From 34b0900d323122113683685b200aae9f9b75e63b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 12 Feb 2009 21:30:48 +0100 Subject: [PATCH] x86: warn if arch_flush_lazy_mmu_cpu is called in preemptible context Impact: Catch cases where lazy MMU state is active in a preemtible context arch_flush_lazy_mmu_cpu() has been changed to disable preemption so the checks in enter/leave will never trigger. Put the preemtible() check into arch_flush_lazy_mmu_cpu() to catch such cases. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/paravirt.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index dcba6c567a2..c6520a4e85d 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -273,6 +273,7 @@ void arch_flush_lazy_mmu_mode(void) preempt_disable(); if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) { + WARN_ON(preempt_count() == 1); arch_leave_lazy_mmu_mode(); arch_enter_lazy_mmu_mode(); } @@ -285,6 +286,7 @@ void arch_flush_lazy_cpu_mode(void) preempt_disable(); if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) { + WARN_ON(preempt_count() == 1); arch_leave_lazy_cpu_mode(); arch_enter_lazy_cpu_mode(); } -- 2.41.1