diff options
| author | Tejun Heo <tj@kernel.org> | 2009-01-21 17:26:05 +0900 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2009-01-21 17:26:05 +0900 |
| commit | 67e68bde02fe783efc2ce2ca31bdb992f5235f8d (patch) | |
| tree | 9dafb5703ff8012920673d448889c6ba4809e871 | |
| parent | 8f5d36ed5bb6e33024619eaee15b7ce2e3d115b3 (diff) | |
x86: update canary handling during switch
Impact: cleanup
In switch_to(), instead of taking offset to irq_stack_union.stack,
make it a proper percpu access using __percpu_arg() and per_cpu_var().
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | arch/x86/include/asm/system.h | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h index 52eb748a68a..2fcc70bc85f 100644 --- a/arch/x86/include/asm/system.h +++ b/arch/x86/include/asm/system.h @@ -89,13 +89,15 @@ do { \ #ifdef CONFIG_CC_STACKPROTECTOR #define __switch_canary \ "movq %P[task_canary](%%rsi),%%r8\n\t" \ - "movq %%r8,%%gs:%P[gs_canary]\n\t" -#define __switch_canary_param \ - , [task_canary] "i" (offsetof(struct task_struct, stack_canary)) \ - , [gs_canary] "i" (offsetof(union irq_stack_union, stack_canary)) + "movq %%r8,"__percpu_arg([gs_canary])"\n\t" +#define __switch_canary_oparam \ + , [gs_canary] "=m" (per_cpu_var(irq_stack_union.stack_canary)) +#define __switch_canary_iparam \ + , [task_canary] "i" (offsetof(struct task_struct, stack_canary)) #else /* CC_STACKPROTECTOR */ #define __switch_canary -#define __switch_canary_param +#define __switch_canary_oparam +#define __switch_canary_iparam #endif /* CC_STACKPROTECTOR */ /* Save restore flags to clear handle leaking NT */ @@ -114,13 +116,14 @@ do { \ "jc ret_from_fork\n\t" \ RESTORE_CONTEXT \ : "=a" (last) \ + __switch_canary_oparam \ : [next] "S" (next), [prev] "D" (prev), \ [threadrsp] "i" (offsetof(struct task_struct, thread.sp)), \ [ti_flags] "i" (offsetof(struct thread_info, flags)), \ [tif_fork] "i" (TIF_FORK), \ [thread_info] "i" (offsetof(struct task_struct, stack)), \ [current_task] "m" (per_cpu_var(current_task)) \ - __switch_canary_param \ + __switch_canary_iparam \ : "memory", "cc" __EXTRA_CLOBBER) #endif |