// SPDX-License-Identifier: GPL-2.0 /* * file.c - part of debugfs, a tiny little debug file system * * Copyright (C) 2004 Greg Kroah-Hartman * Copyright (C) 2004 IBM Inc. * * debugfs is for people to use instead of /proc or /sys. * See Documentation/filesystems/ for more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #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) == 0 && !(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) { 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); 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) { 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); 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); 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; ret = debugfs_file_get(dentry); if (unlikely(ret)) return ret; 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, 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 * 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_u32(const char *name, umode_t mode, struct dentry *parent, u32 *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32, &fops_u32_ro, &fops_u32_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u32); static int debugfs_u64_set(void *data, u64 val) { *(u64 *)data = val; return 0; } static int debugfs_u64_get(void *data, u64 *val) { *val = *(u64 *)data; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); /** * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-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_u64(const char *name, umode_t mode, struct dentry *parent, u64 *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64, &fops_u64_ro, &fops_u64_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u64); static int debugfs_ulong_set(void *data, u64 val) { *(unsigned long *)data = val; return 0; } static int debugfs_ulong_get(void *data, u64 *val) { *val = *(unsigned long *)data; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n"); /** * debugfs_create_ulong - create a debugfs file that is used to read and write * an unsigned long 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_ulong(const char *name, umode_t mode, struct dentry *parent, unsigned long *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_ulong, &fops_ulong_ro, &fops_ulong_wo); } EXPORT_SYMBOL_GPL(debugfs_create_ulong); DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n"); /* * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value * * These functions are exactly the same as the above functions (but use a hex * output for the decimal challenged). For details look at the above unsigned * decimal functions. */ /** * debugfs_create_x8 - 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. */ void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, u8 *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8, &fops_x8_ro, &fops_x8_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x8); /** * debugfs_create_x16 - 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. */ void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, u16 *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16, &fops_x16_ro, &fops_x16_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x16); /** * debugfs_create_x32 - 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 * 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. */ void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, u32 *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32, &fops_x32_ro, &fops_x32_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x32); /** * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-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. */ void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, u64 *value) { debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64, &fops_x64_ro, &fops_x64_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x64); static int debugfs_size_t_set(void *data, u64 val) { *(size_t *)data = val; return 0; } static int debugfs_size_t_get(void *data, u64 *val) { *val = *(size_t *)data; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set, "%llu\n"); /* %llu and %zu are more or less the same */ DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n"); /** * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t 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. */ void debugfs_create_size_t(const char *name, umode_t mode, struct dentry *parent, size_t *value) { 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); static int debugfs_atomic_t_set(void *data, u64 val) { atomic_set((atomic_t *)data, val); return 0; } static int debugfs_atomic_t_get(void *data, u64 *val) { *val = atomic_read((atomic_t *)data); return 0; } DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t, debugfs_atomic_t_get, debugfs_atomic_t_set, "%lld\n"); DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n"); DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n"); /** * debugfs_create_atomic_t - create a debugfs file that is used to read and * write an atomic_t 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. */ void debugfs_create_atomic_t(const char *name, umode_t mode, struct dentry *parent, atomic_t *value) { 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[2]; bool val; int r; struct dentry *dentry = F_DENTRY(file); r = debugfs_file_get(dentry); if (unlikely(r)) return r; val = *(bool *)file->private_data; debugfs_file_put(dentry); if (val) buf[0] = 'Y'; else buf[0] = 'N'; buf[1] = '\n'; return simple_read_from_buffer(user_buf, count, ppos, buf, 2); } EXPORT_SYMBOL_GPL(debugfs_read_file_bool); ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos) { bool bv; int r; bool *val = file->private_data; struct dentry *dentry = F_DENTRY(file); r = kstrtobool_from_user(user_buf, count, &bv); if (!r) { r = debugfs_file_get(dentry); if (unlikely(r)) return r; *val = bv; debugfs_file_put(dentry); } return count; } EXPORT_SYMBOL_GPL(debugfs_write_file_bool); static const struct file_operations fops_bool = { .read = debugfs_read_file_bool, .write = debugfs_write_file_bool, .open = simple_open, .llseek = default_llseek, }; static const struct file_operations fops_bool_ro = { .read = debugfs_read_file_bool, .open = simple_open, .llseek = default_llseek, }; static const struct file_operations fops_bool_wo = { .write = debugfs_write_file_bool, .open = simple_open, .llseek = default_llseek, }; /** * debugfs_create_bool - create a debugfs file that is used to read and write a boolean 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_bool(const char *name, umode_t mode, struct dentry *parent, bool *value) { 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) { 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_read_from_buffer(user_buf, count, ppos, blob->data, blob->size); debugfs_file_put(dentry); 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 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 * directory dentry if set. If this parameter is %NULL, then the * file will be created in the root of the debugfs filesystem. * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer * to the blob data and the size of the data. * * 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 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, ERR_PTR(-ERROR) will be * returned. * * 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 & 0644, parent, blob, &fops_blob); } EXPORT_SYMBOL_GPL(debugfs_create_blob); static size_t u32_format_array(char *buf, size_t bufsize, u32 *array, int array_size) { size_t ret = 0; while (--array_size >= 0) { size_t len; char term = array_size ? ' ' : '\n'; len = snprintf(buf, bufsize, "%u%c", *array++, term); ret += len; buf += len; bufsize -= len; } return ret; } static int u32_array_open(struct inode *inode, struct file *file) { struct debugfs_u32_array *data = inode->i_private; int size, elements = data->n_elements; char *buf; /* * Max size: * - 10 digits + ' '/'\n' = 11 bytes per number * - terminating NUL character */ size = elements*11; buf = kmalloc(size+1, GFP_KERNEL); if (!buf) return -ENOMEM; buf[size] = 0; file->private_data = buf; u32_format_array(buf, size, data->array, data->n_elements); return nonseekable_open(inode, file); } static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len, loff_t *ppos) { size_t size = strlen(file->private_data); return simple_read_from_buffer(buf, len, ppos, file->private_data, size); } static int u32_array_release(struct inode *inode, struct file *file) { kfree(file->private_data); return 0; } static const struct file_operations u32_array_fops = { .owner = THIS_MODULE, .open = u32_array_open, .release = u32_array_release, .read = u32_array_read, .llseek = no_llseek, }; /** * debugfs_create_u32_array - create a debugfs file that is used to read u32 * array. * @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. * @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. */ void debugfs_create_u32_array(const char *name, umode_t mode, struct dentry *parent, struct debugfs_u32_array *array) { debugfs_create_file_unsafe(name, mode, parent, array, &u32_array_fops); } EXPORT_SYMBOL_GPL(debugfs_create_u32_array); #ifdef CONFIG_HAS_IOMEM /* * The regset32 stuff is used to print 32-bit registers using the * seq_file utilities. We offer printing a register set in an already-opened * sequential file or create a debugfs file that only prints a regset32. */ /** * debugfs_print_regs32 - use seq_print to describe a set of registers * @s: the seq_file structure being used to generate output * @regs: an array if struct debugfs_reg32 structures * @nregs: the length of the above array * @base: the base address to be used in reading the registers * @prefix: a string to be prefixed to every output line * * This function outputs a text block describing the current values of * some 32-bit hardware registers. It is meant to be used within debugfs * files based on seq_file that need to show registers, intermixed with other * information. The prefix argument may be used to specify a leading string, * because some peripherals have several blocks of identical registers, * for example configuration of dma channels */ void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, int nregs, void __iomem *base, char *prefix) { int i; for (i = 0; i < nregs; i++, regs++) { if (prefix) seq_printf(s, "%s", prefix); seq_printf(s, "%s = 0x%08x\n", regs->name, readl(base + regs->offset)); if (seq_has_overflowed(s)) break; } } EXPORT_SYMBOL_GPL(debugfs_print_regs32); 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, ""); if (regset->dev) pm_runtime_put(regset->dev); return 0; } DEFINE_SHOW_ATTRIBUTE(debugfs_regset32); /** * debugfs_create_regset32 - create a debugfs file that returns register values * @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. * @regset: a pointer to a struct debugfs_regset32, which contains a pointer * to an array of register definitions, the array size and the base * address where the register bank is to be found. * * 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. */ void debugfs_create_regset32(const char *name, umode_t mode, struct dentry *parent, struct debugfs_regset32 *regset) { debugfs_create_file(name, mode, parent, regset, &debugfs_regset32_fops); } EXPORT_SYMBOL_GPL(debugfs_create_regset32); #endif /* CONFIG_HAS_IOMEM */ struct debugfs_devm_entry { int (*read)(struct seq_file *seq, void *data); struct device *dev; }; static int debugfs_devm_entry_open(struct inode *inode, struct file *f) { struct debugfs_devm_entry *entry = inode->i_private; return single_open(f, entry->read, entry->dev); } static const struct file_operations debugfs_devm_entry_ops = { .owner = THIS_MODULE, .open = debugfs_devm_entry_open, .release = single_release, .read = seq_read, .llseek = seq_lseek }; /** * debugfs_create_devm_seqfile - create a debugfs file that is bound to device. * * @dev: device related to this debugfs file. * @name: name of the debugfs file. * @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. * @read_fn: function pointer called to print the seq_file content. */ 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; entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL); if (!entry) return; entry->read = read_fn; entry->dev = dev; debugfs_create_file(name, S_IRUGO, parent, entry, &debugfs_devm_entry_ops); } EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);