibootmgr releases may be found at: - - -config EFI_VARS_PSTORE - bool "Register efivars backend for pstore" - depends on EFI_VARS && PSTORE - default y - help - Say Y here to enable use efivars as a backend to pstore. This - will allow writing console messages, crash dumps, or anything - else supported by pstore to EFI variables. - -config EFI_VARS_PSTORE_DEFAULT_DISABLE - bool "Disable using efivars as a pstore backend by default" - depends on EFI_VARS_PSTORE - default n - help - Saying Y here will disable the use of efivars as a storage - backend for pstore by default. This setting can be overridden - using the efivars module's pstore_disable parameter. - config EFI_PCDP bool "Console device selection via EFI PCDP or HCDP table" depends on ACPI && EFI && IA64 @@ -164,5 +129,6 @@ config ISCSI_IBFT Otherwise, say N. source "drivers/firmware/google/Kconfig" +source "drivers/firmware/efi/Kconfig" endmenu diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile index 5a7e27399729..31bf68c93593 100644 --- a/drivers/firmware/Makefile +++ b/drivers/firmware/Makefile @@ -14,3 +14,4 @@ obj-$(CONFIG_ISCSI_IBFT) += iscsi_ibft.o obj-$(CONFIG_FIRMWARE_MEMMAP) += memmap.o obj-$(CONFIG_GOOGLE_FIRMWARE) += google/ +obj-$(CONFIG_EFI) += efi/ diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig new file mode 100644 index 000000000000..b0fc7c79dfbb --- /dev/null +++ b/drivers/firmware/efi/Kconfig @@ -0,0 +1,39 @@ +menu "EFI (Extensible Firmware Interface) Support" + depends on EFI + +config EFI_VARS + tristate "EFI Variable Support via sysfs" + depends on EFI + default n + help + If you say Y here, you are able to get EFI (Extensible Firmware + Interface) variable information via sysfs. You may read, + write, create, and destroy EFI variables through this interface. + + Note that using this driver in concert with efibootmgr requires + at least test release version 0.5.0-test3 or later, which is + available from Matt Domsch's website located at: + + + Subsequent efibootmgr releases may be found at: + + +config EFI_VARS_PSTORE + tristate "Register efivars backend for pstore" + depends on EFI_VARS && PSTORE + default y + help + Say Y here to enable use efivars as a backend to pstore. This + will allow writing console messages, crash dumps, or anything + else supported by pstore to EFI variables. + +config EFI_VARS_PSTORE_DEFAULT_DISABLE + bool "Disable using efivars as a pstore backend by default" + depends on EFI_VARS_PSTORE + default n + help + Saying Y here will disable the use of efivars as a storage + backend for pstore by default. This setting can be overridden + using the efivars module's pstore_disable parameter. + +endmenu diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile new file mode 100644 index 000000000000..e03cd51525c2 --- /dev/null +++ b/drivers/firmware/efi/Makefile @@ -0,0 +1,4 @@ +# +# Makefile for linux kernel +# +obj-$(CONFIG_EFI_VARS_PSTORE) += efi-pstore.o diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c new file mode 100644 index 000000000000..47ae712c9504 --- /dev/null +++ b/drivers/firmware/efi/efi-pstore.c @@ -0,0 +1,244 @@ +#include +#include +#include + +#define DUMP_NAME_LEN 52 + +static bool efivars_pstore_disable = + IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE); + +module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); + +#define PSTORE_EFI_ATTRIBUTES \ + (EFI_VARIABLE_NON_VOLATILE | \ + EFI_VARIABLE_BOOTSERVICE_ACCESS | \ + EFI_VARIABLE_RUNTIME_ACCESS) + +static int efi_pstore_open(struct pstore_info *psi) +{ + efivar_entry_iter_begin(); + psi->data = NULL; + return 0; +} + +static int efi_pstore_close(struct pstore_info *psi) +{ + efivar_entry_iter_end(); + psi->data = NULL; + return 0; +} + +struct pstore_read_data { + u64 *id; + enum pstore_type_id *type; + int *count; + struct timespec *timespec; + char **buf; +}; + +static int efi_pstore_read_func(struct efivar_entry *entry, void *data) +{ + efi_guid_t vendor = LINUX_EFI_CRASH_GUID; + struct pstore_read_data *cb_data = data; + char name[DUMP_NAME_LEN]; + int i; + int cnt; + unsigned int part; + unsigned long time, size; + + if (efi_guidcmp(entry->var.VendorGuid, vendor)) + return 0; + + for (i = 0; i < DUMP_NAME_LEN; i++) + name[i] = entry->var.VariableName[i]; + + if (sscanf(name, "dump-type%u-%u-%d-%lu", + cb_data->type, &part, &cnt, &time) == 4) { + *cb_data->id = part; + *cb_data->count = cnt; + cb_data->timespec->tv_sec = time; + cb_data->timespec->tv_nsec = 0; + } else if (sscanf(name, "dump-type%u-%u-%lu", + cb_data->type, &part, &time) == 3) { + /* + * Check if an old format, + * which doesn't support holding + * multiple logs, remains. + */ + *cb_data->id = part; + *cb_data->count = 0; + cb_data->timespec->tv_sec = time; + cb_data->timespec->tv_nsec = 0; + } else + return 0; + + __efivar_entry_size(entry, &size); + *cb_data->buf = kmalloc(size, GFP_KERNEL); + if (*cb_data->buf == NULL) + return -ENOMEM; + memcpy(*cb_data->buf, entry->var.Data, size); + return size; +} + +static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, + int *count, struct timespec *timespec, + char **buf, struct pstore_info *psi) +{ + struct pstore_read_data data; + + data.id = id; + data.type = type; + data.count = count; + data.timespec = timespec; + data.buf = buf; + + return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data, + (struct efivar_entry **)&psi->data); +} + +static int efi_pstore_write(enum pstore_type_id type, + enum kmsg_dump_reason reason, u64 *id, + unsigned int part, int count, size_t size, + struct pstore_info *psi) +{ + char name[DUMP_NAME_LEN]; + efi_char16_t efi_name[DUMP_NAME_LEN]; + efi_guid_t vendor = LINUX_EFI_CRASH_GUID; + int i, ret = 0; + + sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, + get_seconds()); + + for (i = 0; i < DUMP_NAME_LEN; i++) + efi_name[i] = name[i]; + + efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES, + !pstore_cannot_block_path(reason), + size, psi->buf); + + if (reason == KMSG_DUMP_OOPS) + efivar_run_worker(); + + *id = part; + return ret; +}; + +struct pstore_erase_data { + u64 id; + enum pstore_type_id type; + int count; + struct timespec time; + efi_char16_t *name; +}; + +/* + * Clean up an entry with the same name + */ +static int efi_pstore_erase_func(struct efivar_entry *entry, void *data) +{ + struct pstore_erase_data *ed = data; + efi_guid_t vendor = LINUX_EFI_CRASH_GUID; + efi_char16_t efi_name_old[DUMP_NAME_LEN]; + efi_char16_t *efi_name = ed->name; + unsigned long utf16_len = utf16_strlen(ed->name); + char name_old[DUMP_NAME_LEN]; + int i; + + if (efi_guidcmp(entry->var.VendorGuid, vendor)) + return 0; + + if (utf16_strncmp(entry->var.VariableName, + efi_name, (size_t)utf16_len)) { + /* + * Check if an old format, which doesn't support + * holding multiple logs, remains. + */ + sprintf(name_old, "dump-type%u-%u-%lu", ed->type, + (unsigned int)ed->id, ed->time.tv_sec); + + for (i = 0; i < DUMP_NAME_LEN; i++) + efi_name_old[i] = name_old[i]; + + if (utf16_strncmp(entry->var.VariableName, efi_name_old, + utf16_strlen(efi_name_old))) + return 0; + } + + /* found */ + __efivar_entry_delete(entry); + return 1; +} + +static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, + struct timespec time, struct pstore_info *psi) +{ + struct pstore_erase_data edata; + struct efivar_entry *entry; + char name[DUMP_NAME_LEN]; + efi_char16_t efi_name[DUMP_NAME_LEN]; + int found, i; + + sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count, + time.tv_sec); + + for (i = 0; i < DUMP_NAME_LEN; i++) + efi_name[i] = name[i]; + + edata.id = id; + edata.type = type; + edata.count = count; + edata.time = time; + edata.name = efi_name; + + efivar_entry_iter_begin(); + found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry); + efivar_entry_iter_end(); + + if (found) + efivar_unregister(entry); + + return 0; +} + +static struct pstore_info efi_pstore_info = { + .owner = THIS_MODULE, + .name = "efi", + .open = efi_pstore_open, + .close = efi_pstore_close, + .read = efi_pstore_read, + .write = efi_pstore_write, + .erase = efi_pstore_erase, +}; + +static __init int efivars_pstore_init(void) +{ + if (!efi_enabled(EFI_RUNTIME_SERVICES)) + return 0; + + if (!efivars_kobject()) + return 0; + + if (efivars_pstore_disable) + return 0; + + efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); + if (!efi_pstore_info.buf) + return -ENOMEM; + + efi_pstore_info.bufsize = 1024; + spin_lock_init(&efi_pstore_info.buf_lock); + + pstore_register(&efi_pstore_info); + + return 0; +} + +static __exit void efivars_pstore_exit(void) +{ +} + +module_init(efivars_pstore_init); +module_exit(efivars_pstore_exit); + +MODULE_DESCRIPTION("EFI variable backend for pstore"); +MODULE_LICENSE("GPL"); diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 82fd145ead3b..5e7c3b1acde9 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -78,7 +78,6 @@ #include #include #include -#include #include #include @@ -95,15 +94,9 @@ MODULE_DESCRIPTION("sysfs interface to EFI Variables"); MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); -#define DUMP_NAME_LEN 52 - static LIST_HEAD(efivarfs_list); -static LIST_HEAD(efivar_sysfs_list); - -static bool efivars_pstore_disable = - IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE); - -module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); +LIST_HEAD(efivar_sysfs_list); +EXPORT_SYMBOL_GPL(efivar_sysfs_list); struct efivar_attribute { struct attribute attr; @@ -114,11 +107,6 @@ struct efivar_attribute { /* Private pointer to registered efivars */ static struct efivars *__efivars; -#define PSTORE_EFI_ATTRIBUTES \ - (EFI_VARIABLE_NON_VOLATILE | \ - EFI_VARIABLE_BOOTSERVICE_ACCESS | \ - EFI_VARIABLE_RUNTIME_ACCESS) - static struct kset *efivars_kset; static struct bin_attribute *efivars_new_var; @@ -148,34 +136,6 @@ static void efivar_update_sysfs_entries(struct work_struct *); static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries); static bool efivar_wq_enabled = true; -/* - * Return the number of bytes is the length of this string - * Note: this is NOT the same as the number of unicode characters - */ -static inline unsigned long -utf16_strsize(efi_char16_t *data, unsigned long maxlength) -{ - return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t); -} - -static inline int -utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len) -{ - while (1) { - if (len == 0) - return 0; - if (*a < *b) - return -1; - if (*a > *b) - return 1; - if (*a == 0) /* implies *b == 0 */ - return 0; - a++; - b++; - len--; - } -} - static bool validate_device_path(struct efi_variable *var, int match, u8 *buffer, unsigned long len) @@ -598,12 +558,6 @@ static struct kobj_type efivar_ktype = { .default_attrs = def_attrs, }; -static inline void -efivar_unregister(struct efivar_entry *var) -{ - kobject_put(&var->kobj); -} - static int efivarfs_file_open(struct inode *inode, struct file *file) { file->private_data = inode->i_private; @@ -1130,220 +1084,6 @@ static const struct inode_operations efivarfs_dir_inode_operations = { .create = efivarfs_create, }; -#ifdef CONFIG_EFI_VARS_PSTORE - -static int efi_pstore_open(struct pstore_info *psi) -{ - efivar_entry_iter_begin(); - psi->data = NULL; - return 0; -} - -static int efi_pstore_close(struct pstore_info *psi) -{ - efivar_entry_iter_end(); - psi->data = NULL; - return 0; -} - -struct pstore_read_data { - u64 *id; - enum pstore_type_id *type; - int *count; - struct timespec *timespec; - char **buf; -}; - -static int efi_pstore_read_func(struct efivar_entry *entry, void *data) -{ - efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - struct pstore_read_data *cb_data = data; - char name[DUMP_NAME_LEN]; - int i; - int cnt; - unsigned int part; - unsigned long time, size; - - if (efi_guidcmp(entry->var.VendorGuid, vendor)) - return 0; - - for (i = 0; i < DUMP_NAME_LEN; i++) - name[i] = entry->var.VariableName[i]; - - if (sscanf(name, "dump-type%u-%u-%d-%lu", - cb_data->type, &part, &cnt, &time) == 4) { - *cb_data->id = part; - *cb_data->count = cnt; - cb_data->timespec->tv_sec = time; - cb_data->timespec->tv_nsec = 0; - } else if (sscanf(name, "dump-type%u-%u-%lu", - cb_data->type, &part, &time) == 3) { - /* - * Check if an old format, - * which doesn't support holding - * multiple logs, remains. - */ - *cb_data->id = part; - *cb_data->count = 0; - cb_data->timespec->tv_sec = time; - cb_data->timespec->tv_nsec = 0; - } else - return 0; - - __efivar_entry_size(entry, &size); - *cb_data->buf = kmalloc(size, GFP_KERNEL); - if (*cb_data->buf == NULL) - return -ENOMEM; - memcpy(*cb_data->buf, entry->var.Data, size); - return size; -} - -static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, - int *count, struct timespec *timespec, - char **buf, struct pstore_info *psi) -{ - struct pstore_read_data data; - - data.id = id; - data.type = type; - data.count = count; - data.timespec = timespec; - data.buf = buf; - - return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data, - (struct efivar_entry **)&psi->data); -} - -static int efi_pstore_write(enum pstore_type_id type, - enum kmsg_dump_reason reason, u64 *id, - unsigned int part, int count, size_t size, - struct pstore_info *psi) -{ - char name[DUMP_NAME_LEN]; - efi_char16_t efi_name[DUMP_NAME_LEN]; - efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - int i, ret = 0; - - sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, - get_seconds()); - - for (i = 0; i < DUMP_NAME_LEN; i++) - efi_name[i] = name[i]; - - ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES, - !pstore_cannot_block_path(reason), - size, psi->buf); - - if (reason == KMSG_DUMP_OOPS && efivar_wq_enabled) - schedule_work(&efivar_work); - - *id = part; - return ret; -}; - -struct pstore_erase_data { - u64 id; - enum pstore_type_id type; - int count; - struct timespec time; - efi_char16_t *name; -}; - -/* - * Clean up an entry with the same name - */ -static int efi_pstore_erase_func(struct efivar_entry *entry, void *data) -{ - struct pstore_erase_data *ed = data; - efi_guid_t vendor = LINUX_EFI_CRASH_GUID; - efi_char16_t efi_name_old[DUMP_NAME_LEN]; - efi_char16_t *efi_name = ed->name; - unsigned long utf16_len = utf16_strlen(ed->name); - char name_old[DUMP_NAME_LEN]; - int i; - - if (efi_guidcmp(entry->var.VendorGuid, vendor)) - return 0; - - if (utf16_strncmp(entry->var.VariableName, - efi_name, (size_t)utf16_len)) { - /* - * Check if an old format, which doesn't support - * holding multiple logs, remains. - */ - sprintf(name_old, "dump-type%u-%u-%lu", ed->type, - (unsigned int)ed->id, ed->time.tv_sec); - - for (i = 0; i < DUMP_NAME_LEN; i++) - efi_name_old[i] = name_old[i]; - - if (utf16_strncmp(entry->var.VariableName, efi_name_old, - utf16_strlen(efi_name_old))) - return 0; - } - - /* found */ - __efivar_entry_delete(entry); - return 1; -} - -static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, - struct timespec time, struct pstore_info *psi) -{ - struct pstore_erase_data edata; - struct efivar_entry *entry; - char name[DUMP_NAME_LEN]; - efi_char16_t efi_name[DUMP_NAME_LEN]; - int found, i; - - sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count, - time.tv_sec); - - for (i = 0; i < DUMP_NAME_LEN; i++) - efi_name[i] = name[i]; - - edata.id = id; - edata.type = type; - edata.count = count; - edata.time = time; - edata.name = efi_name; - - efivar_entry_iter_begin(); - found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry); - efivar_entry_iter_end(); - - if (found) - efivar_unregister(entry); - - return 0; -} - -static struct pstore_info