bisecting fixing commit since 2187f215ebaac73ddbd814696d7c7fa34f0c3de0
building syzkaller on 79b211f74b08737aeb4934c6ff69a263b3c38013
testing commit 2187f215ebaac73ddbd814696d7c7fa34f0c3de0 with gcc (GCC) 8.1.0
kernel signature: 24ecfd8c01223c0439d1c78e6f3846b1fa98e0b4506d9a41dc4d644d62e76126
run #0: crashed: INFO: rcu detected stall in do_signal
run #1: crashed: INFO: rcu detected stall in do_signal
run #2: crashed: INFO: rcu detected stall in bad_area
run #3: crashed: INFO: rcu detected stall in do_signal
run #4: crashed: INFO: rcu detected stall in do_signal
run #5: crashed: INFO: rcu detected stall in do_signal
run #6: crashed: INFO: rcu detected stall in bad_area
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in do_signal
run #9: crashed: INFO: rcu detected stall in do_signal
testing current HEAD abb3438d69fb6dd5baa4ae23eafbf5b87945eff1
testing commit abb3438d69fb6dd5baa4ae23eafbf5b87945eff1 with gcc (GCC) 8.1.0
kernel signature: 9fa5d083db7237eddd92f75ad125c7b638c73f1f98a1d3e734a55de22ee699ae
all runs: crashed: INFO: rcu detected stall in corrupted
revisions tested: 2, total time: 21m45.07215021s (build: 10m44.713557031s, test: 10m2.563258218s)
the crash still happens on HEAD
commit msg: Merge tag 'm68knommu-for-v5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
crash: INFO: rcu detected stall in corrupted
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=3501, q=555)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294952875-4294942373), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g3501 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:14552 pid:   10 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0x3f3/0x880 kernel/sched/core.c:4527
 schedule+0x3b/0xf0 kernel/sched/core.c:4602
 schedule_timeout+0x1ae/0x2d0 kernel/time/timer.c:1879
 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline]
 rcu_gp_kthread+0x702/0xc70 kernel/rcu/tree.c:2058
 kthread+0x160/0x180 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294