Date:   Fri,  3 Mar 2023 15:14:30 +0100
Mime-Version: 1.0
Message-ID: <20230303141433.3422671-1-glider@google.com>
Subject: [PATCH 1/4] x86: kmsan: Don't rename memintrinsics in uninstrumented files
From:   Alexander Potapenko <glider@google.com>
To:     glider@google.com
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org,
        dave.hansen@linux.intel.com, hpa@zytor.com,
        akpm@linux-foundation.org, elver@google.com, dvyukov@google.com,
        nathan@kernel.org, ndesaulniers@google.com,
        kasan-dev@googlegroups.com, Kees Cook <keescook@chromium.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

clang -fsanitize=kernel-memory already replaces calls to
memset/memcpy/memmove and their __builtin_ versions with
__msan_memset/__msan_memcpy/__msan_memmove in instrumented files, so
there is no need to override them.

In non-instrumented versions we are now required to leave memset()
and friends intact, so we cannot replace them with __msan_XXX() functions.

Cc: Kees Cook <keescook@chromium.org>
Suggested-by: Marco Elver <elver@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>

---
v2:
 - updated patch description
---
 arch/x86/include/asm/string_64.h | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 888731ccf1f67..9be401d971a99 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -15,22 +15,11 @@
 #endif
 
 #define __HAVE_ARCH_MEMCPY 1
-#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY)
-#undef memcpy
-#define memcpy __msan_memcpy
-#else
 extern void *memcpy(void *to, const void *from, size_t len);
-#endif
 extern void *__memcpy(void *to, const void *from, size_t len);
 
 #define __HAVE_ARCH_MEMSET
-#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY)
-extern void *__msan_memset(void *s, int c, size_t n);
-#undef memset
-#define memset __msan_memset
-#else
 void *memset(void *s, int c, size_t n);
-#endif
 void *__memset(void *s, int c, size_t n);
 
 #define __HAVE_ARCH_MEMSET16
@@ -70,13 +59,7 @@ static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
 }
 
 #define __HAVE_ARCH_MEMMOVE
-#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY)
-#undef memmove
-void *__msan_memmove(void *dest, const void *src, size_t len);
-#define memmove __msan_memmove
-#else
 void *memmove(void *dest, const void *src, size_t count);
-#endif
 void *__memmove(void *dest, const void *src, size_t count);
 
 int memcmp(const void *cs, const void *ct, size_t count);
-- 
2.40.0.rc0.216.gc4246ad0f0-goog