* INFO: rcu detected stall in sys_sendfile64 (2)
@ 2019-01-19 11:32 syzbot
2019-01-19 11:32 ` syzbot
` (2 more replies)
0 siblings, 3 replies; 9+ messages in thread
From: syzbot @ 2019-01-19 11:32 UTC (permalink / raw)
To: akpm, amir73il, darrick.wong, david, hannes, hughd, jrdr.linux,
linux-kernel, linux-mm, syzkaller-bugs, willy
Hello,
syzbot found the following crash on:
HEAD commit: 2339e91d0e66 Merge tag 'media/v5.0-1' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=175f2638c00000
kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com
audit: type=1400 audit(1547895693.874:36): avc: denied { map } for
pid=8427 comm="syz-executor786" path="/root/syz-executor786610373"
dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
hrtimer: interrupt took 42996 ns
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 0, t=10502 jiffies, g=6469, q=3)
rcu: All QSes seen, last rcu_preempt kthread activity 10502
(4295051508-4295041006), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor786 R running task 21544 8437 8433 0x00000000
Call Trace:
<IRQ>
sched_show_task kernel/sched/core.c:5293 [inline]
sched_show_task.cold+0x273/0x2d5 kernel/sched/core.c:5268
print_other_cpu_stall.cold+0x7f2/0x8bb kernel/rcu/tree.c:1301
check_cpu_stall kernel/rcu/tree.c:1429 [inline]
rcu_pending kernel/rcu/tree.c:3018 [inline]
rcu_check_callbacks+0xf36/0x1380 kernel/rcu/tree.c:2521
update_process_times+0x32/0x80 kernel/time/timer.c:1635
tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
__run_hrtimer kernel/time/hrtimer.c:1389 [inline]
__hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451
hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
</IRQ>
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline]
RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:122
Code: 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89
34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 80 ee
7f 7e a9 00 01 1f 00 75 51 41 8b 80 d8 12 00 00 83
RSP: 0018:ffff888080466f58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 000000000000226d RBX: ffff888080467140 RCX: ffffffff87f08bdf
RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000007
RBP: ffff888080466f60 R08: ffff888096338480 R09: ffffed1015cc5b90
R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: 1ffff1101008cdf0
R13: ffff888092b64102 R14: ffff888092b64102 R15: ffff888080467158
xa_is_node include/linux/xarray.h:946 [inline]
xas_start+0x1cf/0x720 lib/xarray.c:183
xas_load+0x21/0x160 lib/xarray.c:227
find_get_entry+0x350/0x10a0 mm/filemap.c:1476
pagecache_get_page+0xe6/0x1020 mm/filemap.c:1579
find_get_page include/linux/pagemap.h:272 [inline]
generic_file_buffered_read mm/filemap.c:2076 [inline]
generic_file_read_iter+0x7b2/0x2d40 mm/filemap.c:2350
ext4_file_read_iter+0x180/0x3c0 fs/ext4/file.c:77
call_read_iter include/linux/fs.h:1856 [inline]
generic_file_splice_read+0x5c4/0xa90 fs/splice.c:308
do_splice_to+0x12a/0x190 fs/splice.c:880
splice_direct_to_actor+0x31b/0x9d0 fs/splice.c:957
do_splice_direct+0x2c7/0x420 fs/splice.c:1066
do_sendfile+0x61a/0xe60 fs/read_write.c:1436
__do_sys_sendfile64 fs/read_write.c:1491 [inline]
__se_sys_sendfile64 fs/read_write.c:1483 [inline]
__x64_sys_sendfile64+0x15a/0x240 fs/read_write.c:1483
do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446a19
Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f53e33cfda8 EFLAGS: 00000297 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446a19
RDX: 0000000020000380 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000
R10: 00008080fffffffe R11: 0000000000000297 R12: 00000000006dcc2c
R13: 00008080fffffffe R14: 00007f53e33d09c0 R15: 00000000006dcd2c
rcu: rcu_preempt kthread starved for 10502 jiffies! g6469 f0x2
RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt R running task 26200 10 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x897/0x1e60 kernel/sched/core.c:3472
