next: WARNING: CPU: 0 PID: 1200 at mm/page_alloc.c:4744 __alloc_pages+0x2e8/0x3a0

[Naresh Kamboju]

Following kernel warning has been noticed on qemu-arm64 while running kunit
tests while booting Linux 6.4.0-rc1-next-20230512 and It was started from
6.3.0-rc7-next-20230420.

Reported-by: Linux Kernel Functional Testing <lk...@linaro.org>

This is always reproducible on qemu-arm64, qemu-arm, qemu-x86 and qemu-i386.
Is this expected warning as a part of kunit tests ?

Crash log:
-----------

[ 663.530868] KTAP version 1
[ 663.531545] # Subtest: Handshake API tests
[ 663.533521] 1..11
[ 663.534424] KTAP version 1
[ 663.535406] # Subtest: req_alloc API fuzzing
[ 663.542460] ok 1 handshake_req_alloc NULL proto
[ 663.550345] ok 2 handshake_req_alloc CLASS_NONE
[ 663.558041] ok 3 handshake_req_alloc CLASS_MAX
[ 663.565790] ok 4 handshake_req_alloc no callbacks
[ 663.573882] ok 5 handshake_req_alloc no done callback
[ 663.580284] ------------[ cut here ]------------
[ 663.582129] WARNING: CPU: 0 PID: 1200 at mm/page_alloc.c:4744
__alloc_pages+0x2e8/0x3a0
[ 663.585675] Modules linked in:
[ 663.587808] CPU: 0 PID: 1200 Comm: kunit_try_catch Tainted: G
N 6.4.0-rc1-next-20230512 #1
[ 663.589817] Hardware name: linux,dummy-virt (DT)
[ 663.591426] pstate: 22400005 (nzCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
[ 663.592978] pc : __alloc_pages+0x2e8/0x3a0
[ 663.594236] lr : __kmalloc_large_node+0xbc/0x160
[ 663.595548] sp : ffff80000a317bc0
[ 663.596577] x29: ffff80000a317bc0 x28: 0000000000000000 x27: 0000000000000000
[ 663.598863] x26: ffff0000c8925b20 x25: 0000000000000000 x24: 0000000000000015
[ 663.601098] x23: 0000000000040dc0 x22: ffffbf424e7420c8 x21: ffffbf424e7420c8
[ 663.603100] x20: 1ffff00001462f88 x19: 0000000000040dc0 x18: 0000000078b4155a
[ 663.605582] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
[ 663.607328] x14: 0000000000000000 x13: 6461657268745f68 x12: ffff60001913bc5a
[ 663.609355] x11: 1fffe0001913bc59 x10: ffff60001913bc59 x9 : 1fffe0001913bc59
[ 663.611004] x8 : 0000000041b58ab3 x7 : ffff700001462f88 x6 : dfff800000000000
[ 663.613556] x5 : 00000000f1f1f1f1 x4 : 00000000f2f2f200 x3 : 0000000000000000
[ 663.615364] x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffffbf42516818e2
[ 663.617753] Call trace:
[ 663.618486] __alloc_pages+0x2e8/0x3a0
[ 663.619613] __kmalloc_large_node+0xbc/0x160
[ 663.621454] __kmalloc+0x84/0x94
[ 663.622551] handshake_req_alloc+0x74/0xe8
[ 663.623801] handshake_req_alloc_case+0xa0/0x170
[ 663.625467] kunit_try_run_case+0x7c/0x100
[ 663.626592] kunit_generic_run_threadfn_adapter+0x30/0x4c
[ 663.628998] kthread+0x1d4/0x1e4
[ 663.629715] ret_from_fork+0x10/0x20
[ 663.631094] ---[ end trace 0000000000000000 ]---
[ 663.643101] ok 6 handshake_req_alloc excessive privsize
[ 663.649446] ok 7 handshake_req_alloc all good
[ 663.651032] # req_alloc API fuzzing: pass:7 fail:0 skip:0 total:7
[ 663.653941] ok 1 req_alloc API fuzzing
[ 663.665951] ok 2 req_submit NULL req arg
[ 663.674278] ok 3 req_submit NULL sock arg
[ 663.682968] ok 4 req_submit NULL sock->file
[ 663.694323] ok 5 req_lookup works
[ 663.703604] ok 6 req_submit max pending
[ 663.714655] ok 7 req_submit multiple
[ 663.725174] ok 8 req_cancel before accept
[ 663.733780] ok 9 req_cancel after accept
[ 663.742528] ok 10 req_cancel after done
[ 663.750637] ok 11 req_destroy works
[ 663.751884] # Handshake API tests: pass:11 fail:0 skip:0 total:11
[ 663.753579] # Totals: pass:17 fail:0 skip:0 total:17

