fs/debugfs/file.c

3  *  file.c - part of debugfs, a tiny little debug file system
29 static ssize_t default_read_file(struct file *file, char __user *buf,
35 static ssize_t default_write_file(struct file *file, const char __user *buf,
50 const struct file_operations *debugfs_real_fops(const struct file *filp)
68  * debugfs_file_get - mark the beginning of file data access
72  * into the file removing functions debugfs_remove() and
74  * file data may only get freed after a successful return of any of
78  * If -%EIO is returned, the file has already been removed and thus,
80  * it is allowed to access the file data, zero is returned.
89 	 * debugfs_file_get() on a dentry that isn't even a file, let
136  * debugfs_file_put - mark the end of file data access
155  * @file: the file being accessed
159  * When a debugfs file is removed it needs to wait for all active
175 void debugfs_enter_cancellation(struct file *file,
179 	struct dentry *dentry = F_DENTRY(file);
206  * @file: the file being accessed
212 void debugfs_leave_cancellation(struct file *file,
216 	struct dentry *dentry = F_DENTRY(file);
235  * We also need to exclude any file that has ways to write or alter it as root
239 			       struct file *filp,
255 static int open_proxy_open(struct inode *inode, struct file *filp)
281 		WARN(1, "debugfs file owner did not clean up at exit: %pd",
320 		PROTO(struct file *filp, loff_t offset, int whence),
324 		PROTO(struct file *filp, char __user *buf, size_t size,
329 		PROTO(struct file *filp, const char __user *buf, size_t size,
334 		PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
337 static __poll_t full_proxy_poll(struct file *filp,
353 static int full_proxy_release(struct inode *inode, struct file *filp)
391 static int full_proxy_open(struct inode *inode, struct file *filp)
418 		WARN(1, "debugfs file owner did not clean up at exit: %pd",
438 			/* No protection against file removal anymore. */
439 			WARN(1, "debugfs file owner replaced proxy fops: %pd",
458 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
461 	struct dentry *dentry = F_DENTRY(file);
467 	ret = simple_attr_read(file, buf, len, ppos);
473 static ssize_t debugfs_attr_write_xsigned(struct file *file, const char __user *buf,
476 	struct dentry *dentry = F_DENTRY(file);
483 		ret = simple_attr_write_signed(file, buf, len, ppos);
485 		ret = simple_attr_write(file, buf, len, ppos);
490 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
493 	return debugfs_attr_write_xsigned(file, buf, len, ppos, false);
497 ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
500 	return debugfs_attr_write_xsigned(file, buf, len, ppos, true);
537  * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
538  * @name: a pointer to a string containing the name of the file to create.
539  * @mode: the permission that the file should have
540  * @parent: a pointer to the parent dentry for this file.  This should be a
542  *          file will be created in the root of the debugfs filesystem.
543  * @value: a pointer to the variable that the file should read to and write
546  * This function creates a file in debugfs with the given name that
573  * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
574  * @name: a pointer to a string containing the name of the file to create.
575  * @mode: the permission that the file should have
576  * @parent: a pointer to the parent dentry for this file.  This should be a
578  *          file will be created in the root of the debugfs filesystem.
579  * @value: a pointer to the variable that the file should read to and write
582  * This function creates a file in debugfs with the given name that
609  * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
610  * @name: a pointer to a string containing the name of the file to create.
611  * @mode: the permission that the file should have
612  * @parent: a pointer to the parent dentry for this file.  This should be a
614  *          file will be created in the root of the debugfs filesystem.
615  * @value: a pointer to the variable that the file should read to and write
618  * This function creates a file in debugfs with the given name that
646  * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
647  * @name: a pointer to a string containing the name of the file to create.
648  * @mode: the permission that the file should have
649  * @parent: a pointer to the parent dentry for this file.  This should be a
651  *          file will be created in the root of the debugfs filesystem.
652  * @value: a pointer to the variable that the file should read to and write
655  * This function creates a file in debugfs with the given name that
684  * debugfs_create_ulong - create a debugfs file that is used to read and write
686  * @name: a pointer to a string containing the name of the file to create.
687  * @mode: the permission that the file should have
688  * @parent: a pointer to the parent dentry for this file.  This should be a
690  *          file will be created in the root of the debugfs filesystem.
691  * @value: a pointer to the variable that the file should read to and write
694  * This function creates a file in debugfs with the given name that
726  * 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
734  * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
735  * @name: a pointer to a string containing the name of the file to create.
736  * @mode: the permission that the file should have
737  * @parent: a pointer to the parent dentry for this file.  This should be a
739  *          file will be created in the root of the debugfs filesystem.
740  * @value: a pointer to the variable that the file should read to and write
752  * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
753  * @name: a pointer to a string containing the name of the file to create.
754  * @mode: the permission that the file should have
755  * @parent: a pointer to the parent dentry for this file.  This should be a
757  *          file will be created in the root of the debugfs filesystem.
