From 59bc300b712998d10254ee20e24f2e7ec09c560a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 29 May 2020 23:27:39 +0200 Subject: [PATCH] x86/entry: Clarify irq_{enter,exit}_rcu() Because: irq_enter_rcu() includes lockdep_hardirq_enter() irq_exit_rcu() does *NOT* include lockdep_hardirq_exit() Which resulted in two 'stray' lockdep_hardirq_exit() calls in idtentry.h, and me spending a long time trying to find the matching enter calls. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200529213321.359433429@infradead.org --- arch/x86/include/asm/idtentry.h | 2 -- kernel/softirq.c | 21 ++++++++++++++------- 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h index 38b672ded40b..d203c541a65a 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -206,7 +206,6 @@ __visible noinstr void func(struct pt_regs *regs, \ kvm_set_cpu_l1tf_flush_l1d(); \ __##func (regs, (u8)error_code); \ irq_exit_rcu(); \ - lockdep_hardirq_exit(); \ instrumentation_end(); \ idtentry_exit_cond_rcu(regs, rcu_exit); \ } \ @@ -249,7 +248,6 @@ __visible noinstr void func(struct pt_regs *regs) \ kvm_set_cpu_l1tf_flush_l1d(); \ run_on_irqstack_cond(__##func, regs, regs); \ irq_exit_rcu(); \ - lockdep_hardirq_exit(); \ instrumentation_end(); \ idtentry_exit_cond_rcu(regs, rcu_exit); \ } \ diff --git a/kernel/softirq.c b/kernel/softirq.c index beb8e3a66c7c..c4201b7f42b1 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -404,12 +404,7 @@ static inline void tick_irq_exit(void) #endif } -/** - * irq_exit_rcu() - Exit an interrupt context without updating RCU - * - * Also processes softirqs if needed and possible. - */ -void irq_exit_rcu(void) +static inline void __irq_exit_rcu(void) { #ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED local_irq_disable(); @@ -424,6 +419,18 @@ void irq_exit_rcu(void) tick_irq_exit(); } +/** + * irq_exit_rcu() - Exit an interrupt context without updating RCU + * + * Also processes softirqs if needed and possible. + */ +void irq_exit_rcu(void) +{ + __irq_exit_rcu(); + /* must be last! */ + lockdep_hardirq_exit(); +} + /** * irq_exit - Exit an interrupt context, update RCU and lockdep * @@ -431,7 +438,7 @@ void irq_exit_rcu(void) */ void irq_exit(void) { - irq_exit_rcu(); + __irq_exit_rcu(); rcu_irq_exit(); /* must be last! */ lockdep_hardirq_exit(); -- GitLab