diff options
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/Kconfig | 1 | ||||
| -rw-r--r-- | fs/sysfs/Makefile | 1 | ||||
| -rw-r--r-- | fs/sysfs/dir.c | 9 | ||||
| -rw-r--r-- | fs/sysfs/file.c | 414 | ||||
| -rw-r--r-- | fs/sysfs/group.c | 308 | ||||
| -rw-r--r-- | fs/sysfs/mount.c | 78 | ||||
| -rw-r--r-- | fs/sysfs/symlink.c | 2 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 8 |
8 files changed, 660 insertions, 161 deletions
diff --git a/fs/sysfs/Kconfig b/fs/sysfs/Kconfig index b2756014508c..b0fe1cce33a0 100644 --- a/fs/sysfs/Kconfig +++ b/fs/sysfs/Kconfig @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only config SYSFS bool "sysfs file system support" if EXPERT default y diff --git a/fs/sysfs/Makefile b/fs/sysfs/Makefile index 6eff6e1205a5..0906b9e522fe 100644 --- a/fs/sysfs/Makefile +++ b/fs/sysfs/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only # # Makefile for the sysfs virtual filesystem # diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index aa85f2874a9f..94e12efd92f2 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -6,7 +6,7 @@ * Copyright (c) 2007 SUSE Linux Products GmbH * Copyright (c) 2007 Tejun Heo <teheo@suse.de> * - * Please see Documentation/filesystems/sysfs.txt for more information. + * Please see Documentation/filesystems/sysfs.rst for more information. */ #define pr_fmt(fmt) "sysfs: " fmt @@ -56,8 +56,7 @@ int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) kobject_get_ownership(kobj, &uid, &gid); - kn = kernfs_create_dir_ns(parent, kobject_name(kobj), - S_IRWXU | S_IRUGO | S_IXUGO, uid, gid, + kn = kernfs_create_dir_ns(parent, kobject_name(kobj), 0755, uid, gid, kobj, ns); if (IS_ERR(kn)) { if (PTR_ERR(kn) == -EEXIST) @@ -82,7 +81,7 @@ void sysfs_remove_dir(struct kobject *kobj) struct kernfs_node *kn = kobj->sd; /* - * In general, kboject owner is responsible for ensuring removal + * In general, kobject owner is responsible for ensuring removal * doesn't race with other operations and sysfs doesn't provide any * protection; however, when @kobj is used as a symlink target, the * symlinking entity usually doesn't own @kobj and thus has no @@ -124,7 +123,7 @@ int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, new_parent = new_parent_kobj && new_parent_kobj->sd ? new_parent_kobj->sd : sysfs_root_kn; - return kernfs_rename_ns(kn, new_parent, kn->name, new_ns); + return kernfs_rename_ns(kn, new_parent, NULL, new_ns); } /** diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 51398457fe00..3825e780cc58 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -6,7 +6,7 @@ * Copyright (c) 2007 SUSE Linux Products GmbH * Copyright (c) 2007 Tejun Heo <teheo@suse.de> * - * Please see Documentation/filesystems/sysfs.txt for more information. + * Please see Documentation/filesystems/sysfs.rst for more information. */ #include <linux/module.h> @@ -15,9 +15,15 @@ #include <linux/list.h> #include <linux/mutex.h> #include <linux/seq_file.h> +#include <linux/mm.h> #include "sysfs.h" -#include "../kernfs/kernfs-internal.h" + +static struct kobject *sysfs_file_kobj(struct kernfs_node *kn) +{ + guard(rcu)(); + return rcu_dereference(kn->__parent)->priv; +} /* * Determine ktype->sysfs_ops for the given kernfs_node. This function @@ -25,7 +31,7 @@ */ static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn) { - struct kobject *kobj = kn->parent->priv; + struct kobject *kobj = sysfs_file_kobj(kn); if (kn->flags & KERNFS_LOCKDEP) lockdep_assert_held(kn); @@ -40,11 +46,14 @@ static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn) static int sysfs_kf_seq_show(struct seq_file *sf, void *v) { struct kernfs_open_file *of = sf->private; - struct kobject *kobj = of->kn->parent->priv; + struct kobject *kobj = sysfs_file_kobj(of->kn); const struct sysfs_ops *ops = sysfs_file_ops(of->kn); ssize_t count; char *buf; + if (WARN_ON_ONCE(!ops->show)) + return -EINVAL; + /* acquire buffer and ensure that it's >= PAGE_SIZE and clear */ count = seq_get_buf(sf, &buf); if (count < PAGE_SIZE) { @@ -53,15 +62,9 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v) } memset(buf, 0, PAGE_SIZE); - /* - * Invoke show(). Control may reach here via seq file lseek even - * if @ops->show() isn't implemented. - */ - if (ops->show) { - count = ops->show(kobj, of->kn->priv, buf); - if (count < 0) - return count; - } + count = ops->show(kobj, of->kn->priv, buf); + if (count < 0) + return count; /* * The code