efi_pstore_info = { - .owner = THIS_MODULE, - .name = "efi", - .open = efi_pstore_open, - .close = efi_pstore_close, - .read = efi_pstore_read, - .write = efi_pstore_write, - .erase = efi_pstore_erase, -}; - -static void efivar_pstore_register(void) -{ - efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); - if (efi_pstore_info.buf) { - efi_pstore_info.bufsize = 1024; - spin_lock_init(&efi_pstore_info.buf_lock); - pstore_register(&efi_pstore_info); - } -} -#else -static void efivar_pstore_register(void) -{ - return; -} -#endif - static ssize_t efivar_create(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) @@ -2396,6 +2136,16 @@ struct kobject *efivars_kobject(void) } EXPORT_SYMBOL_GPL(efivars_kobject); +/** + * efivar_run_worker - schedule the efivar worker thread + */ +void efivar_run_worker(void) +{ + if (efivar_wq_enabled) + schedule_work(&efivar_work); +} +EXPORT_SYMBOL_GPL(efivar_run_worker); + /** * efivars_register - register an efivars * @efivars: efivars to register @@ -2414,9 +2164,6 @@ int efivars_register(struct efivars *efivars, __efivars = efivars; - if (!efivars_pstore_disable) - efivar_pstore_register(); - register_filesystem(&efivarfs_type); return 0; -- cgit From d68772b7c83f4b518be15ae96f4827c8ed02f684 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 8 Feb 2013 16:27:24 +0000 Subject: efivarfs: Move to fs/efivarfs Now that efivarfs uses the efivar API, move it out of efivars.c and into fs/efivarfs where it belongs. This move will eventually allow us to enable the efivarfs code without having to also enable CONFIG_EFI_VARS built, and vice versa. Furthermore, things like, mount -t efivarfs none /sys/firmware/efi/efivars will now work if efivarfs is built as a module without requiring the use of MODULE_ALIAS(), which would have been necessary when the efivarfs code was part of efivars.c. Cc: Matthew Garrett Cc: Jeremy Kerr Reviewed-by: Tom Gundersen Tested-by: Tom Gundersen Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 496 --------------------------------------------- 1 file changed, 496 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 5e7c3b1acde9..af396758482f 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -94,7 +94,6 @@ MODULE_DESCRIPTION("sysfs interface to EFI Variables"); MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); -static LIST_HEAD(efivarfs_list); LIST_HEAD(efivar_sysfs_list); EXPORT_SYMBOL_GPL(efivar_sysfs_list); @@ -558,12 +557,6 @@ static struct kobj_type efivar_ktype = { .default_attrs = def_attrs, }; -static int efivarfs_file_open(struct inode *inode, struct file *file) -{ - file->private_data = inode->i_private; - return 0; -} - static int efi_status_to_err(efi_status_t status) { int err; @@ -597,493 +590,6 @@ static int efi_status_to_err(efi_status_t status) return err; } -static ssize_t efivarfs_file_write(struct file *file, - const char __user *userbuf, size_t count, loff_t *ppos) -{ - struct efivar_entry *var = file->private_data; - void *data; - u32 attributes; - struct inode *inode = file->f_mapping->host; - unsigned long datasize = count - sizeof(attributes); - ssize_t bytes = 0; - bool set = false; - - if (count < sizeof(attributes)) - return -EINVAL; - - if (copy_from_user(&attributes, userbuf, sizeof(attributes))) - return -EFAULT; - - if (attributes & ~(EFI_VARIABLE_MASK)) - return -EINVAL; - - data = kmalloc(datasize, GFP_KERNEL); - if (!data) - return -ENOMEM; - - if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) { - bytes = -EFAULT; - goto out; - } - - bytes = efivar_entry_set_get_size(var, attributes, &datasize, - data, &set); - if (!set && bytes) - goto out; - - if (!bytes) { - mutex_lock(&inode->i_mutex); - i_size_write(inode, datasize + sizeof(attributes)); - mutex_unlock(&inode->i_mutex); - } else if (bytes == -ENOENT) { - drop_nlink(inode); - d_delete(file->f_dentry); - dput(file->f_dentry); - } else - pr_warn("efivarfs: inconsistent EFI variable implementation? " - "status=%zu\n", bytes); - - bytes = count; - -out: - kfree(data); - - return bytes; -} - -static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, - size_t count, loff_t *ppos) -{ - struct efivar_entry *var = file->private_data; - unsigned long datasize = 0; - u32 attributes; - void *data; - ssize_t size = 0; - int err; - - err = efivar_entry_size(var, &datasize); - if (err) - return err; - - data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL); - - if (!data) - return -ENOMEM; - - size = efivar_entry_get(var, &attributes, &datasize, - data + sizeof(attributes)); - if (size) - goto out_free; - - memcpy(data, &attributes, sizeof(attributes)); - size = simple_read_from_buffer(userbuf, count, ppos, - data, datasize + sizeof(attributes)); -out_free: - kfree(data); - - return size; -} - -static void efivarfs_evict_inode(struct inode *inode) -{ - clear_inode(inode); -} - -static const struct super_operations efivarfs_ops = { - .statfs = simple_statfs, - .drop_inode = generic_delete_inode, - .evict_inode = efivarfs_evict_inode, - .show_options = generic_show_options, -}; - -static struct super_block *efivarfs_sb; - -static const struct inode_operations efivarfs_dir_inode_operations; - -static const struct file_operations efivarfs_file_operations = { - .open = efivarfs_file_open, - .read = efivarfs_file_read, - .write = efivarfs_file_write, - .llseek = no_llseek, -}; - -static struct inode *efivarfs_get_inode(struct super_block *sb, - const struct inode *dir, int mode, dev_t dev) -{ - struct inode *inode = new_inode(sb); - - if (inode) { - inode->i_ino = get_next_ino(); - inode->i_mode = mode; - inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; - switch (mode & S_IFMT) { - case S_IFREG: - inode->i_fop = &efivarfs_file_operations; - break; - case S_IFDIR: - inode->i_op = &efivarfs_dir_inode_operations; - inode->i_fop = &simple_dir_operations; - inc_nlink(inode); - break; - } - } - return inode; -} - -/* - * Return true if 'str' is a valid efivarfs filename of the form, - * - * VariableName-12345678-1234-1234-1234-1234567891bc - */ -static bool efivarfs_valid_name(const char *str, int len) -{ - static const char dashes[EFI_VARIABLE_GUID_LEN] = { - [8] = 1, [13] = 1, [18] = 1, [23] = 1 - }; - const char *s = str + len - EFI_VARIABLE_GUID_LEN; - int i; - - /* - * We need a GUID, plus at least one letter for the variable name, - * plus the '-' separator - */ - if (len < EFI_VARIABLE_GUID_LEN + 2) - return false; - - /* GUID must be preceded by a '-' */ - if (*(s - 1) != '-') - return false; - - /* - * Validate that 's' is of the correct format, e.g. - * - * 12345678-1234-1234-1234-123456789abc - */ - for (i = 0; i < EFI_VARIABLE_GUID_LEN; i++) { - if (dashes[i]) { - if (*s++ != '-') - return false; - } else { - if (!isxdigit(*s++)) - return false; - } - } - - return true; -} - -static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid) -{ - guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]); - guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]); - guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]); - guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]); - guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]); - guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]); - guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]); - guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]); - guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]); - guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]); - guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]); - guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]); - guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]); - guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]); - guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]); - guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]); -} - -static int efivarfs_create(struct inode *dir, struct dentry *dentry, - umode_t mode, bool excl) -{ - struct inode *inode; - struct efivar_entry *var; - int namelen, i = 0, err = 0; - - if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len)) - return -EINVAL; - - inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0); - if (!inode) - return -ENOMEM; - - var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); - if (!var) { - err = -ENOMEM; - goto out; - } - - /* length of the variable name itself: remove GUID and separator */ - namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1; - - efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1, - &var->var.VendorGuid); - - for (i = 0; i < namelen; i++) - var->var.VariableName[i] = dentry->d_name.name[i]; - - var->var.VariableName[i] = '\0'; - - inode->i_private = var; - - efivar_entry_add(var, &efivarfs_list); - d_instantiate(dentry, inode); - dget(dentry); -out: - if (err) { - kfree(var); - iput(inode); - } - return err; -} - -static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) -{ - struct efivar_entry *var = dentry->d_inode->i_private; - - if (efivar_entry_delete(var)) - return -EINVAL; - - drop_nlink(dentry->d_inode); - dput(dentry); - return 0; -}; - -/* - * Compare two efivarfs file names. - * - * An efivarfs filename is composed of two parts, - * - * 1. A case-sensitive variable name - * 2. A case-insensitive GUID - * - * So we need to perform a case-sensitive match on part 1 and a - * case-insensitive match on part 2. - */ -static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode, - const struct dentry *dentry, const struct inode *inode, - unsigned int len, const char *str, - const struct qstr *name) -{ - int guid = len - EFI_VARIABLE_GUID_LEN; - - if (name->len != len) - return 1; - - /* Case-sensitive compare for the variable name */ - if (memcmp(str, name->name, guid)) - return 1; - - /* Case-insensitive compare for the GUID */ - return strncasecmp(name->name + guid, str + guid, EFI_VARIABLE_GUID_LEN); -} - -static int efivarfs_d_hash(const struct dentry *dentry, - const struct inode *inode, struct qstr *qstr) -{ - unsigned long hash = init_name_hash(); - const unsigned char *s = qstr->name; - unsigned int len = qstr->len; - - if (!efivarfs_valid_name(s, len)) - return -EINVAL; - - while (len-- > EFI_VARIABLE_GUID_LEN) - hash = partial_name_hash(*s++, hash); - - /* GUID is case-insensitive. */ - while (len--) - hash = partial_name_hash(tolower(*s++), hash); - - qstr->hash = end_name_hash(hash); - return 0; -} - -/* - * Retaining negative dentries for an in-memory filesystem just wastes - * memory and lookup time: arrange for them to be deleted immediately. - */ -static int efivarfs_delete_dentry(const struct dentry *dentry) -{ - return 1; -} - -static struct dentry_operations efivarfs_d_ops = { - .d_compare = efivarfs_d_compare, - .d_hash = efivarfs_d_hash, - .d_delete = efivarfs_delete_dentry, -}; - -static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name) -{ - struct dentry *d; - struct qstr q; - int err; - - q.name = name; - q.len = strlen(name); - - err = efivarfs_d_hash(NULL, NULL, &q); - if (err) - return ERR_PTR(err); - - d = d_alloc(parent, &q); - if (d) - return d; - - return ERR_PTR(-ENOMEM); -} - -static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor, - unsigned long name_size, void *data) -{ - struct super_block *sb = (struct super_block *)data; - struct efivar_entry *entry; - struct inode *inode = NULL; - struct dentry *dentry, *root = sb->s_root; - unsigned long size = 0; - char *name; - int len, i; - int err = -ENOMEM; - - entry = kmalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - return err; - - memcpy(entry->var.VariableName, name16, name_size); - memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); - - len = utf16_strlen(entry->var.VariableName); - - /* name, plus '-', plus GUID, plus NUL*/ - name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL); - if (!name) - goto fail; - - for (i = 0; i < len; i++) - name[i] = entry->var.VariableName[i] & 0xFF; - - name[len] = '-'; - - efi_guid_unparse(&entry->var.VendorGuid, name + len + 1); - - name[len + EFI_VARIABLE_GUID_LEN+1] = '\0'; - - inode = efivarfs_get_inode(sb, root->d_inode, S_IFREG | 0644, 0); - if (!inode) - goto fail_name; - - dentry = efivarfs_alloc_dentry(root, name); - if (IS_ERR(dentry)) { - err = PTR_ERR(dentry); - goto fail_inode; - } - - /* copied by the above to local storage in the dentry. */ - kfree(name); - - efivar_entry_size(entry, &size); - efivar_entry_add(entry, &efivarfs_list); - - mutex_lock(&inode->i_mutex); - inode->i_private = entry; - i_size_write(inode, size + sizeof(entry->var.Attributes)); - mutex_unlock(&inode->i_mutex); - d_add(dentry, inode); - - return 0; - -fail_inode: - iput(inode); -fail_name: - kfree(name); -fail: - kfree(entry); - return err; -} - -static int efivarfs_destroy(struct efivar_entry *entry, void *data) -{ - efivar_entry_remove(entry); - kfree(entry); - return 0; -} - -static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) -{ - struct inode *inode = NULL; - struct dentry *root; - int err; - - efivarfs_sb = sb; - - sb->s_maxbytes = MAX_LFS_FILESIZE; - sb->s_blocksize = PAGE_CACHE_SIZE; - sb->s_blocksize_bits = PAGE_CACHE_SHIFT; - sb->s_magic = EFIVARFS_MAGIC; - sb->s_op = &efivarfs_ops; - sb->s_d_op = &efivarfs_d_ops; - sb->s_time_gran = 1; - - inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0); - if (!inode) - return -ENOMEM; - inode->i_op = &efivarfs_dir_inode_operations; - - root = d_make_root(inode); - sb->s_root = root; - if (!root) - return -ENOMEM; - - INIT_LIST_HEAD(&efivarfs_list); - - err = efivar_init(efivarfs_callback, (void *)sb, false, - true, &efivarfs_list); - if (err) - __efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL); - - return err; -} - -static struct dentry *efivarfs_mount(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data) -{ - return mount_single(fs_type, flags, data, efivarfs_fill_super); -} - -static void efivarfs_kill_sb(struct super_block *sb) -{ - kill_litter_super(sb); - efivarfs_sb = NULL; - - /* Remove all entries and destroy */ - __efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL); -} - -static struct file_system_type efivarfs_type = { - .name = "efivarfs", - .mount = efivarfs_mount, - .kill_sb = efivarfs_kill_sb, -}; -MODULE_ALIAS_FS("efivarfs"); - -/* - * Handle negative dentry. - */ -static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry, - unsigned int flags) -{ - if (dentry->d_name.len > NAME_MAX) - return ERR_PTR(-ENAMETOOLONG); - d_add(dentry, NULL); - return NULL; -} - -static const struct inode_operations efivarfs_dir_inode_operations = { - .lookup = efivarfs_lookup, - .unlink = efivarfs_unlink, - .create = efivarfs_create, -}; - static ssize_t efivar_create(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) @@ -2164,8 +1670,6 @@ int efivars_register(struct efivars *efivars, __efivars = efivars; - register_filesystem(&efivarfs_type); - return 0; } EXPORT_SYMBOL_GPL(efivars_register); -- cgit From a9499fa7cd3fd4824a7202d00c766b269fa3bda6 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Fri, 8 Feb 2013 15:37:06 +0000 Subject: efi: split efisubsystem from efivars This registers /sys/firmware/efi/{,systab,efivars/} whenever EFI is enabled and the system is booted with EFI. This allows *) userspace to check for the existence of /sys/firmware/efi as a way to determine whether or it is running on an EFI system. *) 'mount -t efivarfs none /sys/firmware/efi/efivars' without manually loading any modules. [ Also, move the efivar API into vars.c and unconditionally compile it. This allows us to move efivars.c, which now only contains