KMSAN must see as many memory accesses as possible to prevent false
positive reports. Fall back to versions of
memset16()/memset32()/memset64() implemented in lib/string.c instead of
those written in assembly.
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Suggested-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
---
arch/x86/include/asm/string_64.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 9be401d971a99..e9c736f4686f5 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -22,6 +22,11 @@ extern void *__memcpy(void *to, const void *from, size_t len);
void *memset(void *s, int c, size_t n);
void *__memset(void *s, int c, size_t n);
+/*
+ * KMSAN needs to instrument as much code as possible. Use C versions of
+ * memsetXX() from lib/string.c under KMSAN.
+ */
+#if !defined(CONFIG_KMSAN)
#define __HAVE_ARCH_MEMSET16
static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
{
@@ -57,6 +62,7 @@ static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
: "memory");
return s;
}
+#endif
#define __HAVE_ARCH_MEMMOVE
void *memmove(void *dest, const void *src, size_t count);
--
2.40.0.rc0.216.gc4246ad0f0-goog
