diff options
Diffstat (limited to 'include/linux/compiler.h')
| -rw-r--r-- | include/linux/compiler.h | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 3672353a0acd..188ed9f65517 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -88,17 +88,22 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, /* Unreachable code */ #ifdef CONFIG_STACK_VALIDATION +/* + * These macros help objtool understand GCC code flow for unreachable code. + * The __COUNTER__ based labels are a hack to make each instance of the macros + * unique, to convince GCC not to merge duplicate inline asm statements. + */ #define annotate_reachable() ({ \ - asm("%c0:\n\t" \ - ".pushsection .discard.reachable\n\t" \ - ".long %c0b - .\n\t" \ - ".popsection\n\t" : : "i" (__COUNTER__)); \ + asm volatile("%c0:\n\t" \ + ".pushsection .discard.reachable\n\t" \ + ".long %c0b - .\n\t" \ + ".popsection\n\t" : : "i" (__COUNTER__)); \ }) #define annotate_unreachable() ({ \ - asm("%c0:\n\t" \ - ".pushsection .discard.unreachable\n\t" \ - ".long %c0b - .\n\t" \ - ".popsection\n\t" : : "i" (__COUNTER__)); \ + asm volatile("%c0:\n\t" \ + ".pushsection .discard.unreachable\n\t" \ + ".long %c0b - .\n\t" \ + ".popsection\n\t" : : "i" (__COUNTER__)); \ }) #define ASM_UNREACHABLE \ "999:\n\t" \ |