| /* |
| * 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. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License version |
| * 2 as published by the Free Software Foundation. |
| * |
| * debugfs is for people to use instead of /proc or /sys. |
| * See Documentation/DocBook/filesystems for more details. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/pagemap.h> |
| #include <linux/namei.h> |
| #include <linux/debugfs.h> |
| |
| 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; |
| } |
| |
| static int default_open(struct inode *inode, struct file *file) |
| { |
| if (inode->i_private) |
| file->private_data = inode->i_private; |
| |
| return 0; |
| } |
| |
| const struct file_operations debugfs_file_operations = { |
| .read = default_read_file, |
| .write = default_write_file, |
| .open = default_open, |
| }; |
| |
| static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
| { |
| nd_set_link(nd, dentry->d_inode->i_private); |
| return NULL; |
| } |
| |
| const struct inode_operations debugfs_link_operations = { |
| .readlink = generic_readlink, |
| .follow_link = debugfs_follow_link, |
| }; |
| |
| 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_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, 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. |
| * |
| * This function will return a pointer to a dentry if it succeeds. This |
| * pointer must be passed to the debugfs_remove() function when the file is |
| * to be removed (no automatic cleanup happens if your module is unloaded, |
| * you are responsible here.) If an error occurs, %NULL will be returned. |
| * |
| * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| * returned. It is not wise to check for this value, but rather, check for |
| * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| * code. |
| */ |
| struct dentry *debugfs_create_u8(const char *name, mode_t mode, |
| struct dentry *parent, u8 *value) |
| { |
| return debugfs_create_file(name, mode, parent, value, &fops_u8); |
| } |
| 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_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, 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. |
| * |
| * This function will return a pointer to a dentry if it succeeds. This |
| * pointer must be passed to the debugfs_remove() function when the file is |
| * to be removed (no automatic cleanup happens if your module is unloaded, |
| * you are responsible here.) If an error occurs, %NULL will be returned. |
| * |
| * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| * returned. It is not wise to check for this value, but rather, check for |
| * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| * code. |
| */ |
| struct dentry *debugfs_create_u16(const char *name, mode_t mode, |
| struct dentry *parent, u16 *value) |
| { |
| return debugfs_create_file(name, mode, parent, value, &fops_u16); |
| } |
| 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_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, 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. |
| * |
| * This function will return a pointer to a dentry if it succeeds. This |
| * pointer must be passed to the debugfs_remove() function when the file is |
| * to be removed (no automatic cleanup happens if your module is unloaded, |
| * you are responsible here.) If an error occurs, %NULL will be returned. |
| * |
| * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| * returned. It is not wise to check for this value, but rather, check for |
| * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| * code. |
| */ |
| struct dentry *debugfs_create_u32(const char *name, mode_t mode, |
| struct dentry *parent, u32 *value) |
| { |
| return debugfs_create_file(name, mode, parent, value, &fops_u32); |
| } |
| 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_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, 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. |
| * |
| * This function will return a pointer to a dentry if it succeeds. This |
| * pointer must be passed to the debugfs_remove() function when the file is |
| * to be removed (no automatic cleanup happens if your module is unloaded, |
| * you are responsible here.) If an error occurs, %NULL will be returned. |
| * |
| * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| * returned. It is not wise to check for this value, but rather, check for |
| * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| * code. |
| */ |
| struct dentry *debugfs_create_u64(const char *name, mode_t mode, |
| struct dentry *parent, u64 *value) |
| { |
| return debugfs_create_file(name, mode, parent, value, &fops_u64); |
| } |
| EXPORT_SYMBOL_GPL(debugfs_create_u64); |
| |
| DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n"); |
| |
| DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n"); |
| |
| DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n"); |
| |
| /* |
| * debugfs_create_x{8,16,32} - create a debugfs file that is used to read and write an unsigned {8,16,32}-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. |
| */ |
| struct dentry *debugfs_create_x8(const char *name, mode_t mode, |
| struct dentry *parent, u8 *value) |
| { |
| return debugfs_create_file(name, mode, parent, value, &fops_x8); |
| } |
| 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. |
| */ |
| struct dentry *debugfs_create_x16(const char *name, mode_t mode, |
| struct dentry *parent, u16 *value) |
| { |
| return debugfs_create_file(name, mode, parent, value, &fops_x16); |
| } |
| 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. |
| */ |
| struct dentry *debugfs_create_x32(const char *name, mode_t mode, |
| struct dentry *parent, u32 *value) |
| { |
| return debugfs_create_file(name, mode, parent, value, &fops_x32); |
| } |
| EXPORT_SYMBOL_GPL(debugfs_create_x32); |
| |
| static ssize_t read_file_bool(struct file *file, char __user *user_buf, |
| size_t count, loff_t *ppos) |
| { |
| char buf[3]; |
| u32 *val = file->private_data; |
| |
| if (*val) |
| buf[0] = 'Y'; |
| else |
| buf[0] = 'N'; |
| buf[1] = '\n'; |
| buf[2] = 0x00; |
| return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| } |
| |
| static ssize_t write_file_bool(struct file *file, const char __user *user_buf, |
| size_t count, loff_t *ppos) |
| { |
| char buf[32]; |
| int buf_size; |
| u32 *val = file->private_data; |
| |
| buf_size = min(count, (sizeof(buf)-1)); |
| if (copy_from_user(buf, user_buf, buf_size)) |
| return -EFAULT; |
| |
| switch (buf[0]) { |
| case 'y': |
| case 'Y': |
| case '1': |
| *val = 1; |
| break; |
| case 'n': |
| case 'N': |
| case '0': |
| *val = 0; |
| break; |
| } |
| |
| return count; |
| } |
| |
| static const struct file_operations fops_bool = { |
| .read = read_file_bool, |
| .write = write_file_bool, |
| .open = default_open, |
| }; |
| |
| /** |
| * 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. |
| * |
| * This function will return a pointer to a dentry if it succeeds. This |
| * pointer must be passed to the debugfs_remove() function when the file is |
| * to be removed (no automatic cleanup happens if your module is unloaded, |
| * you are responsible here.) If an error occurs, %NULL will be returned. |
| * |
| * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| * returned. It is not wise to check for this value, but rather, check for |
| * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| * code. |
| */ |
| struct dentry *debugfs_create_bool(const char *name, mode_t mode, |
| struct dentry *parent, u32 *value) |
| { |
| return debugfs_create_file(name, mode, parent, value, &fops_bool); |
| } |
| EXPORT_SYMBOL_GPL(debugfs_create_bool); |
| |
| 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; |
| return simple_read_from_buffer(user_buf, count, ppos, blob->data, |
| blob->size); |
| } |
| |
| static const struct file_operations fops_blob = { |
| .read = read_file_blob, |
| .open = default_open, |
| }; |
| |
| /** |
| * 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. Writing is not supported. |
| * |
| * This function will return a pointer to a dentry if it succeeds. This |
| * pointer must be passed to the debugfs_remove() function when the file is |
| * to be removed (no automatic cleanup happens if your module is unloaded, |
| * you are responsible here.) If an error occurs, %NULL will be returned. |
| * |
| * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| * returned. It is not wise to check for this value, but rather, check for |
| * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| * code. |
| */ |
| struct dentry *debugfs_create_blob(const char *name, mode_t mode, |
| struct dentry *parent, |
| struct debugfs_blob_wrapper *blob) |
| { |
| return debugfs_create_file(name, mode, parent, blob, &fops_blob); |
| } |
| EXPORT_SYMBOL_GPL(debugfs_create_blob); |