From 4c07f9046e48c3126978911239e20a5622ad0ad6 Mon Sep 17 00:00:00 2001 From: Roman Kagan Date: Mon, 17 Jul 2017 12:49:07 +0300 Subject: [PATCH] x86/mm, KVM: Fix warning when !CONFIG_PREEMPT_COUNT MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit A recent commit: d6e41f1151fe ("x86/mm, KVM: Teach KVM's VMX code that CR3 isn't a constant") introduced a VM_WARN_ON(!in_atomic()) which generates false positives on every VM entry on !CONFIG_PREEMPT_COUNT kernels. Replace it with a test for preemptible(), which appears to match the original intent and works across different CONFIG_PREEMPT* variations. Signed-off-by: Roman Kagan Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dave Hansen Cc: Linus Torvalds Cc: Mel Gorman Cc: Michal Hocko Cc: Nadav Amit Cc: Nadav Amit Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Rik van Riel Cc: Thomas Gleixner Cc: kvm@vger.kernel.org Cc: linux-mm@kvack.org Fixes: d6e41f1151fe ("x86/mm, KVM: Teach KVM's VMX code that CR3 isn't a constant") Signed-off-by: Ingo Molnar --- arch/x86/include/asm/mmu_context.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index ecfcb6643c9b..265c907d7d4c 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -293,7 +293,7 @@ static inline unsigned long __get_current_cr3_fast(void) unsigned long cr3 = __pa(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd); /* For now, be very restrictive about when this can be called. */ - VM_WARN_ON(in_nmi() || !in_atomic()); + VM_WARN_ON(in_nmi() || preemptible()); VM_BUG_ON(cr3 != __read_cr3()); return cr3; -- 2.20.1