On Sat, 13 May 2023 00:17:57 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Fri, 12 May 2023 07:29:02 -0700
> Yonghong Song <yhs@xxxxxxxx> wrote:
>
> > A fprobe_blacklist might make sense indeed as fprobe and kprobe are
> > quite different... Thanks for working on this.
>
> Hmm, I think I see the problem:
>
> fprobe_kprobe_handler() {
> kprobe_busy_begin() {
> preempt_disable() {
> preempt_count_add() { <-- trace
> fprobe_kprobe_handler() {
> [ wash, rinse, repeat, CRASH!!! ]
>
> Either the kprobe_busy_begin() needs to use preempt_disable_notrace()
> versions, or fprobe_kprobe_handle() needs a
> ftrace_test_recursion_trylock() call.
Oops, I got it. Is preempt_count_add() tracable? If so, kprobe_busy_begin()
should be updated.
Thanks,
>
> -- Steve
--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
