Commit 5a49f996 authored by Steven Rostedt (Google)'s avatar Steven Rostedt (Google)
Browse files

eventfs: Warn if an eventfs_inode is freed without is_freed being set 

There should never be a case where an evenfs_inode is being freed without
is_freed being set. Add a WARN_ON_ONCE() if it ever happens. That would
mean there was one too many put_ei()s.

Link: https://lore.kernel.org/linux-trace-kernel/20240201161616.843551963@goodmis.org



Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Ajay Kaher <ajay.kaher@broadcom.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 1389358b

fs/tracefs/event_inode.c

+14 −4
Original line number Diff line number Diff line
@@ -73,6 +73,9 @@ enum { 
static void release_ei(struct kref *ref)

{

	struct eventfs_inode *ei = container_of(ref, struct eventfs_inode, kref);



	WARN_ON_ONCE(!ei->is_freed);



	kfree(ei->entry_attrs);

	kfree_const(ei->name);

	kfree_rcu(ei, rcu);
@@ -84,6 +87,14 @@ static inline void put_ei(struct eventfs_inode *ei) 
		kref_put(&ei->kref, release_ei);

}



static inline void free_ei(struct eventfs_inode *ei)

{

	if (ei) {

		ei->is_freed = 1;

		put_ei(ei);

	}

}



static inline struct eventfs_inode *get_ei(struct eventfs_inode *ei)

{

	if (ei)
@@ -679,7 +690,7 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode 


	/* Was the parent freed? */

	if (list_empty(&ei->list)) {

		put_ei(ei);

		free_ei(ei);

		ei = NULL;

	}

	return ei;
@@ -770,7 +781,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry 
	return ei;



 fail:

	put_ei(ei);

	free_ei(ei);

	tracefs_failed_creating(dentry);

	return ERR_PTR(-ENOMEM);

}
@@ -801,9 +812,8 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) 
	list_for_each_entry(ei_child, &ei->children, list)

		eventfs_remove_rec(ei_child, level + 1);



	ei->is_freed = 1;

	list_del(&ei->list);

	put_ei(ei);

	free_ei(ei);

}



/**