the sysfs variable code, into the firmware/efi directory. Note that the efivars.c filename is kept to maintain backwards compatability with the old efivars.ko module. With this patch it is now possible for efivarfs to be built without CONFIG_EFI_VARS - Matt ] Cc: Seiji Aguchi Cc: Tony Luck Cc: Mike Waychison Cc: Kay Sievers Cc: Jeremy Kerr Cc: Matthew Garrett Cc: Chun-Yi Lee Cc: Andy Whitcroft Cc: Tobias Powalowski Signed-off-by: Tom Gundersen Signed-off-by: Matt Fleming --- drivers/firmware/Makefile | 1 - drivers/firmware/efi/Makefile | 2 + drivers/firmware/efi/efi.c | 134 +++ drivers/firmware/efi/efivars.c | 617 ++++++++++++++ drivers/firmware/efi/vars.c | 1049 +++++++++++++++++++++++ drivers/firmware/efivars.c | 1794 ---------------------------------------- 6 files changed, 1802 insertions(+), 1795 deletions(-) create mode 100644 drivers/firmware/efi/efi.c create mode 100644 drivers/firmware/efi/efivars.c create mode 100644 drivers/firmware/efi/vars.c delete mode 100644 drivers/firmware/efivars.c (limited to 'drivers/firmware') diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile index 31bf68c93593..299fad6b5867 100644 --- a/drivers/firmware/Makefile +++ b/drivers/firmware/Makefile @@ -4,7 +4,6 @@ obj-$(CONFIG_DMI) += dmi_scan.o obj-$(CONFIG_DMI_SYSFS) += dmi-sysfs.o obj-$(CONFIG_EDD) += edd.o -obj-$(CONFIG_EFI_VARS) += efivars.o obj-$(CONFIG_EFI_PCDP) += pcdp.o obj-$(CONFIG_DELL_RBU) += dell_rbu.o obj-$(CONFIG_DCDBAS) += dcdbas.o diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index e03cd51525c2..99245ab5a79c 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -1,4 +1,6 @@ # # Makefile for linux kernel # +obj-y += efi.o vars.o +obj-$(CONFIG_EFI_VARS) += efivars.o obj-$(CONFIG_EFI_VARS_PSTORE) += efi-pstore.o diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c new file mode 100644 index 000000000000..32bdf4f8e432 --- /dev/null +++ b/drivers/firmware/efi/efi.c @@ -0,0 +1,134 @@ +/* + * efi.c - EFI subsystem + * + * Copyright (C) 2001,2003,2004 Dell + * Copyright (C) 2004 Intel Corporation + * Copyright (C) 2013 Tom Gundersen + * + * This code registers /sys/firmware/efi{,/efivars} when EFI is supported, + * allowing the efivarfs to be mounted or the efivars module to be loaded. + * The existance of /sys/firmware/efi may also be used by userspace to + * determine that the system supports EFI. + * + * This file is released under the GPLv2. + */ + +#include +#include +#include +#include +#include + +static struct kobject *efi_kobj; +static struct kobject *efivars_kobj; + +/* + * Let's not leave out systab information that snuck into + * the efivars driver + */ +static ssize_t systab_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + char *str = buf; + + if (!kobj || !buf) + return -EINVAL; + + if (efi.mps != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "MPS=0x%lx\n", efi.mps); + if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20); + if (efi.acpi != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "ACPI=0x%lx\n", efi.acpi); + if (efi.smbios != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios); + if (efi.hcdp != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp); + if (efi.boot_info != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info); + if (efi.uga != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "UGA=0x%lx\n", efi.uga); + + return str - buf; +} + +static struct kobj_attribute efi_attr_systab = + __ATTR(systab, 0400, systab_show, NULL); + +static struct attribute *efi_subsys_attrs[] = { + &efi_attr_systab.attr, + NULL, /* maybe more in the future? */ +}; + +static struct attribute_group efi_subsys_attr_group = { + .attrs = efi_subsys_attrs, +}; + +static struct efivars generic_efivars; +static struct efivar_operations generic_ops; + +static int generic_ops_register(void) +{ + generic_ops.get_variable = efi.get_variable; + generic_ops.set_variable = efi.set_variable; + generic_ops.get_next_variable = efi.get_next_variable; + generic_ops.query_variable_info = efi.query_variable_info; + + return efivars_register(&generic_efivars, &generic_ops, efi_kobj); +} + +static void generic_ops_unregister(void) +{ + efivars_unregister(&generic_efivars); +} + +/* + * We register the efi subsystem with the firmware subsystem and the + * efivars subsystem with the efi subsystem, if the system was booted with + * EFI. + */ +static int __init efisubsys_init(void) +{ + int error; + + if (!efi_enabled(EFI_BOOT)) + return 0; + + /* We register the efi directory at /sys/firmware/efi */ + efi_kobj = kobject_create_and_add("efi", firmware_kobj); + if (!efi_kobj) { + pr_err("efi: Firmware registration failed.\n"); + return -ENOMEM; + } + + error = generic_ops_register(); + if (error) + goto err_put; + + error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group); + if (error) { + pr_err("efi: Sysfs attribute export failed with error %d.\n", + error); + goto err_unregister; + } + + /* and the standard mountpoint for efivarfs */ + efivars_kobj = kobject_create_and_add("efivars", efi_kobj); + if (!efivars_kobj) { + pr_err("efivars: Subsystem registration failed.\n"); + error = -ENOMEM; + goto err_remove_group; + } + + return 0; + +err_remove_group: + sysfs_remove_group(efi_kobj, &efi_subsys_attr_group); +err_unregister: + generic_ops_unregister(); +err_put: + kobject_put(efi_kobj); + return error; +} + +subsys_initcall(efisubsys_init); diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c new file mode 100644 index 000000000000..70635b3b59d3 --- /dev/null +++ b/drivers/firmware/efi/efivars.c @@ -0,0 +1,617 @@ +/* + * Originally from efivars.c, + * + * Copyright (C) 2001,2003,2004 Dell + * Copyright (C) 2004 Intel Corporation + * + * This code takes all variables accessible from EFI runtime and + * exports them via sysfs + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Changelog: + * + * 17 May 2004 - Matt Domsch + * remove check for efi_enabled in exit + * add MODULE_VERSION + * + * 26 Apr 2004 - Matt Domsch + * minor bug fixes + * + * 21 Apr 2004 - Matt Tolentino + * fix locking per Peter Chubb's findings + * + * 25 Mar 2002 - Matt Domsch + * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse() + * + * 12 Feb 2002 - Matt Domsch + * use list_for_each_safe when deleting vars. + * remove ifdef CONFIG_SMP around include + * v0.04 release to linux-ia64@linuxia64.org + * + * 20 April 2001 - Matt Domsch + * Moved vars from /proc/efi to /proc/efi/vars, and made + * efi.c own the /proc/efi directory. + * v0.03 release to linux-ia64@linuxia64.org + * + * 26 March 2001 - Matt Domsch + * At the request of Stephane, moved ownership of /proc/efi + * to efi.c, and now efivars lives under /proc/efi/vars. + * + * 12 March 2001 - Matt Domsch + * Feedback received from Stephane Eranian incorporated. + * efivar_write() checks copy_from_user() return value. + * efivar_read/write() returns proper errno. + * v0.02 release to linux-ia64@linuxia64.org + * + * 26 February 2001 - Matt Domsch + * v0.01 release to linux-ia64@linuxia64.org + */ + +#include +#include + +#define EFIVARS_VERSION "0.08" +#define EFIVARS_DATE "2004-May-17" + +MODULE_AUTHOR("Matt Domsch "); +MODULE_DESCRIPTION("sysfs interface to EFI Variables"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(EFIVARS_VERSION); + +LIST_HEAD(efivar_sysfs_list); +EXPORT_SYMBOL_GPL(efivar_sysfs_list); + +static struct kset *efivars_kset; + +static struct bin_attribute *efivars_new_var; +static struct bin_attribute *efivars_del_var; + +struct efivar_attribute { + struct attribute attr; + ssize_t (*show) (struct efivar_entry *entry, char *buf); + ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); +}; + +#define EFIVAR_ATTR(_name, _mode, _show, _store) \ +struct efivar_attribute efivar_attr_##_name = { \ + .attr = {.name = __stringify(_name), .mode = _mode}, \ + .show = _show, \ + .store = _store, \ +}; + +#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr) +#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj) + +/* + * Prototype for sysfs creation function + */ +static int +efivar_create_sysfs_entry(struct efivar_entry *new_var); + +static ssize_t +efivar_guid_read(struct efivar_entry *entry, char *buf) +{ + struct efi_variable *var = &entry->var; + char *str = buf; + + if (!entry || !buf) + return 0; + + efi_guid_unparse(&var->VendorGuid, str); + str += strlen(str); + str += sprintf(str, "\n"); + + return str - buf; +} + +static ssize_t +efivar_attr_read(struct efivar_entry *entry, char *buf) +{ + struct efi_variable *var = &entry->var; + char *str = buf; + + if (!entry || !buf) + return -EINVAL; + + var->DataSize = 1024; + if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) + return -EIO; + + if (var->Attributes & EFI_VARIABLE_NON_VOLATILE) + str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n"); + if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) + str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n"); + if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) + str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n"); + if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) + str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n"); + if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) + str += sprintf(str, + "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n"); + if (var->Attributes & + EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) + str += sprintf(str, + "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n"); + if (var->Attributes & EFI_VARIABLE_APPEND_WRITE) + str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n"); + return str - buf; +} + +static ssize_t +efivar_size_read(struct efivar_entry *entry, char *buf) +{ + struct efi_variable *var = &entry->var; + char *str = buf; + + if (!entry || !buf) + return -EINVAL; + + var->DataSize = 1024; + if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) + return -EIO; + + str += sprintf(str, "0x%lx\n", var->DataSize); + return str - buf; +} + +static ssize_t +efivar_data_read(struct efivar_entry *entry, char *buf) +{ + struct efi_variable *var = &entry->var; + + if (!entry || !buf) + return -EINVAL; + + var->DataSize = 1024; + if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) + return -EIO; + + memcpy(buf, var->Data, var->DataSize); + return var->DataSize; +} +/* + * We allow each variable to be edited via rewriting the + * entire efi variable structure. + */ +static ssize_t +efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) +{ + struct efi_variable *new_var, *var = &entry->var; + int err; + + if (count != sizeof(struct efi_variable)) + return -EINVAL; + + new_var = (struct efi_variable *)buf; + /* + * If only updating the variable data, then the name + * and guid should remain the same + */ + if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) || + efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) { + printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n"); + return -EINVAL; + } + + if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){ + printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n"); + return -EINVAL; + } + + if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || + efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) { + printk(KERN_ERR "efivars: Malformed variable content\n"); + return -EINVAL; + } + + memcpy(&entry->var, new_var, count); + + err = efivar_entry_set(entry, new_var->Attributes, + new_var->DataSize, new_var->Data, false); + if (err) { + printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err); + return -EIO; + } + + return count; +} + +static ssize_t +efivar_show_raw(struct efivar_entry *entry, char *buf) +{ + struct efi_variable *var = &entry->var; + + if (!entry || !buf) + return 0; + + var->DataSize = 1024; + if (efivar_entry_get(entry, &entry->var.Attributes, + &entry->var.DataSize, entry->var.Data)) + return -EIO; + + memcpy(buf, var, sizeof(*var)); + + return sizeof(*var); +} + +/* + * Generic read/write functions that call the specific functions of + * the attributes... + */ +static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr, + char *buf) +{ + struct efivar_entry *var = to_efivar_entry(kobj); + struct efivar_attribute *efivar_attr = to_efivar_attr(attr); + ssize_t ret = -EIO; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if (efivar_attr->show) { + ret = efivar_attr->show(var, buf); + } + return ret; +} + +static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr, + const char *buf, size_t count) +{ + struct efivar_entry *var = to_efivar_entry(kobj); + struct efivar_attribute *efivar_attr = to_efivar_attr(attr); + ssize_t ret = -EIO; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if (efivar_attr->store) + ret = efivar_attr->store(var, buf, count); + + return ret; +} + +static const struct sysfs_ops efivar_attr_ops = { + .show = efivar_attr_show, + .store = efivar_attr_store, +}; + +static void efivar_release(struct kobject *kobj) +{ + struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj); + kfree(var); +} + +static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL); +static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL); +static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL); +static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL); +static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw); + +static struct attribute *def_attrs[] = { + &efivar_attr_guid.attr, + &efivar_attr_size.attr, + &efivar_attr_attributes.attr, + &efivar_attr_data.attr, + &efivar_attr_raw_var.attr, + NULL, +}; + +static struct kobj_type efivar_ktype = { + .release = efivar_release, + .sysfs_ops = &efivar_attr_ops, + .default_attrs = def_attrs, +}; + +static ssize_t efivar_create(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t pos, size_t count) +{ + struct efi_variable *new_var = (struct efi_variable *)buf; + struct efivar_entry *new_entry; + int err; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || + efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) { + printk(KERN_ERR "efivars: Malformed variable content\n"); + return -EINVAL; + } + + new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL); + if (!new_entry) + return -ENOMEM; + + memcpy(&new_entry->var, new_var, sizeof(*new_var)); + + err = efivar_entry_set(new_entry, new_var->Attributes, new_var->DataSize, + new_var->Data, &efivar_sysfs_list); + if (err) { + if (err == -EEXIST) + err = -EINVAL; + goto out; + } + + if (efivar_create_sysfs_entry(new_entry)) { + printk(KERN_WARNING "efivars: failed to create sysfs entry.