s390/kasan: improve string/memory functions checks

Avoid using arch specific implementations of string/memory functions
with KASAN since gcc cannot instrument asm code memory accesses and
many bugs could be missed.

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 22 insertions, 6 deletions

diff --git a/arch/s390/include/asm/string.h b/arch/s390/include/asm/string.h
index 116cc15a4b8a..70d87db54e62 100644
--- a/arch/s390/include/asm/string.h
+++ b/arch/s390/include/asm/string.h
@@ -12,15 +12,21 @@
 #include <linux/types.h>
 #endif
 
-#define __HAVE_ARCH_MEMCHR	/* inline & arch function */
-#define __HAVE_ARCH_MEMCMP	/* arch function */
 #define __HAVE_ARCH_MEMCPY	/* gcc builtin & arch function */
 #define __HAVE_ARCH_MEMMOVE	/* gcc builtin & arch function */
-#define __HAVE_ARCH_MEMSCAN	/* inline & arch function */
 #define __HAVE_ARCH_MEMSET	/* gcc builtin & arch function */
 #define __HAVE_ARCH_MEMSET16	/* arch function */
 #define __HAVE_ARCH_MEMSET32	/* arch function */
 #define __HAVE_ARCH_MEMSET64	/* arch function */
+
+void *memcpy(void *dest, const void *src, size_t n);
+void *memset(void *s, int c, size_t n);
+void *memmove(void *dest, const void *src, size_t n);
+
+#ifndef CONFIG_KASAN
+#define __HAVE_ARCH_MEMCHR	/* inline & arch function */
+#define __HAVE_ARCH_MEMCMP	/* arch function */
+#define __HAVE_ARCH_MEMSCAN	/* inline & arch function */
 #define __HAVE_ARCH_STRCAT	/* inline & arch function */
 #define __HAVE_ARCH_STRCMP	/* arch function */
 #define __HAVE_ARCH_STRCPY	/* inline & arch function */
@@ -35,9 +41,6 @@
 
 /* Prototypes for non-inlined arch strings functions. */
 int memcmp(const void *s1, const void *s2, size_t n);
-void *memcpy(void *dest, const void *src, size_t n);
-void *memset(void *s, int c, size_t n);
-void *memmove(void *dest, const void *src, size_t n);
 int strcmp(const char *s1, const char *s2);
 size_t strlcat(char *dest, const char *src, size_t n);
 size_t strlcpy(char *dest, const char *src, size_t size);
@@ -45,6 +48,7 @@ char *strncat(char *dest, const char *src, size_t n);
 char *strncpy(char *dest, const char *src, size_t n);
 char *strrchr(const char *s, int c);
 char *strstr(const char *s1, const char *s2);
+#endif /* !CONFIG_KASAN */
 
 #undef __HAVE_ARCH_STRCHR
 #undef __HAVE_ARCH_STRNCHR
@@ -95,6 +99,7 @@ static inline void *memset64(uint64_t *s, uint64_t v, size_t count)
 
 #if !defined(IN_ARCH_STRING_C) && (!defined(CONFIG_FORTIFY_SOURCE) || defined(__NO_FORTIFY))
 
+#ifdef __HAVE_ARCH_MEMCHR
 static inline void *memchr(const void * s, int c, size_t n)
 {
 	register int r0 asm("0") = (char) c;
@@ -109,7 +114,9 @@ static inline void *memchr(const void * s, int c, size_t n)
 		: "+a" (ret), "+&a" (s) : "d" (r0) : "cc", "memory");
 	return (void *) ret;
 }
+#endif
 
+#ifdef __HAVE_ARCH_MEMSCAN
 static inline void *memscan(void *s, int c, size_t n)
 {
 	register int r0 asm("0") = (char) c;
@@ -121,7 +128,9 @@ static inline void *memscan(void *s, int c, size_t n)
 		: "+a" (ret), "+&a" (s) : "d" (r0) : "cc", "memory");
 	return (void *) ret;
 }
+#endif
 
+#ifdef __HAVE_ARCH_STRCAT
 static inline char *strcat(char *dst, const char *src)
 {
 	register int r0 asm("0") = 0;
@@ -137,7 +146,9 @@ static inline char *strcat(char *dst, const char *src)
 		: "d" (r0), "0" (0) : "cc", "memory" );
 	return ret;
 }
+#endif
 
+#ifdef __HAVE_ARCH_STRCPY
 static inline char *strcpy(char *dst, const char *src)
 {
 	register int r0 asm("0") = 0;
@@ -150,7 +161,9 @@ static inline char *strcpy(char *dst, const char *src)
 		: "cc", "memory");
 	return ret;
 }
+#endif
 
+#ifdef __HAVE_ARCH_STRLEN
 static inline size_t strlen(const char *s)
 {
 	register unsigned long r0 asm("0") = 0;
@@ -162,7 +175,9 @@ static inline size_t strlen(const char *s)
 		: "+d" (r0), "+a" (tmp) :  : "cc", "memory");
 	return r0 - (unsigned long) s;
 }
+#endif
 
+#ifdef __HAVE_ARCH_STRNLEN
 static inline size_t strnlen(const char * s, size_t n)
 {
 	register int r0 asm("0") = 0;
@@ -175,6 +190,7 @@ static inline size_t strnlen(const char * s, size_t n)
 		: "+a" (end), "+a" (tmp) : "d" (r0)  : "cc", "memory");
 	return end - s;
 }
+#endif
 #else /* IN_ARCH_STRING_C */
 void *memchr(const void * s, int c, size_t n);
 void *memscan(void *s, int c, size_t n);