schedule+0xfe/0x350 kernel/sched/core.c:3516
schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803
rcu_gp_fqs_loop+0x6ba/0x970 kernel/rcu/tree.c:1948
rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2105
kthread+0x357/0x430 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
sched: RT throttling activated
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 9+ messages in thread
* INFO: rcu detected stall in sys_sendfile64 (2)
2019-01-19 11:32 INFO: rcu detected stall in sys_sendfile64 (2) syzbot
@ 2019-01-19 11:32 ` syzbot
2019-01-19 11:41 ` Dmitry Vyukov
2019-03-12 3:59 ` syzbot
2 siblings, 0 replies; 9+ messages in thread
From: syzbot @ 2019-01-19 11:32 UTC (permalink / raw)
To: akpm, amir73il, darrick.wong, david, hannes, hughd, jrdr.linux,
linux-kernel, linux-mm, syzkaller-bugs, willy
Hello,
syzbot found the following crash on:
HEAD commit: 2339e91d0e66 Merge tag 'media/v5.0-1' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=175f2638c00000
kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com
audit: type=1400 audit(1547895693.874:36): avc: denied { map } for
pid=8427 comm="syz-executor786" path="/root/syz-executor786610373"
dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
hrtimer: interrupt took 42996 ns
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 0, t=10502 jiffies, g=6469, q=3)
rcu: All QSes seen, last rcu_preempt kthread activity 10502
(4295051508-4295041006), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor786 R running task 21544 8437 8433 0x00000000
Call Trace:
<IRQ>
sched_show_task kernel/sched/core.c:5293 [inline]
sched_show_task.cold+0x273/0x2d5 kernel/sched/core.c:5268
print_other_cpu_stall.cold+0x7f2/0x8bb kernel/rcu/tree.c:1301
check_cpu_stall kernel/rcu/tree.c:1429 [inline]
rcu_pending kernel/rcu/tree.c:3018 [inline]
rcu_check_callbacks+0xf36/0x1380 kernel/rcu/tree.c:2521
update_process_times+0x32/0x80 kernel/time/timer.c:1635
tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
__run_hrtimer kernel/time/hrtimer.c:1389 [inline]
__hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451
hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
</IRQ>
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline]
RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:122
Code: 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89
34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 80 ee
7f 7e a9 00 01 1f 00 75 51 41 8b 80 d8 12 00 00 83
RSP: 0018:ffff888080466f58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 000000000000226d RBX: ffff888080467140 RCX: ffffffff87f08bdf
RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000007
RBP: ffff888080466f60 R08: ffff888096338480 R09: ffffed1015cc5b90
R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: 1ffff1101008cdf0
R13: ffff888092b64102 R14: ffff888092b64102 R15: ffff888080467158
xa_is_node include/linux/xarray.h:946 [inline]
xas_start+0x1cf/0x720 lib/xarray.c:183
xas_load+0x21/0x160 lib/xarray.c:227
find_get_entry+0x350/0x10a0 mm/filemap.c:1476
pagecache_get_page+0xe6/0x1020 mm/filemap.c:1579
find_get_page include/linux/pagemap.h:272 [inline]
generic_file_buffered_read mm/filemap.c:2076 [inline]
generic_file_read_iter+0x7b2/0x2d40 mm/filemap.c:2350
ext4_file_read_iter+0x180/0x3c0 fs/ext4/file.c:77
call_read_iter include/linux/fs.h:1856 [inline]
generic_file_splice_read+0x5c4/0xa90 fs/splice.c:308
do_splice_to+0x12a/0x190 fs/splice.c:880
splice_direct_to_actor+0x31b/0x9d0 fs/splice.c:957
do_splice_direct+0x2c7/0x420 fs/splice.c:1066
do_sendfile+0x61a/0xe60 fs/read_write.c:1436
__do_sys_sendfile64 fs/read_write.c:1491 [inline]
__se_sys_sendfile64 fs/read_write.c:1483 [inline]
__x64_sys_sendfile64+0x15a/0x240 fs/read_write.c:1483
do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446a19
Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f53e33cfda8 EFLAGS: 00000297 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446a19
RDX: 0000000020000380 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000
R10: 00008080fffffffe R11: 0000000000000297 R12: 00000000006dcc2c
R13: 00008080fffffffe R14: 00007f53e33d09c0 R15: 00000000006dcd2c
rcu: rcu_preempt kthread starved for 10502 jiffies! g6469 f0x2
RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt R running task 26200 10 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x897/0x1e60 kernel/sched/core.c:3472
schedule+0xfe/0x350 kernel/sched/core.c:3516
schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803
rcu_gp_fqs_loop+0x6ba/0x970 kernel/rcu/tree.c:1948
rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2105
kthread+0x357/0x430 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
sched: RT throttling activated
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: INFO: rcu detected stall in sys_sendfile64 (2)
2019-01-19 11:32 INFO: rcu detected stall in sys_sendfile64 (2) syzbot
2019-01-19 11:32 ` syzbot
@ 2019-01-19 11:41 ` Dmitry Vyukov
2019-01-19 11:41 ` Dmitry Vyukov
2019-01-19 13:00 ` Tetsuo Handa
2019-03-12 3:59 ` syzbot
2 siblings, 2 replies; 9+ messages in thread
From: Dmitry Vyukov @ 2019-01-19 11:41 UTC (permalink / raw)
To: syzbot, Ingo Molnar, Peter Zijlstra
Cc: Andrew Morton, Amir Goldstein, Darrick J. Wong, Dave Chinner,
Johannes Weiner, Hugh Dickins, Souptick Joarder, LKML, Linux-MM,
syzkaller-bugs, Matthew Wilcox
On Sat, Jan 19, 2019 at 12:32 PM syzbot
<syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 2339e91d0e66 Merge tag 'media/v5.0-1' of git://git.kernel...
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=175f2638c00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
> dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
Looking at the reproducer it looks like something with scheduler as it
involves perf_event_open and sched_setattr. So +Peter and Mingo.
Is it the same root cause as the other stalls involving sched_setattr?
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com
>
> audit: type=1400 audit(1547895693.874:36): avc: denied { map } for
> pid=8427 comm="syz-executor786" path="/root/syz-executor786610373"
> dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
> tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
> hrtimer: interrupt took 42996 ns
> rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
> rcu: (detected by 0, t=10502 jiffies, g=6469, q=3)
> rcu: All QSes seen, last rcu_preempt kthread activity 10502
> (4295051508-4295041006), jiffies_till_next_fqs=1, root ->qsmask 0x0
> syz-executor786 R running task 21544 8437 8433 0x00000000
> Call Trace:
> <IRQ>
> sched_show_task kernel/sched/core.c:5293 [inline]
> sched_show_task.cold+0x273/0x2d5 kernel/sched/core.c:5268
> print_other_cpu_stall.cold+0x7f2/0x8bb kernel/rcu/tree.c:1301
> check_cpu_stall kernel/rcu/tree.c:1429 [inline]
> rcu_pending kernel/rcu/tree.c:3018 [inline]
> rcu_check_callbacks+0xf36/0x1380 kernel/rcu/tree.c:2521
> update_process_times+0x32/0x80 kernel/time/timer.c:1635
> tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
> tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
> __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
> __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451
> hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
> local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
> smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060
> apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
> </IRQ>
> RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
> RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline]
> RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:122
> Code: 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89
