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Diffstat (limited to 'fs/debugfs/file.c')
| -rw-r--r-- | fs/debugfs/file.c | 1239 |
1 files changed, 1239 insertions, 0 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c new file mode 100644 index 000000000..b38304b44 --- /dev/null +++ b/fs/debugfs/file.c @@ -0,0 +1,1239 @@ +// 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; + + /* + * 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)) { + 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; +} + +static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + /* This is really only for read-only strings */ + return -EINVAL; +} + +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. + * + * 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. + */ +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 const struct file_operations fops_blob = { + .read = read_file_blob, + .open = simple_open, + .llseek = default_llseek, +}; + +/** + * debugfs_create_blob - create a debugfs file that is used to read a binary blob + * @name: a pointer to a string containing the name of the file to create. + * @mode: the read permission that the file should have (other permissions are + * masked out) + * @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. 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, 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 & 0444, 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); |