Re: [mainline]Kernel crash while running ftrace selftest

[Venkat Rao Bagalkote]

On 16/04/25 8:32 pm, Steven Rostedt wrote:
> On Wed, 16 Apr 2025 12:37:15 +0530
> Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxx> wrote:
>
>
> Thanks for the bug report!
>
> > [15137.589546] NIP [c0000000003e4738] ops_equal+0x8/0x170
> > [15137.589553] LR [c0000000003ec708] ftrace_update_ops+0x78/0xe0
> Hmm, I'm guessing that you hit a path where the filter_hash or
> notrace_hash never was initialized.
>
> > [15137.589561] Call Trace:
> > [15137.589564] [c00000001473f9c0] [c0000000003ec6ec]
> > ftrace_update_ops+0x5c/0xe0 (unreliable)
> > [15137.589575] [c00000001473fa00] [c0000000003f31b4]
> > ftrace_startup_subops+0x124/0x5c0
> > [15137.589583] [c00000001473faa0] [c
> Can you see if this fixes the issue for you?
>
> Thanks!
>
> -- Steve
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index a8a02868b435..777574fa3095 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -3625,8 +3625,8 @@ static int rebuild_hashes(struct ftrace_hash **filter_hash, struct ftrace_hash *
>    */
>   int ftrace_shutdown_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command)
>   {
> -	struct ftrace_hash *filter_hash;
> -	struct ftrace_hash *notrace_hash;
> +	struct ftrace_hash *filter_hash = EMPTY_HASH;
> +	struct ftrace_hash *notrace_hash = EMPTY_HASH;
>   	int ret;
>   
>   	if (unlikely(ftrace_disabled))


Hello Steve,

Issue still persists with the above patch.


Regards,

Venkat.