\n"); + kfree(new_entry); + } + return count; + +out: + kfree(new_entry); + return err; +} + +static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t pos, size_t count) +{ + struct efi_variable *del_var = (struct efi_variable *)buf; + struct efivar_entry *entry; + int err = 0; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + efivar_entry_iter_begin(); + entry = efivar_entry_find(del_var->VariableName, del_var->VendorGuid, + &efivar_sysfs_list, true); + if (!entry) + err = -EINVAL; + else if (__efivar_entry_delete(entry)) + err = -EIO; + + efivar_entry_iter_end(); + + if (err) + return err; + + efivar_unregister(entry); + + /* It's dead Jim.... */ + return count; +} + +/** + * efivar_create_sysfs_entry - create a new entry in sysfs + * @new_var: efivar entry to create + * + * Returns 1 on failure, 0 on success + */ +static int +efivar_create_sysfs_entry(struct efivar_entry *new_var) +{ + int i, short_name_size; + char *short_name; + unsigned long variable_name_size; + efi_char16_t *variable_name; + + variable_name = new_var->var.VariableName; + variable_name_size = utf16_strlen(variable_name) * sizeof(efi_char16_t); + + /* + * Length of the variable bytes in ASCII, plus the '-' separator, + * plus the GUID, plus trailing NUL + */ + short_name_size = variable_name_size / sizeof(efi_char16_t) + + 1 + EFI_VARIABLE_GUID_LEN + 1; + + short_name = kzalloc(short_name_size, GFP_KERNEL); + + if (!short_name) { + kfree(short_name); + return 1; + } + + /* Convert Unicode to normal chars (assume top bits are 0), + ala UTF-8 */ + for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) { + short_name[i] = variable_name[i] & 0xFF; + } + /* This is ugly, but necessary to separate one vendor's + private variables from another's. */ + + *(short_name + strlen(short_name)) = '-'; + efi_guid_unparse(&new_var->var.VendorGuid, + short_name + strlen(short_name)); + + new_var->kobj.kset = efivars_kset; + + i = kobject_init_and_add(&new_var->kobj, &efivar_ktype, + NULL, "%s", short_name); + kfree(short_name); + if (i) + return 1; + + kobject_uevent(&new_var->kobj, KOBJ_ADD); + efivar_entry_add(new_var, &efivar_sysfs_list); + + return 0; +} + +static int +create_efivars_bin_attributes(void) +{ + struct bin_attribute *attr; + int error; + + /* new_var */ + attr = kzalloc(sizeof(*attr), GFP_KERNEL); + if (!attr) + return -ENOMEM; + + attr->attr.name = "new_var"; + attr->attr.mode = 0200; + attr->write = efivar_create; + efivars_new_var = attr; + + /* del_var */ + attr = kzalloc(sizeof(*attr), GFP_KERNEL); + if (!attr) { + error = -ENOMEM; + goto out_free; + } + attr->attr.name = "del_var"; + attr->attr.mode = 0200; + attr->write = efivar_delete; + efivars_del_var = attr; + + sysfs_bin_attr_init(efivars_new_var); + sysfs_bin_attr_init(efivars_del_var); + + /* Register */ + error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var); + if (error) { + printk(KERN_ERR "efivars: unable to create new_var sysfs file" + " due to error %d\n", error); + goto out_free; + } + + error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var); + if (error) { + printk(KERN_ERR "efivars: unable to create del_var sysfs file" + " due to error %d\n", error); + sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); + goto out_free; + } + + return 0; +out_free: + kfree(efivars_del_var); + efivars_del_var = NULL; + kfree(efivars_new_var); + efivars_new_var = NULL; + return error; +} + +static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor, + unsigned long name_size, void *data) +{ + struct efivar_entry *entry = data; + + if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false)) + return 0; + + memcpy(entry->var.VariableName, name, name_size); + memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); + + return 1; +} + +static void efivar_update_sysfs_entries(struct work_struct *work) +{ + struct efivar_entry *entry; + int err; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return; + + /* Add new sysfs entries */ + while (1) { + memset(entry, 0, sizeof(*entry)); + + err = efivar_init(efivar_update_sysfs_entry, entry, + true, false, &efivar_sysfs_list); + if (!err) + break; + + efivar_create_sysfs_entry(entry); + } + + kfree(entry); +} + +static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor, + unsigned long name_size, void *data) +{ + struct efivar_entry *entry; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + memcpy(entry->var.VariableName, name, name_size); + memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); + + efivar_create_sysfs_entry(entry); + + return 0; +} + +static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data) +{ + efivar_entry_remove(entry); + efivar_unregister(entry); + return 0; +} + +void efivars_sysfs_exit(void) +{ + /* Remove all entries and destroy */ + __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL, NULL); + + if (efivars_new_var) + sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); + if (efivars_del_var) + sysfs_remove_bin_file(&efivars_kset->kobj, efivars_del_var); + kfree(efivars_new_var); + kfree(efivars_del_var); + kset_unregister(efivars_kset); +} + +int efivars_sysfs_init(void) +{ + struct kobject *parent_kobj = efivars_kobject(); + int error = 0; + + /* No efivars has been registered yet */ + if (!parent_kobj) + return 0; + + printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, + EFIVARS_DATE); + + efivars_kset = kset_create_and_add("vars", NULL, parent_kobj); + if (!efivars_kset) { + printk(KERN_ERR "efivars: Subsystem registration failed.\n"); + return -ENOMEM; + } + + efivar_init(efivars_sysfs_callback, NULL, false, + true, &efivar_sysfs_list); + + error = create_efivars_bin_attributes(); + if (error) { + efivars_sysfs_exit(); + return error; + } + + INIT_WORK(&efivar_work, efivar_update_sysfs_entries); + + return 0; +} +EXPORT_SYMBOL_GPL(efivars_sysfs_init); + +module_init(efivars_sysfs_init); +module_exit(efivars_sysfs_exit); diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c new file mode 100644 index 000000000000..dd1c20a426fa --- /dev/null +++ b/drivers/firmware/efi/vars.c @@ -0,0 +1,1049 @@ +/* + * Originally from efivars.c + * + * Copyright (C) 2001,2003,2004 Dell + * Copyright (C) 2004 Intel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Private pointer to registered efivars */ +static struct efivars *__efivars; + +static bool efivar_wq_enabled = true; +DECLARE_WORK(efivar_work, NULL); +EXPORT_SYMBOL_GPL(efivar_work); + +static bool +validate_device_path(struct efi_variable *var, int match, u8 *buffer, + unsigned long len) +{ + struct efi_generic_dev_path *node; + int offset = 0; + + node = (struct efi_generic_dev_path *)buffer; + + if (len < sizeof(*node)) + return false; + + while (offset <= len - sizeof(*node) && + node->length >= sizeof(*node) && + node->length <= len - offset) { + offset += node->length; + + if ((node->type == EFI_DEV_END_PATH || + node->type == EFI_DEV_END_PATH2) && + node->sub_type == EFI_DEV_END_ENTIRE) + return true; + + node = (struct efi_generic_dev_path *)(buffer + offset); + } + + /* + * If we're here then either node->length pointed past the end + * of the buffer or we reached the end of the buffer without + * finding a device path end node. + */ + return false; +} + +static bool +validate_boot_order(struct efi_variable *var, int match, u8 *buffer, + unsigned long len) +{ + /* An array of 16-bit integers */ + if ((len % 2) != 0) + return false; + + return true; +} + +static bool +validate_load_option(struct efi_variable *var, int match, u8 *buffer, + unsigned long len) +{ + u16 filepathlength; + int i, desclength = 0, namelen; + + namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName)); + + /* Either "Boot" or "Driver" followed by four digits of hex */ + for (i = match; i < match+4; i++) { + if (var->VariableName[i] > 127 || + hex_to_bin(var->VariableName[i] & 0xff) < 0) + return true; + } + + /* Reject it if there's 4 digits of hex and then further content */ + if (namelen > match + 4) + return false; + + /* A valid entry must be at least 8 bytes */ + if (len < 8) + return false; + + filepathlength = buffer[4] | buffer[5] << 8; + + /* + * There's no stored length for the description, so it has to be + * found by hand + */ + desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2; + + /* Each boot entry must have a descriptor */ + if (!desclength) + return false; + + /* + * If the sum of the length of the description, the claimed filepath + * length and the original header are greater than the length of the + * variable, it's malformed + */ + if ((desclength + filepathlength + 6) > len) + return false; + + /* + * And, finally, check the filepath + */ + return validate_device_path(var, match, buffer + desclength + 6, + filepathlength); +} + +static bool +validate_uint16(struct efi_variable *var, int match, u8 *buffer, + unsigned long len) +{ + /* A single 16-bit integer */ + if (len != 2) + return false; + + return true; +} + +static bool +validate_ascii_string(struct efi_variable *var, int match, u8 *buffer, + unsigned long len) +{ + int i; + + for (i = 0; i < len; i++) { + if (buffer[i] > 127) + return false; + + if (buffer[i] == 0) + return true; + } + + return false; +} + +struct variable_validate { + char *name; + bool (*validate)(struct efi_variable *var, int match, u8 *data, + unsigned long len); +}; + +static const struct variable_validate variable_validate[] = { + { "BootNext", validate_uint16 }, + { "BootOrder", validate_boot_order }, + { "DriverOrder", validate_boot_order }, + { "Boot*", validate_load_option }, + { "Driver*", validate_load_option }, + { "ConIn", validate_device_path }, + { "ConInDev", validate_device_path }, + { "ConOut", validate_device_path }, + { "ConOutDev", validate_device_path }, + { "ErrOut", validate_device_path }, + { "ErrOutDev", validate_device_path }, + { "Timeout", validate_uint16 }, + { "Lang", validate_ascii_string }, + { "PlatformLang", validate_ascii_string }, + { "", NULL }, +}; + +bool +efivar_validate(struct efi_variable *var, u8 *data, unsigned long len) +{ + int i; + u16 *unicode_name = var->VariableName; + + for (i = 0; variable_validate[i].validate != NULL; i++) { + const char *name = variable_validate[i].name; + int match; + + for (match = 0; ; match++) { + char c = name[match]; + u16 u = unicode_name[match]; + + /* All special variables are plain ascii */ + if (u > 127) + return true; + + /* Wildcard in the matching name means we've matched */ + if (c == '*') + return variable_validate[i].validate(var, + match, data, len); + + /* Case sensitive match */ + if (c != u) + break; + + /* Reached the end of the string while matching */ + if (!c) + return variable_validate[i].validate(var, + match, data, len); + } + } + + return true; +} +EXPORT_SYMBOL_GPL(efivar_validate); + +static efi_status_t +check_var_size(u32 attributes, unsigned long size) +{ + u64 storage_size, remaining_size, max_size; + efi_status_t status; + const struct efivar_operations *fops = __efivars->ops; + + if (!fops->query_variable_info) + return EFI_UNSUPPORTED; + + status = fops->query_variable_info(attributes, &storage_size, + &remaining_size, &max_size); + + if (status != EFI_SUCCESS) + return status; + + if (!storage_size || size > remaining_size || size > max_size || + (remaining_size - size) < (storage_size / 2)) + return EFI_OUT_OF_RESOURCES; + + return status; +} + +static int efi_status_to_err(efi_status_t status) +{ + int err; + + switch (status) { + case EFI_SUCCESS: + err = 0; + break; + case EFI_INVALID_PARAMETER: + err = -EINVAL; + break; + case EFI_OUT_OF_RESOURCES: + err = -ENOSPC; + break; + case EFI_DEVICE_ERROR: + err = -EIO; + break; + case EFI_WRITE_PROTECTED: + err = -EROFS; + break; + case EFI_SECURITY_VIOLATION: + err = -EACCES; + break; + case EFI_NOT_FOUND: + err = -ENOENT; + break; + default: + err = -EINVAL; + } + + return err; +} + +static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor, + struct list_head *head) +{ + struct efivar_entry *entry, *n; + unsigned long strsize1, strsize2; + bool found = false; + + strsize1 = utf16_strsize(variable_name, 1024); + list_for_each_entry_safe(entry, n, head, list) { + strsize2 = utf16_strsize(entry->var.VariableName, 1024); + if (strsize1 == strsize2 && + !memcmp(variable_name, &(entry->var.VariableName), + strsize2) && + !efi_guidcmp(entry->var.VendorGuid, + *vendor)) { + found = true; + break; + } + } + return found; +} + +/* + * Returns the size of variable_name, in bytes, including the + * terminating NULL character, or variable_name_size if no NULL + * character is found among the first variable_name_size bytes. + */ +static unsigned long var_name_strnsize(efi_char16_t *variable_name, + unsigned long variable_name_size) +{ + unsigned long len; + efi_char16_t c; + + /* + * The variable name is, by definition, a NULL-terminated + * string, so make absolutely sure that variable_name_size is + * the value we expect it to be. If not, return the real size. + */ + for (len = 2; len <= variable_name_size; len += sizeof(c)) { + c = variable_name[(len / sizeof(c)) - 1]; + if (!c) + break; + } + + return min(len, variable_name_size); +} + +/* + * Print a warning when duplicate EFI variables are encountered and + * disable the sysfs workqueue since the firmware is buggy. + */ +static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, + unsigned long len16) +{ + size_t i, len8 = len16 / sizeof(efi_char16_t); + char *s8; + + /* + * Disable the workqueue since the algorithm it uses for + * detecting new variables won't work with this buggy + * implementation of GetNextVariableName(). + */ + efivar_wq_enabled = false; + + s8 = kzalloc(len8, GFP_KERNEL); + if (!s8) + return; + + for (i = 0; i < len8; i++) + s8[i] = s16[i]; + + printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n", + s8, vendor_guid); + kfree(s8); +} + +/** + * efivar_init - build the initial list of EFI variables + * @func: callback function to invoke for every variable + * @data: function-specific data to pass to @func + * @atomic: do we need to execute the @func-loop atomically? + * @duplicates: error if we encounter duplicates on @head? + * @head: initialised head of variable list + * + * Get every EFI variable from the firmware and invoke @func. @func + * should call efivar_entry_add() to build the list of variables. + * + * Returns 0 on success, or a kernel error code on failure. + */ +int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *), + void *data, bool atomic, bool duplicates, + struct list_head *head) +{ + const struct efivar_operations *ops = __efivars->ops; + unsigned long variable_name_size = 1024; + efi_char16_t *variable_name; + efi_status_t status; + efi_guid_t vendor_guid; + int err = 0; + + variable_name = kzalloc(variable_name_size, GFP_KERNEL); + if (!variable_name) { + printk(KERN_ERR "efivars: Memory allocation failed.