Re: [lkp-robot] [x86/mm/kasan] d17a1d97dc: WARNING:at_lib/stackdepot.c:#depot_save_stack

From: Dmitry Vyukov
Date: Mon Nov 27 2017 - 09:38:31 EST

On Mon, Nov 27, 2017 at 3:27 PM, Andrey Ryabinin
<aryabinin@xxxxxxxxxxxxx> wrote:
> On 11/26/2017 10:58 AM, kernel test robot wrote:
>>
>> FYI, we noticed the following commit (built with gcc-7):
>>
>> commit: d17a1d97dc208d664c91cc387ffb752c7f85dc61 ("x86/mm/kasan: don't use vmemmap_populate() to initialize shadow")
>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
>>
>
> That commit isn't related to the bug. Bisection pointed to this commit only because .config has a
> SPARSEMEM_VMEMMAP=n and KASAN=y. That combination wasn't possible before d17a1d97dc208.
>
> I think, the real problem is that stackdepot doesn't work very well with CONFIG_UNWINDER_GUESS=y.
> The 'guess' unwinder seems generate awfully large and inaccurate stacktraces, so stackdepot
> can't deduplicate stacktraces well and reaches the capacity limit very fast.
>
> Maybe we should just forbid setting CONFIG_UNWINDER_GUESS if we have CONFIG_STACKDEPOT=y ?

Sounds good to me.


