All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sasha Levin <sasha.levin@oracle.com>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>
Cc: Dave Jones <davej@codemonkey.org.uk>,
	LKML <linux-kernel@vger.kernel.org>,
	nicolas.pitre@linaro.org
Subject: sched: divide error in sg_capacity_factor
Date: Mon, 09 Mar 2015 13:46:43 -0400	[thread overview]
Message-ID: <54FDDC83.3010202@oracle.com> (raw)

Hi all,

While fuzzing with trinity inside the latest -next kernel using trinity I've stumbled on:

[  936.784266] divide error: 0000 [#1] PREEMPT SMP KASAN
[  936.789198] Dumping ftrace buffer:
[  936.793957]    (ftrace buffer empty)
[  936.793957] Modules linked in:
[  936.793957] CPU: 52 PID: 22110 Comm: trinity-c52 Tainted: G        W       4.0.0-rc1-sasha-00044-ge21109a #2039
[  936.793957] task: ffff8807ff293000 ti: ffff880f81fe8000 task.ti: ffff880f81fe8000
[  936.793957] RIP: find_busiest_group (kernel/sched/fair.c:6152 kernel/sched/fair.c:6223 kernel/sched/fair.c:6341 kernel/sched/fair.c:6603)
[  936.829403] RSP: 0000:ffff8810c28079a8  EFLAGS: 00010206
[  936.829403] RAX: 00000000000003ff RBX: 000000000000004e RCX: 0000000000002000
[  936.829403] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  936.829403] RBP: ffff8810c2807be8 R08: 0000000000000001 R09: 0000000000000001
[  936.829403] R10: 0000000000000001 R11: 0000000000000008 R12: dffffc0000000000
[  936.829403] R13: 0000000000000001 R14: ffff8810c2807b40 R15: ffff8810c2807ce8
[  936.829403] FS:  00007f89c95ff700(0000) GS:ffff8810c2800000(0000) knlGS:0000000000000000
[  936.829403] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  936.829403] CR2: 0000000003503ff8 CR3: 0000000f8237b000 CR4: 00000000000007a0
[  936.829403] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  936.829403] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000050602
[  936.829403] Stack:
[  936.829403]  0000000000000082 ffffffff00000001 ffff8810c28079d8 ffff8810c2817a88
[  936.829403]  0000000000000000 1ffff10218500f4b 00000000c2817a88 ffff8810c2807d14
[  936.829403]  ffff8810c2807b50 ffff8810c2807cfc ffff8810c0740010 0000000307418e2e
[  936.829403] Call Trace:
[  936.829403]  <IRQ>
[  936.829403] ? __enqueue_entity (kernel/sched/fair.c:501)
[  936.829403] ? update_group_capacity (kernel/sched/fair.c:6593)
[  936.829403] ? update_cfs_shares (kernel/sched/fair.c:2375)
[  936.829403] ? cpumask_next_and (lib/cpumask.c:40)
[  936.829403] load_balance (kernel/sched/fair.c:6857)
[  936.829403] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
[  936.829403] ? update_blocked_averages (kernel/sched/fair.c:5743)
[  936.829403] ? find_busiest_group (kernel/sched/fair.c:6820)
[  936.829403] ? run_rebalance_domains (kernel/sched/fair.c:7450 kernel/sched/fair.c:7659)
[  936.829403] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2566)
[  936.829403] run_rebalance_domains (kernel/sched/fair.c:7494 kernel/sched/fair.c:7659)
[  936.829403] ? run_rebalance_domains (kernel/sched/fair.c:7450 kernel/sched/fair.c:7659)
[  936.829403] ? pick_next_task_fair (kernel/sched/fair.c:7654)
[  936.829403] ? irq_exit (kernel/softirq.c:350 kernel/softirq.c:391)
[  936.829403] __do_softirq (kernel/softirq.c:273 include/linux/jump_label.h:114 include/trace/events/irq.h:126 kernel/softirq.c:274)
[  936.829403] irq_exit (kernel/softirq.c:350 kernel/softirq.c:391)
[  936.829403] smp_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:918)
[  936.829403] apic_timer_interrupt (arch/x86/kernel/entry_64.S:958)
[  936.829403]  <EOI>
[  936.829403] ? is_module_address (kernel/module.c:3835)
[  936.829403] ? __kernel_text_address (kernel/extable.c:104)
[  936.829403] print_context_stack (arch/x86/kernel/dumpstack.c:105)
[  936.829403] dump_trace (arch/x86/kernel/dumpstack_64.c:244)
[  936.829403] save_stack_trace (arch/x86/kernel/stacktrace.c:64)
[  936.829403] __set_page_owner (mm/page_owner.c:72)
[  936.829403] ? __reset_page_owner (mm/page_owner.c:61)
[  936.829403] ? __inc_zone_state (mm/vmstat.c:271)
[  936.829403] get_page_from_freelist (include/linux/page_owner.h:26 mm/page_alloc.c:2176)
