lkml.org 
[lkml]   [2021]   [Oct]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer
On Wed, Oct 20, 2021 at 01:00:39PM -0700, Kees Cook wrote:
> When Clang is using the hwaddress sanitizer, it sets __SANITIZE_ADDRESS__
> explicitly:
>
> #if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer)
> /* Emulate GCC's __SANITIZE_ADDRESS__ flag */
> #define __SANITIZE_ADDRESS__
> #endif
>
> Once hwaddress sanitizer was added to GCC, however, a separate define
> was created, __SANITIZE_HWADDRESS__. The kernel is expecting to find
> __SANITIZE_ADDRESS__ in either case, though, and the existing string
> macros break on supported architectures:
>
> #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
> !defined(__SANITIZE_ADDRESS__)
>
> where as other architectures (like arm32) have no idea about hwaddress
> sanitizer and just check for __SANITIZE_ADDRESS__:
>
> #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
>
> This would lead to compiler foritfy self-test warnings when building
> with CONFIG_KASAN_SW_TAGS=y:
>
> warning: unsafe memmove() usage lacked '__read_overflow2' symbol in lib/test_fortify/read_overflow2-memmove.c
> warning: unsafe memcpy() usage lacked '__write_overflow' symbol in lib/test_fortify/write_overflow-memcpy.c
> ...
>
> Sort this out by also defining __SANITIZE_ADDRESS__ in GCC under the
> hwaddress sanitizer.
>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Cc: Miguel Ojeda <ojeda@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Marco Elver <elver@google.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Arvind Sankar <nivedita@alum.mit.edu>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: llvm@lists.linux.dev
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
> I'm intending to take this via my overflow series, since that is what introduces
> the compile-test regression tests (which found this legitimate bug). :)
>
> -Kees
> ---
> include/linux/compiler-gcc.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
> index 6f24eb8c5dda..ccbbd31b3aae 100644
> --- a/include/linux/compiler-gcc.h
> +++ b/include/linux/compiler-gcc.h
> @@ -121,6 +121,14 @@
> #define __no_sanitize_coverage
> #endif
>
> +/*
> + * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
> + * matching the defines used by Clang.
> + */
> +#ifdef __SANITIZE_HWADDRESS__
> +#define __SANITIZE_ADDRESS__
> +#endif
> +
> /*
> * Turn individual warnings and errors on and off locally, depending
> * on version.
> --
> 2.30.2
>

\
 
 \ /
  Last update: 2021-10-21 00:01    [W:0.158 / U:5.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site