From: "Steven Rostedt (Google)" rostedt@goodmis.org
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 (cherry picked from commit fc4561226feaad5fcdcb55646c348d77b8ee69c5) --- fs/tracefs/inode.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index 34ffb2f8114e..b9ed8db4f6b9 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -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