linux/kernel/rcu
Paul E. McKenney c583bcb8f5 rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled
The try_invoke_on_locked_down_task() function requires that
interrupts be enabled, but it is called with interrupts disabled from
rcu_print_task_stall(), resulting in an "IRQs not enabled as expected"
diagnostic.  This commit therefore updates rcu_print_task_stall()
to accumulate a list of the first few tasks while holding the current
leaf rcu_node structure's ->lock, then releases that lock and only then
uses try_invoke_on_locked_down_task() to attempt to obtain per-task
detailed information.  Of course, as soon as ->lock is released, the
task might exit, so the get_task_struct() function is used to prevent
the task structure from going away in the meantime.

Link: https://lore.kernel.org/lkml/000000000000903d5805ab908fc4@google.com/
Fixes: 5bef8da66a ("rcu: Add per-task state to RCU CPU stall warnings")
Reported-by: syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com
Reported-by: syzbot+f04854e1c5c9e913cc27@syzkaller.appspotmail.com
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-10 17:10:38 -08:00
..
Kconfig rcu: Reduce leaf fanout for strict RCU grace periods 2020-08-24 18:40:23 -07:00
Kconfig.debug Merge branch 'strictgp.2020.08.24a' into HEAD 2020-09-03 09:47:42 -07:00
Makefile rcuperf: Change rcuperf to rcuscale 2020-08-24 18:39:24 -07:00
rcu_segcblist.c rcu/segcblist: Prevent useless GP start if no CBs to accelerate 2020-09-03 09:39:59 -07:00
rcu_segcblist.h rcu: Remove kfree_rcu() special casing and lazy-callback handling 2020-01-24 10:24:31 -08:00
rcu.h treewide: Make all debug_obj_descriptors const 2020-09-24 21:56:25 +02:00
rcuscale.c rcuperf: Change rcuperf to rcuscale 2020-08-24 18:39:24 -07:00
rcutorture.c rcutorture: Allow pointer leaks to test diagnostic code 2020-08-24 18:45:36 -07:00
refscale.c refperf: Avoid null pointer dereference when buf fails to allocate 2020-08-24 18:45:35 -07:00
srcutiny.c rcu: Use CONFIG_PREEMPTION where appropriate 2019-12-09 12:37:51 -08:00
srcutree.c srcu: Remove KCSAN stubs 2020-08-24 18:36:03 -07:00
sync.c rcu/sync: Simplify the state machine 2019-05-28 09:05:23 -07:00
tasks.h rcu-tasks: Enclose task-list scan in rcu_read_lock() 2020-09-16 16:32:38 -07:00
tiny.c rcu: Rename *_kfree_callback/*_kfree_rcu_offset/kfree_call_* 2020-06-29 11:59:25 -07:00
tree_exp.h rcu: Initialize at declaration time in rcu_exp_handler() 2020-08-24 18:36:03 -07:00
tree_plugin.h Merge branch 'strictgp.2020.08.24a' into HEAD 2020-09-03 09:47:42 -07:00
tree_stall.h rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled 2020-11-10 17:10:38 -08:00
tree.c Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-10-18 14:34:50 -07:00
tree.h Merge branch 'strictgp.2020.08.24a' into HEAD 2020-09-03 09:47:42 -07:00
update.c Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-10-18 14:34:50 -07:00