\n"); + return -ENOMEM; + } + + spin_lock_irq(&__efivars->lock); + + /* + * Per EFI spec, the maximum storage allocated for both + * the variable name and variable data is 1024 bytes. + */ + + do { + variable_name_size = 1024; + + status = ops->get_next_variable(&variable_name_size, + variable_name, + &vendor_guid); + switch (status) { + case EFI_SUCCESS: + if (!atomic) + spin_unlock_irq(&__efivars->lock); + + variable_name_size = var_name_strnsize(variable_name, + variable_name_size); + + /* + * Some firmware implementations return the + * same variable name on multiple calls to + * get_next_variable(). Terminate the loop + * immediately as there is no guarantee that + * we'll ever see a different variable name, + * and may end up looping here forever. + */ + if (duplicates && + variable_is_present(variable_name, &vendor_guid, head)) { + dup_variable_bug(variable_name, &vendor_guid, + variable_name_size); + if (!atomic) + spin_lock_irq(&__efivars->lock); + + status = EFI_NOT_FOUND; + break; + } + + err = func(variable_name, vendor_guid, variable_name_size, data); + if (err) + status = EFI_NOT_FOUND; + + if (!atomic) + spin_lock_irq(&__efivars->lock); + + break; + case EFI_NOT_FOUND: + break; + default: + printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n", + status); + status = EFI_NOT_FOUND; + break; + } + + } while (status != EFI_NOT_FOUND); + + spin_unlock_irq(&__efivars->lock); + + kfree(variable_name); + + return err; +} +EXPORT_SYMBOL_GPL(efivar_init); + +/** + * efivar_entry_add - add entry to variable list + * @entry: entry to add to list + * @head: list head + */ +void efivar_entry_add(struct efivar_entry *entry, struct list_head *head) +{ + spin_lock_irq(&__efivars->lock); + list_add(&entry->list, head); + spin_unlock_irq(&__efivars->lock); +} +EXPORT_SYMBOL_GPL(efivar_entry_add); + +/** + * efivar_entry_remove - remove entry from variable list + * @entry: entry to remove from list + */ +void efivar_entry_remove(struct efivar_entry *entry) +{ + spin_lock_irq(&__efivars->lock); + list_del(&entry->list); + spin_unlock_irq(&__efivars->lock); +} +EXPORT_SYMBOL_GPL(efivar_entry_remove); + +/* + * efivar_entry_list_del_unlock - remove entry from variable list + * @entry: entry to remove + * + * Remove @entry from the variable list and release the list lock. + * + * NOTE: slightly weird locking semantics here - we expect to be + * called with the efivars lock already held, and we release it before + * returning. This is because this function is usually called after + * set_variable() while the lock is still held. + */ +static void efivar_entry_list_del_unlock(struct efivar_entry *entry) +{ + WARN_ON(!spin_is_locked(&__efivars->lock)); + + list_del(&entry->list); + spin_unlock_irq(&__efivars->lock); +} + +/** + * __efivar_entry_delete - delete an EFI variable + * @entry: entry containing EFI variable to delete + * + * Delete the variable from the firmware but leave @entry on the + * variable list. + * + * This function differs from efivar_entry_delete() because it does + * not remove @entry from the variable list. Also, it is safe to be + * called from within a efivar_entry_iter_begin() and + * efivar_entry_iter_end() region, unlike efivar_entry_delete(). + * + * Returns 0 on success, or a converted EFI status code if + * set_variable() fails. + */ +int __efivar_entry_delete(struct efivar_entry *entry) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + WARN_ON(!spin_is_locked(&__efivars->lock)); + + status = ops->set_variable(entry->var.VariableName, + &entry->var.VendorGuid, + 0, 0, NULL); + + return efi_status_to_err(status); +} +EXPORT_SYMBOL_GPL(__efivar_entry_delete); + +/** + * efivar_entry_delete - delete variable and remove entry from list + * @entry: entry containing variable to delete + * + * Delete the variable from the firmware and remove @entry from the + * variable list. It is the caller's responsibility to free @entry + * once we return. + * + * Returns 0 on success, or a converted EFI status code if + * set_variable() fails. + */ +int efivar_entry_delete(struct efivar_entry *entry) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + spin_lock_irq(&__efivars->lock); + status = ops->set_variable(entry->var.VariableName, + &entry->var.VendorGuid, + 0, 0, NULL); + if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) { + spin_unlock_irq(&__efivars->lock); + return efi_status_to_err(status); + } + + efivar_entry_list_del_unlock(entry); + return 0; +} +EXPORT_SYMBOL_GPL(efivar_entry_delete); + +/** + * efivar_entry_set - call set_variable() + * @entry: entry containing the EFI variable to write + * @attributes: variable attributes + * @size: size of @data buffer + * @data: buffer containing variable data + * @head: head of variable list + * + * Calls set_variable() for an EFI variable. If creating a new EFI + * variable, this function is usually followed by efivar_entry_add(). + * + * Before writing the variable, the remaining EFI variable storage + * space is checked to ensure there is enough room available. + * + * If @head is not NULL a lookup is performed to determine whether + * the entry is already on the list. + * + * Returns 0 on success, -EEXIST if a lookup is performed and the entry + * already exists on the list, or a converted EFI status code if + * set_variable() fails. + */ +int efivar_entry_set(struct efivar_entry *entry, u32 attributes, + unsigned long size, void *data, struct list_head *head) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + efi_char16_t *name = entry->var.VariableName; + efi_guid_t vendor = entry->var.VendorGuid; + + spin_lock_irq(&__efivars->lock); + + if (head && efivar_entry_find(name, vendor, head, false)) { + spin_unlock_irq(&__efivars->lock); + return -EEXIST; + } + + status = check_var_size(attributes, size + utf16_strsize(name, 1024)); + if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) + status = ops->set_variable(name, &vendor, + attributes, size, data); + + spin_unlock_irq(&__efivars->lock); + + return efi_status_to_err(status); + +} +EXPORT_SYMBOL_GPL(efivar_entry_set); + +/** + * efivar_entry_set_safe - call set_variable() if enough space in firmware + * @name: buffer containing the variable name + * @vendor: variable vendor guid + * @attributes: variable attributes + * @block: can we block in this context? + * @size: size of @data buffer + * @data: buffer containing variable data + * + * Ensures there is enough free storage in the firmware for this variable, and + * if so, calls set_variable(). If creating a new EFI variable, this function + * is usually followed by efivar_entry_add(). + * + * Returns 0 on success, -ENOSPC if the firmware does not have enough + * space for set_variable() to succeed, or a converted EFI status code + * if set_variable() fails. + */ +int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, + bool block, unsigned long size, void *data) +{ + const struct efivar_operations *ops = __efivars->ops; + unsigned long flags; + efi_status_t status; + + if (!ops->query_variable_info) + return -ENOSYS; + + if (!block && spin_trylock_irqsave(&__efivars->lock, flags)) + return -EBUSY; + else + spin_lock_irqsave(&__efivars->lock, flags); + + status = check_var_size(attributes, size + utf16_strsize(name, 1024)); + if (status != EFI_SUCCESS) { + spin_unlock_irqrestore(&__efivars->lock, flags); + return -ENOSPC; + } + + status = ops->set_variable(name, &vendor, attributes, size, data); + + spin_unlock_irqrestore(&__efivars->lock, flags); + + return efi_status_to_err(status); +} +EXPORT_SYMBOL_GPL(efivar_entry_set_safe); + +/** + * efivar_entry_find - search for an entry + * @name: the EFI variable name + * @guid: the EFI variable vendor's guid + * @head: head of the variable list + * @remove: should we remove the entry from the list? + * + * Search for an entry on the variable list that has the EFI variable + * name @name and vendor guid @guid. If an entry is found on the list + * and @remove is true, the entry is removed from the list. + * + * The caller MUST call efivar_entry_iter_begin() and + * efivar_entry_iter_end() before and after the invocation of this + * function, respectively. + * + * Returns the entry if found on the list, %NULL otherwise. + */ +struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, + struct list_head *head, bool remove) +{ + struct efivar_entry *entry, *n; + int strsize1, strsize2; + bool found = false; + + WARN_ON(!spin_is_locked(&__efivars->lock)); + + list_for_each_entry_safe(entry, n, head, list) { + strsize1 = utf16_strsize(name, 1024); + strsize2 = utf16_strsize(entry->var.VariableName, 1024); + if (strsize1 == strsize2 && + !memcmp(name, &(entry->var.VariableName), strsize1) && + !efi_guidcmp(guid, entry->var.VendorGuid)) { + found = true; + break; + } + } + + if (!found) + return NULL; + + if (remove) + list_del(&entry->list); + + return entry; +} +EXPORT_SYMBOL_GPL(efivar_entry_find); + +/** + * __efivar_entry_size - obtain the size of a variable + * @entry: entry for this variable + * @size: location to store the variable's size + * + * The caller MUST call efivar_entry_iter_begin() and + * efivar_entry_iter_end() before and after the invocation of this + * function, respectively. + */ +int __efivar_entry_size(struct efivar_entry *entry, unsigned long *size) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + WARN_ON(!spin_is_locked(&__efivars->lock)); + + *size = 0; + status = ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, NULL, size, NULL); + if (status != EFI_BUFFER_TOO_SMALL) + return efi_status_to_err(status); + + return 0; +} +EXPORT_SYMBOL_GPL(__efivar_entry_size); + +/** + * efivar_entry_size - obtain the size of a variable + * @entry: entry for this variable + * @size: location to store the variable's size + */ +int efivar_entry_size(struct efivar_entry *entry, unsigned long *size) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + *size = 0; + + spin_lock_irq(&__efivars->lock); + status = ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, NULL, size, NULL); + spin_unlock_irq(&__efivars->lock); + + if (status != EFI_BUFFER_TOO_SMALL) + return efi_status_to_err(status); + + return 0; +} +EXPORT_SYMBOL_GPL(efivar_entry_size); + +/** + * efivar_entry_get - call get_variable() + * @entry: read data for this variable + * @attributes: variable attributes + * @size: size of @data buffer + * @data: buffer to store variable data + */ +int efivar_entry_get(struct efivar_entry *entry, u32 *attributes, + unsigned long *size, void *data) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_status_t status; + + spin_lock_irq(&__efivars->lock); + status = ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, + attributes, size, data); + spin_unlock_irq(&__efivars->lock); + + return efi_status_to_err(status); +} +EXPORT_SYMBOL_GPL(efivar_entry_get); + +/** + * efivar_entry_set_get_size - call set_variable() and get new size (atomic) + * @entry: entry containing variable to set and get + * @attributes: attributes of variable to be written + * @size: size of data buffer + * @data: buffer containing data to write + * @set: did the set_variable() call succeed? + * + * This is a pretty special (complex) function. See efivarfs_file_write(). + * + * Atomically call set_variable() for @entry and if the call is + * successful, return the new size of the variable from get_variable() + * in @size. The success of set_variable() is indicated by @set. + * + * Returns 0 on success, -EINVAL if the variable data is invalid, + * -ENOSPC if the firmware does not have enough available space, or a + * converted EFI status code if either of set_variable() or + * get_variable() fail. + * + * If the EFI variable does not exist when calling set_variable() + * (EFI_NOT_FOUND), @entry is removed from the variable list. + */ +int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes, + unsigned long *size, void *data, bool *set) +{ + const struct efivar_operations *ops = __efivars->ops; + efi_char16_t *name = entry->var.VariableName; + efi_guid_t *vendor = &entry->var.VendorGuid; + efi_status_t status; + int err; + + *set = false; + + if (efivar_validate(&entry->var, data, *size) == false) + return -EINVAL; + + /* + * The lock here protects the get_variable call, the conditional + * set_variable call, and removal of the variable from the efivars + * list (in the case of an authenticated delete). + */ + spin_lock_irq(&__efivars->lock); + + /* + * Ensure that the available space hasn't shrunk below the safe level + */ + status = check_var_size(attributes, *size + utf16_strsize(name, 1024)); + if (status != EFI_SUCCESS) { + if (status != EFI_UNSUPPORTED) { + err = efi_status_to_err(status); + goto out; + } + + if (*size > 65536) { + err = -ENOSPC; + goto out; + } + } + + status = ops->set_variable(name, vendor, attributes, *size, data); + if (status != EFI_SUCCESS) { + err = efi_status_to_err(status); + goto out; + } + + *set = true; + + /* + * Writing to the variable may have caused a change in size (which + * could either be an append or an overwrite), or the variable to be + * deleted. Perform a GetVariable() so we can tell what actually + * happened. + */ + *size = 0; + status = ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, + NULL, size, NULL); + + if (status == EFI_NOT_FOUND) + efivar_entry_list_del_unlock(entry); + else + spin_unlock_irq(&__efivars->lock); + + if (status && status != EFI_BUFFER_TOO_SMALL) + return efi_status_to_err(status); + + return 0; + +out: + spin_unlock_irq(&__efivars->lock); + return err; + +} +EXPORT_SYMBOL_GPL(efivar_entry_set_get_size); + +/** + * efivar_entry_iter_begin - begin iterating the variable list + * + * Lock the variable list to prevent entry insertion and removal until + * efivar_entry_iter_end() is called. This function is usually used in + * conjunction with __efivar_entry_iter() or efivar_entry_iter(). + */ +void efivar_entry_iter_begin(void) +{ + spin_lock_irq(&__efivars->lock); +} +EXPORT_SYMBOL_GPL(efivar_entry_iter_begin); + +/** + * efivar_entry_iter_end - finish iterating the variable list + * + * Unlock the variable list and allow modifications to the list again. + */ +void efivar_entry_iter_end(void) +{ + spin_unlock_irq(&__efivars->lock); +} +EXPORT_SYMBOL_GPL(efivar_entry_iter_end); + +/** + * __efivar_entry_iter - iterate over variable list + * @func: callback function + * @head: head of the variable list + * @data: function-specific data to pass to callback + * @prev: entry to begin iterating from + * + * Iterate over the list of EFI variables and call @func with every + * entry on the list. It is safe for @func to remove entries in the + * list via efivar_entry_delete(). + * + * You MUST call efivar_enter_iter_begin() before this function, and + * efivar_entry_iter_end() afterwards. + * + * It is possible to begin iteration from an arbitrary entry within + * the list by passing @prev. @prev is updated on return to point to + * the last entry passed to @func. To begin iterating from the + * beginning of the list @prev must be %NULL. + * + * The restrictions for @func are the same as documented for + * efivar_entry_iter(). + */ +int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *), + struct list_head *head, void *data, + struct efivar_entry **prev) +{ + struct efivar_entry *entry, *n; + int err = 0; + + if (!prev || !*prev) { + list_for_each_entry_safe(entry, n, head, list) { + err = func(entry, data); + if (err) + break; + } + + if (prev) + *prev = entry; + + return err; + } + + + list_for_each_entry_safe_continue((*prev), n, head, list) { + err = func(*prev, data); + if (err) + break; + } + + return err; +} +EXPORT_SYMBOL_GPL(__efivar_entry_iter); + +/** + * efivar_entry_iter - iterate over variable list + * @func: callback function + * @head: head of variable list + * @data: function-specific data to pass to callback + * + * Iterate over the list of EFI variables and call @func with every + * entry on the list. It is safe for @func to remove entries in the + * list via efivar_entry_delete() while iterating. + * + * Some notes for the callback function: + * - a non-zero return value indicates an error and terminates the loop + * - @func is called from atomic context + */ +int efivar_entry_iter(int (*func)(struct efivar_entry *, void *), + struct list_head *head, void *data) +{ + int err = 0; + + efivar_entry_iter_begin(); + err = __efivar_entry_iter(func, head, data, NULL); + efivar_entry_iter_end(); + + return err; +} +EXPORT_SYMBOL_GPL(efivar_entry_iter); + +/** + * efivars_kobject - get the kobject for the registered efivars + * + * If efivars_register() has not been called we return NULL, + * otherwise return the kobject used at registration time. + */ +struct kobject *efivars_kobject(void) +{ + if (!