works fine with PAGE_SIZE return but it's likely to @@ -80,8 +83,8 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v) static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) { - struct bin_attribute *battr = of->kn->priv; - struct kobject *kobj = of->kn->parent->priv; + const struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = sysfs_file_kobj(of->kn); loff_t size = file_inode(of->file)->i_size; if (!count) @@ -105,7 +108,7 @@ static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) { const struct sysfs_ops *ops = sysfs_file_ops(of->kn); - struct kobject *kobj = of->kn->parent->priv; + struct kobject *kobj = sysfs_file_kobj(of->kn); ssize_t len; /* @@ -131,7 +134,7 @@ static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) { const struct sysfs_ops *ops = sysfs_file_ops(of->kn); - struct kobject *kobj = of->kn->parent->priv; + struct kobject *kobj = sysfs_file_kobj(of->kn); if (!count) return 0; @@ -143,8 +146,8 @@ static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf, static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) { - struct bin_attribute *battr = of->kn->priv; - struct kobject *kobj = of->kn->parent->priv; + const struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = sysfs_file_kobj(of->kn); loff_t size = file_inode(of->file)->i_size; if (size) { @@ -164,12 +167,34 @@ static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf, static int sysfs_kf_bin_mmap(struct kernfs_open_file *of, struct vm_area_struct *vma) { - struct bin_attribute *battr = of->kn->priv; - struct kobject *kobj = of->kn->parent->priv; + const struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = sysfs_file_kobj(of->kn); return battr->mmap(of->file, kobj, battr, vma); } +static loff_t sysfs_kf_bin_llseek(struct kernfs_open_file *of, loff_t offset, + int whence) +{ + const struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = sysfs_file_kobj(of->kn); + + if (battr->llseek) + return battr->llseek(of->file, kobj, battr, offset, whence); + else + return generic_file_llseek(of->file, offset, whence); +} + +static int sysfs_kf_bin_open(struct kernfs_open_file *of) +{ + const struct bin_attribute *battr = of->kn->priv; + + if (battr->f_mapping) + of->file->f_mapping = battr->f_mapping(); + + return 0; +} + void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr) { struct kernfs_node *kn = kobj->sd, *tmp; @@ -241,62 +266,79 @@ static const struct kernfs_ops sysfs_bin_kfops_mmap = { .read = sysfs_kf_bin_read, .write = sysfs_kf_bin_write, .mmap = sysfs_kf_bin_mmap, + .open = sysfs_kf_bin_open, + .llseek = sysfs_kf_bin_llseek, }; int sysfs_add_file_mode_ns(struct kernfs_node *parent, - const struct attribute *attr, bool is_bin, - umode_t mode, kuid_t uid, kgid_t gid, const void *ns) + const struct attribute *attr, umode_t mode, kuid_t uid, + kgid_t gid, const void *ns) { + struct kobject *kobj = parent->priv; + const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops; struct lock_class_key *key = NULL; - const struct kernfs_ops *ops; + const struct kernfs_ops *ops = NULL; struct kernfs_node *kn; - loff_t size; - - if (!is_bin) { - struct kobject *kobj = parent->priv; - const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops; - - /* every kobject with an attribute needs a ktype assigned */ - if (WARN(!sysfs_ops, KERN_ERR - "missing sysfs attribute operations for kobject: %s\n", - kobject_name(kobj))) - return -EINVAL; - - if (sysfs_ops->show && sysfs_ops->store) { - if (mode & SYSFS_PREALLOC) - ops = &sysfs_prealloc_kfops_rw; - else - ops = &sysfs_file_kfops_rw; - } else if (sysfs_ops->show) { - if (mode & SYSFS_PREALLOC) - ops = &sysfs_prealloc_kfops_ro; - else - ops = &sysfs_file_kfops_ro; - } else if (sysfs_ops->store) { - if (mode & SYSFS_PREALLOC) - ops = &sysfs_prealloc_kfops_wo; - else - ops = &sysfs_file_kfops_wo; - } else - ops = &sysfs_file_kfops_empty; - - size = PAGE_SIZE; + + /* every kobject with an attribute needs a ktype assigned */ + if (WARN(!sysfs_ops, KERN_ERR + "missing sysfs attribute operations for kobject: %s\n", + kobject_name(kobj))) + return -EINVAL; + + if (mode & SYSFS_PREALLOC) { + if (sysfs_ops->show && sysfs_ops->store) + ops = &sysfs_prealloc_kfops_rw; + else if (sysfs_ops->show) + ops = &sysfs_prealloc_kfops_ro; + else if (sysfs_ops->store) + ops = &sysfs_prealloc_kfops_wo; } else { - struct bin_attribute *battr = (void *)attr; - - if (battr->mmap) - ops = &sysfs_bin_kfops_mmap; - else