Re: WARNING at __ftrace_hash_rec_update()

[Steven Rostedt]

On Tue, 2011-11-01 at 19:45 +0530, Rabin Vincent wrote:
> On v3.1-7810-g094803e (current linus git), I'm able to trigger the below
> FTRACE_WARN_ON() by running the following sequence of commands.
> DYNAMIC_FTRACE is enabled.
> 
> ftrace.c:1384:
> 	if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
> 		return;
> 	rec->flags--;
> 

Thanks for reporting. Can you try this patch please.

-- Steve


diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 0fcc6ca..9af2ea6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1210,7 +1210,8 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
 	if (!src->count) {
 		free_ftrace_hash_rcu(*dst);
 		rcu_assign_pointer(*dst, EMPTY_HASH);
-		return 0;
+		/* still need to update the function records */
+		goto out;
 	}
 
 	/*


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