From 658fdbef66e5e9be79b457edc2cbbb3add840aa9 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 26 Sep 2006 10:52:41 +0200 Subject: [PATCH] Don't leak NT bit into next task SYSENTER can cause a NT to be set which might cause crashes on the IRET in the next task. Following similar i386 patch from Linus. Signed-off-by: Andi Kleen --- include/asm-x86_64/system.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/asm-x86_64') diff --git a/include/asm-x86_64/system.h b/include/asm-x86_64/system.h index 6bf170bceae1..bd376bc8c4ab 100644 --- a/include/asm-x86_64/system.h +++ b/include/asm-x86_64/system.h @@ -14,12 +14,13 @@ #define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t" /* frame pointer must be last for get_wchan */ -#define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t" -#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\n\t" +#define SAVE_CONTEXT "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t" +#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t" #define __EXTRA_CLOBBER \ ,"rcx","rbx","rdx","r8","r9","r10","r11","r12","r13","r14","r15" +/* Save restore flags to clear handle leaking NT */ #define switch_to(prev,next,last) \ asm volatile(SAVE_CONTEXT \ "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \ -- cgit v1.2.2