From: "José Pekkarinen" <jose.pekkarinen@foxhound.fi>
To: Maxime Ripard <mripard@kernel.org>
Cc: airlied@gmail.com, daniel@ffwll.ch, christian.koenig@amd.com,
dakr@redhat.com, boris.brezillon@collabora.com,
alexander.deucher@amd.com, arthurgrillo@riseup.net,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [PATCH] drm/tests: provide exit function
Date: Thu, 14 Sep 2023 17:24:42 +0300 [thread overview]
Message-ID: <def731d19e2fc0f0a9225d7a10c1dd00@foxhound.fi> (raw)
In-Reply-To: <q37ckz3xj6zhuxrrwymw5oda4su7phw5gsgdtlevunhu645wzv@x4pzm6vm7yqt>
On 2023-09-14 15:00, Maxime Ripard wrote:
> On Wed, Sep 13, 2023 at 07:35:57PM +0300, José Pekkarinen wrote:
>> On 2023-09-13 17:41, mripard@kernel.org wrote:
>> > On Wed, Sep 13, 2023 at 05:01:40PM +0300, José Pekkarinen wrote:
>> > > On 2023-09-13 12:50, Maxime Ripard wrote:
>> > > > Hi,
>> > > >
>> > > > On Wed, Sep 13, 2023 at 11:32:23AM +0300, José Pekkarinen wrote:
>> > > > > Running drm_exec_test by modprobing the module I
>> > > > > observe the following output:
>> > > > >
>> > > > > [ 424.471936] KTAP version 1
>> > > > > [ 424.471942] 1..1
>> > > > > [ 424.472446] KTAP version 1
>> > > > > [ 424.472450] # Subtest: drm_exec
>> > > > > [ 424.472453] # module: drm_exec_test
>> > > > > [ 424.472459] 1..7
>> > > > > [ 424.479082]
>> > > > > ==================================================================
>> > > > > [ 424.479095] BUG: KASAN: slab-use-after-free in
>> > > > > drm_dev_put.part.0+0x4b/0x90 [drm]
>> > > > > [ 424.479426] Read of size 8 at addr ffff888132d3e028 by task
>> > > > > kunit_try_catch/1866
>> > > > > [ 424.479436]
>> > > > > [ 424.479442] CPU: 1 PID: 1866 Comm: kunit_try_catch Tainted: G
>> > > > > N 6.6.0-rc1-dirty #2
>> > > >
>> > > > That's suspicious
>> > > >
>> > > > > [ 424.479446] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
>> > > > > BIOS 0.0.0 02/06/2015
>> > > > > [ 424.479446] Call Trace:
>> > > > > [ 424.479446] <TASK>
>> > > > > [ 424.479446] dump_stack_lvl+0x43/0x60
>> > > > > [ 424.479446] print_report+0xcf/0x660
>> > > > > [ 424.479446] ? __virt_addr_valid+0xd9/0x160
>> > > > > [ 424.479446] ? drm_dev_put.part.0+0x4b/0x90 [drm]
>> > > > > [ 424.479446] kasan_report+0xda/0x110
>> > > > > [ 424.479446] ? drm_dev_put.part.0+0x4b/0x90 [drm]
>> > > > > [ 424.479446] drm_dev_put.part.0+0x4b/0x90 [drm]
>> > > > > [ 424.479446] release_nodes+0x83/0x160
>> > > > > [ 424.479446] devres_release_all+0xe6/0x130
>> > > > > [ 424.479446] ? __pfx_devres_release_all+0x10/0x10
>> > > > > [ 424.479446] ? mutex_unlock+0x80/0xd0
>> > > > > [ 424.479446] ? __pfx_mutex_unlock+0x10/0x10
>> > > > > [ 424.479446] device_unbind_cleanup+0x16/0xc0
>> > > > > [ 424.479446] device_release_driver_internal+0x28b/0x2e0
>> > > > > [ 424.479446] bus_remove_device+0x124/0x1d0
>> > > > > [ 424.479446] device_del+0x23d/0x580
>> > > > > [ 424.479446] ? __pfx_device_del+0x10/0x10
>> > > > > [ 424.479446] ? kasan_set_track+0x21/0x30
>> > > > > [ 424.479446] ? _raw_spin_lock_irqsave+0x98/0xf0
>> > > > > [ 424.479446] platform_device_del.part.0+0x19/0xe0
>> > > > > [ 424.479446] kunit_remove_resource+0xfa/0x140 [kunit]
>> > > > > [ 424.479446] kunit_cleanup+0x47/0xa0 [kunit]
