// SPDX-License-Identifier: GPL-2.0/* * file.c - part of debugfs, a tiny little debug file system * * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> * Copyright (C) 2004 IBM Inc. * * debugfs is for people to use instead of /proc or /sys. * See Documentation/filesystems/ for more details. */ #include <linux/module.h>#include <linux/fs.h>#include <linux/seq_file.h>#include <linux/pagemap.h>#include <linux/debugfs.h>#include <linux/io.h>#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" struct poll_table_struct; static ssize_t default_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos){ return 0;} static ssize_t default_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos){ return count;} const struct file_operations debugfs_noop_file_operations = { .read = default_read_file, .write = default_write_file, .open = simple_open, .llseek = noop_llseek,}; #define F_DENTRY(filp) ((filp)->f_path.dentry) const struct file_operations *debugfs_real_fops(const struct file *filp){ 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;}EXPORT_SYMBOL_GPL(debugfs_real_fops); /** * 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){ struct debugfs_fsdata *fsd; void *d_fsd; d_fsd = READ_ONCE(dentry->d_fsdata); if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) { fsd = d_fsd; } else { fsd = kmalloc(sizeof(*fsd), GFP_KERNEL); if (!fsd) return -ENOMEM; fsd->real_fops = (void *)((unsigned long)d_fsd & ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT); refcount_set(&fsd->active_users, 1); init_completion(&fsd->active_users_drained); if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) { kfree(fsd); fsd = READ_ONCE(dentry->d_fsdata); } } /* * In case of a successful cmpxchg() above, this check is * strictly necessary and must follow it, see the comment in * __debugfs_remove_file(). * OTOH, if the cmpxchg() hasn't been executed or wasn't * successful, this serves the purpose of not starving * removers. */ if (d_unlinked(dentry)) return -EIO; if (!refcount_inc_not_zero(&fsd->active_users)) return -EIO; return 0;}EXPORT_SYMBOL_GPL(debugfs_file_get); /** * debugfs_file_put - mark the end of file data access * @dentry: the dentry object formerly passed to * debugfs_file_get(). * * Allow any ongoing concurrent call into debugfs_remove() or * debugfs_remove_recursive() blocked by a former call to * debugfs_file_get() to proceed and return to its caller. */void debugfs_file_put(struct dentry *dentry){ struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata); if (refcount_dec_and_test(&fsd->active_users)) complete(&fsd->active_users_drained);}EXPORT_SYMBOL_GPL(debugfs_file_put); /* * 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 && !(filp->f_mode & FMODE_WRITE) && !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; int r; r = debugfs_file_get(dentry); if (r) return r == -EIO ? -ENOENT : r; real_fops = debugfs_real_fops(filp); 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) 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); r = -ENXIO; goto out; } replace_fops(filp, real_fops); if (real_fops->open) r = real_fops->open(inode, filp); out: debugfs_file_put(dentry); return r;} const struct file_operations debugfs_open_proxy_file_operations = { .open = open_proxy_open,}; #define PROTO(args...) args#define ARGS(args...) args #define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \static ret_type full_proxy_ ## name(proto) \{ \ struct dentry *dentry = F_DENTRY(filp); \ const struct file_operations *real_fops; \ ret_type r; \ \ r = debugfs_file_get(dentry); \ if (unlikely(r)) \ return r; \ real_fops = debugfs_real_fops(filp); \ r = real_fops->name(args); \ debugfs_file_put(dentry); \ return r; \} FULL_PROXY_FUNC(llseek, loff_t, filp, PROTO(struct file *filp, loff_t offset, int whence), ARGS(filp, offset, whence)); 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)); 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)); FULL_PROXY_FUNC(unlocked_ioctl, long, filp, PROTO(struct file *filp, unsigned int cmd, unsigned long arg), ARGS(filp, cmd, arg)); static __poll_t full_proxy_poll(struct file *filp, struct poll_table_struct *wait){ struct dentry *dentry = F_DENTRY(filp); __poll_t r = 0; const struct file_operations *real_fops; if (debugfs_file_get(dentry)) return EPOLLHUP; real_fops = debugfs_real_fops(filp); r = real_fops->poll(filp, wait); debugfs_file_put(dentry); return r;} static int full_proxy_release(struct inode *inode, struct file *filp){ 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; int r = 0; /* * We must not protect this against removal races here: the * original releaser should be called unconditionally in order * not to leak any resources. Releasers must not assume that * ->i_private is still being meaningful here. */ if (real_fops->release) r = real_fops->release(inode, filp); replace_fops(filp, d_inode(dentry)->i_fop); kfree(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){ struct dentry *dentry = F_DENTRY(filp); const struct file_operations *real_fops = NULL; struct file_operations *proxy_fops = NULL; int r; r = debugfs_file_get(dentry); if (r) return r == -EIO ? -ENOENT : r; real_fops = debugfs_real_fops(filp); 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) 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); r = -ENXIO; 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) { /* No protection against file removal anymore. */ WARN(1, "debugfs file owner replaced proxy fops: %pd", dentry); goto free_proxy; } } 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,}; ssize_t debugfs_attr_read(struct file *file, char __user *buf, size_t len, loff_t *ppos){ struct dentry *dentry = F_DENTRY(file); ssize_t ret; ret = debugfs_file_get(dentry); if (unlikely(ret)) return ret; ret = simple_attr_read(file, buf, len, ppos); debugfs_file_put(dentry); return ret;}EXPORT_SYMBOL_GPL(debugfs_attr_read); ssize_t debugfs_attr_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos){ struct dentry *dentry = F_DENTRY(file); ssize_t ret; ret = debugfs_file_get(dentry); if (unlikely(ret)) return ret; ret = simple_attr_write(file, buf, len, ppos); debugfs_file_put(dentry); return ret;}EXPORT_SYMBOL_GPL(debugfs_attr_write); static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode, struct dentry *parent, void *value, const struct file_operations *fops, const struct file_operations *fops_ro, const struct file_operations *fops_wo){ /* if there are no write bits set, make read only */ if (!(mode & S_IWUGO)) return debugfs_create_file_unsafe(name, mode, parent, value, fops_ro); /* if there are no read bits set, make write only */ if (!(mode & S_IRUGO)) return debugfs_create_file_unsafe(name, mode, parent, value, fops_wo); return debugfs_create_file_unsafe(name, mode, parent, value, fops);} static int debugfs_u8_set(void *data, u64 val){ *(u8 *)data = val; return 0;}static int debugfs_u8_get(void *data, u64 *val){ *val = *(u8 *)data; return 0;}DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); /** * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit 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_u8(const char *name, umode_t mode, struct dentry *parent, u8 *value){ debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8, &fops_u8_ro, &fops_u8_wo);}EXPORT_SYMBOL_GPL(debugfs_create_u8); static int debugfs_u16_set(void *data, u64 val){ *(u16 *)data = val; return 0;}static int debugfs_u16_get(void *data, u64 *val){ *val = *(u16 *)data; return 0;}DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); /** * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit 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_u16(const char *name, umode_t mode, struct dentry *parent, u16 *value){ debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16, &fops_u16_ro, &fops_u16_wo);}EXPORT_SYMBOL_GPL(debugfs_create_u16); static int debugfs_u32_set(void *data, u64 val){ *(u32 *)data = val; return 0;}static int debugfs_u32_get(void *data, u64 *val){ *val = *(u32 *)data; return 0;}DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); /** * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit 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 aLines 1–500 of 1239. Load more
// SPDX-License-Identifier: GPL-2.0 /* * file.c - part of debugfs, a tiny little debug file system * * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> * Copyright (C) 2004 IBM Inc. * * debugfs is for people to use instead of /proc or /sys. * See Documentation/filesystems/ for more details. */ #include <linux/module.h> #include <linux/fs.h> #include <linux/seq_file.h> #include <linux/pagemap.h> #include <linux/debugfs.h> #include <linux/io.h> #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" struct poll_table_struct; static ssize_t default_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) { return 0; } static ssize_t default_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { return count; } const struct file_operations debugfs_noop_file_operations = { .read = default_read_file, .write = default_write_file, .open = simple_open, .llseek = noop_llseek, }; #define F_DENTRY(filp) ((filp)->f_path.dentry) const struct file_operations *debugfs_real_fops(const struct file *filp) { 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; } EXPORT_SYMBOL_GPL(debugfs_real_fops); /** * 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) { struct debugfs_fsdata *fsd; void *d_fsd; d_fsd = READ_ONCE(dentry->d_fsdata); if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) { fsd = d_fsd; } else { fsd = kmalloc(sizeof(*fsd), GFP_KERNEL); if (!fsd) return -ENOMEM; fsd->real_fops = (void *)((unsigned long)d_fsd & ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT); refcount_set(&fsd->active_users, 1); init_completion(&fsd->active_users_drained); if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) { kfree(fsd); fsd = READ_ONCE(dentry->d_fsdata); } } /* * In case of a successful cmpxchg() above, this check is * strictly necessary and must follow it, see the comment in * __debugfs_remove_file(). * OTOH, if the cmpxchg() hasn't been executed or wasn't * successful, this serves the purpose of not starving * removers. */ if (d_unlinked(dentry)) return -EIO; if (!refcount_inc_not_zero(&fsd->active_users)) return -EIO; return 0; } EXPORT_SYMBOL_GPL(debugfs_file_get); /** * debugfs_file_put - mark the end of file data access * @dentry: the dentry object formerly passed to * debugfs_file_get(). * * Allow any ongoing concurrent call into debugfs_remove() or * debugfs_remove_recursive() blocked by a former call to * debugfs_file_get() to proceed and return to its caller. */ void debugfs_file_put(struct dentry *dentry) { struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata); if (refcount_dec_and_test(&fsd->active_users)) complete(&fsd->active_users_drained); } EXPORT_SYMBOL_GPL(debugfs_file_put); /* * 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 && !