Commit fc456122 authored Nov 21, 2023 by Steven Rostedt (Google)

eventfs: Do not allow NULL parent to eventfs_start_creating()

The eventfs directory is dynamically created via the meta data supplied by
the existing trace events. All files and directories in eventfs has a
parent. Do not allow NULL to be passed into eventfs_start_creating() as
the parent because that should never happen. Warn if it does.

Link: https://lkml.kernel.org/r/20231121231112.693841807@goodmis.org



Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

parent bcae32c5

fs/tracefs/inode.c

+4 −9

Original line number	Diff line number	Diff line
		@@ -509,20 +509,15 @@ struct dentry eventfs_start_creating(const char name, struct dentry *parent)
		struct dentry *dentry;
		int error;

		/* Must always have a parent. */
		if (WARN_ON_ONCE(!parent))
		return ERR_PTR(-EINVAL);

		error = simple_pin_fs(&trace_fs_type, &tracefs_mount,
		&tracefs_mount_count);
		if (error)
		return ERR_PTR(error);

		/*
		* If the parent is not specified, we create it in the root.
		* We need the root dentry to do this, which is in the super
		* block. A pointer to that is in the struct vfsmount that we
		* have around.
		*/
		if (!parent)
		parent = tracefs_mount->mnt_root;

		if (unlikely(IS_DEADDIR(parent->d_inode)))
		dentry = ERR_PTR(-ENOENT);
		else