bisecting fixing commit since b0314565da2b95e73feab484467ad171fcce6dff
building syzkaller on aa4feb03290ee285b276e5a9c9abddd5296e79e0
testing commit b0314565da2b95e73feab484467ad171fcce6dff with gcc (GCC) 8.1.0
run #0: crashed: INFO: rcu detected stall in __perf_sw_event
run #1: crashed: INFO: rcu detected stall in __perf_sw_event
run #2: crashed: INFO: rcu detected stall in __perf_sw_event
run #3: crashed: INFO: rcu detected stall in __perf_sw_event
run #4: crashed: INFO: rcu detected stall in __perf_sw_event
run #5: crashed: INFO: rcu detected stall in __perf_sw_event
run #6: crashed: INFO: rcu detected stall in __perf_sw_event
run #7: OK
run #8: OK
run #9: OK
testing current HEAD 00aff6836241ae5654895dcea10e6d4fc5878ca6
testing commit 00aff6836241ae5654895dcea10e6d4fc5878ca6 with gcc (GCC) 8.1.0
run #0: crashed: INFO: rcu detected stall in __perf_sw_event
run #1: crashed: INFO: rcu detected stall in __perf_sw_event
run #2: crashed: INFO: rcu detected stall in __perf_sw_event
run #3: crashed: INFO: rcu detected stall in __perf_sw_event
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: crashed: INFO: rcu detected stall in __perf_sw_event
revisions tested: 2, total time: 34m36.057994144s (build: 12m1.23801213s, test: 21m13.92043223s)
the crash still happens on HEAD
commit msg: Merge tag 'for-5.4-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
crash: INFO: rcu detected stall in __perf_sw_event
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (1 GPs behind) idle=55e/1/0x4000000000000002 softirq=31613/31614 fqs=5230
(t=10500 jiffies g=53245 q=1302)
NMI backtrace for cpu 0
CPU: 0 PID: 17402 Comm: syz-executor0 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x12d/0x187 lib/dump_stack.c:118
nmi_cpu_backtrace.cold.7+0x4b/0x84 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x18b/0x1b7 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:164 [inline]
rcu_dump_cpu_stacks+0x16f/0x1bc kernel/rcu/tree_stall.h:254
print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
rcu_pending kernel/rcu/tree.c:2795 [inline]
rcu_sched_clock_irq.cold.84+0x4fb/0xc3e kernel/rcu/tree.c:2244
update_process_times+0x23/0x50 kernel/time/timer.c:1726
tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:167
tick_sched_timer+0x43/0x100 kernel/time/tick-sched.c:1299
__run_hrtimer kernel/time/hrtimer.c:1514 [inline]
__hrtimer_run_queues+0x332/0xb50 kernel/time/hrtimer.c:1576
hrtimer_interrupt+0x2df/0x760 kernel/time/hrtimer.c:1638
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
smp_apic_timer_interrupt+0x16f/0x600 arch/x86/kernel/apic/apic.c:1135
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
RIP: 0010:perf_output_read_group kernel/events/core.c:6299 [inline]
RIP: 0010:perf_output_read+0xd94/0x1470 kernel/events/core.c:6343
Code: 47 18 00 10 00 00 49 89 47 28 4c 39 e9 0f 82 f1 fe ff ff 48 8b 9d 18 fe ff ff 48 8d 7b 10 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <0f> 85 3f 04 00 00 48 8b 5b 10 48 83 eb 10 48 39 9d 48 fe ff ff 0f
RSP: 0018:ffff88809102f180 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff11011796402 RBX: ffff88808bcb2000 RCX: 00000000000006c8
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff88808bcb2010
RBP: ffff88809102f3b0 R08: ffffed1011552d29 R09: ffffed1011552d29
R10: ffffed1011552d28 R11: ffff88808aa96947 R12: 0000000000000010
R13: 0000000000000010 R14: dffffc0000000000 R15: ffff88809102f570
perf_output_sample+0x1000/0x18c0 kernel/events/core.c:6385
__perf_event_output kernel/events/core.c:6709 [inline]
perf_event_output_forward+0x10e/0x1f0 kernel/events/core.c:6723
__perf_event_overflow+0x11f/0x320 kernel/events/core.c:8190
perf_swevent_overflow+0x62/0xc0 kernel/events/core.c:8266
perf_swevent_event+0x1f5/0x2f0 kernel/events/core.c:8299
do_perf_sw_event kernel/events/core.c:8407 [inline]
___perf_sw_event+0x25b/0x3f0 kernel/events/core.c:8438
__perf_sw_event+0x3c/0x60 kernel/events/core.c:8450
perf_sw_event include/linux/perf_event.h:1109 [inline]
do_user_addr_fault arch/x86/mm/fault.c:1482 [inline]
__do_page_fault+0x618/0xa50 arch/x86/mm/fault.c:1506
do_page_fault+0x2d/0x3c8 arch/x86/mm/fault.c:1530
page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1202
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x30 arch/x86/lib/copy_user_64.S:205
Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f 80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 f3 a4
RSP: 0018:ffff88809102fb18 EFLAGS: 00010206
RAX: 0000000000000001 RBX: ffff88809f0b2000 RCX: 0000000000000340
RDX: 0000000000001000 RSI: 0000000020940000 RDI: ffff88809f0b2cc0
RBP: ffff88809102fb40 R08: ffffed1013e16600 R09: 0000000000000000
R10: ffffed1013e165ff R11: ffff88809f0b2fff R12: 000000002093f340
R13: ffff888095eb8340 R14: 0000000000001000 R15: ffff88809102fcd0
copy_page_from_iter_iovec lib/iov_iter.c:295 [inline]
copy_page_from_iter+0x1bc/0x780 lib/iov_iter.c:921
pipe_write+0x210/0xcd0 fs/pipe.c:455
call_write_iter include/linux/fs.h:1895 [inline]
new_sync_write+0x402/0x7e0 fs/read_write.c:483
__vfs_write+0x97/0x110 fs/read_write.c:496
vfs_write+0x18a/0x520 fs/read_write.c:558
ksys_write+0x105/0x220 fs/read_write.c:611
__do_sys_write fs/read_write.c:623 [inline]
__se_sys_write fs/read_write.c:620 [inline]
__x64_sys_write+0x6e/0xb0 fs/read_write.c:620
do_syscall_64+0xd0/0x5e0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457f89
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f140bb40c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457f89
RDX: 0000000041395527 RSI: 0000000020000340 RDI: 0000000000000006
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f140bb416d4
R13: 00000000004c3cae R14: 00000000004dc448 R15: 00000000ffffffff