pkg/report: ignore kthread more precisely in stall reports

2 files changed, 51 insertions, 1 deletions

diff --git a/pkg/report/linux.go b/pkg/report/linux.go
index c01afe235..e3242c602 100644
--- a/pkg/report/linux.go
+++ b/pkg/report/linux.go
@@ -648,7 +648,7 @@ var linuxStallAnchorFrames = []*regexp.Regexp{
 	compile("hrtimer_run"),
 	compile("run_ksoftirqd"),
 	compile("smpboot_thread_fn"),
-	compile("kthread"),
+	compile("^kthread$"),
 	compile("start_secondary"),
 	compile("cpu_startup_entry"),
 	compile("ret_from_fork"),
diff --git a/pkg/report/testdata/linux/report/588 b/pkg/report/testdata/linux/report/588
new file mode 100644
index 000000000..9635f73d0
--- /dev/null
+++ b/pkg/report/testdata/linux/report/588
@@ -0,0 +1,50 @@
+TITLE: INFO: rcu detected stall in io_sq_thread
+TYPE: HANG
+
+[  589.079232] rcu: INFO: rcu_sched self-detected stall on CPU
+[  589.085351] rcu: 	0-....: (10499 ticks this GP) idle=d0a/1/0x4000000000000002 softirq=51093/51093 fqs=3111 
+[  589.095364] rcu: 	 (t=10500 jiffies g=51445 q=1360)
+[  589.100420] NMI backtrace for cpu 0
+[  589.104157] CPU: 0 PID: 17938 Comm: io_uring-sq Not tainted 4.15.0-syzkaller #0
+[  589.111615] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  589.120984] Call Trace:
+[  589.123632]  <IRQ>
+[  589.125842]  [<ffffffff849381e4>] dump_stack+0xe1/0x157
+[  589.131235]  [<ffffffff81391101>] ? lapic_can_unplug_cpu+0x41/0x80
+[  589.137578]  [<ffffffff849384ac>] nmi_cpu_backtrace.cold+0x63/0xa5
+[  589.144040]  [<ffffffff81391140>] ? lapic_can_unplug_cpu+0x80/0x80
+[  589.150560]  [<ffffffff847d8dc6>] nmi_trigger_cpumask_backtrace+0x1a6/0x1e0
+[  589.157694]  [<ffffffff81391244>] arch_trigger_cpumask_backtrace+0x14/0x20
+[  589.164738]  [<ffffffff84837133>] rcu_dump_cpu_stacks+0x183/0x1cf
+[  589.170992]  [<ffffffff822fe0f7>] ? find_next_bit+0x107/0x130
+[  589.176900]  [<ffffffff848381a7>] rcu_sched_clock_irq.cold+0x4d7/0x8a8
+[  589.183583]  [<ffffffff81431a83>] ? raise_softirq+0x183/0x240
+[  589.189495]  [<ffffffff8165c90d>] update_process_times+0x2d/0x70
+[  589.195676]  [<ffffffff8168dd90>] tick_sched_handle+0xa0/0x180
+[  589.201767]  [<ffffffff8168e384>] tick_sched_timer+0x44/0x130
+[  589.207685]  [<ffffffff8166054b>] __hrtimer_run_queues+0x33b/0xd10
+[  589.214033]  [<ffffffff8168e340>] ? tick_sched_do_timer+0x110/0x110
+[  589.220465]  [<ffffffff81660210>] ? hrtimer_fixup_activate+0x30/0x30
+[  589.226994]  [<ffffffff81661f5a>] hrtimer_interrupt+0x2ea/0x730
+[  589.233080]  [<ffffffff84a04a69>] smp_apic_timer_interrupt+0x159/0x580
+[  589.239769]  [<ffffffff84a019a3>] apic_timer_interrupt+0x93/0xa0
+[  589.245935]  </IRQ>
+[  589.248181] RIP: 0010:write_comp_data+0x9/0x70
+[  589.252758] RSP: 0018:ffff8801e1757da8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff12
+[  589.260594] RAX: 0000000000000007 RBX: ffff8801ef81c000 RCX: ffffffff81492f64
+[  589.267982] RDX: 0000000000200000 RSI: 0000000000000000 RDI: 0000000000000005
+[  589.275264] RBP: ffff8801e1757db0 R08: ffff8801ef81c000 R09: fffffbfff14ca71c
+[  589.282674] R10: ffff8801e1757dd0 R11: 0000000000000000 R12: 0000000000200000
+[  589.289959] R13: ffff8801a7091000 R14: 0000000000000002 R15: dffffc0000000000
+[  589.297452]  [<ffffffff81492f64>] ? kthread_should_park+0x54/0xd0
+[  589.304431]  [<ffffffff817436f6>] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
+[  589.311816]  [<ffffffff81492f64>] kthread_should_park+0x54/0xd0
+[  589.318011]  [<ffffffff81d0a9d3>] io_sq_thread+0x213/0xc80
+[  589.323709]  [<ffffffff81d0a7c0>] ? io_submit_sqes+0x28b0/0x28b0
+[  589.329983]  [<ffffffff814934c0>] ? __kthread_parkme+0x250/0x360
+[  589.336146]  [<ffffffff81000370>] ? __startup_64+0x180/0x180
+[  589.341974]  [<ffffffff81558630>] ? finish_wait+0x260/0x260
+[  589.347728]  [<ffffffff81496355>] kthread+0x345/0x410
+[  589.352926]  [<ffffffff81d0a7c0>] ? io_submit_sqes+0x28b0/0x28b0
+[  589.359083]  [<ffffffff81496010>] ? kthread_create_worker_on_cpu+0xf0/0xf0
+[  589.366440]  [<ffffffff84a0019f>] ret_from_fork+0x3f/0x50