links:
------

- https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20230512/testrun/16901289/suite/log-parser-boot/test/check-kernel-exception/log
- https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20230512/testrun/16901289/suite/log-parser-boot/tests/
- https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20230420/testrun/16385677/suite/log-parser-boot/test/check-kernel-warning-ac79d2ca0f443d407d9749244f1738c9a2b123c609820f82d9e8907c756f5340/log
- https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20230512/testrun/16901289/suite/log-parser-boot/test/check-kernel-warning-ac79d2ca0f443d407d9749244f1738c9a2b123c609820f82d9e8907c756f5340/history/


--
Linaro LKFT
https://lkft.linaro.org

[Dan Carpenter]

I'm pretty sure Chuck Lever did this intentionally, but he's not on the
CC list. Let's add him.

regards,
dan carpenter

[Chuck Lever III]

> On May 12, 2023, at 6:32 AM, Dan Carpenter <dan.ca...@linaro.org> wrote:
>
> I'm pretty sure Chuck Lever did this intentionally, but he's not on the
> CC list. Let's add him.
>
> regards,
> dan carpenter
>
> On Fri, May 12, 2023 at 06:15:04PM +0530, Naresh Kamboju wrote:
>> Following kernel warning has been noticed on qemu-arm64 while running kunit
>> tests while booting Linux 6.4.0-rc1-next-20230512 and It was started from
>> 6.3.0-rc7-next-20230420.
>>
>> Reported-by: Linux Kernel Functional Testing <lk...@linaro.org>
>>
>> This is always reproducible on qemu-arm64, qemu-arm, qemu-x86 and qemu-i386.
>> Is this expected warning as a part of kunit tests ?

Dan's correct, this Kunit test is supposed to check the
behavior of the API when a too-large privsize is specified.

I'm not sure how to make this work without the superfluous
warning. Would adding GFP_NOWARN to the allocation help?

--
Chuck Lever

[Mike Rapoport]

On Fri, May 12, 2023 at 01:56:30PM +0000, Chuck Lever III wrote:
>
>
> > On May 12, 2023, at 6:32 AM, Dan Carpenter <dan.ca...@linaro.org> wrote:
> >
> > I'm pretty sure Chuck Lever did this intentionally, but he's not on the
> > CC list. Let's add him.
> >
> > regards,
> > dan carpenter
> >
> > On Fri, May 12, 2023 at 06:15:04PM +0530, Naresh Kamboju wrote:
> >> Following kernel warning has been noticed on qemu-arm64 while running kunit
> >> tests while booting Linux 6.4.0-rc1-next-20230512 and It was started from
> >> 6.3.0-rc7-next-20230420.
> >>
> >> Reported-by: Linux Kernel Functional Testing <lk...@linaro.org>
> >>
> >> This is always reproducible on qemu-arm64, qemu-arm, qemu-x86 and qemu-i386.
> >> Is this expected warning as a part of kunit tests ?
>
> Dan's correct, this Kunit test is supposed to check the
> behavior of the API when a too-large privsize is specified.
>
> I'm not sure how to make this work without the superfluous
> warning. Would adding GFP_NOWARN to the allocation help?

Yes, it should.

--
Sincerely yours,
Mike.

[Dan Carpenter]

On Fri, May 12, 2023 at 01:56:30PM +0000, Chuck Lever III wrote:
>
>

> > On May 12, 2023, at 6:32 AM, Dan Carpenter <dan.ca...@linaro.org> wrote:
> >
> > I'm pretty sure Chuck Lever did this intentionally, but he's not on the
> > CC list. Let's add him.
> >
> > regards,
> > dan carpenter
> >
> > On Fri, May 12, 2023 at 06:15:04PM +0530, Naresh Kamboju wrote:
> >> Following kernel warning has been noticed on qemu-arm64 while running kunit
> >> tests while booting Linux 6.4.0-rc1-next-20230512 and It was started from
> >> 6.3.0-rc7-next-20230420.
> >>
> >> Reported-by: Linux Kernel Functional Testing <lk...@linaro.org>
> >>
> >> This is always reproducible on qemu-arm64, qemu-arm, qemu-x86 and qemu-i386.
> >> Is this expected warning as a part of kunit tests ?
>
> Dan's correct, this Kunit test is supposed to check the
> behavior of the API when a too-large privsize is specified.
>
> I'm not sure how to make this work without the superfluous
> warning. Would adding GFP_NOWARN to the allocation help?