if (battr->read && battr->write) - ops = &sysfs_bin_kfops_rw; - else if (battr->read) - ops = &sysfs_bin_kfops_ro; - else if (battr->write) - ops = &sysfs_bin_kfops_wo; - else - ops = &sysfs_file_kfops_empty; - - size = battr->size; + if (sysfs_ops->show && sysfs_ops->store) + ops = &sysfs_file_kfops_rw; + else if (sysfs_ops->show) + ops = &sysfs_file_kfops_ro; + else if (sysfs_ops->store) + ops = &sysfs_file_kfops_wo; + } + + if (!ops) + ops = &sysfs_file_kfops_empty; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + if (!attr->ignore_lockdep) + key = attr->key ?: (struct lock_class_key *)&attr->skey; +#endif + + kn = __kernfs_create_file(parent, attr->name, mode & 0777, uid, gid, + PAGE_SIZE, ops, (void *)attr, ns, key); + if (IS_ERR(kn)) { + if (PTR_ERR(kn) == -EEXIST) + sysfs_warn_dup(parent, attr->name); + return PTR_ERR(kn); } + return 0; +} + +int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent, + const struct bin_attribute *battr, umode_t mode, size_t size, + kuid_t uid, kgid_t gid, const void *ns) +{ + const struct attribute *attr = &battr->attr; + struct lock_class_key *key = NULL; + const struct kernfs_ops *ops; + struct kernfs_node *kn; + + if (battr->mmap) + ops = &sysfs_bin_kfops_mmap; + else if (battr->read && battr->write) + ops = &sysfs_bin_kfops_rw; + else if (battr->read) + ops = &sysfs_bin_kfops_ro; + else if (battr->write) + ops = &sysfs_bin_kfops_wo; + else + ops = &sysfs_file_kfops_empty; #ifdef CONFIG_DEBUG_LOCK_ALLOC if (!attr->ignore_lockdep) @@ -329,9 +371,7 @@ int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, return -EINVAL; kobject_get_ownership(kobj, &uid, &gid); - return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, - uid, gid, ns); - + return sysfs_add_file_mode_ns(kobj->sd, attr, attr->mode, uid, gid, ns); } EXPORT_SYMBOL_GPL(sysfs_create_file_ns); @@ -374,8 +414,8 @@ int sysfs_add_file_to_group(struct kobject *kobj, return -ENOENT; kobject_get_ownership(kobj, &uid, &gid); - error = sysfs_add_file_mode_ns(parent, attr, false, - attr->mode, uid, gid, NULL); + error = sysfs_add_file_mode_ns(parent, attr, attr->mode, uid, gid, + NULL); kernfs_put(parent); return error; @@ -429,6 +469,8 @@ struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj, kn = kernfs_find_and_get(kobj->sd, attr->name); if (kn) kernfs_break_active_protection(kn); + else + kobject_put(kobj); return kn; } EXPORT_SYMBOL_GPL(sysfs_break_active_protection); @@ -446,7 +488,7 @@ EXPORT_SYMBOL_GPL(sysfs_break_active_protection); */ void sysfs_unbreak_active_protection(struct kernfs_node *kn) { - struct kobject *kobj = kn->parent->priv; + struct kobject *kobj = sysfs_file_kobj(kn); kernfs_unbreak_active_protection(kn); kernfs_put(kn); @@ -493,10 +535,12 @@ bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr) kernfs_put(kn); return ret; } +EXPORT_SYMBOL_GPL(sysfs_remove_file_self); void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *ptr) { int i; + for (i = 0; ptr[i]; i++) sysfs_remove_file(kobj, ptr[i]); } @@ -542,8 +586,8 @@ int sysfs_create_bin_file(struct kobject *kobj, return -EINVAL; kobject_get_ownership(kobj, &uid, &gid); - return sysfs_add_file_mode_ns(kobj->sd, &attr->attr, true, - attr->attr.mode, uid, gid, NULL); + return sysfs_add_bin_file_mode_ns(kobj->sd, attr, attr->attr.mode, + attr->size, uid, gid, NULL); } EXPORT_SYMBOL_GPL(sysfs_create_bin_file); @@ -558,3 +602,219 @@ void sysfs_remove_bin_file(struct kobject *kobj, kernfs_remove_by_name(kobj->sd, attr->attr.name); } EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); + +static int internal_change_owner(struct kernfs_node *kn, kuid_t kuid, + kgid_t kgid) +{ + struct iattr newattrs = { + .ia_valid = ATTR_UID | ATTR_GID, + .ia_uid = kuid, + .ia_gid = kgid, + }; + return kernfs_setattr(kn, &newattrs); +} + +/** + * sysfs_link_change_owner - change owner of a sysfs file. + * @kobj: object of the kernfs_node the symlink is located in. + * @targ: object of the kernfs_node the symlink points to. + * @name: name of the link. + * @kuid: new owner's kuid + * @kgid: new owner's kgid + * + * This function looks up the sysfs symlink entry @name under @kobj and changes + * the ownership to @kuid/@kgid. The symlink is looked up in the namespace of + * @targ. + * + * Returns 0 on success or error code on failure. + */ +int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ, + const char *name, kuid_t kuid, kgid_t kgid) +{ + struct