> 34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 80 ee
> 7f 7e a9 00 01 1f 00 75 51 41 8b 80 d8 12 00 00 83
> RSP: 0018:ffff888080466f58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> RAX: 000000000000226d RBX: ffff888080467140 RCX: ffffffff87f08bdf
> RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000007
> RBP: ffff888080466f60 R08: ffff888096338480 R09: ffffed1015cc5b90
> R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: 1ffff1101008cdf0
> R13: ffff888092b64102 R14: ffff888092b64102 R15: ffff888080467158
> xa_is_node include/linux/xarray.h:946 [inline]
> xas_start+0x1cf/0x720 lib/xarray.c:183
> xas_load+0x21/0x160 lib/xarray.c:227
> find_get_entry+0x350/0x10a0 mm/filemap.c:1476
> pagecache_get_page+0xe6/0x1020 mm/filemap.c:1579
> find_get_page include/linux/pagemap.h:272 [inline]
> generic_file_buffered_read mm/filemap.c:2076 [inline]
> generic_file_read_iter+0x7b2/0x2d40 mm/filemap.c:2350
> ext4_file_read_iter+0x180/0x3c0 fs/ext4/file.c:77
> call_read_iter include/linux/fs.h:1856 [inline]
> generic_file_splice_read+0x5c4/0xa90 fs/splice.c:308
> do_splice_to+0x12a/0x190 fs/splice.c:880
> splice_direct_to_actor+0x31b/0x9d0 fs/splice.c:957
> do_splice_direct+0x2c7/0x420 fs/splice.c:1066
> do_sendfile+0x61a/0xe60 fs/read_write.c:1436
> __do_sys_sendfile64 fs/read_write.c:1491 [inline]
> __se_sys_sendfile64 fs/read_write.c:1483 [inline]
> __x64_sys_sendfile64+0x15a/0x240 fs/read_write.c:1483
> do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x446a19
> Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007f53e33cfda8 EFLAGS: 00000297 ORIG_RAX: 0000000000000028
> RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446a19
> RDX: 0000000020000380 RSI: 0000000000000003 RDI: 0000000000000003
> RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000
> R10: 00008080fffffffe R11: 0000000000000297 R12: 00000000006dcc2c
> R13: 00008080fffffffe R14: 00007f53e33d09c0 R15: 00000000006dcd2c
> rcu: rcu_preempt kthread starved for 10502 jiffies! g6469 f0x2
> RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
> rcu: RCU grace-period kthread stack dump:
> rcu_preempt R running task 26200 10 2 0x80000000
> Call Trace:
> context_switch kernel/sched/core.c:2831 [inline]
> __schedule+0x897/0x1e60 kernel/sched/core.c:3472
> schedule+0xfe/0x350 kernel/sched/core.c:3516
> schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803
> rcu_gp_fqs_loop+0x6ba/0x970 kernel/rcu/tree.c:1948
> rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2105
> kthread+0x357/0x430 kernel/kthread.c:246
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> sched: RT throttling activated
>
>
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
> syzbot.
> syzbot can test patches for this bug, for details see:
> https://goo.gl/tpsmEJ#testing-patches
>
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: INFO: rcu detected stall in sys_sendfile64 (2)
2019-01-19 11:41 ` Dmitry Vyukov
@ 2019-01-19 11:41 ` Dmitry Vyukov
2019-01-19 13:00 ` Tetsuo Handa
1 sibling, 0 replies; 9+ messages in thread
From: Dmitry Vyukov @ 2019-01-19 11:41 UTC (permalink / raw)
To: syzbot, Ingo Molnar, Peter Zijlstra
Cc: Andrew Morton, Amir Goldstein, Darrick J. Wong, Dave Chinner,
Johannes Weiner, Hugh Dickins, Souptick Joarder, LKML, Linux-MM,
syzkaller-bugs, Matthew Wilcox
On Sat, Jan 19, 2019 at 12:32 PM syzbot
<syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 2339e91d0e66 Merge tag 'media/v5.0-1' of git://git.kernel...
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=175f2638c00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
> dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
Looking at the reproducer it looks like something with scheduler as it
involves perf_event_open and sched_setattr. So +Peter and Mingo.
Is it the same root cause as the other stalls involving sched_setattr?
