Messages in this thread Patch in this message | | | Date | Thu, 21 Feb 2013 09:45:03 -0800 | From | tip-bot for Thomas Gleixner <> | Subject | [tip:irq/urgent] irq: Ensure irq_exit() code runs with interrupts disabled |
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Commit-ID: 630e7580f681475d92d87e78373e4136096e12f2 Gitweb: http://git.kernel.org/tip/630e7580f681475d92d87e78373e4136096e12f2 Author: Thomas Gleixner <tglx@linutronix.de> AuthorDate: Wed, 20 Feb 2013 22:00:48 +0100 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Thu, 21 Feb 2013 18:32:44 +0100
irq: Ensure irq_exit() code runs with interrupts disabled
We had already a few problems with code called from irq_exit() when interrupted from a nesting interrupt. This can happen on architectures which do not define __ARCH_IRQ_EXIT_IRQS_DISABLED.
__ARCH_IRQ_EXIT_IRQS_DISABLED should go away and we want to make it mandatory to call irq_exit() with interrupts disabled.
As a temporary protection disable interrupts for those architectures which do not define __ARCH_IRQ_EXIT_IRQS_DISABLED and add a WARN_ONCE when an architecture which defines __ARCH_IRQ_EXIT_IRQS_DISABLED calls irq_exit() with interrupts enabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1302202155320.22263@ionos
--- kernel/softirq.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/kernel/softirq.c b/kernel/softirq.c index f5cc25f..d1f7943 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -341,6 +341,14 @@ static inline void invoke_softirq(void) */ void irq_exit(void) { +#ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED + unsigned long flags; + + local_irq_save(flags); +#else + WARN_ON_ONCE(!irqs_disabled(); +#endif + account_irq_exit_time(current); trace_hardirq_exit(); sub_preempt_count(IRQ_EXIT_OFFSET); @@ -354,6 +362,9 @@ void irq_exit(void) #endif rcu_irq_exit(); sched_preempt_enable_no_resched(); +#ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED + local_irq_restore(flags); +#endif } /*
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