diff options
| -rw-r--r-- | fs/debugfs/file.c | 46 | ||||
| -rw-r--r-- | include/linux/debugfs.h | 15 |
2 files changed, 61 insertions, 0 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index d575452cd9f7..40c4fc973fad 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -251,3 +251,49 @@ struct dentry *debugfs_create_bool(const char *name, mode_t mode, } 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 struct file_operations fops_blob = { + .read = read_file_blob, + .open = default_open, +}; + +/** + * debugfs_create_blob - create a file in the debugfs filesystem 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 paramater 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); diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index a5fa6a6eede8..4b0428e335be 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -21,6 +21,11 @@ struct file_operations; +struct debugfs_blob_wrapper { + void *data; + unsigned long size; +}; + #if defined(CONFIG_DEBUG_FS) struct dentry *debugfs_create_file(const char *name, mode_t mode, struct dentry *parent, void *data, @@ -39,6 +44,9 @@ struct dentry *debugfs_create_u32(const char *name, mode_t mode, struct dentry *debugfs_create_bool(const char *name, mode_t mode, struct dentry *parent, u32 *value); +struct dentry *debugfs_create_blob(const char *name, mode_t mode, + struct dentry *parent, + struct debugfs_blob_wrapper *blob); #else #include <linux/err.h> @@ -94,6 +102,13 @@ static inline struct dentry *debugfs_create_bool(const char *name, mode_t mode, return ERR_PTR(-ENODEV); } +static inline struct dentry *debugfs_create_blob(const char *name, mode_t mode, + struct dentry *parent, + struct debugfs_blob_wrapper *blob) +{ + return ERR_PTR(-ENODEV); +} + #endif #endif |