kernfs_node *kn = NULL; + int error; + + if (!name || !kobj->state_in_sysfs || !targ->state_in_sysfs) + return -EINVAL; + + error = -ENOENT; + kn = kernfs_find_and_get_ns(kobj->sd, name, targ->sd->ns); + if (!kn) + goto out; + + error = -EINVAL; + if (kernfs_type(kn) != KERNFS_LINK) + goto out; + if (kn->symlink.target_kn->priv != targ) + goto out; + + error = internal_change_owner(kn, kuid, kgid); + +out: + kernfs_put(kn); + return error; +} + +/** + * sysfs_file_change_owner - change owner of a sysfs file. + * @kobj: object. + * @name: name of the file to change. + * @kuid: new owner's kuid + * @kgid: new owner's kgid + * + * This function looks up the sysfs entry @name under @kobj and changes the + * ownership to @kuid/@kgid. + * + * Returns 0 on success or error code on failure. + */ +int sysfs_file_change_owner(struct kobject *kobj, const char *name, kuid_t kuid, + kgid_t kgid) +{ + struct kernfs_node *kn; + int error; + + if (!name) + return -EINVAL; + + if (!kobj->state_in_sysfs) + return -EINVAL; + + kn = kernfs_find_and_get(kobj->sd, name); + if (!kn) + return -ENOENT; + + error = internal_change_owner(kn, kuid, kgid); + + kernfs_put(kn); + + return error; +} +EXPORT_SYMBOL_GPL(sysfs_file_change_owner); + +/** + * sysfs_change_owner - change owner of the given object. + * @kobj: object. + * @kuid: new owner's kuid + * @kgid: new owner's kgid + * + * Change the owner of the default directory, files, groups, and attributes of + * @kobj to @kuid/@kgid. Note that sysfs_change_owner mirrors how the sysfs + * entries for a kobject are added by driver core. In summary, + * sysfs_change_owner() takes care of the default directory entry for @kobj, + * the default attributes associated with the ktype of @kobj and the default + * attributes associated with the ktype of @kobj. + * Additional properties not added by driver core have to be changed by the + * driver or subsystem which created them. This is similar to how + * driver/subsystem specific entries are removed. + * + * Returns 0 on success or error code on failure. + */ +int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid) +{ + int error; + const struct kobj_type *ktype; + + if (!kobj->state_in_sysfs) + return -EINVAL; + + /* Change the owner of the kobject itself. */ + error = internal_change_owner(kobj->sd, kuid, kgid); + if (error) + return error; + + ktype = get_ktype(kobj); + if (ktype) { + /* + * Change owner of the default groups associated with the + * ktype of @kobj. + */ + error = sysfs_groups_change_owner(kobj, ktype->default_groups, + kuid, kgid); + if (error) + return error; + } + + return 0; +} +EXPORT_SYMBOL_GPL(sysfs_change_owner); + +/** + * sysfs_emit - scnprintf equivalent, aware of PAGE_SIZE buffer. + * @buf: start of PAGE_SIZE buffer. + * @fmt: format + * @...: optional arguments to @format + * + * + * Returns number of characters written to @buf. + */ +int sysfs_emit(char *buf, const char *fmt, ...) +{ + va_list args; + int len; + + if (WARN(!buf || offset_in_page(buf), + "invalid sysfs_emit: buf:%p\n", buf)) + return 0; + + va_start(args, fmt); + len = vscnprintf(buf, PAGE_SIZE, fmt, args); + va_end(args); + + return len; +} +EXPORT_SYMBOL_GPL(sysfs_emit); + +/** + * sysfs_emit_at - scnprintf equivalent, aware of PAGE_SIZE buffer. + * @buf: start of PAGE_SIZE buffer. + * @at: offset in @buf to start write in bytes + * @at must be >= 0 && < PAGE_SIZE + * @fmt: format + * @...: optional arguments to @fmt + * + * + * Returns number of characters written starting at &@buf[@at]. + */ +int sysfs_emit_at(char *buf, int at, const char *fmt, ...) +{ + va_list args; + int len; + + if (WARN(!buf || offset_in_page(buf) || at < 0 || at >= PAGE_SIZE, + "invalid sysfs_emit_at: buf:%p at:%d\n", buf, at)) + return 0; + + va_start(args, fmt); + len = vscnprintf(buf + at, PAGE_SIZE - at, fmt, args); + va_end(args); + + return len; +} +EXPORT_SYMBOL_GPL(sysfs_emit_at); + +/** + * sysfs_bin_attr_simple_read - read callback to simply copy from memory. + * @file: attribute file which is being read. + * @kobj: object to which the attribute belongs. + * @attr: attribute descriptor. + * @buf: destination buffer. + * @off: offset in bytes from which to read. + * @count: maximum number of bytes to read. + * + * Simple ->read() callback for bin_attributes backed by a buffer in memory. + * The @private and @size members in struct bin_attribute must be set to the + * buffer's location