1 files changed, 40 insertions, 13 deletions

diff --git a/arch/arm/include/asm/string.h b/arch/arm/include/asm/string.h
index cf4f3aad0fc1..6c607c68f3ad 100644
--- a/arch/arm/include/asm/string.h
+++ b/arch/arm/include/asm/string.h
@@ -1,9 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ASM_ARM_STRING_H
 #define __ASM_ARM_STRING_H
 
 /*
  * We don't do inline string functions, since the
  * optimised inline asm versions are not small.
+ *
+ * The __underscore versions of some functions are for KASan to be able
+ * to replace them with instrumented versions.
  */
 
 #define __HAVE_ARCH_STRRCHR
@@ -14,28 +18,51 @@ extern char * strchr(const char * s, int c);
 
 #define __HAVE_ARCH_MEMCPY
 extern void * memcpy(void *, const void *, __kernel_size_t);
+extern void *__memcpy(void *dest, const void *src, __kernel_size_t n);
 
 #define __HAVE_ARCH_MEMMOVE
 extern void * memmove(void *, const void *, __kernel_size_t);
+extern void *__memmove(void *dest, const void *src, __kernel_size_t n);
 
 #define __HAVE_ARCH_MEMCHR
 extern void * memchr(const void *, int, __kernel_size_t);
 
 #define __HAVE_ARCH_MEMSET
 extern void * memset(void *, int, __kernel_size_t);
+extern void *__memset(void *s, int c, __kernel_size_t n);
 
-extern void __memzero(void *ptr, __kernel_size_t n);
-
-#define memset(p,v,n)							\
-	({								\
-	 	void *__p = (p); size_t __n = n;			\
-		if ((__n) != 0) {					\
-			if (__builtin_constant_p((v)) && (v) == 0)	\
-				__memzero((__p),(__n));			\
-			else						\
-				memset((__p),(v),(__n));		\
-		}							\
-		(__p);							\
-	})
+#define __HAVE_ARCH_MEMSET32
+extern void *__memset32(uint32_t *, uint32_t v, __kernel_size_t);
+static inline void *memset32(uint32_t *p, uint32_t v, __kernel_size_t n)
+{
+	return __memset32(p, v, n * 4);
+}
+
+#define __HAVE_ARCH_MEMSET64
+extern void *__memset64(uint64_t *, uint32_t low, __kernel_size_t, uint32_t hi);
+static inline void *memset64(uint64_t *p, uint64_t v, __kernel_size_t n)
+{
+	return __memset64(p, v, n * 8, v >> 32);
+}
+
+/*
+ * For files that are not instrumented (e.g. mm/slub.c) we
+ * must use non-instrumented versions of the mem*
+ * functions named __memcpy() etc. All such kernel code has
+ * been tagged with KASAN_SANITIZE_file.o = n, which means
+ * that the address sanitization argument isn't passed to the
+ * compiler, and __SANITIZE_ADDRESS__ is not set. As a result
+ * these defines kick in.
+ */
+#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
+#define memcpy(dst, src, len) __memcpy(dst, src, len)
+#define memmove(dst, src, len) __memmove(dst, src, len)
+#define memset(s, c, n) __memset(s, c, n)
+
+#ifndef __NO_FORTIFY
+#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
+#endif
+
+#endif
 
 #endif