Messages in this thread | | | Date | Thu, 14 Sep 2023 17:24:42 +0300 | From | José Pekkarinen <> | Subject | Re: [PATCH] drm/tests: provide exit function |
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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.
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