From: "tip-bot2 for Peter Zijlstra" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com,
Peter Zijlstra <peterz@infradead.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: core/rcu] sched/core: Allow try_invoke_on_locked_down_task() with irqs disabled
Date: Fri, 12 Feb 2021 12:37:24 -0000 [thread overview]
Message-ID: <161313344449.23325.1624790552720937291.tip-bot2@tip-bot2> (raw)
The following commit has been merged into the core/rcu branch of tip:
Commit-ID: 1b7af295541d75535374325fd617944534853919
Gitweb: https://git.kernel.org/tip/1b7af295541d75535374325fd617944534853919
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Sat, 29 Aug 2020 10:22:24 -07:00
Committer: Paul E. McKenney <paulmck@kernel.org>
CommitterDate: Mon, 04 Jan 2021 15:49:52 -08:00
sched/core: Allow try_invoke_on_locked_down_task() with irqs disabled
The try_invoke_on_locked_down_task() function currently 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
try_invoke_on_locked_down_task() to use raw_spin_lock_irqsave() instead
of raw_spin_lock_irq(), thus allowing use from either context.
Link: https://lore.kernel.org/lkml/000000000000903d5805ab908fc4@google.com/
Link: https://lore.kernel.org/lkml/20200928075729.GC2611@hirez.programming.kicks-ass.net/
Reported-by: syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/sched/core.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e7e4534..f768bb0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2989,7 +2989,7 @@ out:
/**
* try_invoke_on_locked_down_task - Invoke a function on task in fixed state
- * @p: Process for which the function is to be invoked.
+ * @p: Process for which the function is to be invoked, can be @current.
* @func: Function to invoke.
* @arg: Argument to function.
*
@@ -3007,12 +3007,11 @@ out:
*/
bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg)
{
- bool ret = false;
struct rq_flags rf;
+ bool ret = false;
struct rq *rq;
- lockdep_assert_irqs_enabled();
- raw_spin_lock_irq(&p->pi_lock);
+ raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
if (p->on_rq) {
rq = __task_rq_lock(p, &rf);
if (task_rq(p) == rq)
@@ -3029,7 +3028,7 @@ bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct t
ret = func(p, arg);
}
}
- raw_spin_unlock_irq(&p->pi_lock);
+ raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags);
return ret;
}
reply other threads:[~2021-02-12 13:05 UTC|newest]
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