From e5fc6434d710894b5fc5a676d7f4c41608ab3ae6 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Tue, 22 Oct 2013 17:11:16 +0200 Subject: x86/irq: local_irq_restore() should not blindly popf local_irq_restore() should only be concerned with possibly changing the interrupt flag. A blind popf could corrupt other system flags. While playing in this area, fixup an opencoded use of X86_EFLAGS_IF. Signed-off-by: Andrew Cooper Acked-by: Keir Fraser --- xen/include/asm-x86/system.h | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/xen/include/asm-x86/system.h b/xen/include/asm-x86/system.h index 6ab7d56fbd..e9602aa3d8 100644 --- a/xen/include/asm-x86/system.h +++ b/xen/include/asm-x86/system.h @@ -3,6 +3,7 @@ #include #include +#include #define read_segment_register(name) \ ({ u16 __sel; \ @@ -159,15 +160,19 @@ static always_inline unsigned long __cmpxchg( #define local_irq_restore(x) \ ({ \ BUILD_BUG_ON(sizeof(x) != sizeof(long)); \ - asm volatile ( "push" __OS " %0 ; popf" __OS \ - : : "g" (x) : "memory", "cc" ); \ + asm volatile ( "pushfq\n\t" \ + "andq %0, (%%rsp)\n\t" \ + "orq %1, (%%rsp)\n\t" \ + "popfq" \ + : : "i?r" ( ~X86_EFLAGS_IF ), \ + "ri" ( (x) & X86_EFLAGS_IF ) ); \ }) static inline int local_irq_is_enabled(void) { unsigned long flags; local_save_flags(flags); - return !!(flags & (1<<9)); /* EFLAGS_IF */ + return !!(flags & X86_EFLAGS_IF); } #define BROKEN_ACPI_Sx 0x0001 -- cgit v1.2.3