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From:   Li Qiang <liq3ea@gmail.com>
Date:   Thu, 8 Sep 2022 12:51:11 +0800
Message-ID: <CAKXe6SJpzUMkjyb1hGagaNUiXS0h5xen95iTqCMs0UcGVW1ECQ@mail.gmail.com>
Subject: Re: [PATCH] kprobe: reverse kp->flags when arm_kprobe failed
To:     Li Qiang <liq3ea@163.com>
Cc:     naveen.n.rao@linux.ibm.com, anil.s.keshavamurthy@intel.com,
        davem@davemloft.net, mhiramat@kernel.org,
        linux-kernel@vger.kernel.org
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Kindly ping.

Li Qiang <liq3ea@163.com> =E4=BA=8E2022=E5=B9=B49=E6=9C=883=E6=97=A5=E5=91=
=A8=E5=85=AD 00:00=E5=86=99=E9=81=93=EF=BC=9A
>
> In aggregate kprobe case, when arm_kprobe failed,
> we need set the kp->flags with KPROBE_FLAG_DISABLED again.
> If not, the 'kp' kprobe will been considered as enabled
> but it actually not enabled.
>
> Signed-off-by: Li Qiang <liq3ea@163.com>
> ---
>  kernel/kprobes.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 08350e35a..333454df5 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -2424,8 +2424,11 @@ int enable_kprobe(struct kprobe *kp)
>         if (!kprobes_all_disarmed && kprobe_disabled(p)) {
>                 p->flags &=3D ~KPROBE_FLAG_DISABLED;
>                 ret =3D arm_kprobe(p);
> -               if (ret)
> +               if (ret) {
>                         p->flags |=3D KPROBE_FLAG_DISABLED;
> +                       if (p !=3D kp)
> +                               kp->flags |=3D KPROBE_FLAG_DISABLED;
> +               }
>         }
>  out:
>         mutex_unlock(&kprobe_mutex);
> --
> 2.25.1
>