and size before the bin_attribute is created in sysfs. + * + * Bounds check for @off and @count is done in sysfs_kf_bin_read(). + * Negative value check for @off is done in vfs_setpos() and default_llseek(). + * + * Returns number of bytes written to @buf. + */ +ssize_t sysfs_bin_attr_simple_read(struct file *file, struct kobject *kobj, + const struct bin_attribute *attr, char *buf, + loff_t off, size_t count) +{ + memcpy(buf, attr->private + off, count); + return count; +} +EXPORT_SYMBOL_GPL(sysfs_bin_attr_simple_read); diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 57038604d4a8..e1e639f515a0 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -13,6 +13,7 @@ #include <linux/dcache.h> #include <linux/namei.h> #include <linux/err.h> +#include <linux/fs.h> #include "sysfs.h" @@ -20,7 +21,7 @@ static void remove_files(struct kernfs_node *parent, const struct attribute_group *grp) { struct attribute *const *attr; - struct bin_attribute *const *bin_attr; + const struct bin_attribute *const *bin_attr; if (grp->attrs) for (attr = grp->attrs; *attr; attr++) @@ -30,12 +31,26 @@ static void remove_files(struct kernfs_node *parent, kernfs_remove_by_name(parent, (*bin_attr)->attr.name); } +static umode_t __first_visible(const struct attribute_group *grp, struct kobject *kobj) +{ + if (grp->attrs && grp->attrs[0] && grp->is_visible) + return grp->is_visible(kobj, grp->attrs[0], 0); + + if (grp->attrs && grp->attrs[0] && grp->is_visible_const) + return grp->is_visible_const(kobj, grp->attrs[0], 0); + + if (grp->bin_attrs && grp->bin_attrs[0] && grp->is_bin_visible) + return grp->is_bin_visible(kobj, grp->bin_attrs[0], 0); + + return 0; +} + static int create_files(struct kernfs_node *parent, struct kobject *kobj, kuid_t uid, kgid_t gid, const struct attribute_group *grp, int update) { struct attribute *const *attr; - struct bin_attribute *const *bin_attr; + const struct bin_attribute *const *bin_attr; int error = 0, i; if (grp->attrs) { @@ -49,8 +64,12 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, */ if (update) kernfs_remove_by_name(parent, (*attr)->name); - if (grp->is_visible) { - mode = grp->is_visible(kobj, *attr, i); + if (grp->is_visible || grp->is_visible_const) { + if (grp->is_visible) + mode = grp->is_visible(kobj, *attr, i); + else + mode = grp->is_visible_const(kobj, *attr, i); + mode &= ~SYSFS_GROUP_INVISIBLE; if (!mode) continue; } @@ -60,8 +79,8 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, (*attr)->name, mode); mode &= SYSFS_PREALLOC | 0664; - error = sysfs_add_file_mode_ns(parent, *attr, false, - mode, uid, gid, NULL); + error = sysfs_add_file_mode_ns(parent, *attr, mode, uid, + gid, NULL); if (unlikely(error)) break; } @@ -74,25 +93,28 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, if (grp->bin_attrs) { for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) { umode_t mode = (*bin_attr)->attr.mode; + size_t size = (*bin_attr)->size; if (update) kernfs_remove_by_name(parent, (*bin_attr)->attr.name); if (grp->is_bin_visible) { mode = grp->is_bin_visible(kobj, *bin_attr, i); + mode &= ~SYSFS_GROUP_INVISIBLE; if (!mode) continue; } + if (grp->bin_size) + size = grp->bin_size(kobj, *bin_attr, i); WARN(mode & ~(SYSFS_PREALLOC | 0664), "Attribute %s: Invalid permissions 0%o\n", (*bin_attr)->attr.name, mode); mode &= SYSFS_PREALLOC | 0664; - error = sysfs_add_file_mode_ns(parent, - &(*bin_attr)->attr, true, - mode, - uid, gid, NULL); + error = sysfs_add_bin_file_mode_ns(parent, *bin_attr, + mode, size, uid, gid, + NULL); if (error) break; } @@ -118,23 +140,40 @@ static int internal_create_group(struct kobject *kobj, int update, /* Updates may happen before the object has been instantiated */ if (unlikely(update && !kobj->sd)) return -EINVAL; + if (!grp->attrs && !grp->bin_attrs) { - WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n", - kobj->name, grp->name ?: ""); - return -EINVAL; + pr_debug("sysfs: (bin_)attrs not set by subsystem for group: %s/%s, skipping\n", + kobj->name, grp->name ?: ""); + return 0; } + kobject_get_ownership(kobj, &uid, &gid); if (grp->name) { + umode_t mode = __first_visible(grp, kobj); + + if (mode & SYSFS_GROUP_INVISIBLE) + mode = 0; + else + mode = S_IRWXU | S_IRUGO | S_IXUGO; + if (update) { kn = kernfs_find_and_get(kobj->sd, grp->name); if (!kn) { - pr_warn("Can't update unknown attr grp name: %s/%s\n", - kobj->name, grp->name); - return -EINVAL; + pr_debug("attr grp %s/%s