Received-SPF: pass (google.com: domain of linux-kernel+bounces-204313-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Precedence: bulk
MIME-Version: 1.0
Date: Thu, 06 Jun 2024 06:05:55 -0700
In-Reply-To: <000000000000adb08b061413919e@google.com>
Message-ID: <000000000000e0e0e8061a385789@google.com>
Subject: Re: [syzbot] Re: 000000000000fcfa6406141cc8ac@google.com
From: syzbot <syzbot+9d95beb2a3c260622518@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: Re: 000000000000fcfa6406141cc8ac@google.com
Author: wojciech.gladysz@infogain.com

#syz test: https://linux.googlesource.com/linux/kernel/git/torvalds/linux e=
377d803b65ee4130213b3c041fc25fdfec1bd90

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 2d29bc0f21cc..75fdb8e3abaa 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2393,12 +2393,21 @@ void __bpf_trace_run(struct bpf_raw_tp_link *link, =
u64 *args)
       cant_sleep();

       // return if instrumentation disabled, see: bpf_disable_instrumentat=
ion
-       if (unlikely(__this_cpu_read(bpf_prog_active))) {
+       int instrumentation =3D unlikely(__this_cpu_read(bpf_prog_active));
+       if (instrumentation) {
+               printk("SKIP FOR INSTRUMENTATION: %s > %s > %p /%i =3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D\n",
+                               prog->aux->name,
+                               link->btp->tp->name, prog, instrumentation)=
;
               bpf_prog_inc_misses_counter(prog);
               return;
       }

-       if (unlikely(this_cpu_inc_return(*(prog->active)) !=3D 1)) {
+       int active =3D this_cpu_inc_return(*(prog->active));
+       // printk("%s > %s > %p /%i\n", prog->aux->name, link->btp->tp->nam=
e, prog, active);
+       if (active !=3D 1) {
+               printk("SKIP FOR ACTIVE: %s > %s > %p /%i =3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D\n",
+                               prog->aux->name,
+                               link->btp->tp->name, prog, active);
               bpf_prog_inc_misses_counter(prog);
               goto out;
       }
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 8d1507dd0724..e756262d8df7 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -298,6 +308,8 @@ static enum tp_func_state nr_func_state(const struct tr=
acepoint_func *tp_funcs)
{
       if (!tp_funcs)
               return TP_FUNC_0;
+       if (!tp_funcs[0].func)
+               return TP_FUNC_0;
       if (!tp_funcs[1].func)
               return TP_FUNC_1;
       if (!tp_funcs[2].func)

--

The information in this email is confidential and may be legally privileged=
. It is intended solely for the addressee and access to it by anyone else i=
s unauthorized. If you are not the intended recipient, any disclosure, copy=
ing, distribution or any action taken or omitted to be taken based on it, i=
s strictly prohibited and may be unlawful.