diff options
| author | Kees Cook <kees@kernel.org> | 2025-07-29 16:41:00 -0700 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2025-07-29 17:19:35 -0700 |
| commit | f627b51aaa041cba715b59026cf2d9cb1476c7ed (patch) | |
| tree | 7a3e2be2e44dde88a731b7b536a51728b5f3654c /include/linux/compiler-clang.h | |
| parent | 94fd44648dae2a5b6149a41faa0b07928c3e1963 (diff) | |
compiler_types: Provide __no_kstack_erase to disable coverage only on Clang
In order to support Clang's stack depth tracking (for Linux's kstack_erase
feature), the coverage sanitizer needed to be disabled for __init (and
__head) section code. Doing this universally (i.e. for GCC too) created
a number of unexpected problems, ranging from changes to inlining logic
to failures to DCE code on earlier GCC versions.
Since this change is only needed for Clang, specialize it so that GCC
doesn't see the change as it isn't needed there (the GCC implementation
of kstack_erase uses a GCC plugin that removes stack depth tracking
instrumentation from __init sections during a late pass in the IR).
Successfully build and boot tested with GCC 12 and Clang 22.
Fixes: 381a38ea53d2 ("init.h: Disable sanitizer coverage for __init and __head")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507270258.neWuiXLd-lkp@intel.com/
Reported-by: syzbot+5245cb609175fb6e8122@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6888d004.a00a0220.26d0e1.0004.GAE@google.com/
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20250729234055.it.233-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Diffstat (limited to 'include/linux/compiler-clang.h')
| -rw-r--r-- | include/linux/compiler-clang.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 4fc8e26914ad..fa4ffe037bc7 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -89,6 +89,9 @@ #define __no_sanitize_coverage #endif +/* Only Clang needs to disable the coverage sanitizer for kstack_erase. */ +#define __no_kstack_erase __no_sanitize_coverage + #if __has_feature(shadow_call_stack) # define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) #endif |