From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>,
LKML <linux-kernel@vger.kernel.org>,
kasan-dev <kasan-dev@googlegroups.com>,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org, Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [RFC PATCH v1] powerpc: Enable KFENCE for PPC32
Date: Tue, 2 Mar 2021 10:27:35 +0100 [thread overview]
Message-ID: <f806de26-daf9-9317-fdaa-a0f7a32d8fe0@csgroup.eu> (raw)
In-Reply-To: <CAG_fn=WFffkVzqC9b6pyNuweFhFswZfa8RRio2nL9-Wq10nBbw@mail.gmail.com>
Le 02/03/2021 à 10:21, Alexander Potapenko a écrit :
>> [ 14.998426] BUG: KFENCE: invalid read in finish_task_switch.isra.0+0x54/0x23c
>> [ 14.998426]
>> [ 15.007061] Invalid read at 0x(ptrval):
>> [ 15.010906] finish_task_switch.isra.0+0x54/0x23c
>> [ 15.015633] kunit_try_run_case+0x5c/0xd0
>> [ 15.019682] kunit_generic_run_threadfn_adapter+0x24/0x30
>> [ 15.025099] kthread+0x15c/0x174
>> [ 15.028359] ret_from_kernel_thread+0x14/0x1c
>> [ 15.032747]
>> [ 15.034251] CPU: 0 PID: 111 Comm: kunit_try_catch Tainted: G B
>> 5.12.0-rc1-s3k-dev-01534-g4f14ae75edf0-dirty #4674
>> [ 15.045811] ==================================================================
>> [ 15.053324] # test_invalid_access: EXPECTATION FAILED at mm/kfence/kfence_test.c:636
>> [ 15.053324] Expected report_matches(&expect) to be true, but is false
>> [ 15.068359] not ok 21 - test_invalid_access
>
> The test expects the function name to be test_invalid_access, i. e.
> the first line should be "BUG: KFENCE: invalid read in
> test_invalid_access".
> The error reporting function unwinds the stack, skips a couple of
> "uninteresting" frames
> (https://elixir.bootlin.com/linux/v5.12-rc1/source/mm/kfence/report.c#L43)
> and uses the first "interesting" one frame to print the report header
> (https://elixir.bootlin.com/linux/v5.12-rc1/source/mm/kfence/report.c#L226).
>
> It's strange that test_invalid_access is missing altogether from the
> stack trace - is that expected?
> Can you try printing the whole stacktrace without skipping any frames
> to see if that function is there?
>
Booting with 'no_hash_pointers" I get the following. Does it helps ?
[ 16.837198] ==================================================================
[ 16.848521] BUG: KFENCE: invalid read in finish_task_switch.isra.0+0x54/0x23c
[ 16.848521]
[ 16.857158] Invalid read at 0xdf98800a:
[ 16.861004] finish_task_switch.isra.0+0x54/0x23c
[ 16.865731] kunit_try_run_case+0x5c/0xd0
[ 16.869780] kunit_generic_run_threadfn_adapter+0x24/0x30
[ 16.875199] kthread+0x15c/0x174
[ 16.878460] ret_from_kernel_thread+0x14/0x1c
[ 16.882847]
[ 16.884351] CPU: 0 PID: 111 Comm: kunit_try_catch Tainted: G B
5.12.0-rc1-s3k-dev-01534-g4f14ae75edf0-dirty #4674
[ 16.895908] NIP: c016eb8c LR: c02f50dc CTR: c016eb38
[ 16.900963] REGS: e2449d90 TRAP: 0301 Tainted: G B
(5.12.0-rc1-s3k-dev-01534-g4f14ae75edf0-dirty)
[ 16.911386] MSR: 00009032 <EE,ME,IR,DR,RI> CR: 22000004 XER: 00000000
[ 16.918153] DAR: df98800a DSISR: 20000000
[ 16.918153] GPR00: c02f50dc e2449e50 c1140d00 e100dd24 c084b13c 00000008 c084b32b c016eb38
[ 16.918153] GPR08: c0850000 df988000 c0d10000 e2449eb0 22000288
[ 16.936695] NIP [c016eb8c] test_invalid_access+0x54/0x108
[ 16.942125] LR [c02f50dc] kunit_try_run_case+0x5c/0xd0
[ 16.947292] Call Trace:
[ 16.949746] [e2449e50] [c005a5ec] finish_task_switch.isra.0+0x54/0x23c (unreliable)
[ 16.957443] [e2449eb0] [c02f50dc] kunit_try_run_case+0x5c/0xd0
[ 16.963319] [e2449ed0] [c02f63ec] kunit_generic_run_threadfn_adapter+0x24/0x30
[ 16.970574] [e2449ef0] [c004e710] kthread+0x15c/0x174
[ 16.975670] [e2449f30] [c001317c] ret_from_kernel_thread+0x14/0x1c
[ 16.981896] Instruction dump:
[ 16.984879] 8129d608 38e7eb38 81020280 911f004c 39000000 995f0024 907f0028 90ff001c
[ 16.992710] 3949000a 915f0020 3d40c0d1 3d00c085 <8929000a> 3908adb0 812a4b98 3d40c02f
[ 17.000711] ==================================================================
[ 17.008223] # test_invalid_access: EXPECTATION FAILED at mm/kfence/kfence_test.c:636
[ 17.008223] Expected report_matches(&expect) to be true, but is false
[ 17.023243] not ok 21 - test_invalid_access
next prev parent reply other threads:[~2021-03-02 9:28 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-02 8:37 [RFC PATCH v1] powerpc: Enable KFENCE for PPC32 Christophe Leroy
2021-03-02 8:58 ` Marco Elver
2021-03-02 9:05 ` Christophe Leroy
2021-03-02 9:21 ` Alexander Potapenko
2021-03-02 9:27 ` Christophe Leroy [this message]
2021-03-02 9:53 ` Marco Elver
2021-03-02 11:21 ` Christophe Leroy
2021-03-02 11:39 ` Marco Elver
2021-03-03 10:38 ` Christophe Leroy
2021-03-03 10:56 ` Marco Elver
2021-03-04 11:23 ` Christophe Leroy
2021-03-04 11:31 ` Marco Elver
2021-03-04 11:48 ` Christophe Leroy
2021-03-04 12:00 ` Christophe Leroy
2021-03-04 12:02 ` Marco Elver
2021-03-04 12:48 ` Marco Elver
2021-03-04 14:08 ` Christophe Leroy
2021-03-04 14:19 ` Marco Elver
2021-03-05 5:01 ` Michael Ellerman
2021-03-05 7:50 ` Marco Elver
2021-03-05 8:23 ` Christophe Leroy
2021-03-05 9:14 ` Marco Elver
2021-03-05 11:49 ` Michael Ellerman
2021-03-05 13:46 ` Marco Elver
2021-03-02 11:40 ` Michael Ellerman
2021-03-02 18:48 ` Segher Boessenkool
2021-03-03 10:28 ` Christophe Leroy
2021-03-03 10:31 ` Christophe Leroy
2021-03-03 10:39 ` Marco Elver
2021-03-03 10:56 ` Christophe Leroy
[not found] ` <CANpmjNMKEObjf=WyfDQB5vPmR5RuyUMBJyfr6P2ykCd67wyMbA__49537.1361424745$1614767987$gmane$org@mail.gmail.com>
2021-03-03 10:46 ` Andreas Schwab
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