diff options
Diffstat (limited to 'fs/debugfs/file.c')
| -rw-r--r-- | fs/debugfs/file.c | 823 |
1 files changed, 541 insertions, 282 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 4fce1da7db23..3ec3324c2060 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -18,7 +18,9 @@ #include <linux/slab.h> #include <linux/atomic.h> #include <linux/device.h> +#include <linux/pm_runtime.h> #include <linux/poll.h> +#include <linux/security.h> #include "internal.h" @@ -45,58 +47,81 @@ const struct file_operations debugfs_noop_file_operations = { #define F_DENTRY(filp) ((filp)->f_path.dentry) -const struct file_operations *debugfs_real_fops(const struct file *filp) +void *debugfs_get_aux(const struct file *file) { - struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata; - - if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) { - /* - * Urgh, we've been called w/o a protecting - * debugfs_file_get(). - */ - WARN_ON(1); - return NULL; - } - - return fsd->real_fops; + return DEBUGFS_I(file_inode(file))->aux; } -EXPORT_SYMBOL_GPL(debugfs_real_fops); +EXPORT_SYMBOL_GPL(debugfs_get_aux); -/** - * debugfs_file_get - mark the beginning of file data access - * @dentry: the dentry object whose data is being accessed. - * - * Up to a matching call to debugfs_file_put(), any successive call - * into the file removing functions debugfs_remove() and - * debugfs_remove_recursive() will block. Since associated private - * file data may only get freed after a successful return of any of - * the removal functions, you may safely access it after a successful - * call to debugfs_file_get() without worrying about lifetime issues. - * - * If -%EIO is returned, the file has already been removed and thus, - * it is not safe to access any of its data. If, on the other hand, - * it is allowed to access the file data, zero is returned. - */ -int debugfs_file_get(struct dentry *dentry) +enum dbgfs_get_mode { + DBGFS_GET_ALREADY, + DBGFS_GET_REGULAR, + DBGFS_GET_SHORT, +}; + +static int __debugfs_file_get(struct dentry *dentry, enum dbgfs_get_mode mode) { struct debugfs_fsdata *fsd; void *d_fsd; + /* + * This could only happen if some debugfs user erroneously calls + * debugfs_file_get() on a dentry that isn't even a file, let + * them know about it. + */ + if (WARN_ON(!d_is_reg(dentry))) + return -EINVAL; + d_fsd = READ_ONCE(dentry->d_fsdata); - if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) { + if (d_fsd) { fsd = d_fsd; } else { + struct inode *inode = dentry->d_inode; + unsigned int methods = 0; + + if (WARN_ON(mode == DBGFS_GET_ALREADY)) + return -EINVAL; + fsd = kmalloc(sizeof(*fsd), GFP_KERNEL); if (!fsd) return -ENOMEM; - fsd->real_fops = (void *)((unsigned long)d_fsd & - ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT); + if (mode == DBGFS_GET_SHORT) { + const struct debugfs_short_fops *ops; + ops = fsd->short_fops = DEBUGFS_I(inode)->short_fops; + if (ops->llseek) + methods |= HAS_LSEEK; + if (ops->read) + methods |= HAS_READ; + if (ops->write) + methods |= HAS_WRITE; + fsd->real_fops = NULL; + } else { + const struct file_operations *ops; + ops = fsd->real_fops = DEBUGFS_I(inode)->real_fops; + if (ops->llseek) + methods |= HAS_LSEEK; + if (ops->read) + methods |= HAS_READ; + if (ops->write) + methods |= HAS_WRITE; + if (ops->unlocked_ioctl) + methods |= HAS_IOCTL; + if (ops->poll) + methods |= HAS_POLL; + fsd->short_fops = NULL; + } + fsd->methods = methods; refcount_set(&fsd->active_users, 1); init_completion(&fsd->active_users_drained); - if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) { + INIT_LIST_HEAD(&fsd->cancellations); + mutex_init(&fsd->cancellations_mtx); + + d_fsd = cmpxchg(&dentry->d_fsdata, NULL, fsd); + if (d_fsd) { + mutex_destroy(&fsd->cancellations_mtx); kfree(fsd); - fsd = READ_ONCE(dentry->d_fsdata); + fsd = d_fsd; } } @@ -116,6 +141,26 @@ int debugfs_file_get(struct dentry *dentry) return 0; } + +/** + * debugfs_file_get - mark the beginning of file data access + * @dentry: the dentry object whose data is being accessed. + * + * Up to a matching call to debugfs_file_put(), any successive call + * into the file removing functions debugfs_remove() and + * debugfs_remove_recursive() will block. Since associated private + * file data may only get freed after a successful return of any of + * the removal functions, you may safely access it after a successful + * call to debugfs_file_get() without