not created yet\n", + kobj->name, grp->name); + /* may have been invisible prior to this update */ + update = 0; + } else if (!mode) { + sysfs_remove_group(kobj, grp); + kernfs_put(kn); + return 0; } - } else { - kn = kernfs_create_dir_ns(kobj->sd, grp->name, - S_IRWXU | S_IRUGO | S_IXUGO, + } + + if (!update) { + if (!mode) + return 0; + kn = kernfs_create_dir_ns(kobj->sd, grp->name, mode, uid, gid, kobj, NULL); if (IS_ERR(kn)) { if (PTR_ERR(kn) == -EEXIST) @@ -142,8 +181,10 @@ static int internal_create_group(struct kobject *kobj, int update, return PTR_ERR(kn); } } - } else + } else { kn = kobj->sd; + } + kernfs_get(kn); error = create_files(kn, kobj, uid, gid, grp, update); if (error) { @@ -175,6 +216,26 @@ int sysfs_create_group(struct kobject *kobj, } EXPORT_SYMBOL_GPL(sysfs_create_group); +static int internal_create_groups(struct kobject *kobj, int update, + const struct attribute_group **groups) +{ + int error = 0; + int i; + + if (!groups) + return 0; + + for (i = 0; groups[i]; i++) { + error = internal_create_group(kobj, update, groups[i]); + if (error) { + while (--i >= 0) + sysfs_remove_group(kobj, groups[i]); + break; + } + } + return error; +} + /** * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups * @kobj: The kobject to create the group on @@ -191,25 +252,29 @@ EXPORT_SYMBOL_GPL(sysfs_create_group); int sysfs_create_groups(struct kobject *kobj, const struct attribute_group **groups) { - int error = 0; - int i; - - if (!groups) - return 0; - - for (i = 0; groups[i]; i++) { - error = sysfs_create_group(kobj, groups[i]); - if (error) { - while (--i >= 0) - sysfs_remove_group(kobj, groups[i]); - break; - } - } - return error; + return internal_create_groups(kobj, 0, groups); } EXPORT_SYMBOL_GPL(sysfs_create_groups); /** + * sysfs_update_groups - given a directory kobject, create a bunch of attribute groups + * @kobj: The kobject to update the group on + * @groups: The attribute groups to update, NULL terminated + * + * This function update a bunch of attribute groups. If an error occurs when + * updating a group, all previously updated groups will be removed together + * with already existing (not updated) attributes. + * + * Returns 0 on success or error code from sysfs_update_group on failure. + */ +int sysfs_update_groups(struct kobject *kobj, + const struct attribute_group **groups) +{ + return internal_create_groups(kobj, 1, groups); +} +EXPORT_SYMBOL_GPL(sysfs_update_groups); + +/** * sysfs_update_group - given a directory kobject, update an attribute group * @kobj: The kobject to update the group on * @grp: The attribute group to update @@ -251,9 +316,8 @@ void sysfs_remove_group(struct kobject *kobj, if (grp->name) { kn = kernfs_find_and_get(parent, grp->name); if (!kn) { - WARN(!kn, KERN_WARNING - "sysfs group '%s' not found for kobject '%s'\n", - grp->name, kobject_name(kobj)); + pr_debug("sysfs group '%s' not found for kobject '%s'\n", + grp->name, kobject_name(kobj)); return; } } else { @@ -290,13 +354,13 @@ void sysfs_remove_groups(struct kobject *kobj, EXPORT_SYMBOL_GPL(sysfs_remove_groups); /** - * sysfs_merge_group - merge files into a pre-existing attribute group. + * sysfs_merge_group - merge files into a pre-existing named attribute group. * @kobj: The kobject containing the group. * @grp: The files to create and the attribute group they belong to. * - * This function returns an error if the group doesn't exist or any of the - * files already exist in that group, in which case none of the new files - * are created. + * This function returns an error if the group doesn't exist, the .name field is + * NULL or any of the files already exist in that group, in which case none of + * the new files are created. */ int sysfs_merge_group(struct kobject *kobj, const struct attribute_group *grp) @@ -315,8 +379,8 @@ int sysfs_merge_group(struct kobject *kobj, kobject_get_ownership(kobj, &uid, &gid); for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr)) - error = sysfs_add_file_mode_ns(parent, *attr, false, - (*attr)->mode, uid, gid, NULL); + error = sysfs_add_file_mode_ns(parent, *attr, (*attr)->mode, + uid, gid, NULL); if (error) { while (--i >= 0) kernfs_remove_by_name(parent, (*--attr)->name); @@ -328,7 +392,7 @@ int sysfs_merge_group(struct kobject *kobj, EXPORT_SYMBOL_GPL(sysfs_merge_group); /** - * sysfs_unmerge_group - remove files from a pre-existing attribute group. + * sysfs_unmerge_group - remove