lkml.org 
[lkml]   [2023]   [Jul]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] fprobe: add unlock to match a succeeded ftrace_test_recursion_trylock
On Mon,  3 Jul 2023 15:16:40 +0800
Ze Gao <zegao2021@gmail.com> wrote:

Good catch! but please add description here, something like;

----
Unlock ftrace recursion lock when fprobe_kprobe_handler() is failed
because another kprobe is running.
----

The code itself is OK to me.


> Fixes: 3cc4e2c5fbae ("fprobe: make fprobe_kprobe_handler recursion free")
> Reported-by: Yafang <laoar.shao@gmail.com>
> Closes: https://lore.kernel.org/linux-trace-kernel/CALOAHbC6UpfFOOibdDiC7xFc5YFUgZnk3MZ=3Ny6we=AcrNbew@mail.gmail.com/
> Signed-off-by: Ze Gao <zegao@tencent.com>
> ---
> kernel/trace/fprobe.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> index 18d36842faf5..93b3e361bb97 100644
> --- a/kernel/trace/fprobe.c
> +++ b/kernel/trace/fprobe.c
> @@ -102,12 +102,14 @@ static void fprobe_kprobe_handler(unsigned long ip, unsigned long parent_ip,
>
> if (unlikely(kprobe_running())) {
> fp->nmissed++;
> - return;
> + goto recursion_unlock;
> }
>
> kprobe_busy_begin();
> __fprobe_handler(ip, parent_ip, ops, fregs);
> kprobe_busy_end();
> +
> +recursion_unlock:
> ftrace_test_recursion_unlock(bit);
> }
>
> --
> 2.40.1
>


--
Masami Hiramatsu (Google) <mhiramat@kernel.org>

\
 
 \ /
  Last update: 2023-07-03 10:20    [W:0.035 / U:0.864 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site