__efivars) + return NULL; + + return __efivars->kobject; +} +EXPORT_SYMBOL_GPL(efivars_kobject); + +/** + * efivar_run_worker - schedule the efivar worker thread + */ +void efivar_run_worker(void) +{ + if (efivar_wq_enabled) + schedule_work(&efivar_work); +} +EXPORT_SYMBOL_GPL(efivar_run_worker); + +/** + * efivars_register - register an efivars + * @efivars: efivars to register + * @ops: efivars operations + * @kobject: @efivars-specific kobject + * + * Only a single efivars can be registered at any time. + */ +int efivars_register(struct efivars *efivars, + const struct efivar_operations *ops, + struct kobject *kobject) +{ + spin_lock_init(&efivars->lock); + efivars->ops = ops; + efivars->kobject = kobject; + + __efivars = efivars; + + return 0; +} +EXPORT_SYMBOL_GPL(efivars_register); + +/** + * efivars_unregister - unregister an efivars + * @efivars: efivars to unregister + * + * The caller must have already removed every entry from the list, + * failure to do so is an error. + */ +int efivars_unregister(struct efivars *efivars) +{ + int rv; + + if (!__efivars) { + printk(KERN_ERR "efivars not registered\n"); + rv = -EINVAL; + goto out; + } + + if (__efivars != efivars) { + rv = -EINVAL; + goto out; + } + + __efivars = NULL; + + rv = 0; +out: + return rv; +} +EXPORT_SYMBOL_GPL(efivars_unregister); diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c deleted file mode 100644 index af396758482f..000000000000 --- a/drivers/firmware/efivars.c +++ /dev/null @@ -1,1794 +0,0 @@ -/* - * EFI Variables - efivars.c - * - * Copyright (C) 2001,2003,2004 Dell - * Copyright (C) 2004 Intel Corporation - * - * This code takes all variables accessible from EFI runtime and - * exports them via sysfs - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * - * Changelog: - * - * 17 May 2004 - Matt Domsch - * remove check for efi_enabled in exit - * add MODULE_VERSION - * - * 26 Apr 2004 - Matt Domsch - * minor bug fixes - * - * 21 Apr 2004 - Matt Tolentino - * fix locking per Peter Chubb's findings - * - * 25 Mar 2002 - Matt Domsch - * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse() - * - * 12 Feb 2002 - Matt Domsch - * use list_for_each_safe when deleting vars. - * remove ifdef CONFIG_SMP around include - * v0.04 release to linux-ia64@linuxia64.org - * - * 20 April 2001 - Matt Domsch - * Moved vars from /proc/efi to /proc/efi/vars, and made - * efi.c own the /proc/efi directory. - * v0.03 release to linux-ia64@linuxia64.org - * - * 26 March 2001 - Matt Domsch - * At the request of Stephane, moved ownership of /proc/efi - * to efi.c, and now efivars lives under /proc/efi/vars. - * - * 12 March 2001 - Matt Domsch - * Feedback received from Stephane Eranian incorporated. - * efivar_write() checks copy_from_user() return value. - * efivar_read/write() returns proper errno. - * v0.02 release to linux-ia64@linuxia64.org - * - * 26 February 2001 - Matt Domsch - * v0.01 release to linux-ia64@linuxia64.org - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -#include - -#define EFIVARS_VERSION "0.08" -#define EFIVARS_DATE "2004-May-17" - -MODULE_AUTHOR("Matt Domsch "); -MODULE_DESCRIPTION("sysfs interface to EFI Variables"); -MODULE_LICENSE("GPL"); -MODULE_VERSION(EFIVARS_VERSION); - -LIST_HEAD(efivar_sysfs_list); -EXPORT_SYMBOL_GPL(efivar_sysfs_list); - -struct efivar_attribute { - struct attribute attr; - ssize_t (*show) (struct efivar_entry *entry, char *buf); - ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); -}; - -/* Private pointer to registered efivars */ -static struct efivars *__efivars; - -static struct kset *efivars_kset; - -static struct bin_attribute *efivars_new_var; -static struct bin_attribute *efivars_del_var; - -#define EFIVAR_ATTR(_name, _mode, _show, _store) \ -struct efivar_attribute efivar_attr_##_name = { \ - .attr = {.name = __stringify(_name), .mode = _mode}, \ - .show = _show, \ - .store = _store, \ -}; - -#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr) -#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj) - -/* - * Prototype for sysfs creation function - */ -static int -efivar_create_sysfs_entry(struct efivar_entry *new_var); - -/* - * Prototype for workqueue functions updating sysfs entry - */ - -static void efivar_update_sysfs_entries(struct work_struct *); -static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries); -static bool efivar_wq_enabled = true; - -static bool -validate_device_path(struct efi_variable *var, int match, u8 *buffer, - unsigned long len) -{ - struct efi_generic_dev_path *node; - int offset = 0; - - node = (struct efi_generic_dev_path *)buffer; - - if (len < sizeof(*node)) - return false; - - while (offset <= len - sizeof(*node) && - node->length >= sizeof(*node) && - node->length <= len - offset) { - offset += node->length; - - if ((node->type == EFI_DEV_END_PATH || - node->type == EFI_DEV_END_PATH2) && - node->sub_type == EFI_DEV_END_ENTIRE) - return true; - - node = (struct efi_generic_dev_path *)(buffer + offset); - } - - /* - * If we're here then either node->length pointed past the end - * of the buffer or we reached the end of the buffer without - * finding a device path end node. - */ - return false; -} - -static bool -validate_boot_order(struct efi_variable *var, int match, u8 *buffer, - unsigned long len) -{ - /* An array of 16-bit integers */ - if ((len % 2) != 0) - return false; - - return true; -} - -static bool -validate_load_option(struct efi_variable *var, int match, u8 *buffer, - unsigned long len) -{ - u16 filepathlength; - int i, desclength = 0, namelen; - - namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName)); - - /* Either "Boot" or "Driver" followed by four digits of hex */ - for (i = match; i < match+4; i++) { - if (var->VariableName[i] > 127 || - hex_to_bin(var->VariableName[i] & 0xff) < 0) - return true; - } - - /* Reject it if there's 4 digits of hex and then further content */ - if (namelen > match + 4) - return false; - - /* A valid entry must be at least 8 bytes */ - if (len < 8) - return false; - - filepathlength = buffer[4] | buffer[5] << 8; - - /* - * There's no stored length for the description, so it has to be - * found by hand - */ - desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2; - - /* Each boot entry must have a descriptor */ - if (!desclength) - return false; - - /* - * If the sum of the length of the description, the claimed filepath - * length and the original header are greater than the length of the - * variable, it's malformed - */ - if ((desclength + filepathlength + 6) > len) - return false; - - /* - * And, finally, check the filepath - */ - return validate_device_path(var, match, buffer + desclength + 6, - filepathlength); -} - -static bool -validate_uint16(struct efi_variable *var, int match, u8 *buffer, - unsigned long len) -{ - /* A single 16-bit integer */ - if (len != 2) - return false; - - return true; -} - -static bool -validate_ascii_string(struct efi_variable *var, int match, u8 *buffer, - unsigned long len) -{ - int i; - - for (i = 0; i < len; i++) { - if (buffer[i] > 127) - return false; - - if (buffer[i] == 0) - return true; - } - - return false; -} - -struct variable_validate { - char *name; - bool (*validate)(struct efi_variable *var, int match, u8 *data, - unsigned long len); -}; - -static const struct variable_validate variable_validate[] = { - { "BootNext", validate_uint16 }, - { "BootOrder", validate_boot_order }, - { "DriverOrder", validate_boot_order }, - { "Boot*", validate_load_option }, - { "Driver*", validate_load_option }, - { "ConIn", validate_device_path }, - { "ConInDev", validate_device_path }, - { "ConOut", validate_device_path }, - { "ConOutDev", validate_device_path }, - { "ErrOut", validate_device_path }, - { "ErrOutDev", validate_device_path }, - { "Timeout", validate_uint16 }, - { "Lang", validate_ascii_string }, - { "PlatformLang", validate_ascii_string }, - { "", NULL }, -}; - -bool -efivar_validate(struct efi_variable *var, u8 *data, unsigned long len) -{ - int i; - u16 *unicode_name = var->VariableName; - - for (i = 0; variable_validate[i].validate != NULL; i++) { - const char *name = variable_validate[i].name; - int match; - - for (match = 0; ; match++) { - char c = name[match]; - u16 u = unicode_name[match]; - - /* All special variables are plain ascii */ - if (u > 127) - return true; - - /* Wildcard in the matching name means we've matched */ - if (c == '*') - return variable_validate[i].validate(var, - match, data, len); - - /* Case sensitive match */ - if (c != u) - break; - - /* Reached the end of the string while matching */ - if (!c) - return variable_validate[i].validate(var, - match, data, len); - } - } - - return true; -} -EXPORT_SYMBOL_GPL(efivar_validate); - -static efi_status_t -check_var_size(u32 attributes, unsigned long size) -{ - u64 storage_size, remaining_size, max_size; - efi_status_t status; - const struct efivar_operations *fops = __efivars->ops; - - if (!fops->query_variable_info) - return EFI_UNSUPPORTED; - - status = fops->query_variable_info(attributes, &storage_size, - &remaining_size, &max_size); - - if (status != EFI_SUCCESS) - return status; - - if (!storage_size || size > remaining_size || size > max_size || - (remaining_size - size) < (storage_size / 2)) - return EFI_OUT_OF_RESOURCES; - - return status; -} - -static ssize_t -efivar_guid_read(struct efivar_entry *entry, char *buf) -{ - struct efi_variable *var = &entry->var; - char *str = buf; - - if (!entry || !buf) - return 0; - - efi_guid_unparse(&var->VendorGuid, str); - str += strlen(str); - str += sprintf(str, "\n"); - - return str - buf; -} - -static ssize_t -efivar_attr_read(struct efivar_entry *entry, char *buf) -{ - struct efi_variable *var = &entry->var; - char *str = buf; - - if (!entry || !buf) - return -EINVAL; - - var->DataSize = 1024; - if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) - return -EIO; - - if (var->Attributes & EFI_VARIABLE_NON_VOLATILE) - str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n"); - if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) - str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n"); - if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) - str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n"); - if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) - str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n"); - if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) - str += sprintf(str, - "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n"); - if (var->Attributes & - EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) - str += sprintf(str, - "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n"); - if (var->Attributes & EFI_VARIABLE_APPEND_WRITE) - str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n"); - return str - buf; -} - -static ssize_t -efivar_size_read(struct efivar_entry *entry, char *buf) -{ - struct efi_variable *var = &entry->var; - char *str = buf; - - if (!entry || !buf) - return -EINVAL; - - var->DataSize = 1024; - if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) - return -EIO; - - str += sprintf(str, "0x%lx\n", var->DataSize); - return str - buf; -} - -static ssize_t -efivar_data_read(struct efivar_entry *entry, char *buf) -{ - struct efi_variable *var = &entry->var; - - if (!entry || !buf) - return -EINVAL; - - var->DataSize = 1024; - if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) - return -EIO; - - memcpy(buf, var->Data, var->DataSize); - return var->DataSize; -} -/* - * We allow each variable to be edited via rewriting the - * entire efi variable structure. - */ -static ssize_t -efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) -{ - struct efi_variable *new_var, *var = &entry->var; - int err; - - if (count != sizeof(struct efi_variable)) - return -EINVAL; - - new_var = (struct efi_variable *)buf; - /* - * If only updating the variable data, then the name - * and guid should remain the same - */ - if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) || - efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) { - printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n"); - return -EINVAL; - } - - if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){ - printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n"); - return -EINVAL; - } - - if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || - efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) { - printk(KERN_ERR "efivars: Malformed variable content\n"); - return -EINVAL; - } - - memcpy(&entry->var, new_var, count); - - err = efivar_entry_set(entry, new_var->Attributes, - new_var->DataSize, new_var->Data, false); - if (err) { - printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err); - return -EIO; - } - - return count; -} - -static ssize_t -efivar_show_raw(struct efivar_entry *entry, char *buf) -{ - struct efi_variable *var = &entry->var; - - if (!entry || !buf) - return 0; - - var->DataSize = 1024; - if (efivar_entry_get(entry, &entry->var.Attributes, - &entry->var.DataSize, entry->var.Data)) - return -EIO; - - memcpy(buf, var, sizeof(*var)); - - return sizeof(*var); -} - -/* - * Generic read/write functions that call the specific functions of - * the attributes... - */ -static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr, - char *buf) -{ - struct efivar_entry *var = to_efivar_entry(kobj); - struct efivar_attribute *efivar_attr = to_efivar_attr(attr); - ssize_t ret = -EIO; - - if (!capable(CAP_SYS_ADMIN)) - return -EACCES; - - if (efivar_attr->show) { - ret = efivar_attr->show(var, buf); - } - return ret; -} - -static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr, - const char *buf, size_t count) -{ - struct efivar_entry *var = to_efivar_entry(kobj); - struct efivar_attribute *efivar_attr = to_efivar_attr(attr); - ssize_t ret = -EIO; - - if (!capable(CAP_SYS_ADMIN)) - return -EACCES; - - if (efivar_attr->store) - ret = efivar_attr->store(var, buf, count); - - return ret; -} - -static const struct sysfs_ops efivar_attr_ops = { - .show = efivar_attr_show, - .store = efivar_attr_store, -}; - -static void efivar_release(struct kobject *kobj) -{ - struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj); - kfree(var); -} - -static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL); -static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL); -static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL); -static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL); -static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw); - -static struct attribute *def_attrs[] = { - &efivar_attr_guid.attr, - &efivar_attr_size.attr, - &efivar_attr_attributes.attr, - &efivar_attr_data.attr, - &efivar_attr_raw_var.attr, - NULL, -}; - -static struct kobj_type efivar_ktype = { - .release = efivar_release, - .sysfs_ops = &efivar_attr_ops, - .default_attrs = def_attrs, -}; - -static int efi_status_to_err(efi_status_t status) -{ - int err; - - switch (status) { - case EFI_SUCCESS: - err = 0; - break; - case EFI_INVALID_PARAMETER: - err = -EINVAL; - break; - case EFI_OUT_OF_RESOURCES: - err = -ENOSPC; - break; - case EFI_DEVICE_ERROR: - err = -EIO; - break; - case EFI_WRITE_PROTECTED: - err = -EROFS; - break; - case EFI_SECURITY_VIOLATION: - err = -EACCES; - break; - case EFI_NOT_FOUND: - err = -ENOENT; - break; - default: - err = -EINVAL; - } - - return err; -} - -static ssize_t efivar_create(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buf, loff_t pos, size_t count) -{ - struct efi_variable *new_var = (struct efi_variable *)buf; - struct efivar_entry *new_entry; - int err; - - if (!capable(CAP_SYS_ADMIN)) - return -EACCES; - - if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || - efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) { - printk(KERN_ERR "efivars: Malformed variable content\n"); - return -EINVAL; - } - - new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL); - if (!new_entry) - return -ENOMEM; - - memcpy(&new_entry->var, new_var, sizeof(*new_var)); - - err = efivar_entry_set(new_entry, new_var->Attributes, new_var->DataSize, - new_var->Data, &efivar_sysfs_list); - if (err) { - if (err == -EEXIST) - err = -EINVAL; - goto out; - } - - if (efivar_create_sysfs_entry(new_entry)) { - printk(KERN_WARNING "efivars: failed to create sysfs entry.