worrying about lifetime issues. + * + * If -%EIO is returned, the file has already been removed and thus, + * it is not safe to access any of its data. If, on the other hand, + * it is allowed to access the file data, zero is returned. + */ +int debugfs_file_get(struct dentry *dentry) +{ + return __debugfs_file_get(dentry, DBGFS_GET_ALREADY); +} EXPORT_SYMBOL_GPL(debugfs_file_get); /** @@ -136,19 +181,130 @@ void debugfs_file_put(struct dentry *dentry) } EXPORT_SYMBOL_GPL(debugfs_file_put); +/** + * debugfs_enter_cancellation - enter a debugfs cancellation + * @file: the file being accessed + * @cancellation: the cancellation object, the cancel callback + * inside of it must be initialized + * + * When a debugfs file is removed it needs to wait for all active + * operations to complete. However, the operation itself may need + * to wait for hardware or completion of some asynchronous process + * or similar. As such, it may need to be cancelled to avoid long + * waits or even deadlocks. + * + * This function can be used inside a debugfs handler that may + * need to be cancelled. As soon as this function is called, the + * cancellation's 'cancel' callback may be called, at which point + * the caller should proceed to call debugfs_leave_cancellation() + * and leave the debugfs handler function as soon as possible. + * Note that the 'cancel' callback is only ever called in the + * context of some kind of debugfs_remove(). + * + * This function must be paired with debugfs_leave_cancellation(). + */ +void debugfs_enter_cancellation(struct file *file, + struct debugfs_cancellation *cancellation) +{ + struct debugfs_fsdata *fsd; + struct dentry *dentry = F_DENTRY(file); + + INIT_LIST_HEAD(&cancellation->list); + + if (WARN_ON(!d_is_reg(dentry))) + return; + + if (WARN_ON(!cancellation->cancel)) + return; + + fsd = READ_ONCE(dentry->d_fsdata); + if (WARN_ON(!fsd)) + return; + + mutex_lock(&fsd->cancellations_mtx); + list_add(&cancellation->list, &fsd->cancellations); + mutex_unlock(&fsd->cancellations_mtx); + + /* if we're already removing wake it up to cancel */ + if (d_unlinked(dentry)) + complete(&fsd->active_users_drained); +} +EXPORT_SYMBOL_GPL(debugfs_enter_cancellation); + +/** + * debugfs_leave_cancellation - leave cancellation section + * @file: the file being accessed + * @cancellation: the cancellation previously registered with + * debugfs_enter_cancellation() + * + * See the documentation of debugfs_enter_cancellation(). + */ +void debugfs_leave_cancellation(struct file *file, + struct debugfs_cancellation *cancellation) +{ + struct debugfs_fsdata *fsd; + struct dentry *dentry = F_DENTRY(file); + + if (WARN_ON(!d_is_reg(dentry))) + return; + + fsd = READ_ONCE(dentry->d_fsdata); + if (WARN_ON(!fsd)) + return; + + mutex_lock(&fsd->cancellations_mtx); + if (!list_empty(&cancellation->list)) + list_del(&cancellation->list); + mutex_unlock(&fsd->cancellations_mtx); +} +EXPORT_SYMBOL_GPL(debugfs_leave_cancellation); + +/* + * Only permit access to world-readable files when the kernel is locked down. + * We also need to exclude any file that has ways to write or alter it as root + * can bypass the permissions check. + */ +static int debugfs_locked_down(struct inode *inode, + struct file *filp, + const struct file_operations *real_fops) +{ + if ((inode->i_mode & 07777 & ~0444) == 0 && + !(filp->f_mode & FMODE_WRITE) && + (!real_fops || + (!real_fops->unlocked_ioctl && + !real_fops->compat_ioctl && + !real_fops->mmap))) + return 0; + + if (security_locked_down(LOCKDOWN_DEBUGFS)) + return -EPERM; + + return 0; +} + static int open_proxy_open(struct inode *inode, struct file *filp) { struct dentry *dentry = F_DENTRY(filp); - const struct file_operations *real_fops = NULL; + const struct file_operations *real_fops = DEBUGFS_I(inode)->real_fops; int r; - r = debugfs_file_get(dentry); + r = __debugfs_file_get(dentry, DBGFS_GET_REGULAR); if (r) return r == -EIO ? -ENOENT : r; - real_fops = debugfs_real_fops(filp); - real_fops = fops_get(real_fops); - if (!real_fops) { + r = debugfs_locked_down(inode, filp, real_fops); + if (r) + goto out; + + if (!fops_get(real_fops)) { +#ifdef CONFIG_MODULES + if (real_fops->owner && + real_fops->owner->state == MODULE_STATE_GOING) { + r = -ENXIO; + goto out; + } +#endif + /* Huh? Module did not clean up after itself at exit? */ WARN(1, "debugfs file owner did not clean up at exit: %pd", dentry); @@ -172,61 +328,93 @@ const struct file_operations debugfs_open_proxy_file_operations = { #define PROTO(args...) args #define ARGS(args...) args -#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \ +#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args, bit, ret) \ static ret_type full_proxy_ ## name(proto) \ { \ - struct dentry *dentry = F_DENTRY(filp); \ - const struct file_operations *real_fops; \ + struct dentry *dentry = F_DENTRY(filp); \ + struct debugfs_fsdata *fsd = dentry->d_fsdata; \ ret_type r; \ \ + if (!