[  936.829403] __alloc_pages_nodemask (mm/page_alloc.c:2844)
[  936.829403] ? alloc_pages_vma (mm/mempolicy.c:2007)
[  936.829403] ? debug_check_no_locks_freed (kernel/locking/lockdep.c:3051)
[  936.829403] ? debug_check_no_locks_freed (kernel/locking/lockdep.c:3051)
[  936.829403] ? __alloc_pages_direct_compact (mm/page_alloc.c:2797)
[  936.829403] ? debug_check_no_locks_freed (kernel/locking/lockdep.c:3051)
[  936.829403] ? arch_local_irq_restore (init/do_mounts.h:19)
[  936.829403] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2566)
[  936.829403] alloc_pages_vma (mm/mempolicy.c:2007)
[  936.829403] ? handle_mm_fault (mm/memory.c:2156 mm/memory.c:3164 mm/memory.c:3269 mm/memory.c:3298)
[  936.829403] handle_mm_fault (mm/memory.c:2156 mm/memory.c:3164 mm/memory.c:3269 mm/memory.c:3298)
[  936.829403] ? debug_check_no_locks_freed (kernel/locking/lockdep.c:3051)
[  936.829403] ? __pmd_alloc (mm/memory.c:3280)
[  936.829403] ? perf_event_context_sched_in (kernel/events/core.c:2755)
[  936.829403] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2566)
[  936.829403] ? __do_page_fault (arch/x86/mm/fault.c:1173)
[  936.829403] ? ___might_sleep (kernel/sched/core.c:7297 (discriminator 1))
[  936.829403] ? find_vma (mm/mmap.c:2035)
[  936.829403] __do_page_fault (arch/x86/mm/fault.c:1235)
[  936.829403] ? finish_task_switch (kernel/sched/core.c:2214)
[  936.829403] ? finish_task_switch (kernel/sched/sched.h:1058 kernel/sched/core.c:2210)
[  936.829403] trace_do_page_fault (arch/x86/mm/fault.c:1329)
[  936.829403] do_async_page_fault (arch/x86/kernel/kvm.c:280)
[  936.829403] async_page_fault (arch/x86/kernel/entry_64.S:1295)
[ 936.829403] Code: 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e 3a 18 00 00 8b 7e 08 44 89 e8 48 c1 e0 0a 48 8d 44 07 ff 48 89 fe 48 99 <48> f7 ff 31 d2 48 89 c7 44 89 e8 f7 f7 45 89 c5 49 81 c5 00 02
All code
========
   0:	89 f8                	mov    %edi,%eax
   2:	48 c1 e8 03          	shr    $0x3,%rax
   6:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
   b:	84 c0                	test   %al,%al
   d:	74 08                	je     0x17
   f:	3c 03                	cmp    $0x3,%al
  11:	0f 8e 3a 18 00 00    	jle    0x1851
  17:	8b 7e 08             	mov    0x8(%rsi),%edi
  1a:	44 89 e8             	mov    %r13d,%eax
  1d:	48 c1 e0 0a          	shl    $0xa,%rax
  21:	48 8d 44 07 ff       	lea    -0x1(%rdi,%rax,1),%rax
  26:	48 89 fe             	mov    %rdi,%rsi
  29:	48 99                	cqto
  2b:*	48 f7 ff             	idiv   %rdi		<-- trapping instruction
  2e:	31 d2                	xor    %edx,%edx
  30:	48 89 c7             	mov    %rax,%rdi
  33:	44 89 e8             	mov    %r13d,%eax
  36:	f7 f7                	div    %edi
  38:	45 89 c5             	mov    %r8d,%r13d
  3b:	49                   	rex.WB
  3c:	81                   	.byte 0x81
  3d:	c5 00 02             	(bad)
	...

Code starting with the faulting instruction
===========================================
   0:	48 f7 ff             	idiv   %rdi
   3:	31 d2                	xor    %edx,%edx
   5:	48 89 c7             	mov    %rax,%rdi
   8:	44 89 e8             	mov    %r13d,%eax
   b:	f7 f7                	div    %edi
   d:	45 89 c5             	mov    %r8d,%r13d
  10:	49                   	rex.WB
  11:	81                   	.byte 0x81
  12:	c5 00 02             	(bad)
	...
[  936.829403] RIP find_busiest_group (kernel/sched/fair.c:6152 kernel/sched/fair.c:6223 kernel/sched/fair.c:6341 kernel/sched/fair.c:6603)
[  936.829403]  RSP <ffff8810c28079a8>


Thanks,
Sasha

             reply	other threads:[~2015-03-09 17:47 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-09 17:46 Sasha Levin [this message]
2015-03-10  4:29 ` sched: divide error in sg_capacity_factor Ingo Molnar
2015-03-10 10:55   ` Sasha Levin

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=54FDDC83.3010202@oracle.com \
    --to=sasha.levin@oracle.com \
    --cc=davej@codemonkey.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=nicolas.pitre@linaro.org \
    --cc=peterz@infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.