758  * @value: a pointer to the variable that the file should read to and write
770  * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
771  * @name: a pointer to a string containing the name of the file to create.
772  * @mode: the permission that the file should have
773  * @parent: a pointer to the parent dentry for this file.  This should be a
775  *          file will be created in the root of the debugfs filesystem.
776  * @value: a pointer to the variable that the file should read to and write
788  * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
789  * @name: a pointer to a string containing the name of the file to create.
790  * @mode: the permission that the file should have
791  * @parent: a pointer to the parent dentry for this file.  This should be a
793  *          file will be created in the root of the debugfs filesystem.
794  * @value: a pointer to the variable that the file should read to and write
822  * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
823  * @name: a pointer to a string containing the name of the file to create.
824  * @mode: the permission that the file should have
825  * @parent: a pointer to the parent dentry for this file.  This should be a
827  *          file will be created in the root of the debugfs filesystem.
828  * @value: a pointer to the variable that the file should read to and write
857  * debugfs_create_atomic_t - create a debugfs file that is used to read and
859  * @name: a pointer to a string containing the name of the file to create.
860  * @mode: the permission that the file should have
861  * @parent: a pointer to the parent dentry for this file.  This should be a
863  *          file will be created in the root of the debugfs filesystem.
864  * @value: a pointer to the variable that the file should read to and write
875 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
881 	struct dentry *dentry = F_DENTRY(file);
886 	val = *(bool *)file->private_data;
898 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
903 	bool *val = file->private_data;
904 	struct dentry *dentry = F_DENTRY(file);
939  * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
940  * @name: a pointer to a string containing the name of the file to create.
941  * @mode: the permission that the file should have
942  * @parent: a pointer to the parent dentry for this file.  This should be a
944  *          file will be created in the root of the debugfs filesystem.
945  * @value: a pointer to the variable that the file should read to and write
948  * This function creates a file in debugfs with the given name that
960 ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
963 	struct dentry *dentry = F_DENTRY(file);
972 	str = *(char **)file->private_data;
996 static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf,
999 	struct dentry *dentry = F_DENTRY(file);
1008 	old = *(char **)file->private_data;
1034 	rcu_assign_pointer(*(char __rcu **)file->private_data, new);
1067  * debugfs_create_str - create a debugfs file that is used to read and write a string value
1068  * @name: a pointer to a string containing the name of the file to create.
1069  * @mode: the permission that the file should have
1070  * @parent: a pointer to the parent dentry for this file.  This should be a
1072  *          file will be created in the root of the debugfs filesystem.
1073  * @value: a pointer to the variable that the file should read to and write
1076  * This function creates a file in debugfs with the given name that
1087 static ssize_t read_file_blob(struct file *file, char __user *user_buf,
1090 	struct debugfs_blob_wrapper *blob = file->private_data;
1091 	struct dentry *dentry = F_DENTRY(file);
1103 static ssize_t write_file_blob(struct file *file, const char __user *user_buf,
1106 	struct debugfs_blob_wrapper *blob = file->private_data;
1107 	struct dentry *dentry = F_DENTRY(file);
1128  * debugfs_create_blob - create a debugfs file that is used to read and write
1130  * @name: a pointer to a string containing the name of the file to create.
1131  * @mode: the permission that the file should have
1132  * @parent: a pointer to the parent dentry for this file.  This should be a
1134  *          file will be created in the root of the debugfs filesystem.
1138  * This function creates a file in debugfs with the given name that exports
1143  * pointer must be passed to the debugfs_remove() function when the file is
1177 static int u32_array_open(struct inode *inode, struct file *file)
1194 	file->private_data = buf;
1197 	return nonseekable_open(inode, file);
1200 static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
1203 	size_t size = strlen(file->private_data);
1206 					file->private_data, size);
1209 static int u32_array_release(struct inode *inode, struct file *file)
1211 	kfree(file->private_data);
1225  * debugfs_create_u32_array - create a debugfs file that is used to read u32
1227  * @name: a pointer to a string containing the name of the file to create.
1228  * @mode: the permission that the file should have.
1229  * @parent: a pointer to the parent dentry for this file.  This should be a
1231  *          file will be created in the root of the debugfs filesystem.
1234  * This function creates a file in debugfs with the given name that exports
1236  * Writing is not supported. Seek within the file is also not supported.
1252  * sequential file or create a debugfs file that only prints a regset32.
1304  * debugfs_create_regset32 - create a debugfs file that returns register values
1305  * @name: a pointer to a string containing the name of the file to create.
1306  * @mode: the permission that the file should have
1307  * @parent: a pointer to the parent dentry for this file.  This should be a
1309  *          file will be created in the root of the debugfs filesystem.
1314  * This function creates a file in debugfs with the given name that reports
1333 static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
1349  * debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
1351  * @dev: device related to this debugfs file.
1352  * @name: name of the debugfs file.
1353  * @parent: a pointer to the parent dentry for this file.  This should be a
1355  *	file will be created in the root of the debugfs filesystem.