Commit 9f68b5b7 authored Nov 17, 2020 by Frederic Weisbecker Committed by Peter Zijlstra Nov 19, 2020

sched: Detect call to schedule from critical entry code



Detect calls to schedule() between user_enter() and user_exit(). Those
are symptoms of early entry code that either forgot to protect a call
to schedule() inside exception_enter()/exception_exit() or, in the case
of HAVE_CONTEXT_TRACKING_OFFSTACK, enabled interrupts or preemption in
a wrong spot.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201117151637.259084-4-frederic@kernel.org

parent 179a9cf7

kernel/sched/core.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -4291,6 +4291,7 @@ static inline void schedule_debug(struct task_struct *prev, bool preempt)
		preempt_count_set(PREEMPT_DISABLED);
		}
		rcu_sleep_check();
		SCHED_WARN_ON(ct_state() == CONTEXT_USER);

		profile_hit(SCHED_PROFILING, __builtin_return_address(0));

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