From 7a10e2a9190628a4024ea394ce7bd641ae40ffd1 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:23 +0100 Subject: [PATCH] x86: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. It also makes no more sense to fix the IRQ flags when a bug is detected as the assertion is now pure config-dependent debugging. And to quote Peter Zijlstra: The whole if !disabled, disable logic is uber paranoid programming, but I don't think we've ever seen that WARN trigger, and if it does (and then burns the kernel) we at least know what happend. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-8-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/entry/common.c | 4 +--- arch/x86/kernel/smpboot.c | 2 +- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index eaa0ba66cf96..d7d3cc24baf4 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -186,9 +186,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) addr_limit_user_check(); - if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled())) - local_irq_disable(); - + lockdep_assert_irqs_disabled(); lockdep_sys_exit(); cached_flags = READ_ONCE(ti->flags); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 198416ddff01..4008b6b9ad72 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1095,7 +1095,7 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle) unsigned long flags; int err, ret = 0; - WARN_ON(irqs_disabled()); + lockdep_assert_irqs_enabled(); pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);