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 /arch/x86/include/asm/init.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 'arch/x86/include/asm/init.h')
| -rw-r--r-- | arch/x86/include/asm/init.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/init.h b/arch/x86/include/asm/init.h index 6bfdaeddbae8..5a68e9db6518 100644 --- a/arch/x86/include/asm/init.h +++ b/arch/x86/include/asm/init.h @@ -5,7 +5,7 @@ #if defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 170000 #define __head __section(".head.text") __no_sanitize_undefined __no_stack_protector #else -#define __head __section(".head.text") __no_sanitize_undefined __no_sanitize_coverage +#define __head __section(".head.text") __no_sanitize_undefined __no_kstack_erase #endif struct x86_mapping_info { |