>> > > > > [ 424.479446] ? __pfx_kunit_try_run_case_cleanup+0x10/0x10 [kunit]
>> > > > > [ 424.479446] ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
>> > > > > [kunit]
>> > > > > [ 424.479446] kunit_generic_run_threadfn_adapter+0x29/0x50 [kunit]
>> > > > > [ 424.479446] kthread+0x184/0x1c0
>> > > > > [ 424.479446] ? __pfx_kthread+0x10/0x10
>> > > > > [ 424.479446] ret_from_fork+0x30/0x50
>> > > > > [ 424.479446] ? __pfx_kthread+0x10/0x10
>> > > > > [ 424.479446] ret_from_fork_asm+0x1b/0x30
>> > > > > [ 424.479446] </TASK>
>> > > > > [ 424.479446]
>> > > > > [ 424.479446] Allocated by task 1865:
>> > > > > [ 424.479446] kasan_save_stack+0x2f/0x50
>> > > > > [ 424.479446] kasan_set_track+0x21/0x30
>> > > > > [ 424.479446] __kasan_kmalloc+0xa6/0xb0
>> > > > > [ 424.479446] __kmalloc+0x5d/0x160
>> > > > > [ 424.479446] kunit_kmalloc_array+0x1c/0x50 [kunit]
>> > > > > [ 424.479446] drm_exec_test_init+0xef/0x260 [drm_exec_test]
>> > > > > [ 424.479446] kunit_try_run_case+0x6e/0x100 [kunit]
>> > > > > [ 424.479446] kunit_generic_run_threadfn_adapter+0x29/0x50 [kunit]
>> > > > > [ 424.479446] kthread+0x184/0x1c0
>> > > > > [ 424.479446] ret_from_fork+0x30/0x50
>> > > > > [ 424.479446] ret_from_fork_asm+0x1b/0x30
>> > > > > [ 424.479446]
>> > > > > [ 424.479446] Freed by task 1866:
>> > > > > [ 424.479446] kasan_save_stack+0x2f/0x50
>> > > > > [ 424.479446] kasan_set_track+0x21/0x30
>> > > > > [ 424.479446] kasan_save_free_info+0x27/0x40
>> > > > > [ 424.479446] ____kasan_slab_free+0x166/0x1c0
>> > > > > [ 424.479446] slab_free_freelist_hook+0x9f/0x1e0
>> > > > > [ 424.479446] __kmem_cache_free+0x187/0x2d0
>> > > > > [ 424.479446] kunit_remove_resource+0xfa/0x140 [kunit]
>> > > > > [ 424.479446] kunit_cleanup+0x47/0xa0 [kunit]
>> > > > > [ 424.479446] kunit_generic_run_threadfn_adapter+0x29/0x50 [kunit]
>> > > > > [ 424.479446] kthread+0x184/0x1c0
>> > > > > [ 424.479446] ret_from_fork+0x30/0x50
>> > > > > [ 424.479446] ret_from_fork_asm+0x1b/0x30
>> > > > > [ 424.479446]
>> > > > > [ 424.479446] The buggy address belongs to the object at
>> > > > > ffff888132d3e000
>> > > > > [ 424.479446] which belongs to the cache kmalloc-256 of size 256
>> > > > > [ 424.479446] The buggy address is located 40 bytes inside of
>> > > > > [ 424.479446] freed 256-byte region [ffff888132d3e000,
>> > > > > ffff888132d3e100)
>> > > > > [ 424.479446]
>> > > > > [ 424.479446] The buggy address belongs to the physical page:
>> > > > > [ 424.479446] page:0000000092ff6551 refcount:1 mapcount:0
>> > > > > mapping:0000000000000000 index:0xffff888132d3f600 pfn:0x132d3c
>> > > > > [ 424.479446] head:0000000092ff6551 order:2 entire_mapcount:0
>> > > > > nr_pages_mapped:0 pincount:0
>> > > > > [ 424.479446] ksm flags:
>> > > > > 0x17ffffc0000840(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
>> > > > > [ 424.479446] page_type: 0xffffffff()
>> > > > > [ 424.479446] raw: 0017ffffc0000840 ffff888100042b40
>> > > > > ffffea00042c8000 dead000000000003
>> > > > > [ 424.479446] raw: ffff888132d3f600 000000008020001f
>> > > > > 00000001ffffffff 0000000000000000
>> > > > > [ 424.479446] page dumped because: kasan: bad access detected
>> > > > > [ 424.479446]
>> > > > > [ 424.479446] Memory state around the buggy address:
