The patch titled
Subject: x86: kmsan: use C versions of memset16/memset32/memset64
has been added to the -mm mm-unstable branch. Its filename is
x86-kmsan-use-c-versions-of-memset16-memset32-memset64.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/x86-kmsan-use-c-versions-of-memset16-memset32-memset64.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Alexander Potapenko <glider@xxxxxxxxxx>
Subject: x86: kmsan: use C versions of memset16/memset32/memset64
Date: Fri, 3 Mar 2023 15:14:32 +0100
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.
Link: https://lkml.kernel.org/r/20230303141433.3422671-3-glider@xxxxxxxxxx
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Suggested-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/arch/x86/include/asm/string_64.h~x86-kmsan-use-c-versions-of-memset16-memset32-memset64
+++ a/arch/x86/include/asm/string_64.h
@@ -22,6 +22,11 @@ extern void *__memcpy(void *to, const vo
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
: "memory");
return s;
}
+#endif
#define __HAVE_ARCH_MEMMOVE
void *memmove(void *dest, const void *src, size_t count);
_
Patches currently in -mm which might be from glider@xxxxxxxxxx are
x86-kmsan-dont-rename-memintrinsics-in-uninstrumented-files.patch
kmsan-another-take-at-fixing-memcpy-tests.patch
x86-kmsan-use-c-versions-of-memset16-memset32-memset64.patch
kmsan-add-memsetxx-tests.patch
