Commit fd844ba9 authored Jun 17, 2020 by Scott Wood Committed by Borislav Petkov Jun 28, 2020

sched/core: Check cpus_mask, not cpus_ptr in __set_cpus_allowed_ptr(), to fix mask corruption



This function is concerned with the long-term CPU mask, not the
transitory mask the task might have while migrate disabled.  Before
this patch, if a task was migrate-disabled at the time
__set_cpus_allowed_ptr() was called, and the new mask happened to be
equal to the CPU that the task was running on, then the mask update
would be lost.

Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200617121742.cpxppyi7twxmpin7@linutronix.de

parent 4f311afc

kernel/sched/core.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -1637,7 +1637,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
	goto out;		goto out;
	}		}

	if (cpumask_equal(p->cpus_ptr, new_mask))		if (cpumask_equal(&p->cpus_mask, new_mask))
	goto out;		goto out;

	/*		/*

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