>> > > > > [ 424.479446] ffff888132d3df00: fc fc fc fc fc fc fc fc fc fc fc
>> > > > > fc fc fc fc fc
>> > > > > [ 424.479446] ffff888132d3df80: fc fc fc fc fc fc fc fc fc fc fc
>> > > > > fc fc fc fc fc
>> > > > > [ 424.479446] >ffff888132d3e000: fa fb fb fb fb fb fb fb fb fb fb
>> > > > > fb fb fb fb fb
>> > > > > [ 424.479446] ^
>> > > > > [ 424.479446] ffff888132d3e080: fb fb fb fb fb fb fb fb fb fb fb
>> > > > > fb fb fb fb fb
>> > > > > [ 424.479446] ffff888132d3e100: fc fc fc fc fc fc fc fc fc fc fc
>> > > > > fc fc fc fc fc
>> > > > > [ 424.479446]
>> > > > > ==================================================================
>> > > > > [ 424.481686] Disabling lock debugging due to kernel taint
>> > > > > [ 424.484124] not ok 1 sanitycheck
>> > > > > [ 424.492981] ok 2 test_lock
>> > > > > [ 424.503610] ok 3 test_lock_unlock
>> > > > > [ 424.515058] ok 4 test_duplicates
>> > > > > [ 424.530453] ok 5 test_prepare
>> > > > > [ 424.539099] ok 6 test_prepare_array
>> > > > > [ 424.550730] ok 7 test_multiple_loops
>> > > > > [ 424.550743] # drm_exec: pass:6 fail:1 skip:0 total:7
>> > > > > [ 424.550750] # Totals: pass:6 fail:1 skip:0 total:7
>> > > > > [ 424.550756] not ok 5 drm_exec
>> > > > >
>> > > > > The ouptut suggest the init function is allocating a drm_device
>> > > > > that is not being freed. This patch provides the function and
>> > > > > add it to the kunit_suite to produce the following result of
>> > > > > the test:
>> > > > >
>> > > > > [ 3363.342560] KTAP version 1
>> > > > > [ 3363.342571] 1..1
>> > > > > [ 3363.343090] KTAP version 1
>> > > > > [ 3363.343095] # Subtest: drm_exec
>> > > > > [ 3363.343098] # module: drm_exec_test
>> > > > > [ 3363.343103] 1..7
>> > > > > [ 3363.353659] ok 1 sanitycheck
>> > > > > [ 3363.364281] ok 2 test_lock
>> > > > > [ 3363.375616] ok 3 test_lock_unlock
>> > > > > [ 3363.388741] ok 4 test_duplicates
>> > > > > [ 3363.402544] ok 5 test_prepare
>> > > > > [ 3363.413163] ok 6 test_prepare_array
>> > > > > [ 3363.424614] ok 7 test_multiple_loops
>> > > > > [ 3363.424630] # drm_exec: pass:7 fail:0 skip:0 total:7
>> > > > > [ 3363.424637] # Totals: pass:7 fail:0 skip:0 total:7
>> > > > > [ 3363.424643] ok 1 drm_exec
>> > > > >
>> > > > > Signed-off-by: José Pekkarinen <jose.pekkarinen@foxhound.fi>
>> > > > > ---
>> > > > > drivers/gpu/drm/tests/drm_exec_test.c | 14 ++++++++++++++
>> > > > > 1 file changed, 14 insertions(+)
>> > > > >
>> > > > > diff --git a/drivers/gpu/drm/tests/drm_exec_test.c
>> > > > > b/drivers/gpu/drm/tests/drm_exec_test.c
>> > > > > index 563949d777dd..7ff6bc6467d4 100644
>> > > > > --- a/drivers/gpu/drm/tests/drm_exec_test.c
>> > > > > +++ b/drivers/gpu/drm/tests/drm_exec_test.c
>> > > > > @@ -42,6 +42,19 @@ static int drm_exec_test_init(struct kunit *test)
>> > > > > return 0;
>> > > > > }
>> > > > >
>> > > > > +static void drm_exec_test_exit(struct kunit *test)
>> > > > > +{
>> > > > > + struct drm_exec_priv *priv = test->priv;
>> > > > > +
>> > > > > + drm_kunit_helper_free_device(test, priv->dev);
>> > > > > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev);
>> > > >
>> > > > This shouldn't be necessary at all since 4f2b0b583baa.