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com
>
> audit: type=1400 audit(1547895693.874:36): avc: denied { map } for
> pid=8427 comm="syz-executor786" path="/root/syz-executor786610373"
> dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
> tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
> hrtimer: interrupt took 42996 ns
> rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
> rcu: (detected by 0, t=10502 jiffies, g=6469, q=3)
> rcu: All QSes seen, last rcu_preempt kthread activity 10502
> (4295051508-4295041006), jiffies_till_next_fqs=1, root ->qsmask 0x0
> syz-executor786 R running task 21544 8437 8433 0x00000000
> Call Trace:
> <IRQ>
> sched_show_task kernel/sched/core.c:5293 [inline]
> sched_show_task.cold+0x273/0x2d5 kernel/sched/core.c:5268
> print_other_cpu_stall.cold+0x7f2/0x8bb kernel/rcu/tree.c:1301
> check_cpu_stall kernel/rcu/tree.c:1429 [inline]
> rcu_pending kernel/rcu/tree.c:3018 [inline]
> rcu_check_callbacks+0xf36/0x1380 kernel/rcu/tree.c:2521
> update_process_times+0x32/0x80 kernel/time/timer.c:1635
> tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
> tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
> __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
> __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451
> hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
> local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
> smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060
> apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
> </IRQ>
> RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
> RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline]
> RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:122
> Code: 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89
> 34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 80 ee
> 7f 7e a9 00 01 1f 00 75 51 41 8b 80 d8 12 00 00 83
> RSP: 0018:ffff888080466f58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> RAX: 000000000000226d RBX: ffff888080467140 RCX: ffffffff87f08bdf
> RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000007
> RBP: ffff888080466f60 R08: ffff888096338480 R09: ffffed1015cc5b90
> R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: 1ffff1101008cdf0
> R13: ffff888092b64102 R14: ffff888092b64102 R15: ffff888080467158
> xa_is_node include/linux/xarray.h:946 [inline]
> xas_start+0x1cf/0x720 lib/xarray.c:183
> xas_load+0x21/0x160 lib/xarray.c:227
> find_get_entry+0x350/0x10a0 mm/filemap.c:1476
> pagecache_get_page+0xe6/0x1020 mm/filemap.c:1579
> find_get_page include/linux/pagemap.h:272 [inline]
> generic_file_buffered_read mm/filemap.c:2076 [inline]
> generic_file_read_iter+0x7b2/0x2d40 mm/filemap.c:2350
> ext4_file_read_iter+0x180/0x3c0 fs/ext4/file.c:77
> call_read_iter include/linux/fs.h:1856 [inline]
> generic_file_splice_read+0x5c4/0xa90 fs/splice.c:308
> do_splice_to+0x12a/0x190 fs/splice.c:880
> splice_direct_to_actor+0x31b/0x9d0 fs/splice.c:957
> do_splice_direct+0x2c7/0x420 fs/splice.c:1066
> do_sendfile+0x61a/0xe60 fs/read_write.c:1436
> __do_sys_sendfile64 fs/read_write.c:1491 [inline]
> __se_sys_sendfile64 fs/read_write.c:1483 [inline]
> __x64_sys_sendfile64+0x15a/0x240 fs/read_write.c:1483
> do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x446a19
> Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007f53e33cfda8 EFLAGS: 00000297 ORIG_RAX: 0000000000000028
> RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446a19
> RDX: 0000000020000380 RSI: 0000000000000003 RDI: 0000000000000003
> RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000
> R10: 00008080fffffffe R11: 0000000000000297 R12: 00000000006dcc2c
> R13: 00008080fffffffe R14: 00007f53e33d09c0 R15: 00000000006dcd2c
> rcu: rcu_preempt kthread starved for 10502 jiffies! g6469 f0x2
> RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
> rcu: RCU grace-period kthread stack dump:
> rcu_preempt R running task 26200 10 2 0x80000000
> Call Trace:
> context_switch kernel/sched/core.c:2831 [inline]
> __schedule+0x897/0x1e60 kernel/sched/core.c:3472
> schedule+0xfe/0x350 kernel/sched/core.c:3516
> schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803
> rcu_gp_fqs_loop+0x6ba/0x970 kernel/rcu/tree.c:1948
> rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2105
> kthread+0x357/0x430 kernel/kthread.c:246
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> sched: RT throttling activated
>
>
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
> syzbot.
