d20b484c67
If *any* object of a certain WW mutex class is locked, lockdep will consider *all* mutexes of that class as locked. Also the lock allocation tracking code will apparently register only the address of the first mutex of a given class locked in a sequence. This has the odd consequence that if that first mutex is unlocked while other mutexes of the same class remain locked and then its memory then freed, the lock alloc tracking code will incorrectly assume that memory is freed with a held lock in there. For now, work around that for drm_exec by releasing the first grabbed object lock last. v2: - Fix a typo (Danilo Krummrich) - Reword the commit message a bit. - Add a Fixes: tag Related lock alloc tracking warning: [ 322.660067] ========================= [ 322.660070] WARNING: held lock freed! [ 322.660074] 6.5.0-rc7+ #155 Tainted: G U N [ 322.660078] ------------------------- [ 322.660081] kunit_try_catch/4981 is freeing memory ffff888112adc000-ffff888112adc3ff, with a lock still held there! [ 322.660089] ffff888112adc1a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: drm_exec_lock_obj+0x11a/0x600 [drm_exec] [ 322.660104] 2 locks held by kunit_try_catch/4981: [ 322.660108] #0: ffffc9000343fe18 (reservation_ww_class_acquire){+.+.}-{0:0}, at: test_early_put+0x22f/0x490 [drm_exec_test] [ 322.660123] #1: ffff888112adc1a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: drm_exec_lock_obj+0x11a/0x600 [drm_exec] [ 322.660135] stack backtrace: [ 322.660139] CPU: 7 PID: 4981 Comm: kunit_try_catch Tainted: G U N 6.5.0-rc7+ #155 [ 322.660146] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 0403 01/26/2021 [ 322.660152] Call Trace: [ 322.660155] <TASK> [ 322.660158] dump_stack_lvl+0x57/0x90 [ 322.660164] debug_check_no_locks_freed+0x20b/0x2b0 [ 322.660172] slab_free_freelist_hook+0xa1/0x160 [ 322.660179] ? drm_exec_unlock_all+0x168/0x2a0 [drm_exec] [ 322.660186] __kmem_cache_free+0xb2/0x290 [ 322.660192] drm_exec_unlock_all+0x168/0x2a0 [drm_exec] [ 322.660200] drm_exec_fini+0xf/0x1c0 [drm_exec] [ 322.660206] test_early_put+0x289/0x490 [drm_exec_test] [ 322.660215] ? __pfx_test_early_put+0x10/0x10 [drm_exec_test] [ 322.660222] ? __kasan_check_byte+0xf/0x40 [ 322.660227] ? __ksize+0x63/0x140 [ 322.660233] ? drmm_add_final_kfree+0x3e/0xa0 [drm] [ 322.660289] ? _raw_spin_unlock_irqrestore+0x30/0x60 [ 322.660294] ? lockdep_hardirqs_on+0x7d/0x100 [ 322.660301] ? __pfx_kunit_try_run_case+0x10/0x10 [kunit] [ 322.660310] ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10 [kunit] [ 322.660319] kunit_generic_run_threadfn_adapter+0x4a/0x90 [kunit] [ 322.660328] kthread+0x2e7/0x3c0 [ 322.660334] ? __pfx_kthread+0x10/0x10 [ 322.660339] ret_from_fork+0x2d/0x70 [ 322.660345] ? __pfx_kthread+0x10/0x10 [ 322.660349] ret_from_fork_asm+0x1b/0x30 [ 322.660358] </TASK> [ 322.660818] ok 8 test_early_put Cc: Christian König <christian.koenig@amd.com> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Danilo Krummrich <dakr@redhat.com> Cc: dri-devel@lists.freedesktop.org Fixes: 09593216bff1 ("drm: execution context for GEM buffers v7") Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> Reviewed-by: Danilo Krummrich <dakr@redhat.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230906095039.3320-4-thomas.hellstrom@linux.intel.com |
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| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||