Commit 903fd31d authored Sep 15, 2020 by Nicholas Piggin Committed by Michael Ellerman Oct 06, 2020

powerpc/64: fix irq replay missing preempt



Prior to commit 3282a3da ("powerpc/64: Implement soft interrupt
replay in C"), replayed interrupts returned by the regular interrupt
exit code, which performs preemption in case an interrupt had set
need_resched.

This logic was missed by the conversion. Adding preempt_disable/enable
around the interrupt replay and final irq enable will reschedule if
needed.

Fixes: 3282a3da ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-1-npiggin@gmail.com

parent cdb1ea02

arch/powerpc/kernel/irq.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -368,6 +368,12 @@ notrace void arch_local_irq_restore(unsigned long mask)
		}
		}

		/*
		* Disable preempt here, so that the below preempt_enable will
		* perform resched if required (a replayed interrupt may set
		* need_resched).
		*/
		preempt_disable();
		irq_soft_mask_set(IRQS_ALL_DISABLED);
		trace_hardirqs_off();

		@@ -377,6 +383,7 @@ notrace void arch_local_irq_restore(unsigned long mask)
		trace_hardirqs_on();
		irq_soft_mask_set(IRQS_ENABLED);
		__hard_irq_enable();
		preempt_enable();
		}
		EXPORT_SYMBOL(arch_local_irq_restore);

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