> syzbot can test patches for this bug, for details see:
> https://goo.gl/tpsmEJ#testing-patches
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
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> For more options, visit https://groups.google.com/d/optout.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: INFO: rcu detected stall in sys_sendfile64 (2)
2019-01-19 11:41 ` Dmitry Vyukov
2019-01-19 11:41 ` Dmitry Vyukov
@ 2019-01-19 13:00 ` Tetsuo Handa
1 sibling, 0 replies; 9+ messages in thread
From: Tetsuo Handa @ 2019-01-19 13:00 UTC (permalink / raw)
To: Dmitry Vyukov, syzbot, Ingo Molnar, Peter Zijlstra
Cc: Andrew Morton, Amir Goldstein, Darrick J. Wong, Dave Chinner,
Johannes Weiner, Hugh Dickins, Souptick Joarder, LKML, Linux-MM,
syzkaller-bugs, Matthew Wilcox
On 2019/01/19 20:41, Dmitry Vyukov wrote:
> On Sat, Jan 19, 2019 at 12:32 PM syzbot
> <syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com> wrote:
>>
>> Hello,
>>
>> syzbot found the following crash on:
>>
>> HEAD commit: 2339e91d0e66 Merge tag 'media/v5.0-1' of git://git.kernel...
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=175f2638c00000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
>> dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
>> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
>
> Looking at the reproducer it looks like something with scheduler as it
> involves perf_event_open and sched_setattr. So +Peter and Mingo.
> Is it the same root cause as the other stalls involving sched_setattr?
Yes. I think sched_setattr() involves this problem.
Reproducers from "BUG: workqueue lockup (4)" at
https://syzkaller.appspot.com/text?tag=ReproC&x=13ec31a5400000
involves sched_setattr(SCHED_DEADLINE) and
https://syzkaller.appspot.com/text?tag=ReproC&x=104da690c00000
also involves sched_setattr().
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: INFO: rcu detected stall in sys_sendfile64 (2)
2019-01-19 11:32 INFO: rcu detected stall in sys_sendfile64 (2) syzbot
2019-01-19 11:32 ` syzbot
2019-01-19 11:41 ` Dmitry Vyukov
@ 2019-03-12 3:59 ` syzbot
2019-03-12 4:08 ` Al Viro
2 siblings, 1 reply; 9+ messages in thread
From: syzbot @ 2019-03-12 3:59 UTC (permalink / raw)
To: airlied, akpm, amir73il, chris, darrick.wong, david, dri-devel,
dvyukov, eparis, hannes, hughd, intel-gfx, jack, jani.nikula,
joonas.lahtinen, jrdr.linux, linux-kernel, linux-mm, mingo,
mszeredi, penguin-kernel, peterz, rodrigo.vivi, syzkaller-bugs,
viro, willy
syzbot has bisected this bug to:
commit 34e07e42c55aeaa78e93b057a6664e2ecde3fadb
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu Feb 8 10:54:48 2018 +0000
drm/i915: Add missing kerneldoc for 'ent' in i915_driver_init_early
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13220283200000
start commit: 34e07e42 drm/i915: Add missing kerneldoc for 'ent' in i915..