That would silence the splat, yes.

regards,
dan carpenter

[Geert Uytterhoeven]

But introduce a build failure, as GFP_NOWARN does not exist.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

[Chuck Lever III]

> On Jun 25, 2023, at 4:46 AM, Geert Uytterhoeven <ge...@linux-m68k.org> wrote:
>
> On Sat, May 13, 2023 at 10:54 AM Dan Carpenter <dan.ca...@linaro.org> wrote:
>> On Fri, May 12, 2023 at 01:56:30PM +0000, Chuck Lever III wrote:
>>>> On May 12, 2023, at 6:32 AM, Dan Carpenter <dan.ca...@linaro.org> wrote:
>>>> I'm pretty sure Chuck Lever did this intentionally, but he's not on the
>>>> CC list. Let's add him.
>>>>
>>>> regards,
>>>> dan carpenter
>>>>
>>>> On Fri, May 12, 2023 at 06:15:04PM +0530, Naresh Kamboju wrote:
>>>>> Following kernel warning has been noticed on qemu-arm64 while running kunit
>>>>> tests while booting Linux 6.4.0-rc1-next-20230512 and It was started from
>>>>> 6.3.0-rc7-next-20230420.
>>>>>
>>>>> Reported-by: Linux Kernel Functional Testing <lk...@linaro.org>
>>>>>
>>>>> This is always reproducible on qemu-arm64, qemu-arm, qemu-x86 and qemu-i386.
>>>>> Is this expected warning as a part of kunit tests ?
>>>
>>> Dan's correct, this Kunit test is supposed to check the
>>> behavior of the API when a too-large privsize is specified.
>>>
>>> I'm not sure how to make this work without the superfluous
>>> warning. Would adding GFP_NOWARN to the allocation help?
>>
>> That would silence the splat, yes.
>
> But introduce a build failure, as GFP_NOWARN does not exist.

This is the fix that went in:

commit b21c7ba6d9a5532add3827a3b49f49cbc0cb9779
Author: Chuck Lever <chuck...@oracle.com>
AuthorDate: Fri May 19 13:12:50 2023 -0400
Commit: Jakub Kicinski <ku...@kernel.org>
CommitDate: Mon May 22 19:24:52 2023 -0700

net/handshake: Squelch allocation warning during Kunit test

The "handshake_req_alloc excessive privsize" kunit test is intended
to check what happens when the maximum privsize is exceeded. The
WARN_ON_ONCE_GFP at mm/page_alloc.c:4744 can be disabled safely for
this test.

Reported-by: Linux Kernel Functional Testing <lk...@linaro.org>

Fixes: 88232ec1ec5e ("net/handshake: Add Kunit tests for the handshake consumer API")
Signed-off-by: Chuck Lever <chuck...@oracle.com>
Link: https://lore.kernel.org/r/168451636052.47152.960...@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <ku...@kernel.org>

diff --git a/net/handshake/handshake-test.c b/net/handshake/handshake-test.c
index e6adc5dec11a..6193e46ee6d9 100644
--- a/net/handshake/handshake-test.c
+++ b/net/handshake/handshake-test.c
@@ -102,7 +102,7 @@ struct handshake_req_alloc_test_param handshake_req_alloc_params[] = {
{
.desc = "handshake_req_alloc excessive privsize",
.proto = &handshake_req_alloc_proto_6,
- .gfp = GFP_KERNEL,
+ .gfp = GFP_KERNEL | __GFP_NOWARN,
.expect_success = false,
},
{

Is there a platform where __GPF_NOWARN is not defined?


--
Chuck Lever

[Geert Uytterhoeven]

Hi Chuck,

"git grep" says all of them, as you misspelled it in your question ;-)

"__GFP_NOWARN" is defined in include/linux/gfp_types.h,
so it should be available everywhere.

Note the use of "__GFP_NOWARN" instead of "GFP_NOWARN".
Once in a while, people do submit patches using "GFP_NOWARN"...