[PATCH 5.10 043/451] compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer

[PATCH 5.10 043/451] compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer

[Greg Kroah-Hartman]

5.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kees Cook <keescook@chromium.org>

[ Upstream commit 9a48e7564ac83fb0f1d5b0eac5fe8a7af62da398 ]

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: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
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>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20211020200039.170424-1-keescook@chromium.org
Stable-dep-of: ced37e9ceae5 ("x86/dumpstack: Prevent KASAN false positive warnings in __show_regs()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 ae9a8e17287ce..faf0fd509cb5a 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -140,6 +140,14 @@
 #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.
-- 
2.51.0