git tree: upstream
final crash: https://syzkaller.appspot.com/x/report.txt?x=10a20283200000
console output: https://syzkaller.appspot.com/x/log.txt?x=17220283200000
kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
userspace arch: amd64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com
Fixes: 34e07e42 ("drm/i915: Add missing kerneldoc for 'ent' in
i915_driver_init_early")
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: INFO: rcu detected stall in sys_sendfile64 (2)
2019-03-12 3:59 ` syzbot
@ 2019-03-12 4:08 ` Al Viro
2019-03-12 8:00 ` Jani Nikula
2019-03-12 17:10 ` Dmitry Vyukov
0 siblings, 2 replies; 9+ messages in thread
From: Al Viro @ 2019-03-12 4:08 UTC (permalink / raw)
To: syzbot
Cc: airlied, akpm, amir73il, chris, darrick.wong, david, dri-devel,
dvyukov, eparis, hannes, hughd, intel-gfx, jack, jani.nikula,
joonas.lahtinen, jrdr.linux, linux-kernel, linux-mm, mingo,
mszeredi, penguin-kernel, peterz, rodrigo.vivi, syzkaller-bugs,
willy
On Mon, Mar 11, 2019 at 08:59:00PM -0700, syzbot wrote:
> syzbot has bisected this bug to:
>
> commit 34e07e42c55aeaa78e93b057a6664e2ecde3fadb
> Author: Chris Wilson <chris@chris-wilson.co.uk>
> Date: Thu Feb 8 10:54:48 2018 +0000
>
> drm/i915: Add missing kerneldoc for 'ent' in i915_driver_init_early
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13220283200000
> start commit: 34e07e42 drm/i915: Add missing kerneldoc for 'ent' in i915..
> git tree: upstream
> final crash: https://syzkaller.appspot.com/x/report.txt?x=10a20283200000
> console output: https://syzkaller.appspot.com/x/log.txt?x=17220283200000
> kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
> dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
> userspace arch: amd64
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
>
> Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com
> Fixes: 34e07e42 ("drm/i915: Add missing kerneldoc for 'ent' in
> i915_driver_init_early")
Umm... Might be a good idea to add some plausibility filters - it is,
in theory, possible that adding a line in a comment changes behaviour
(without compiler bugs, even - playing with __LINE__ is all it would
take), but the odds that it's _not_ a false positive are very low.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: INFO: rcu detected stall in sys_sendfile64 (2)
2019-03-12 4:08 ` Al Viro
@ 2019-03-12 8:00 ` Jani Nikula
2019-03-12 17:10 ` Dmitry Vyukov
1 sibling, 0 replies; 9+ messages in thread
From: Jani Nikula @ 2019-03-12 8:00 UTC (permalink / raw)
To: Al Viro, syzbot
Cc: airlied, akpm, amir73il, chris, darrick.wong, david, dri-devel,
dvyukov, eparis, hannes, hughd, intel-gfx, jack, joonas.lahtinen,
jrdr.linux, linux-kernel, linux-mm, mingo, mszeredi,
penguin-kernel, peterz, rodrigo.vivi, syzkaller-bugs, willy
On Tue, 12 Mar 2019, Al Viro <viro@zeniv.linux.org.uk> wrote:
> On Mon, Mar 11, 2019 at 08:59:00PM -0700, syzbot wrote:
>> syzbot has bisected this bug to:
>>
>> commit 34e07e42c55aeaa78e93b057a6664e2ecde3fadb
>> Author: Chris Wilson <chris@chris-wilson.co.uk>
>> Date: Thu Feb 8 10:54:48 2018 +0000
>>
>> drm/i915: Add missing kerneldoc for 'ent' in i915_driver_init_early
>>
>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13220283200000
>> start commit: 34e07e42 drm/i915: Add missing kerneldoc for 'ent' in i915..
>> git tree: upstream
>> final crash: https://syzkaller.appspot.com/x/report.txt?x=10a20283200000
>> console output: https://syzkaller.appspot.com/x/log.txt?x=17220283200000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
>> dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
>> userspace arch: amd64
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
>>
>> Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com
>> Fixes: 34e07e42 ("drm/i915: Add missing kerneldoc for 'ent' in
>> i915_driver_init_early")
>
> Umm... Might be a good idea to add some plausibility filters - it is,
> in theory, possible that adding a line in a comment changes behaviour
> (without compiler bugs, even - playing with __LINE__ is all it would
> take), but the odds that it's _not_ a false positive are very low.
