compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer

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 <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Arvind Sankar <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Acked-by: Miguel Ojeda <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: kees

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.