diff options
Diffstat (limited to 'arch/x86/include/asm/system.h')
| -rw-r--r-- | arch/x86/include/asm/system.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h index 79b98e5b96f4..2692ee8ef031 100644 --- a/arch/x86/include/asm/system.h +++ b/arch/x86/include/asm/system.h @@ -23,6 +23,22 @@ struct task_struct *__switch_to(struct task_struct *prev, #ifdef CONFIG_X86_32 +#ifdef CONFIG_CC_STACKPROTECTOR +#define __switch_canary \ + "movl "__percpu_arg([current_task])",%%ebx\n\t" \ + "movl %P[task_canary](%%ebx),%%ebx\n\t" \ + "movl %%ebx,"__percpu_arg([stack_canary])"\n\t" +#define __switch_canary_oparam \ + , [stack_canary] "=m" (per_cpu_var(stack_canary)) +#define __switch_canary_iparam \ + , [current_task] "m" (per_cpu_var(current_task)) \ + , [task_canary] "i" (offsetof(struct task_struct, stack_canary)) +#else /* CC_STACKPROTECTOR */ +#define __switch_canary +#define __switch_canary_oparam +#define __switch_canary_iparam +#endif /* CC_STACKPROTECTOR */ + /* * Saving eflags is important. It switches not only IOPL between tasks, * it also protects other tasks from NT leaking through sysenter etc. @@ -46,6 +62,7 @@ do { \ "pushl %[next_ip]\n\t" /* restore EIP */ \ "jmp __switch_to\n" /* regparm call */ \ "1:\t" \ + __switch_canary \ "popl %%ebp\n\t" /* restore EBP */ \ "popfl\n" /* restore flags */ \ \ @@ -58,6 +75,8 @@ do { \ "=b" (ebx), "=c" (ecx), "=d" (edx), \ "=S" (esi), "=D" (edi) \ \ + __switch_canary_oparam \ + \ /* input parameters: */ \ : [next_sp] "m" (next->thread.sp), \ [next_ip] "m" (next->thread.ip), \ @@ -66,6 +85,8 @@ do { \ [prev] "a" (prev), \ [next] "d" (next) \ \ + __switch_canary_iparam \ + \ : /* reloaded segment registers */ \ "memory"); \ } while (0) |