diff options
Diffstat (limited to 'include/linux/instruction_pointer.h')
| -rw-r--r-- | include/linux/instruction_pointer.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/instruction_pointer.h b/include/linux/instruction_pointer.h index aa0b3ffea935..ea5bc756bd99 100644 --- a/include/linux/instruction_pointer.h +++ b/include/linux/instruction_pointer.h @@ -8,6 +8,30 @@ #ifndef _THIS_IP_ #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) +/* + * The current generic definition of _THIS_IP_ is considered broken by GCC [1] + * and Clang [2]. In particular, the address of a label is only expected to be + * used with a computed goto. + * + * [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120071 + * [2] https://github.com/llvm/llvm-project/issues/138272 + * + * Mark it as broken, so that appropriate fallback options can be implemented + * for architectures that do not define their own _THIS_IP_. + */ +#define HAS_BROKEN_THIS_IP +#endif + +/* + * _CODE_LOCATION_ provides a unique identifier for the current code location. + * When _THIS_IP_ is broken (generic version), we fall back to a static marker + * which guarantees uniqueness and resolves to a constant address at link time, + * avoiding runtime overhead and compiler optimizations breaking it. + */ +#ifdef HAS_BROKEN_THIS_IP +#define _CODE_LOCATION_ ({ static const char __here; (unsigned long)&__here; }) +#else +#define _CODE_LOCATION_ _THIS_IP_ #endif #endif /* _LINUX_INSTRUCTION_POINTER_H */ |