>> > >
>> > >
>> > > Reading this suggested patch I see only references to
>> > > platform_driver_unregister, platform_device_put, and
>> > > platform_device_del, not the ones used in this patch.
>> >
>> > I mean, what is drm_kunit_helper_free_device calling?
>>
>> That seems to be triggering any registered release
>> action immediately, so it calls platform_device_del,
>> followed by platform_device_put, followed by
>> platform_driver_unregister.
>
>
> Please test with:
> https://lore.kernel.org/all/20230907135339.7971-2-thomas.hellstrom@linux.intel.com/
>
> Maxime
Hi,
Yes, I was looking into that road, but Thomas
was faster, here is the output of my tests after
applying Thomas patch:
[ 874.063255] KTAP version 1
[ 874.063262] 1..1
[ 874.064550] KTAP version 1
[ 874.064555] # Subtest: drm_modes_analog_tv
[ 874.064559] # module: drm_modes_test
[ 874.064565] 1..4
[ 874.076778] ok 1 drm_test_modes_analog_tv_ntsc_480i
[ 874.091584] ok 2 drm_test_modes_analog_tv_ntsc_480i_inlined
[ 874.104682] ok 3 drm_test_modes_analog_tv_pal_576i
[ 874.116266] ok 4 drm_test_modes_analog_tv_pal_576i_inlined
[ 874.116285] # drm_modes_analog_tv: pass:4 fail:0 skip:0 total:4
[ 874.116297] # Totals: pass:4 fail:0 skip:0 total:4
[ 874.116305] ok 1 drm_modes_analog_tv
[ 888.785690] KTAP version 1
[ 888.785697] 1..1
[ 888.786186] KTAP version 1
[ 888.786192] # Subtest: drm_exec
[ 888.786196] # module: drm_exec_test
[ 888.786202] 1..7
[ 888.796416] ok 1 sanitycheck
[ 888.807215] ok 2 test_lock
[ 888.820305] ok 3 test_lock_unlock
[ 888.829242] ok 4 test_duplicates
[ 888.840362] ok 5 test_prepare
[ 888.851022] ok 6 test_prepare_array
[ 888.865011] ok 7 test_multiple_loops
[ 888.865034] # drm_exec: pass:7 fail:0 skip:0 total:7
[ 888.865044] # Totals: pass:7 fail:0 skip:0 total:7
[ 888.865053] ok 2 drm_exec
Tested-by: José Pekkarinen<jose.pekkarinen@foxhound.fi>
Thanks!
José.
next prev parent reply other threads:[~2023-09-14 14:40 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-13 8:32 José Pekkarinen
2023-09-13 9:50 ` Maxime Ripard
2023-09-13 14:01 ` José Pekkarinen
2023-09-13 14:41 ` mripard
2023-09-13 16:35 ` José Pekkarinen
2023-09-14 12:00 ` Maxime Ripard
2023-09-14 14:24 ` José Pekkarinen [this message]
2023-09-13 12:19 José Pekkarinen
2023-09-13 14:44 ` Maxime Ripard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=def731d19e2fc0f0a9225d7a10c1dd00@foxhound.fi \
--to=jose.pekkarinen@foxhound.fi \
--cc=airlied@gmail.com \
--cc=alexander.deucher@amd.com \
--cc=arthurgrillo@riseup.net \
--cc=boris.brezillon@collabora.com \
--cc=christian.koenig@amd.com \
--cc=dakr@redhat.com \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-kernel-mentees@lists.linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mripard@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®