(fsd->methods & bit)) \ + return ret; \ r = debugfs_file_get(dentry); \ if (unlikely(r)) \ return r; \ - real_fops = debugfs_real_fops(filp); \ - r = real_fops->name(args); \ + r = fsd->real_fops->name(args); \ debugfs_file_put(dentry); \ return r; \ } +#define SHORT_PROXY_FUNC(name, ret_type, filp, proto, args, bit, ret) \ +static ret_type short_proxy_ ## name(proto) \ +{ \ + struct dentry *dentry = F_DENTRY(filp); \ + struct debugfs_fsdata *fsd = dentry->d_fsdata; \ + ret_type r; \ + \ + if (!(fsd->methods & bit)) \ + return ret; \ + r = debugfs_file_get(dentry); \ + if (unlikely(r)) \ + return r; \ + r = fsd->short_fops->name(args); \ + debugfs_file_put(dentry); \ + return r; \ +} + +SHORT_PROXY_FUNC(llseek, loff_t, filp, + PROTO(struct file *filp, loff_t offset, int whence), + ARGS(filp, offset, whence), HAS_LSEEK, -ESPIPE); + FULL_PROXY_FUNC(llseek, loff_t, filp, PROTO(struct file *filp, loff_t offset, int whence), - ARGS(filp, offset, whence)); + ARGS(filp, offset, whence), HAS_LSEEK, -ESPIPE); + +SHORT_PROXY_FUNC(read, ssize_t, filp, + PROTO(struct file *filp, char __user *buf, size_t size, + loff_t *ppos), + ARGS(filp, buf, size, ppos), HAS_READ, -EINVAL); FULL_PROXY_FUNC(read, ssize_t, filp, PROTO(struct file *filp, char __user *buf, size_t size, loff_t *ppos), - ARGS(filp, buf, size, ppos)); + ARGS(filp, buf, size, ppos), HAS_READ, -EINVAL); + +SHORT_PROXY_FUNC(write, ssize_t, filp, + PROTO(struct file *filp, const char __user *buf, + size_t size, loff_t *ppos), + ARGS(filp, buf, size, ppos), HAS_WRITE, -EINVAL); FULL_PROXY_FUNC(write, ssize_t, filp, - PROTO(struct file *filp, const char __user *buf, size_t size, - loff_t *ppos), - ARGS(filp, buf, size, ppos)); + PROTO(struct file *filp, const char __user *buf, + size_t size, loff_t *ppos), + ARGS(filp, buf, size, ppos), HAS_WRITE, -EINVAL); FULL_PROXY_FUNC(unlocked_ioctl, long, filp, PROTO(struct file *filp, unsigned int cmd, unsigned long arg), - ARGS(filp, cmd, arg)); + ARGS(filp, cmd, arg), HAS_IOCTL, -ENOTTY); static __poll_t full_proxy_poll(struct file *filp, struct poll_table_struct *wait) { struct dentry *dentry = F_DENTRY(filp); + struct debugfs_fsdata *fsd = dentry->d_fsdata; __poll_t r = 0; - const struct file_operations *real_fops; + if (!(fsd->methods & HAS_POLL)) + return DEFAULT_POLLMASK; if (debugfs_file_get(dentry)) return EPOLLHUP; - real_fops = debugfs_real_fops(filp); - r = real_fops->poll(filp, wait); + r = fsd->real_fops->poll(filp, wait); debugfs_file_put(dentry); return r; } -static int full_proxy_release(struct inode *inode, struct file *filp) +static int full_proxy_release(struct inode *inode, struct file *file) { - const struct dentry *dentry = F_DENTRY(filp); - const struct file_operations *real_fops = debugfs_real_fops(filp); - const struct file_operations *proxy_fops = filp->f_op; + struct debugfs_fsdata *fsd = F_DENTRY(file)->d_fsdata; + const struct file_operations *real_fops = fsd->real_fops; int r = 0; /* @@ -236,44 +424,38 @@ static int full_proxy_release(struct inode *inode, struct file *filp) * ->i_private is still being meaningful here. */ if (real_fops->release) - r = real_fops->release(inode, filp); + r = real_fops->release(inode, file); - replace_fops(filp, d_inode(dentry)->i_fop); - kfree((void *)proxy_fops); fops_put(real_fops); return r; } -static void __full_proxy_fops_init(struct file_operations *proxy_fops, - const struct file_operations *real_fops) -{ - proxy_fops->release = full_proxy_release; - if (real_fops->llseek) - proxy_fops->llseek = full_proxy_llseek; - if (real_fops->read) - proxy_fops->read = full_proxy_read; - if (real_fops->write) - proxy_fops->write = full_proxy_write; - if (real_fops->poll) - proxy_fops->poll = full_proxy_poll; - if (real_fops->unlocked_ioctl) - proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl; -} - -static int full_proxy_open(struct inode *inode, struct file *filp) +static int full_proxy_open_regular(struct inode *inode, struct file *filp) { struct dentry *dentry = F_DENTRY(filp); - const struct file_operations *real_fops = NULL; - struct file_operations *proxy_fops = NULL; + const struct file_operations *real_fops; + struct debugfs_fsdata *fsd; int r; - r = debugfs_file_get(dentry); + r = __debugfs_file_get(dentry, DBGFS_GET_REGULAR); if (r) return r == -EIO ? -ENOENT : r; - real_fops = debugfs_real_fops(filp); - real_fops = fops_get(real_fops); - if (!real_fops) { + fsd = dentry->d_fsdata; + real_fops = fsd->real_fops; + r = debugfs_locked_down(inode, filp, real_fops); + if (r) + goto out; + + if (!fops_get(real_fops)) { +#ifdef CONFIG_MODULES + if (real_fops->owner && + real_fops->owner->state == MODULE_STATE_GOING) { + r = -ENXIO; + goto out; + } +#endif + /* Huh? Module did not cleanup after itself at exit? */ WARN(1, "debugfs file owner did not clean up at exit: %pd", dentry); @@ -281,38 +463,52 @@ static int full_proxy_open(struct inode *inode, struct file *filp) goto out; } - proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL); - if (!proxy_fops) { - r = -ENOMEM; - goto free_proxy; - } - __full_proxy_fops_init(proxy_fops, real_fops); - replace_fops(filp, proxy_fops); - if (real_fops->open) { r = real_fops->open(inode, filp); if (r) { - replace_fops(filp, d_inode(dentry)->i_fop); - goto free_proxy; - } else if (filp->f_op != proxy_fops) { + fops_put(real_fops); + } else if (filp->f_op != &debugfs_full_proxy_file_operations) { /* No protection against file removal anymore. */ WARN(1, "debugfs file owner replaced proxy fops: %pd", dentry); - goto free_proxy; + fops_put(real_fops); } } - - goto out; -free_proxy: - kfree(proxy_fops); - fops_put(real_fops); out: debugfs_file_put(dentry); return r; } const struct file_operations debugfs_full_proxy_file_operations = { - .open = full_proxy_open, + .open = full_proxy_open_regular, + .release = full_proxy_release, + .llseek = full_proxy_llseek, + .read = full_proxy_read, + .write = full_proxy_write, + .poll = full_proxy_poll, + .unlocked_ioctl = full_proxy_unlocked_ioctl +}; + +static int full_proxy_open_short(struct inode *inode, struct file *filp) +{ + struct dentry *dentry = F_DENTRY(filp); + int r; + + r = __debugfs_file_get(dentry, DBGFS_GET_SHORT); + if (r) + return r == -EIO ? -ENOENT : r; + r = debugfs_locked_down(inode, filp, NULL); + if (!r) + r = simple_open(inode, filp); + debugfs_file_put(dentry); + return r; +} + +const struct file_operations debugfs_full_short_proxy_file_operations = { + .open = full_proxy_open_short, + .llseek = short_proxy_llseek, + .read = short_proxy_read, + .write = short_proxy_write, }; ssize_t debugfs_attr_read(struct file *file, char __user *buf, @@ -330,8 +526,8 @@ ssize_t debugfs_attr_read(struct file *file, char __user *buf, } EXPORT_SYMBOL_GPL(debugfs_attr_read); -ssize_t debugfs_attr_write(struct file *file, const char __user *buf, - size_t len, loff_t *ppos) +static ssize_t debugfs_attr_write_xsigned(struct file *file, const char __user *buf, + size_t len, loff_t *ppos, bool is_signed) { struct dentry *dentry = F_DENTRY(file); ssize_t ret; @@ -339,12 +535,28 @@ ssize_t debugfs_attr_write(struct file *file, const char __user *buf, ret = debugfs_file_get(dentry); if (unlikely(ret)) return ret; - ret = simple_attr_write(file, buf, len, ppos); + if (is_signed) + ret = simple_attr_write_signed(file, buf, len, ppos); + else + ret = simple_attr_write(file, buf, len, ppos); debugfs_file_put(dentry); return ret; } + +ssize_t debugfs_attr_write(struct file *file, const char __user *buf, + size_t len, loff_t *ppos) +{ + return debugfs_attr_write_xsigned(file, buf, len, ppos, false); +} EXPORT_SYMBOL_GPL(debugfs_attr_write); +ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf, + size_t len, loff_t *ppos) +{ + return debugfs_attr_write_xsigned(file, buf, len, ppos, true); +} +EXPORT_SYMBOL_GPL(debugfs_attr_write_signed); + static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode, struct dentry *parent, void *value, const struct file_operations *fops, @@ -390,21 +602,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); * This function creates a file in debugfs with the given name that * contains the value of the variable @value. If the @mode variable is so * set, it can be read from, and written to. