Messages in this thread | | | Date | Fri, 13 Apr 2018 10:24:01 -0700 | Subject | INFO: rcu detected stall in vfs_rmdir | From | syzbot <> |
| |
Hello,
syzbot hit the following crash on upstream commit 16e205cf42da1f497b10a4a24f563e6c0d574eec (Fri Apr 13 03:56:10 2018 +0000) Merge tag 'drm-fixes-for-v4.17-rc1' of git://people.freedesktop.org/~airlied/linux syzbot dashboard link: https://syzkaller.appspot.com/bug?extid=da69f0eccf07cdcf6710
Unfortunately, I don't have any reproducer for this crash yet. Raw console output: https://syzkaller.appspot.com/x/log.txt?id=5006146695856128 Kernel config: https://syzkaller.appspot.com/x/.config?id=-5947642240294114534 compiler: gcc (GCC) 8.0.1 20180301 (experimental)
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+da69f0eccf07cdcf6710@syzkaller.appspotmail.com It will help syzbot understand when the bug is fixed. See footer for details. If you forward the report, please keep this part and the footer.
INFO: rcu_sched self-detected stall on CPU 0-...!: (124998 ticks this GP) idle=10e/1/4611686018427387906 softirq=30640/30640 fqs=8 (t=125000 jiffies g=15921 c=15920 q=62) rcu_sched kthread starved for 124967 jiffies! g15921 c15920 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1 RCU grace-period kthread stack dump: rcu_sched R running task 23768 9 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3490 schedule+0xef/0x430 kernel/sched/core.c:3549 schedule_timeout+0x138/0x240 kernel/time/timer.c:1801 rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231 kthread+0x345/0x410 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411 NMI backtrace for cpu 0 CPU: 0 PID: 4595 Comm: syz-executor3 Not tainted 4.16.0+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline] rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376 print_cpu_stall kernel/rcu/tree.c:1525 [inline] check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593 __rcu_pending kernel/rcu/tree.c:3356 [inline] rcu_pending kernel/rcu/tree.c:3401 [inline] rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763 update_process_times+0x2d/0x70 kernel/time/timer.c:1636 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:173 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1283 __run_hrtimer kernel/time/hrtimer.c:1386 [inline] __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1448 hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1506 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862 </IRQ> RIP: 0010:shrink_dcache_parent+0x174/0x230 fs/dcache.c:1484 RSP: 0018:ffff88018cacfb68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffffffff81c20160 RSI: ffff88018cacfbf0 RDI: ffff8801d5252b80 RBP: ffff88018cacfc58 R08: ffff88018cac2480 R09: ffffed003aa4a580 R10: ffffed003aa4a580 R11: ffff8801d5252c03 R12: ffff88018cacfc30 R13: ffff88018cacfbf0 R14: 1ffff10031959f7e R15: ffffed0031959f81 vfs_rmdir+0x202/0x470 fs/namei.c:3850 do_rmdir+0x523/0x610 fs/namei.c:3911 SYSC_rmdir fs/namei.c:3929 [inline] SyS_rmdir+0x1a/0x20 fs/namei.c:3927 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x455087 RSP: 002b:00007fffa68fc118 EFLAGS: 00000206 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 0000000000455087 RDX: 0000000000000000 RSI: 00007fffa68fdec0 RDI: 00007fffa68fdec0 RBP: 00007fffa68fdec0 R08: 0000000000000000 R09: 0000000000000001 R10: 000000000000000a R11: 0000000000000206 R12: 0000000001ea2940 R13: 0000000000000000 R14: 00000000000001b8 R15: 0000000000017faa
--- This bug is generated by a dumb bot. It may contain errors. See https://goo.gl/tpsmEJ for details. Direct all questions to syzkaller@googlegroups.com.
syzbot will keep track of this bug report. If you forgot to add the Reported-by tag, once the fix for this bug is merged into any tree, please reply to this email with: #syz fix: exact-commit-title To mark this as a duplicate of another syzbot report, please reply with: #syz dup: exact-subject-of-another-report If it's a one-off invalid bug report, please reply with: #syz invalid Note: if the crash happens again, it will cause creation of a new bug report. Note: all commands must start from beginning of the line in the email body.
| |