diff options
| -rw-r--r-- | include/asm-x86/system.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/asm-x86/system.h b/include/asm-x86/system.h index 299ae9605cb..33b0017156a 100644 --- a/include/asm-x86/system.h +++ b/include/asm-x86/system.h @@ -29,7 +29,14 @@ struct task_struct *__switch_to(struct task_struct *prev, */ #define switch_to(prev, next, last) \ do { \ - unsigned long esi, edi; \ + /* \ + * Context-switching clobbers all registers, so we clobber \ + * them explicitly, via unused output variables. \ + * (EAX and EBP is not listed because EBP is saved/restored \ + * explicitly for wchan access and EAX is the return value of \ + * __switch_to()) \ + */ \ + unsigned long ebx, ecx, edx, esi, edi; \ \ asm volatile( \ "pushfl \n\t" /* save flags */ \ @@ -49,6 +56,7 @@ do { \ "=a" (last), \ \ /* clobbered output registers: */ \ + "=b" (ebx), "=c" (ecx), "=d" (edx), \ "=S" (esi), "=D" (edi) \ \ /* input parameters: */ \ |