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the debugfs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. */ -struct dentry *debugfs_create_u8(const char *name, umode_t mode, - struct dentry *parent, u8 *value) +void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, + u8 *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8, &fops_u8_ro, &fops_u8_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u8); @@ -436,21 +638,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); * This function creates a file in debugfs with the given name that * contains the value of the variable @value. If the @mode variable is so * set, it can be read from, and written to. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the debugfs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. */ -struct dentry *debugfs_create_u16(const char *name, umode_t mode, - struct dentry *parent, u16 *value) +void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, + u16 *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16, &fops_u16_ro, &fops_u16_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u16); @@ -482,21 +674,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); * This function creates a file in debugfs with the given name that * contains the value of the variable @value. If the @mode variable is so * set, it can be read from, and written to. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the debugfs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. */ -struct dentry *debugfs_create_u32(const char *name, umode_t mode, - struct dentry *parent, u32 *value) +void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, + u32 *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32, &fops_u32_ro, &fops_u32_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u32); @@ -529,21 +711,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); * This function creates a file in debugfs with the given name that * contains the value of the variable @value. If the @mode variable is so * set, it can be read from, and written to. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the debugfs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. */ -struct dentry *debugfs_create_u64(const char *name, umode_t mode, - struct dentry *parent, u64 *value) +void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, + u64 *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64, &fops_u64_ro, &fops_u64_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u64); @@ -578,23 +750,12 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n"); * This function creates a file in debugfs with the given name that * contains the value of the variable @value. If the @mode variable is so * set, it can be read from, and written to. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the debugfs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. */ -struct dentry *debugfs_create_ulong(const char *name, umode_t mode, - struct dentry *parent, unsigned long *value) +void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, + unsigned long *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, - &fops_ulong, &fops_ulong_ro, - &fops_ulong_wo); + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_ulong, + &fops_ulong_ro, &fops_ulong_wo); } EXPORT_SYMBOL_GPL(debugfs_create_ulong); @@ -635,10 +796,10 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n"); * @value: a pointer to the variable that the file should read to and write * from. */ -struct dentry *debugfs_create_x8(const char *name, umode_t mode, - struct dentry *parent, u8 *value) +void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, + u8 *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8, &fops_x8_ro, &fops_x8_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x8); @@ -653,10 +814,10 @@ EXPORT_SYMBOL_GPL(debugfs_create_x8); * @value: a pointer to the variable that the file should read to and write * from. */ -struct dentry *debugfs_create_x16(const char *name, umode_t mode, - struct dentry *parent, u16 *value) +void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, + u16 *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16, &fops_x16_ro, &fops_x16_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x16); @@ -671,10 +832,10 @@ EXPORT_SYMBOL_GPL(debugfs_create_x16); * @value: a pointer to the variable that the file should read to and write * from. */ -struct dentry *debugfs_create_x32(const char *name, umode_t mode, - struct dentry *parent, u32 *value) +void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, + u32 *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32, &fops_x32_ro, &fops_x32_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x32); @@ -689,10 +850,10 @@ EXPORT_SYMBOL_GPL(debugfs_create_x32); * @value: a pointer to the variable that the file should read to and write * from. */ -struct dentry *debugfs_create_x64(const char *name, umode_t mode, - struct dentry *parent, u64 *value) +void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, + u64 *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64, &fops_x64_ro, &fops_x64_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x64); @@ -723,12 +884,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n"); * @value: a pointer to the variable that the file should read to and write * from. */ -struct dentry *debugfs_create_size_t(const char *name, umode_t mode, - struct dentry *parent, size_t *value) +void debugfs_create_size_t(const char *name, umode_t mode, + struct dentry *parent, size_t *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, - &fops_size_t, &fops_size_t_ro, - &fops_size_t_wo); + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_size_t, + &fops_size_t_ro, &fops_size_t_wo); } EXPORT_SYMBOL_GPL(debugfs_create_size_t); @@ -742,11 +902,11 @@ static int debugfs_atomic_t_get(void *data, u64 *val) *val = atomic_read((atomic_t *)data); return 0; } -DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get, +DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t, debugfs_atomic_t_get, debugfs_atomic_t_set, "%lld\n"); -DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, +DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n"); -DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, +DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n"); /** @@ -760,19 +920,18 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, * @value: a pointer to the variable that the file should read to and write * from. */ -struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, - struct dentry *parent, atomic_t *value) +void debugfs_create_atomic_t(const char *name, umode_t mode, + struct dentry *parent, atomic_t *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, - &fops_atomic_t, &fops_atomic_t_ro, - &fops_atomic_t_wo); + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_atomic_t, + &fops_atomic_t_ro, &fops_atomic_t_wo); } EXPORT_SYMBOL_GPL(debugfs_create_atomic_t); ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { - char buf[3]; + char buf[2]; bool val; int r; struct dentry *dentry = F_DENTRY(file); @@ -788,7 +947,6 @@ ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, else buf[0] = 'N'; buf[1] = '\n'; - buf[2] = 0x00; return simple_read_from_buffer(user_buf, count, ppos, buf, 2); } EXPORT_SYMBOL_GPL(debugfs_read_file_bool); @@ -846,25 +1004,142 @@ static const struct file_operations fops_bool_wo = { * This function creates a file in debugfs with the given name that * contains the value of the variable @value. If the @mode variable is so * set, it can be read from, and written to. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the debugfs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. */ -struct dentry *debugfs_create_bool(const char *name, umode_t mode, - struct dentry *parent, bool *value) +void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, + bool *value) { - return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool, + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool, &fops_bool_ro, &fops_bool_wo); } EXPORT_SYMBOL_GPL(debugfs_create_bool); +ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct dentry *dentry = F_DENTRY(file); + char *str, *copy = NULL; + int copy_len, len; + ssize_t ret; + + ret = debugfs_file_get(dentry); + if (unlikely(ret)) + return ret; + + str = *(char **)file->private_data; + len = strlen(str) + 1; + copy = kmalloc(len, GFP_KERNEL); + if (!copy) { + debugfs_file_put(dentry); + return -ENOMEM; + } + + copy_len = strscpy(copy, str, len); + debugfs_file_put(dentry); + if (copy_len < 0) { + kfree(copy); + return copy_len; + } + + copy[copy_len] = '\n'; + + ret = simple_read_from_buffer(user_buf, count, ppos, copy, len); + kfree(copy); + + return ret; +} +EXPORT_SYMBOL_GPL(debugfs_create_str); + +static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct dentry *dentry = F_DENTRY(file); + char *old, *new = NULL; + int pos = *ppos; + int