>> [ 177.837316] WARNING: CPU: 0 PID: 545 at lib/stackdepot.c:119 depot_save_stack+0x28e/0x550
>> [ 177.837987] CPU: 0 PID: 545 Comm: trinity-main Not tainted 4.14.0-04319-gd17a1d9 #30
>> [ 177.838518] task: ffff88000cd80000 task.stack: ffff88000b4f8000
>> [ 177.838933] RIP: 0010:depot_save_stack+0x28e/0x550
>> [ 177.839268] RSP: 0018:ffff88000b4fec18 EFLAGS: 00010086
>> [ 177.839632] RAX: 0000000000000022 RBX: 000000006bdd725e RCX: ffffffffa014cf41
>> [ 177.840127] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000000
>> [ 177.840619] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
>> [ 177.841117] R10: 0000000032ae8775 R11: 6f706564206b6361 R12: 0000000000000040
>> [ 177.841609] R13: 0000000000000040 R14: 00000000000d725e R15: 0000000000000220
>> [ 177.842104] FS: 000000000104a880(0000) GS:ffffffffa2ca4000(0000) knlGS:0000000000000000
>> [ 177.842663] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 177.843061] CR2: 00007f3301646000 CR3: 000000000b1c2000 CR4: 00000000000006b0
>> [ 177.843553] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> [ 177.844046] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> [ 177.844535] Call Trace:
>> [ 177.844721] ? kasan_kmalloc+0x144/0x160
>> [ 177.844999] ? depot_save_stack+0x1f5/0x550
>> [ 177.845295] ? do_raw_spin_unlock+0xda/0xf0
>> [ 177.845590] ? preempt_count_sub+0x13/0xc0
>> [ 177.845887] ? _raw_spin_unlock_irqrestore+0x52/0x70
>> [ 177.846236] ? depot_save_stack+0x3b8/0x550
>> [ 177.846533] ? kasan_kmalloc+0x144/0x160
>> [ 177.846816] ? do_raw_spin_unlock+0xda/0xf0
>> [ 177.847113] ? preempt_count_sub+0x13/0xc0
>> [ 177.847404] ? _raw_spin_unlock+0x29/0x40
>> [ 177.847693] ? get_partial_node+0x2ca/0x300
>> [ 177.848031] ? preempt_count_sub+0x13/0xc0
>> [ 177.848321] ? __might_sleep+0x2e/0xd0
>> [ 177.848591] ? perf_output_begin_backward+0x840/0x840
>> [ 177.848952] ? __vm_enough_memory+0x333/0x390
>> [ 177.849260] ? preempt_count_sub+0x13/0xc0
>> [ 177.849551] ? in_sched_functions+0x30/0x30
>> [ 177.849851] ? preempt_count_sub+0x13/0xc0
>> [ 177.850142] ? __vm_enough_memory+0x333/0x390
>> [ 177.850453] ? debug_lockdep_rcu_enabled+0x27/0x60
>> [ 177.850794] ? in_sched_functions+0x30/0x30
>> [ 177.851090] ? debug_lockdep_rcu_enabled+0x27/0x60
>> [ 177.851425] ? in_sched_functions+0x30/0x30
>> [ 177.851724] ? fs_reclaim_acquire+0xd/0x30
>> [ 177.852013] ? debug_lockdep_rcu_enabled+0x27/0x60
>> [ 177.852348] ? in_sched_functions+0x30/0x30
>> [ 177.852642] ? fs_reclaim_acquire+0xd/0x30
>> [ 177.852936] ? ___slab_alloc+0x2f9/0x330
>> [ 177.853334] ? debug_lockdep_rcu_enabled+0x27/0x60
>> [ 177.853673] ? ___slab_alloc+0x2f9/0x330
>> [ 177.854070] ? preempt_count_add+0xa6/0xc0
>> [ 177.854358] ? preempt_count_sub+0x13/0xc0
>> [ 177.854647] ? __vm_enough_memory+0x333/0x390
>> [ 177.854956] ? vm_memory_committed+0x10/0x10
>> [ 177.855257] ? __cleanup_sighand+0x30/0x30
>> [ 177.855545] ? rb_erase_cached+0x43a/0x1230
>> [ 177.855845] ? debug_show_all_locks+0x2c0/0x2c0
>> [ 177.856176] ? rb_next+0x80/0x80
>> [ 177.856409] ? __need_fs_reclaim+0x2d/0x80
>> [ 177.856704] ? kmem_cache_alloc+0xd4/0xf0
>> [ 177.856991] ? anon_vma_clone+0x6e/0x280
>> [ 177.857271] ? anon_vma_fork+0xb9/0x2f0
>> [ 177.857545] ? rcu_segcblist_enqueue+0xe7/0x130
>> [ 177.857868] ? rcu_segcblist_first_pend_cb+0x40/0x40
>> [ 177.858217] ? anon_vma_clone+0x280/0x280
>> [ 177.858503] ? __rcu_read_lock+0x20/0x20
>> [ 177.858787] ? trace_hardirqs_on_caller+0x11/0x260
>> [ 177.859125] ? lock_downgrade+0x300/0x300
>> [ 177.859409] ? lock_acquire+0x99/0xd0
>> [ 177.859674] ? perf_event_task_disable+0xe0/0xe0
>> [ 177.860000] ? copy_process+0x209c/0x3b60
>> [ 177.860285] ? __cleanup_sighand+0x30/0x30
>> [ 177.860576] ? perf_output_begin_backward+0x840/0x840
>> [ 177.860932] ? rb_erase_cached+0x43a/0x1230
>> [ 177.861228] ? debug_show_all_locks+0x2c0/0x2c0
>> [ 177.861545] ? rb_next+0x80/0x80
>> [ 177.861780] ? lock_downgrade+0x300/0x300
>> [ 177.862066] ? debug_object_active_state+0xdb/0x280
>> [ 177.862409] ? do_raw_spin_unlock+0xda/0xf0
>> [ 177.862708] ? preempt_count_sub+0x13/0xc0
>> [ 177.862998] ? _raw_spin_unlock_irqrestore+0x52/0x70
>> [ 177.863345] ? debug_object_active_state+0x23a/0x280
>> [ 177.863695] ? debug_object_assert_init+0x290/0x290
>> [ 177.864037] ? path_check_mount+0x130/0x130
>> [ 177.864332] ? rcu_segcblist_enqueue+0xe7/0x130
>> [ 177.864651] ? kmem_cache_alloc+0xd4/0xf0
>> [ 177.864940] ? anon_vma_clone+0x6e/0x280
>> [ 177.865217] ? anon_vma_fork+0xb9/0x2f0
>> [ 177.865489] ? rcu_segcblist_enqueue+0xe7/0x130
>> [ 177.865812] ? rcu_segcblist_first_pend_cb+0x40/0x40
>> [ 177.866159] ? anon_vma_clone+0x280/0x280
>> [ 177.866442] ? __rcu_read_lock+0x20/0x20
>> [ 177.866725] ? trace_hardirqs_on_caller+0x11/0x260
>> [ 177.867060] ? lock_downgrade+0x300/0x300
>> [ 177.867343] ? lock_acquire+0x99/0xd0
>> [ 177.867602] ? perf_event_task_disable+0xe0/0xe0
>> [ 177.867932] ? copy_process+0x209c/0x3b60
>> [ 177.868218] ? __cleanup_sighand+0x30/0x30
>> [ 177.868509] ? perf_output_begin_backward+0x840/0x840
>> [ 177.868868] ? rb_erase_cached+0x43a/0x1230
>> [ 177.869165] ? debug_show_all_locks+0x2c0/0x2c0
>> [ 177.869484] ? rb_next+0x80/0x80
>> [ 177.869720] ? lock_downgrade+0x300/0x300
>> [ 177.870003] ? debug_object_active_state+0xdb/0x280
>> [ 177.870350] ? do_raw_spin_unlock+0xda/0xf0
>>
>>
>> To reproduce:
>>
>> git clone https://github.com/intel/lkp-tests.git
>> cd lkp-tests
>> bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email
>>
>>
>>
>> Thanks,
>> Xiaolong
>>