summaryrefslogtreecommitdiff
path: root/fs/debugfs
diff options
context:
space:
mode:
Diffstat (limited to 'fs/debugfs')
-rw-r--r--fs/debugfs/file.c46
1 files changed, 46 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);