r; + + r = debugfs_file_get(dentry); + if (unlikely(r)) + return r; + + old = *(char **)file->private_data; + + /* only allow strict concatenation */ + r = -EINVAL; + if (pos && pos != strlen(old)) + goto error; + + r = -E2BIG; + if (pos + count + 1 > PAGE_SIZE) + goto error; + + r = -ENOMEM; + new = kmalloc(pos + count + 1, GFP_KERNEL); + if (!new) + goto error; + + if (pos) + memcpy(new, old, pos); + + r = -EFAULT; + if (copy_from_user(new + pos, user_buf, count)) + goto error; + + new[pos + count] = '\0'; + strim(new); + + rcu_assign_pointer(*(char __rcu **)file->private_data, new); + synchronize_rcu(); + kfree(old); + + debugfs_file_put(dentry); + return count; + +error: + kfree(new); + debugfs_file_put(dentry); + return r; +} + +static const struct file_operations fops_str = { + .read = debugfs_read_file_str, + .write = debugfs_write_file_str, + .open = simple_open, + .llseek = default_llseek, +}; + +static const struct file_operations fops_str_ro = { + .read = debugfs_read_file_str, + .open = simple_open, + .llseek = default_llseek, +}; + +static const struct file_operations fops_str_wo = { + .write = debugfs_write_file_str, + .open = simple_open, + .llseek = default_llseek, +}; + +/** + * debugfs_create_str - create a debugfs file that is used to read and write a string value + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the debugfs filesystem. + * @value: a pointer to the variable that the file should read to and write + * from. + * + * This function creates a file in debugfs with the given name that + * contains the value of the variable @value. If the @mode variable is so + * set, it can be read from, and written to. + */ +void debugfs_create_str(const char *name, umode_t mode, + struct dentry *parent, char **value) +{ + debugfs_create_mode_unsafe(name, mode, parent, value, &fops_str, + &fops_str_ro, &fops_str_wo); +} + static ssize_t read_file_blob(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { @@ -881,14 +1156,33 @@ static ssize_t read_file_blob(struct file *file, char __user *user_buf, return r; } +static ssize_t write_file_blob(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct debugfs_blob_wrapper *blob = file->private_data; + struct dentry *dentry = F_DENTRY(file); + ssize_t r; + + r = debugfs_file_get(dentry); + if (unlikely(r)) + return r; + r = simple_write_to_buffer(blob->data, blob->size, ppos, user_buf, + count); + + debugfs_file_put(dentry); + return r; +} + static const struct file_operations fops_blob = { .read = read_file_blob, + .write = write_file_blob, .open = simple_open, .llseek = default_llseek, }; /** - * debugfs_create_blob - create a debugfs file that is used to read a binary blob + * debugfs_create_blob - create a debugfs file that is used to read and write + * a binary blob * @name: a pointer to a string containing the name of the file to create. * @mode: the permission that the file should have * @parent: a pointer to the parent dentry for this file. This should be a @@ -899,31 +1193,25 @@ static const struct file_operations fops_blob = { * * This function creates a file in debugfs with the given name that exports * @blob->data as a binary blob. If the @mode variable is so set it can be - * read from. Writing is not supported. + * read from and written to. * * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_blob(const char *name, umode_t mode, struct dentry *parent, struct debugfs_blob_wrapper *blob) { - return debugfs_create_file_unsafe(name, mode, parent, blob, &fops_blob); + return debugfs_create_file_unsafe(name, mode & 0644, parent, blob, &fops_blob); } EXPORT_SYMBOL_GPL(debugfs_create_blob); -struct array_data { - void *array; - u32 elements; -}; - static size_t u32_format_array(char *buf, size_t bufsize, u32 *array, int array_size) { @@ -944,8 +1232,8 @@ static size_t u32_format_array(char *buf, size_t bufsize, static int u32_array_open(struct inode *inode, struct file *file) { - struct array_data *data = inode->i_private; - int size, elements = data->elements; + struct debugfs_u32_array *data = inode->i_private; + int size, elements = data->n_elements; char *buf; /* @@ -960,7 +1248,7 @@ static int u32_array_open(struct inode *inode, struct file *file) buf[size] = 0; file->private_data = buf; - u32_format_array(buf, size, data->array, data->elements); + u32_format_array(buf, size, data->array, data->n_elements); return nonseekable_open(inode, file); } @@ -986,7 +1274,6 @@ static const struct file_operations u32_array_fops = { .open = u32_array_open, .release = u32_array_release, .read = u32_array_read, - .llseek = no_llseek, }; /** @@ -997,31 +1284,18 @@ static const struct file_operations u32_array_fops = { * @parent: a pointer to the parent dentry for this file. This should be a * directory dentry if set. If this parameter is %NULL, then the * file will be created in the root of the debugfs filesystem. - * @array: u32 array that provides data. - * @elements: total number of elements in the array. + * @array: wrapper struct containing data pointer and size of the array. * * This function creates a file in debugfs with the given name that exports * @array as data. If the @mode variable is so set it can be read from. * Writing is not supported. Seek within the file is also not supported. * Once array is created its size can not be changed. - * - * The function returns a pointer to dentry on success. If debugfs is not - * enabled in the kernel, the value -%ENODEV will be returned. */ -struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, - struct dentry *parent, - u32 *array, u32 elements) +void debugfs_create_u32_array(const char *name, umode_t mode, + struct dentry *parent, + struct debugfs_u32_array *array) { - struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL); - - if (data == NULL) - return NULL; - - data->array = array; - data->elements = elements; - - return debugfs_create_file_unsafe(name, mode, parent, data, - &u32_array_fops); + debugfs_create_file_unsafe(name, mode, parent, array, &u32_array_fops); } EXPORT_SYMBOL_GPL(debugfs_create_u32_array); @@ -1064,25 +1338,22 @@ void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, } EXPORT_SYMBOL_GPL(debugfs_print_regs32); -static int debugfs_show_regset32(struct seq_file *s, void *data) +static int debugfs_regset32_show(struct seq_file *s, void *data) { struct debugfs_regset32 *regset = s->private; + if (regset->dev) + pm_runtime_get_sync(regset->dev); + debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, ""); - return 0; -} -static int debugfs_open_regset32(struct inode *inode, struct file *file) -{ - return single_open(file, debugfs_show_regset32, inode->i_private); + if (regset->dev) + pm_runtime_put(regset->dev); + + return 0; } -static const struct file_operations fops_regset32 = { - .open = debugfs_open_regset32, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; +DEFINE_SHOW_ATTRIBUTE(debugfs_regset32); /** * debugfs_create_regset32 - create a debugfs file that returns register values @@ -1098,22 +1369,12 @@ static const struct file_operations fops_regset32 = { * This function creates a file in debugfs with the given name that reports * the names and values of a set of 32-bit registers. If the @mode variable * is so set it can be read from. Writing is not supported. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the debugfs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. */ -struct dentry *debugfs_create_regset32(const char *name, umode_t mode, - struct dentry *parent, - struct debugfs_regset32 *regset) +void debugfs_create_regset32(const char *name, umode_t mode, + struct dentry *parent, + struct debugfs_regset32 *regset) { - return debugfs_create_file(name, mode, parent, regset, &fops_regset32); + debugfs_create_file(name, mode, parent, regset, &debugfs_regset32_fops); } EXPORT_SYMBOL_GPL(debugfs_create_regset32); @@ -1149,25 +1410,23 @@ static const struct file_operations debugfs_devm_entry_ops = { * file will be created in the root of the debugfs filesystem. * @read_fn: function pointer called to print the seq_file content. */ -struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, - struct dentry *parent, - int (*read_fn)(struct seq_file *s, - void *data)) +void debugfs_create_devm_seqfile(struct device *dev, const char *name, + struct dentry *parent, + int (*read_fn)(struct seq_file *s, void *data)) { struct debugfs_devm_entry *entry; if (IS_ERR(parent)) - return ERR_PTR(-ENOENT); + return; entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL); if (!entry) - return ERR_PTR(-ENOMEM); + return; entry->read = read_fn; entry->dev = dev; - return debugfs_create_file(name, S_IRUGO, parent, entry, - &debugfs_devm_entry_ops); + debugfs_create_file(name, S_IRUGO, parent, entry, + &debugfs_devm_entry_ops); } EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile); - |