If it's not a false positive, it's bound to be good source material for
IOCCC.
BR,
Jani.
--
Jani Nikula, Intel Open Source Graphics Center
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: INFO: rcu detected stall in sys_sendfile64 (2)
2019-03-12 4:08 ` Al Viro
2019-03-12 8:00 ` Jani Nikula
@ 2019-03-12 17:10 ` Dmitry Vyukov
1 sibling, 0 replies; 9+ messages in thread
From: Dmitry Vyukov @ 2019-03-12 17:10 UTC (permalink / raw)
To: Al Viro
Cc: syzbot, David Airlie, Andrew Morton, Amir Goldstein,
Chris Wilson, Darrick J. Wong, Dave Chinner, DRI, eparis,
Johannes Weiner, Hugh Dickins, intel-gfx, Jan Kara, Jani Nikula,
Joonas Lahtinen, Souptick Joarder, LKML, Linux-MM, Ingo Molnar,
mszeredi, Tetsuo Handa, Peter Zijlstra, Rodrigo Vivi,
syzkaller-bugs, Matthew Wilcox
On Tue, Mar 12, 2019 at 5:08 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Mon, Mar 11, 2019 at 08:59:00PM -0700, syzbot wrote:
> > syzbot has bisected this bug to:
> >
> > commit 34e07e42c55aeaa78e93b057a6664e2ecde3fadb
> > Author: Chris Wilson <chris@chris-wilson.co.uk>
> > Date: Thu Feb 8 10:54:48 2018 +0000
> >
> > drm/i915: Add missing kerneldoc for 'ent' in i915_driver_init_early
> >
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13220283200000
> > start commit: 34e07e42 drm/i915: Add missing kerneldoc for 'ent' in i915..
> > git tree: upstream
> > final crash: https://syzkaller.appspot.com/x/report.txt?x=10a20283200000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=17220283200000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258
> > dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5
> > userspace arch: amd64
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000
> >
> > Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com
> > Fixes: 34e07e42 ("drm/i915: Add missing kerneldoc for 'ent' in
> > i915_driver_init_early")
>
> Umm... Might be a good idea to add some plausibility filters - it is,
> in theory, possible that adding a line in a comment changes behaviour
> (without compiler bugs, even - playing with __LINE__ is all it would
> take), but the odds that it's _not_ a false positive are very low.
Thanks for pointing this out.
I've started collecting all such cases, so that we are able to draw
broader conclusions later:
https://github.com/google/syzkaller/issues/1051
added for this one:
=========
A mix of problems: unrelated bug triggered by the same repro
("WARNING: ODEBUG bug in netdev_freemem"); lots of infrastructure
failures ("failed to copy test binary to VM"); also the original
failure seems to be flaky. All this contributed to pointing to a
random commit.
Al Viro points out that the commit only touches comments, so we could
mark the end result as suspicious.
=========
The infrastructure problems is definitely something we need to fix
("failed to copy test binary to VM") (currently the machine hangs
periodically with lots of time consumed by dmcrypt, but I don't know
if it's related or not yet).
Re the comment-only changes, I would like to see more cases where it
would help before we start creating new universes for this. We could
parse sources with clang to understand that a change was comment-only,
but I guess kernel is mostly broken with clang throughout history....
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2019-03-12 17:10 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-01-19 11:32 INFO: rcu detected stall in sys_sendfile64 (2) syzbot
2019-01-19 11:32 ` syzbot
2019-01-19 11:41 ` Dmitry Vyukov
2019-01-19 11:41 ` Dmitry Vyukov
2019-01-19 13:00 ` Tetsuo Handa
2019-03-12 3:59 ` syzbot
2019-03-12 4:08 ` Al Viro
2019-03-12 8:00 ` Jani Nikula
2019-03-12 17:10 ` Dmitry Vyukov
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