\n"); - kfree(new_entry); - } - return count; - -out: - kfree(new_entry); - return err; -} - -static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buf, loff_t pos, size_t count) -{ - struct efi_variable *del_var = (struct efi_variable *)buf; - struct efivar_entry *entry; - int err = 0; - - if (!capable(CAP_SYS_ADMIN)) - return -EACCES; - - efivar_entry_iter_begin(); - entry = efivar_entry_find(del_var->VariableName, del_var->VendorGuid, - &efivar_sysfs_list, true); - if (!entry) - err = -EINVAL; - else if (__efivar_entry_delete(entry)) - err = -EIO; - - efivar_entry_iter_end(); - - if (err) - return err; - - efivar_unregister(entry); - - /* It's dead Jim.... */ - return count; -} - -static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor, - struct list_head *head) -{ - struct efivar_entry *entry, *n; - unsigned long strsize1, strsize2; - bool found = false; - - strsize1 = utf16_strsize(variable_name, 1024); - list_for_each_entry_safe(entry, n, head, list) { - strsize2 = utf16_strsize(entry->var.VariableName, 1024); - if (strsize1 == strsize2 && - !memcmp(variable_name, &(entry->var.VariableName), - strsize2) && - !efi_guidcmp(entry->var.VendorGuid, - *vendor)) { - found = true; - break; - } - } - return found; -} - -static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor, - unsigned long name_size, void *data) -{ - struct efivar_entry *entry = data; - - if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false)) - return 0; - - memcpy(entry->var.VariableName, name, name_size); - memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); - - return 1; -} - -/* - * Returns the size of variable_name, in bytes, including the - * terminating NULL character, or variable_name_size if no NULL - * character is found among the first variable_name_size bytes. - */ -static unsigned long var_name_strnsize(efi_char16_t *variable_name, - unsigned long variable_name_size) -{ - unsigned long len; - efi_char16_t c; - - /* - * The variable name is, by definition, a NULL-terminated - * string, so make absolutely sure that variable_name_size is - * the value we expect it to be. If not, return the real size. - */ - for (len = 2; len <= variable_name_size; len += sizeof(c)) { - c = variable_name[(len / sizeof(c)) - 1]; - if (!c) - break; - } - - return min(len, variable_name_size); -} - -static void efivar_update_sysfs_entries(struct work_struct *work) -{ - struct efivar_entry *entry; - int err; - - entry = kzalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - return; - - /* Add new sysfs entries */ - while (1) { - memset(entry, 0, sizeof(*entry)); - - err = efivar_init(efivar_update_sysfs_entry, entry, - true, false, &efivar_sysfs_list); - if (!err) - break; - - efivar_create_sysfs_entry(entry); - } - - kfree(entry); -} - -/* - * Let's not leave out systab information that snuck into - * the efivars driver - */ -static ssize_t systab_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) -{ - char *str = buf; - - if (!kobj || !buf) - return -EINVAL; - - if (efi.mps != EFI_INVALID_TABLE_ADDR) - str += sprintf(str, "MPS=0x%lx\n", efi.mps); - if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) - str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20); - if (efi.acpi != EFI_INVALID_TABLE_ADDR) - str += sprintf(str, "ACPI=0x%lx\n", efi.acpi); - if (efi.smbios != EFI_INVALID_TABLE_ADDR) - str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios); - if (efi.hcdp != EFI_INVALID_TABLE_ADDR) - str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp); - if (efi.boot_info != EFI_INVALID_TABLE_ADDR) - str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info); - if (efi.uga != EFI_INVALID_TABLE_ADDR) - str += sprintf(str, "UGA=0x%lx\n", efi.uga); - - return str - buf; -} - -static struct kobj_attribute efi_attr_systab = - __ATTR(systab, 0400, systab_show, NULL); - -static struct attribute *efi_subsys_attrs[] = { - &efi_attr_systab.attr, - NULL, /* maybe more in the future? */ -}; - -static struct attribute_group efi_subsys_attr_group = { - .attrs = efi_subsys_attrs, -}; - -static struct kobject *efi_kobj; - -/** - * efivar_create_sysfs_entry - create a new entry in sysfs - * @new_var: efivar entry to create - * - * Returns 1 on failure, 0 on success - */ -static int -efivar_create_sysfs_entry(struct efivar_entry *new_var) -{ - int i, short_name_size; - char *short_name; - unsigned long variable_name_size; - efi_char16_t *variable_name; - - variable_name = new_var->var.VariableName; - variable_name_size = utf16_strlen(variable_name) * sizeof(efi_char16_t); - - /* - * Length of the variable bytes in ASCII, plus the '-' separator, - * plus the GUID, plus trailing NUL - */ - short_name_size = variable_name_size / sizeof(efi_char16_t) - + 1 + EFI_VARIABLE_GUID_LEN + 1; - - short_name = kzalloc(short_name_size, GFP_KERNEL); - - if (!short_name) { - kfree(short_name); - return 1; - } - - /* Convert Unicode to normal chars (assume top bits are 0), - ala UTF-8 */ - for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) { - short_name[i] = variable_name[i] & 0xFF; - } - /* This is ugly, but necessary to separate one vendor's - private variables from another's. */ - - *(short_name + strlen(short_name)) = '-'; - efi_guid_unparse(&new_var->var.VendorGuid, - short_name + strlen(short_name)); - - new_var->kobj.kset = efivars_kset; - - i = kobject_init_and_add(&new_var->kobj, &efivar_ktype, - NULL, "%s", short_name); - kfree(short_name); - if (i) - return 1; - - kobject_uevent(&new_var->kobj, KOBJ_ADD); - efivar_entry_add(new_var, &efivar_sysfs_list); - - return 0; -} - -static int -create_efivars_bin_attributes(void) -{ - struct bin_attribute *attr; - int error; - - /* new_var */ - attr = kzalloc(sizeof(*attr), GFP_KERNEL); - if (!attr) - return -ENOMEM; - - attr->attr.name = "new_var"; - attr->attr.mode = 0200; - attr->write = efivar_create; - efivars_new_var = attr; - - /* del_var */ - attr = kzalloc(sizeof(*attr), GFP_KERNEL); - if (!attr) { - error = -ENOMEM; - goto out_free; - } - attr->attr.name = "del_var"; - attr->attr.mode = 0200; - attr->write = efivar_delete; - efivars_del_var = attr; - - sysfs_bin_attr_init(efivars_new_var); - sysfs_bin_attr_init(efivars_del_var); - - /* Register */ - error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var); - if (error) { - printk(KERN_ERR "efivars: unable to create new_var sysfs file" - " due to error %d\n", error); - goto out_free; - } - - error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var); - if (error) { - printk(KERN_ERR "efivars: unable to create del_var sysfs file" - " due to error %d\n", error); - sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); - goto out_free; - } - - return 0; -out_free: - kfree(efivars_del_var); - efivars_del_var = NULL; - kfree(efivars_new_var); - efivars_new_var = NULL; - return error; -} - -static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor, - unsigned long name_size, void *data) -{ - struct efivar_entry *entry; - - entry = kzalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - return -ENOMEM; - - memcpy(entry->var.VariableName, name, name_size); - memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); - - efivar_create_sysfs_entry(entry); - - return 0; -} - -static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data) -{ - efivar_entry_remove(entry); - efivar_unregister(entry); - return 0; -} - -/* - * Print a warning when duplicate EFI variables are encountered and - * disable the sysfs workqueue since the firmware is buggy. - */ -static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, - unsigned long len16) -{ - size_t i, len8 = len16 / sizeof(efi_char16_t); - char *s8; - - /* - * Disable the workqueue since the algorithm it uses for - * detecting new variables won't work with this buggy - * implementation of GetNextVariableName(). - */ - efivar_wq_enabled = false; - - s8 = kzalloc(len8, GFP_KERNEL); - if (!s8) - return; - - for (i = 0; i < len8; i++) - s8[i] = s16[i]; - - printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n", - s8, vendor_guid); - kfree(s8); -} - -static struct kobject *efivars_kobj; - -void efivars_sysfs_exit(void) -{ - /* Remove all entries and destroy */ - __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL, NULL); - - if (efivars_new_var) - sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); - if (efivars_del_var) - sysfs_remove_bin_file(&efivars_kset->kobj, efivars_del_var); - kfree(efivars_new_var); - kfree(efivars_del_var); - kobject_put(efivars_kobj); - kset_unregister(efivars_kset); -} - -int efivars_sysfs_init(void) -{ - struct kobject *parent_kobj = efivars_kobject(); - int error = 0; - - /* No efivars has been registered yet */ - if (!parent_kobj) - return 0; - - printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, - EFIVARS_DATE); - - efivars_kset = kset_create_and_add("vars", NULL, parent_kobj); - if (!efivars_kset) { - printk(KERN_ERR "efivars: Subsystem registration failed.\n"); - return -ENOMEM; - } - - efivars_kobj = kobject_create_and_add("efivars", parent_kobj); - if (!efivars_kobj) { - pr_err("efivars: Subsystem registration failed.\n"); - kset_unregister(efivars_kset); - return -ENOMEM; - } - - efivar_init(efivars_sysfs_callback, NULL, false, - true, &efivar_sysfs_list); - - error = create_efivars_bin_attributes(); - if (error) - efivars_sysfs_exit(); - - return error; -} -EXPORT_SYMBOL_GPL(efivars_sysfs_init); - -/** - * efivar_init - build the initial list of EFI variables - * @func: callback function to invoke for every variable - * @data: function-specific data to pass to @func - * @atomic: do we need to execute the @func-loop atomically? - * @duplicates: error if we encounter duplicates on @head? - * @head: initialised head of variable list - * - * Get every EFI variable from the firmware and invoke @func. @func - * should call efivar_entry_add() to build the list of variables. - * - * Returns 0 on success, or a kernel error code on failure. - */ -int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *), - void *data, bool atomic, bool duplicates, - struct list_head *head) -{ - const struct efivar_operations *ops = __efivars->ops; - unsigned long variable_name_size = 1024; - efi_char16_t *variable_name; - efi_status_t status; - efi_guid_t vendor_guid; - int err = 0; - - variable_name = kzalloc(variable_name_size, GFP_KERNEL); - if (!variable_name) { - printk(KERN_ERR "efivars: Memory allocation failed.\n"); - return -ENOMEM; - } - - spin_lock_irq(&__efivars->lock); - - /* - * Per EFI spec, the maximum storage allocated for both - * the variable name and variable data is 1024 bytes. - */ - - do { - variable_name_size = 1024; - - status = ops->get_next_variable(&variable_name_size, - variable_name, - &vendor_guid); - switch (status) { - case EFI_SUCCESS: - if (!atomic) - spin_unlock_irq(&__efivars->lock); - - variable_name_size = var_name_strnsize(variable_name, - variable_name_size); - - /* - * Some firmware implementations return the - * same variable name on multiple calls to - * get_next_variable(). Terminate the loop - * immediately as there is no guarantee that - * we'll ever see a different variable name, - * and may end up looping here forever. - */ - if (duplicates && - variable_is_present(variable_name, &vendor_guid, head)) { - dup_variable_bug(variable_name, &vendor_guid, - variable_name_size); - if (!atomic) - spin_lock_irq(&__efivars->lock); - - status = EFI_NOT_FOUND; - break; - } - - err = func(variable_name, vendor_guid, variable_name_size, data); - if (err) - status = EFI_NOT_FOUND; - - if (!atomic) - spin_lock_irq(&__efivars->lock); - - break; - case EFI_NOT_FOUND: - break; - default: - printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n", - status); - status = EFI_NOT_FOUND; - break; - } - - } while (status != EFI_NOT_FOUND); - - spin_unlock_irq(&__efivars->lock); - - kfree(variable_name); - - return err; -} -EXPORT_SYMBOL_GPL(efivar_init); - -/** - * efivar_entry_add - add entry to variable list - * @entry: entry to add to list - * @head: list head - */ -void efivar_entry_add(struct efivar_entry *entry, struct list_head *head) -{ - spin_lock_irq(&__efivars->lock); - list_add(&entry->list, head); - spin_unlock_irq(&__efivars->lock); -} -EXPORT_SYMBOL_GPL(efivar_entry_add); - -/** - * efivar_entry_remove - remove entry from variable list - * @entry: entry to remove from list - */ -void efivar_entry_remove(struct efivar_entry *entry) -{ - spin_lock_irq(&__efivars->lock); - list_del(&entry->list); - spin_unlock_irq(&__efivars->lock); -} -EXPORT_SYMBOL_GPL(efivar_entry_remove); - -/* - * efivar_entry_list_del_unlock - remove entry from variable list - * @entry: entry to remove - * - * Remove @entry from the variable list and release the list lock. - * - * NOTE: slightly weird locking semantics here - we expect to be - * called with the efivars lock already held, and we release it before - * returning. This is because this function is usually called after - * set_variable() while the lock is still held. - */ -static void efivar_entry_list_del_unlock(struct efivar_entry *entry) -{ - WARN_ON(!spin_is_locked(&__efivars->lock)); - - list_del(&entry->list); - spin_unlock_irq(&__efivars->lock); -} - -/** - * __efivar_entry_delete - delete an EFI variable - * @entry: entry containing EFI variable to delete - * - * Delete the variable from the firmware and remove @entry from the - * variable list. It is the caller's responsibility to free @entry - * once we return. - * - * This function differs from efivar_entry_delete() because it is - * safe to be called from within a efivar_entry_iter_begin() and - * efivar_entry_iter_end() region, unlike efivar_entry_delete(). - * - * Returns 0 on success, or a converted EFI status code if - * set_variable() fails. If set_variable() fails the entry remains - * on the list. - */ -int __efivar_entry_delete(struct efivar_entry *entry) -{ - const struct efivar_operations *ops = __efivars->ops; - efi_status_t status; - - WARN_ON(!spin_is_locked(&__efivars->lock)); - - status = ops->set_variable(entry->var.VariableName, - &entry->var.VendorGuid, - 0, 0, NULL); - if (status) - return efi_status_to_err(status); - - list_del(&entry->list); - - return 0; -} -EXPORT_SYMBOL_GPL(__efivar_entry_delete); - -/** - * efivar_entry_delete - delete variable and remove entry from list - * @entry: entry containing variable to delete - * - * Delete the variable from the firmware and remove @entry from the - * variable list. It is the caller's responsibility to free @entry - * once we return. - * - * Returns 0 on success, or a converted EFI status code if - * set_variable() fails. - */ -int efivar_entry_delete(struct efivar_entry *entry) -{ - const struct efivar_operations *ops = __efivars->ops; - efi_status_t status; - - spin_lock_irq(&__efivars->lock); - status = ops->set_variable(entry->var.VariableName, - &entry->var.VendorGuid, - 0, 0, NULL); - if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) { - spin_unlock_irq(&__efivars->lock); - return efi_status_to_err(status); - } - - efivar_entry_list_del_unlock(entry); - return 0; -} -EXPORT_SYMBOL_GPL(efivar_entry_delete); - -/** - * efivar_entry_set - call set_variable() - * @entry: entry containing the EFI variable to write - * @attributes: variable attributes - * @size: size of @data buffer - * @data: buffer containing variable data - * @head: head of variable list - * - * Calls set_variable() for an EFI variable. If creating a new EFI - * variable, this function is usually followed by efivar_entry_add(). - * - * Before writing the variable, the remaining EFI variable storage - * space is checked to ensure there is enough room available. - * - * If @head is not NULL a lookup is performed to determine whether - * the entry is already on the list. - * - * Returns 0 on success, -EEXIST if a lookup is performed and the entry - * already exists on the list, or a converted EFI status code if - * set_variable() fails. - */ -int efivar_entry_set(struct efivar_entry *entry, u32 attributes, - unsigned long size, void *data, struct list_head *head) -{ - const struct efivar_operations *ops = __efivars->ops; - efi_status_t status; - efi_char16_t *name = entry->var.VariableName; - efi_guid_t vendor = entry->var.VendorGuid; - - spin_lock_irq(&__efivars->lock); - - if (head && efivar_entry_find(name, vendor, head, false)) { - spin_unlock_irq(&__efivars->lock); - return -EEXIST; - } - - status = check_var_size(attributes, size + utf16_strsize(name, 1024)); - if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) - status = ops->set_variable(name, &vendor, - attributes, size, data); - - spin_unlock_irq(&__efivars->lock); - - return efi_status_to_err(status); -} -EXPORT_SYMBOL_GPL(efivar_entry_set); - -/** - * efivar_entry_set_safe - call set_variable() if enough space in firmware - * @name: buffer containing the variable name - * @vendor: variable vendor guid - * @attributes: variable attributes - * @block: can we block in this context? - * @size: size of @data buffer - * @data: buffer containing variable data - * - * Ensures there is enough free storage in the firmware for this variable, and - * if so, calls set_variable(). If creating a new EFI variable, this function - * is usually followed by efivar_entry_add(). - * - * Returns 0 on success, -ENOSPC if the firmware does not have enough - * space for set_variable() to succeed, or a converted EFI status code - * if set_variable() fails. - */ -int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, - bool block, unsigned long size, void *data) -{ - const struct efivar_operations *ops = __efivars->ops; - unsigned long flags; - efi_status_t status; - - if (!ops->query_variable_info) - return -ENOSYS; - - if (!block && !spin_trylock_irqsave(&__efivars->lock, flags)) - return -EBUSY; - else - spin_lock_irqsave(&__efivars->lock, flags); - - status = check_var_size(attributes, size + utf16_strsize(name, 1024)); - if (status != EFI_SUCCESS) { - spin_unlock_irqrestore(&__efivars->lock, flags); - return -ENOSPC; - } - - status = ops->set_variable(name, &vendor, attributes, size, data); - - spin_unlock_irqrestore(&__efivars->lock, flags); - - return efi_status_to_err(status); -} -EXPORT_SYMBOL_GPL(efivar_entry_set_safe); - -/** - * efivar_entry_find - search for an entry - * @name: the EFI variable name - * @guid: the EFI variable vendor's guid - * @head: head of the variable list - * @remove: should we remove the entry from the list? - * - * Search for an entry on the variable list that has the EFI variable - * name @name and vendor guid @guid. If an entry is found on the list - * and @remove is true, the entry is removed from the list. - * - * The caller MUST call efivar_entry_iter_begin() and - * efivar_entry_iter_end() before and after the invocation of this - * function, respectively. - * - * Returns the entry if found on the list, %NULL otherwise. - */ -struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, - struct list_head *head, bool remove) -{ - struct efivar_entry *entry, *n; - int strsize1, strsize2; - bool found = false; - - WARN_ON(!spin_is_locked(&__efivars->lock)); - - list_for_each_entry_safe(entry, n, head, list) { - strsize1 = utf16_strsize(name, 1024); - strsize2 = utf16_strsize(entry->var.VariableName, 1024); - if (strsize1 == strsize2 && - !memcmp(name, &(entry->var.VariableName), strsize1) && - !efi_guidcmp(guid, entry->var.VendorGuid)) { - found = true; - break; - } - } - - if (!found) - return NULL; - - if (remove) - list_del(&entry->list); - - return entry; -} -EXPORT_SYMBOL_GPL(efivar_entry_find); - -/** - * __efivar_entry_size - obtain the size of a variable - * @entry: entry for this variable - * @size: location to store the variable's size - * - * The caller MUST call efivar_entry_iter_begin() and - * efivar_entry_iter_end() before and after the invocation of this - * function, respectively. - */ -int __efivar_entry_size(struct efivar_entry *entry, unsigned long *size) -{ - const struct efivar_operations *ops = __efivars->ops; - efi_status_t status; - - WARN_ON(!spin_is_locked(&__efivars->lock)); - - *size = 0; - status = ops->get_variable(entry->var.VariableName, - &entry->var.VendorGuid, NULL, size, NULL); - if (status != EFI_BUFFER_TOO_SMALL) - return efi_status_to_err(status); - - return 0; -} -EXPORT_SYMBOL_GPL(__efivar_entry_size); - -/** - * efivar_entry_size - obtain the size of a variable - * @entry: entry for this variable - * @size: location to store the variable's size - */ -int efivar_entry_size(struct efivar_entry *entry, unsigned long *size) -{ - const struct efivar_operations *ops = __efivars->ops; - efi_status_t status; - - *size = 0; - - spin_lock_irq(&__efivars->lock); - status = ops->get_variable(entry->var.VariableName, - &entry->var.VendorGuid, NULL, size, NULL); - spin_unlock_irq(&__efivars->lock); - - if (status != EFI_BUFFER_TOO_SMALL) - return efi_status_to_err(status); - - return 0; -} -EXPORT_SYMBOL_GPL(efivar_entry_size); - -/** - * efivar_entry_get - call get_variable() - * @entry: read data for this variable - * @attributes: variable attributes - * @size: size of @data buffer - * @data: buffer to store variable data - */ -int efivar_entry_get(struct efivar_entry *entry, u32 *attributes, - unsigned long *size, void *data) -{ - const struct efivar_operations *ops = __efivars->ops; - efi_status_t status; - - spin_lock_irq(&__efivars->lock); - status = ops->get_variable(entry->var.VariableName, - &entry->var.VendorGuid, - attributes, size, data); - spin_unlock_irq(&__efivars->lock); - - return efi_status_to_err(status); -} -EXPORT_SYMBOL_GPL(efivar_entry_get); - -/** - * efivar_entry_set_get_size - call set_variable() and get new size (atomic) - * @entry: entry containing variable to set and get - * @attributes: attributes of variable to be written - * @size: size of data buffer - * @data: buffer containing data to write - * @set: did the set_variable() call succeed? - * - * This is a pretty special (complex) function. See efivarfs_file_write(). - * - * Atomically call set_variable() for @entry and if the call is - * successful, return the new size of the variable from get_variable() - * in @size. The success of set_variable() is indicated by @set. - * - * Returns 0 on success, -EINVAL if the variable data is invalid, - * -ENOSPC if the firmware does not have enough available space, or a - * converted EFI status code if either of set_variable() or - * get_variable() fail. - * - * If the EFI variable does not exist when calling set_variable() - * (EFI_NOT_FOUND), @entry is removed from the variable list. - */ -int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes, - unsigned long *size, void *data, bool *set) -{ - const struct efivar_operations *ops = __efivars->ops; - efi_char16_t *name = entry->var.VariableName; - efi_guid_t *vendor = &entry->var.VendorGuid; - efi_status_t status; - int err; - - *set = false; - - if (efivar_validate(&entry->var, data, *size) == false) - return -EINVAL; - - /* - * The lock here protects the get_variable call, the conditional - * set_variable call, and removal of the variable from the efivars - * list (in the case of an authenticated delete). - */ - spin_lock_irq(&__efivars->lock); - - /* - * Ensure that the available space hasn't shrunk below the safe level - */ - status = check_var_size(attributes, *size + utf16_strsize(name, 1024)); - if (status != EFI_SUCCESS) { - if (status != EFI_UNSUPPORTED) { - err = efi_status_to_err(status); - goto out; - } - - if (*size > 65536) { - err = -ENOSPC; - goto out; - } - } - - status = ops->set_variable(name, vendor, attributes, *size, data); - if (status != EFI_SUCCESS) { - err = efi_status_to_err(status); - goto out; - } - - *set = true; - - /* - * Writing to the variable may have caused a change in size (which - * could either be an append or an overwrite), or the variable to be - * deleted. Perform a GetVariable() so we can tell what actually - * happened. - */ - *size = 0; - status = ops->get_variable(entry->var.VariableName, - &entry->var.VendorGuid, - NULL, size, NULL); - - if (status == EFI_NOT_FOUND) - efivar_entry_list_del_unlock(entry); - else - spin_unlock_irq(&__efivars->lock); - - if (status && status != EFI_BUFFER_TOO_SMALL) - return efi_status_to_err(status); - - return 0; - -out: - spin_unlock_irq(&__efivars->lock); - return err; - -} -EXPORT_SYMBOL_GPL(efivar_entry_set_get_size); - -/** - * efivar_entry_iter_begin - begin iterating the variable list - * - * Lock the variable list to prevent entry insertion and removal until - * efivar_entry_iter_end() is called. This function is usually used in - * conjunction with __efivar_entry_iter() or efivar_entry_iter(). - */ -void efivar_entry_iter_begin(void) -{ - spin_lock_irq(&__efivars->lock); -} -EXPORT_SYMBOL_GPL(efivar_entry_iter_begin); - -/** - * efivar_entry_iter_end - finish iterating the variable list - * - * Unlock the variable list and allow modifications to the list again. - */ -void efivar_entry_iter_end(void) -{ - spin_unlock_irq(&__efivars->lock); -} -EXPORT_SYMBOL_GPL(efivar_entry_iter_end); - -/** - * __efivar_entry_iter - iterate over variable list - * @func: callback function - * @head: head of the variable list - * @data: function-specific data to pass to callback - * @prev: entry to begin iterating from - * - * Iterate over the list of EFI variables and call @func with every - * entry on the list. It is safe for @func to remove entries in the - * list via efivar_entry_delete(). - * - * You MUST call efivar_enter_iter_begin() before this function, and - * efivar_entry_iter_end() afterwards. - * - * It is possible to begin iteration from an arbitrary entry within - * the list by passing @prev. @prev is updated on return to point to - * the last entry passed to @func. To begin iterating from the - * beginning of the list @prev must be %NULL. - * - * The restrictions for @func are the same as documented for - * efivar_entry_iter(). - */ -int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *), - struct list_head *head, void *data, - struct efivar_entry **prev) -{ - struct efivar_entry *entry, *n; - int err = 0; - - if (!prev || !*prev) { - list_for_each_entry_safe(entry, n, head, list) { - err = func(entry, data); - if (err) - break; - } - - if (prev) - *prev = entry; - - return err; - } - - - list_for_each_entry_safe_continue((*prev), n, head, list) { - err = func(*prev, data); - if (err) - break; - } - - return err; -} -EXPORT_SYMBOL_GPL(__efivar_entry_iter); - -/** - * efivar_entry_iter - iterate over variable list - * @func: callback function - * @head: head of variable list - * @data: function-specific data to pass to callback - * - * Iterate over the list of EFI variables and call @func with every - * entry on the list. It is safe for @func to remove entries in the - * list via efivar_entry_delete() while iterating. - * - * Some notes for the callback function: - * - a non-zero return value indicates an error and terminates the loop - * - @func is called from atomic context - */ -int efivar_entry_iter(int (*func)(struct efivar_entry *, void *), - struct list_head *head, void *data) -{ - int err = 0; - - efivar_entry_iter_begin(); - err = __efivar_entry_iter(func, head, data, NULL); - efivar_entry_iter_end(); - - return err; -} -EXPORT_SYMBOL_GPL(efivar_entry_iter); - -/** - * efivars_kobject - get the kobject for the registered efivars - * - * If efivars_register() has not been called we return NULL, - * otherwise return the kobject used at registration time. - */ -struct kobject *efivars_kobject(void) -{ - if (!__efivars) - return NULL; - - return __efivars->kobject; -} -EXPORT_SYMBOL_GPL(efivars_kobject); - -/** - * efivar_run_worker - schedule the efivar worker thread - */ -void efivar_run_worker(void) -{ - if (efivar_wq_enabled) - schedule_work(&efivar_work); -} -EXPORT_SYMBOL_GPL(efivar_run_worker); - -/** - * efivars_register - register an efivars - * @efivars: efivars to register - * @ops: efivars operations - * @kobject: @efivars-specific kobject - * - * Only a single efivars can be registered at any time. - */ -int efivars_register(struct efivars *efivars, - const struct efivar_operations *ops, - struct kobject *kobject) -{ - spin_lock_init(&efivars->lock); - efivars->ops = ops; - efivars->kobject = kobject; - - __efivars = efivars; - - return 0; -} -EXPORT_SYMBOL_GPL(efivars_register); - -/** - * efivars_unregister - unregister an efivars - * @efivars: efivars to unregister - * - * The caller must have already removed every entry from the list, - * failure to do so is an error. - */ -int efivars_unregister(struct efivars *efivars) -{ - int rv; - - if (!__efivars) { - printk(KERN_ERR "efivars not registered\n"); - rv = -EINVAL; - goto out; - } - - if (__efivars != efivars) { - rv = -EINVAL; - goto out; - } - - __efivars = NULL; - - rv = 0; -out: - return rv; -} -EXPORT_SYMBOL_GPL(efivars_unregister); - -static struct efivars generic_efivars; -static struct efivar_operations generic_ops; - -static int generic_ops_register(void) -{ - int error; - - generic_ops.get_variable = efi.get_variable; - generic_ops.set_variable = efi.set_variable; - generic_ops.get_next_variable = efi.get_next_variable; - generic_ops.query_variable_info = efi.query_variable_info; - - error = efivars_register(&generic_efivars, &generic_ops, efi_kobj); - if (error) - return error; - - error = efivars_sysfs_init(); - if (error) - efivars_unregister(&generic_efivars); - - return error; -} - -static void generic_ops_unregister(void) -{ - efivars_sysfs_exit(); - efivars_unregister(&generic_efivars); -} - -/* - * For now we register the efi subsystem with the firmware subsystem - * and the vars subsystem with the efi subsystem. In the future, it - * might make sense to split off the efi subsystem into its own - * driver, but for now only efivars will register with it, so just - * include it here. - */ - -static int __init -efivars_init(void) -{ - int error; - - if (!efi_enabled(EFI_RUNTIME_SERVICES)) - return 0; - - /* Register the efi directory at /sys/firmware/efi */ - efi_kobj = kobject_create_and_add("efi", firmware_kobj); - if (!efi_kobj) { - printk(KERN_ERR "efivars: Firmware registration failed.\n"); - return -ENOMEM; - } - - error = generic_ops_register(); - if (error) - goto err_put; - - /* Don't forget the systab entry */ - error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group); - if (error) { - printk(KERN_ERR - "efivars: Sysfs attribute export failed with error %d.\n", - error); - goto err_unregister; - } - - return 0; - -err_unregister: - generic_ops_unregister(); -err_put: - kobject_put(efi_kobj); - return error; -} - -static void __exit -efivars_exit(void) -{ - cancel_work_sync(&efivar_work); - - if (efi_enabled(EFI_RUNTIME_SERVICES)) { - generic_ops_unregister(); - kobject_put(efi_kobj); - } -} - -module_init(efivars_init); -module_exit(efivars_exit); - -- cgit