diff mbox series

fprobe: add unlock to match a succeeded ftrace_test_recursion_trylock

Message ID 20230703071640.106204-1-zegao@tencent.com
State New
Headers
Series fprobe: add unlock to match a succeeded ftrace_test_recursion_trylock |

Commit Message

Ze Gao July 3, 2023, 7:16 a.m. UTC 
  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(-)

Comments

Masami Hiramatsu (Google) July 3, 2023, 8:19 a.m. UTC | #1 
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
>
Ze Gao July 3, 2023, 9:26 a.m. UTC | #2 
Good suggestion! Will amend and push v2 ASAP.

Thanks,
Ze

On Mon, Jul 3, 2023 at 4:19 PM Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> 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>
diff mbox series

Patch

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);
 }