(filp->f_mode & FMODE_WRITE) && !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; int r; r = debugfs_file_get(dentry); if (r) return r == -EIO ? -ENOENT : r; real_fops = debugfs_real_fops(filp); 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) 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); r = -ENXIO; goto out; } replace_fops(filp, real_fops); if (real_fops->open) r = real_fops->open(inode, filp); out: debugfs_file_put(dentry); return r; } const struct file_operations debugfs_open_proxy_file_operations = { .open = open_proxy_open, }; #define PROTO(args...) args #define ARGS(args...) args #define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \ static ret_type full_proxy_ ## name(proto) \ { \ struct dentry *dentry = F_DENTRY(filp); \ const struct file_operations *real_fops; \ ret_type r; \ \ r = debugfs_file_get(dentry); \ if (unlikely(r)) \ return r; \ real_fops = debugfs_real_fops(filp); \ r = real_fops->name(args); \ debugfs_file_put(dentry); \ return r; \ } FULL_PROXY_FUNC(llseek, loff_t, filp, PROTO(struct file *filp, loff_t offset, int whence), ARGS(filp, offset, whence)); 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)); 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)); FULL_PROXY_FUNC(unlocked_ioctl, long, filp, PROTO(struct file *filp, unsigned int cmd, unsigned long arg), ARGS(filp, cmd, arg)); static __poll_t full_proxy_poll(struct file *filp, struct poll_table_struct *wait) { struct dentry *dentry = F_DENTRY(filp); __poll_t r = 0; const struct file_operations *real_fops; if (debugfs_file_get(dentry)) return EPOLLHUP; real_fops = debugfs_real_fops(filp); r = real_fops->poll(filp, wait); debugfs_file_put(dentry); return r; } static int full_proxy_release(struct inode *inode, struct file *filp) { 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; int r = 0; /* * We must not protect this against removal races here: the * original releaser should be called unconditionally in order * not to leak any resources. Releasers must not assume that * ->i_private is still being meaningful here. */ if (real_fops->release) r = real_fops->release(inode, filp); replace_fops(filp, d_inode(dentry)->i_fop); kfree(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) { struct dentry *dentry = F_DENTRY(filp); const struct file_operations *real_fops = NULL; struct file_operations *proxy_fops = NULL; int r; r = debugfs_file_get(dentry); if (r) return r == -EIO ? -ENOENT : r; real_fops = debugfs_real_fops(filp); 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) 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); r = -ENXIO; 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) { /* No protection against file removal anymore. */ WARN(1, "debugfs file owner replaced proxy fops: %pd", dentry); goto free_proxy; } } 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, }; ssize_t debugfs_attr_read(struct file *file, char __user *buf, size_t len, loff_t *ppos) { struct dentry *dentry = F_DENTRY(file); ssize_t ret; ret = debugfs_file_get(dentry); if (unlikely(ret)) return ret; ret = simple_attr_read(file, buf, len, ppos); debugfs_file_put(dentry); return ret; } EXPORT_SYMBOL_GPL(debugfs_attr_read); ssize_t debugfs_attr_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos) { struct dentry *dentry = F_DENTRY(file); ssize_t ret; ret = debugfs_file_get(dentry); if (unlikely(ret)) return ret; ret = simple_attr_write(file, buf, len, ppos); debugfs_file_put(dentry); return ret; } EXPORT_SYMBOL_GPL(debugfs_attr_write); static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode, struct dentry *parent, void *value, const struct file_operations *fops, const struct file_operations *fops_ro, const struct file_operations *fops_wo) { /* if there are no write bits set, make read only */ if (!(mode & S_IWUGO)) return debugfs_create_file_unsafe(name, mode, parent, value, fops_ro); /* if there are no read bits set, make write only */ if (!(mode & S_IRUGO)) return debugfs_create_file_unsafe(name, mode, parent, value, fops_wo); return debugfs_create_file_unsafe(name, mode, parent, value, fops); } static int debugfs_u8_set(void *data, u64 val) { *(u8 *)data = val; return 0; } static int debugfs_u8_get(void *data, u64 *val) { *val = *(u8 *)data; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); /** * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit 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_u8(const char *name, umode_t mode, struct dentry *parent, u8 *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8, &fops_u8_ro, &fops_u8_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u8); static int debugfs_u16_set(void *data, u64 val) { *(u16 *)data = val; return 0; } static int debugfs_u16_get(void *data, u64 *val) { *val = *(u16 *)data; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); /** * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit 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_u16(const char *name, umode_t mode, struct dentry *parent, u16 *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16, &fops_u16_ro, &fops_u16_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u16); static int debugfs_u32_set(void *data, u64 val) { *(u32 *)data = val; return 0; } static int debugfs_u32_get(void *data, u64 *val) { *val = *(u32 *)data; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); /** * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit 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