files from a pre-existing named attribute group. * @kobj: The kobject containing the group. * @grp: The files to remove and the attribute group they belong to. */ @@ -391,15 +455,18 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group); /** - * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing + * compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing * to a group or an attribute * @kobj: The kobject containing the group. * @target_kobj: The target kobject. * @target_name: The name of the target group or attribute. + * @symlink_name: The name of the symlink file (target_name will be + * considered if symlink_name is NULL). */ -int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, - struct kobject *target_kobj, - const char *target_name) +int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, + struct kobject *target_kobj, + const char *target_name, + const char *symlink_name) { struct kernfs_node *target; struct kernfs_node *entry; @@ -418,18 +485,151 @@ int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, if (!target) return -ENOENT; - entry = kernfs_find_and_get(target_kobj->sd, target_name); + entry = kernfs_find_and_get(target, target_name); if (!entry) { kernfs_put(target); return -ENOENT; } - link = kernfs_create_link(kobj->sd, target_name, entry); - if (IS_ERR(link) && PTR_ERR(link) == -EEXIST) - sysfs_warn_dup(kobj->sd, target_name); + if (!symlink_name) + symlink_name = target_name; + + link = kernfs_create_link(kobj->sd, symlink_name, entry); + if (PTR_ERR(link) == -EEXIST) + sysfs_warn_dup(kobj->sd, symlink_name); kernfs_put(entry); kernfs_put(target); return PTR_ERR_OR_ZERO(link); } -EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj); +EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj); + +static int sysfs_group_attrs_change_owner(struct kobject *kobj, + struct kernfs_node *grp_kn, + const struct attribute_group *grp, + struct iattr *newattrs) +{ + struct kernfs_node *kn; + int error, i; + umode_t mode; + + if (grp->attrs) { + struct attribute *const *attr; + + for (i = 0, attr = grp->attrs; *attr; i++, attr++) { + if (grp->is_visible) { + mode = grp->is_visible(kobj, *attr, i); + if (mode & SYSFS_GROUP_INVISIBLE) + break; + if (!mode) + continue; + } + kn = kernfs_find_and_get(grp_kn, (*attr)->name); + if (!kn) + return -ENOENT; + + error = kernfs_setattr(kn, newattrs); + kernfs_put(kn); + if (error) + return error; + } + } + + if (grp->bin_attrs) { + const struct bin_attribute *const *bin_attr; + + for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) { + if (grp->is_bin_visible) { + mode = grp->is_bin_visible(kobj, *bin_attr, i); + if (mode & SYSFS_GROUP_INVISIBLE) + break; + if (!mode) + continue; + } + kn = kernfs_find_and_get(grp_kn, (*bin_attr)->attr.name); + if (!kn) + return -ENOENT; + + error = kernfs_setattr(kn, newattrs); + kernfs_put(kn); + if (error) + return error; + } + } + + return 0; +} + +/** + * sysfs_group_change_owner - change owner of an attribute group. + * @kobj: The kobject containing the group. + * @grp: The attribute group. + * @kuid: new owner's kuid + * @kgid: new owner's kgid + * + * Returns 0 on success or error code on failure. + */ +int sysfs_group_change_owner(struct kobject *kobj, + const struct attribute_group *grp, kuid_t kuid, + kgid_t kgid) +{ + struct kernfs_node *grp_kn; + int error; + struct iattr newattrs = { + .ia_valid = ATTR_UID | ATTR_GID, + .ia_uid = kuid, + .ia_gid = kgid, + }; + + if (!kobj->state_in_sysfs) + return -EINVAL; + + if (grp->name) { + grp_kn = kernfs_find_and_get(kobj->sd, grp->name); + } else { + kernfs_get(kobj->sd); + grp_kn = kobj->sd; + } + if (!grp_kn) + return -ENOENT; + + error = kernfs_setattr(grp_kn, &newattrs); + if (!error) + error = sysfs_group_attrs_change_owner(kobj, grp_kn, grp, &newattrs); + + kernfs_put(grp_kn); + + return error; +} +EXPORT_SYMBOL_GPL(sysfs_group_change_owner); + +/** + * sysfs_groups_change_owner - change owner of a set of attribute groups. + * @kobj: The kobject containing the groups. + * @groups: The attribute groups. + * @kuid: new owner's kuid + * @kgid: new owner's kgid + * + * Returns 0 on success or error code on failure. + */ +int sysfs_groups_change_owner(struct kobject *kobj, + const struct attribute_group **groups, + kuid_t kuid, kgid_t kgid) +{ + int error = 0, i; + + if (!kobj->state_in_sysfs) + return -EINVAL; + + if (!groups) + return 0; + + for (i = 0; groups[i]; i++) { + error = sysfs_group_change_owner(kobj, groups[i], kuid, kgid); + if (error) + break; + } + + return error; +} +EXPORT_SYMBOL_GPL(sysfs_groups_change_owner); diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 92682fcc41f6..98467bb76737 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -6,41 +6,77 @@ * Copyright (c) 2007 SUSE Linux Products GmbH * Copyright (c) 2007 Tejun Heo <teheo@suse.de> * - * Please see Documentation/filesystems/sysfs.txt for more information. + * Please see Documentation/filesystems/sysfs.rst for more information. */ #include <linux/fs.h> #include <linux/magic.h> #include <linux/mount.h> #include <linux/init.h> +#include <linux/slab.h> #include <linux/user_namespace.h> +#include <linux/fs_context.h> +#include <net/net_namespace.h> #include "sysfs.h" static struct kernfs_root *sysfs_root; struct kernfs_node *sysfs_root_kn; -static struct dentry *sysfs_mount(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data) +static int sysfs_get_tree(struct fs_context *fc) { - struct dentry *root; - void *ns; - bool new_sb = false; + struct kernfs_fs_context *kfc = fc->fs_private; + int ret; - if (!(flags & SB_KERNMOUNT)) { + ret = kernfs_get_tree(fc); + if (ret) + return ret; + + if (kfc->new_sb_created) + fc->root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE; + return 0; +} + +static void sysfs_fs_context_free(struct fs_context *fc) +{ + struct kernfs_fs_context *kfc = fc->fs_private; + + if (kfc->ns_tag) + kobj_ns_drop(KOBJ_NS_TYPE_NET, kfc->ns_tag); + kernfs_free_fs_context(fc); + kfree(kfc); +} + +static const struct fs_context_operations sysfs_fs_context_ops = { + .free = sysfs_fs_context_free, + .get_tree = sysfs_get_tree, +}; + +static int sysfs_init_fs_context(struct fs_context *fc) +{ + struct kernfs_fs_context *kfc; + struct net *netns; + + if (!(fc->sb_flags & SB_KERNMOUNT)) { if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET)) - return ERR_PTR(-EPERM); + return -EPERM; } - ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET); - root = kernfs_mount_ns(fs_type, flags, sysfs_root, - SYSFS_MAGIC, &new_sb, ns); - if (!new_sb) - kobj_ns_drop(KOBJ_NS_TYPE_NET, ns); - else if (!IS_ERR(root)) - root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE; + kfc = kzalloc(sizeof(struct kernfs_fs_context), GFP_KERNEL); + if (!kfc) + return -ENOMEM; - return root; + kfc->ns_tag = netns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET); + kfc->root = sysfs_root; + kfc->magic = SYSFS_MAGIC; + fc->fs_private = kfc; + fc->ops = &sysfs_fs_context_ops; + if (netns) { + put_user_ns(fc->user_ns); + fc->user_ns = get_user_ns(netns->user_ns); + } + fc->global = true; + return 0; } static void sysfs_kill_sb(struct super_block *sb) @@ -52,10 +88,10 @@ static void sysfs_kill_sb(struct super_block *sb) } static struct file_system_type sysfs_fs_type = { - .name = "sysfs", - .mount = sysfs_mount, - .kill_sb = sysfs_kill_sb, - .fs_flags = FS_USERNS_MOUNT, + .name = "sysfs", + .init_fs_context = sysfs_init_fs_context, + .kill_sb = sysfs_kill_sb, + .fs_flags = FS_USERNS_MOUNT, }; int __init sysfs_init(void) @@ -67,7 +103,7 @@ int __init sysfs_init(void) if (IS_ERR(sysfs_root)) return PTR_ERR(sysfs_root); - sysfs_root_kn = sysfs_root->kn; + sysfs_root_kn = kernfs_root_to_node(sysfs_root); err = register_filesystem(&sysfs_fs_type); if (err) { diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index c4deecc80f67..5603530a1a52 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -6,7 +6,7 @@ * Copyright (c) 2007 SUSE Linux Products GmbH * Copyright (c) 2007 Tejun Heo <teheo@suse.de> * - * Please see Documentation/filesystems/sysfs.txt for more information. + * Please see Documentation/filesystems/sysfs.rst for more information. */ #include <linux/fs.h> diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 0050cc0c0236..8e012f25e1c0 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -28,9 +28,11 @@ void sysfs_warn_dup(struct kernfs_node *parent, const char *name); * file.c */ int sysfs_add_file_mode_ns(struct kernfs_node *parent, - const struct attribute *attr, bool is_bin, - umode_t amode, kuid_t uid, kgid_t gid, - const void *ns); + const struct attribute *attr, umode_t amode, kuid_t uid, + kgid_t gid, const void *ns); +int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent, + const struct bin_attribute *battr, umode_t mode, size_t size, + kuid_t uid, kgid_t gid, const void *ns); /* * symlink.c |