=============================
WARNING: suspicious RCU usage
5.12.0-next-20210506-syzkaller #0 Not tainted
-----------------------------
kernel/sched/core.c:8304 Illegal context switch in RCU-sched read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 0
1 lock held by iou-sqp-25121/25124:
 #0: ffff888030df5870 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread+0x132c/0x15e0 fs/io_uring.c:6899

stack backtrace:
CPU: 0 PID: 25124 Comm: iou-sqp-25121 Not tainted 5.12.0-next-20210506-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 ___might_sleep+0x266/0x2c0 kernel/sched/core.c:8304
 io_sq_thread+0xdeb/0x15e0 fs/io_uring.c:6872
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294