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Commit 7e0d92f0 authored by Vasily Gorbik's avatar Vasily Gorbik Committed by Martin Schwidefsky
Browse files

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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 32b77252

arch/s390/boot/string.c

+1 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#include <linux/ctype.h>

#include <linux/kernel.h>

#include <linux/errno.h>

#undef CONFIG_KASAN

#include "../lib/string.c"



int strncmp(const char *cs, const char *ct, size_t count)

arch/s390/include/asm/string.h

+22 −6
Original line number Diff line number Diff line
@@ -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);

arch/s390/lib/string.c

+28 −0
Original line number Diff line number Diff line
@@ -43,11 +43,13 @@ static inline char *__strnend(const char *s, size_t n) 
 *

 * returns the length of @s

 */

#ifdef __HAVE_ARCH_STRLEN

size_t strlen(const char *s)

{

	return __strend(s) - s;

}

EXPORT_SYMBOL(strlen);

#endif



/**

 * strnlen - Find the length of a length-limited string
@@ -56,11 +58,13 @@ EXPORT_SYMBOL(strlen); 
 *

 * returns the minimum of the length of @s and @n

 */

#ifdef __HAVE_ARCH_STRNLEN

size_t strnlen(const char *s, size_t n)

{

	return __strnend(s, n) - s;

}

EXPORT_SYMBOL(strnlen);

#endif



/**

 * strcpy - Copy a %NUL terminated string
@@ -69,6 +73,7 @@ EXPORT_SYMBOL(strnlen); 
 *

 * returns a pointer to @dest

 */

#ifdef __HAVE_ARCH_STRCPY

char *strcpy(char *dest, const char *src)

{

	register int r0 asm("0") = 0;
@@ -81,6 +86,7 @@ char *strcpy(char *dest, const char *src) 
	return ret;

}

EXPORT_SYMBOL(strcpy);

#endif



/**

 * strlcpy - Copy a %NUL terminated string into a sized buffer
@@ -93,6 +99,7 @@ EXPORT_SYMBOL(strcpy); 
 * of course, the buffer size is zero). It does not pad

 * out the result like strncpy() does.

 */

#ifdef __HAVE_ARCH_STRLCPY

size_t strlcpy(char *dest, const char *src, size_t size)

{

	size_t ret = __strend(src) - src;
@@ -105,6 +112,7 @@ size_t strlcpy(char *dest, const char *src, size_t size) 
	return ret;

}

EXPORT_SYMBOL(strlcpy);

#endif



/**

 * strncpy - Copy a length-limited, %NUL-terminated string
@@ -115,6 +123,7 @@ EXPORT_SYMBOL(strlcpy); 
 * The result is not %NUL-terminated if the source exceeds

 * @n bytes.

 */

#ifdef __HAVE_ARCH_STRNCPY

char *strncpy(char *dest, const char *src, size_t n)

{

	size_t len = __strnend(src, n) - src;
@@ -123,6 +132,7 @@ char *strncpy(char *dest, const char *src, size_t n) 
	return dest;

}

EXPORT_SYMBOL(strncpy);

#endif



/**

 * strcat - Append one %NUL-terminated string to another
@@ -131,6 +141,7 @@ EXPORT_SYMBOL(strncpy); 
 *

 * returns a pointer to @dest

 */

#ifdef __HAVE_ARCH_STRCAT

char *strcat(char *dest, const char *src)

{

	register int r0 asm("0") = 0;
@@ -146,6 +157,7 @@ char *strcat(char *dest, const char *src) 
	return ret;

}

EXPORT_SYMBOL(strcat);

#endif



/**

 * strlcat - Append a length-limited, %NUL-terminated string to another
@@ -153,6 +165,7 @@ EXPORT_SYMBOL(strcat); 
 * @src: The string to append to it

 * @n: The size of the destination buffer.

 */

#ifdef __HAVE_ARCH_STRLCAT

size_t strlcat(char *dest, const char *src, size_t n)

{

	size_t dsize = __strend(dest) - dest;
@@ -170,6 +183,7 @@ size_t strlcat(char *dest, const char *src, size_t n) 
	return res;

}

EXPORT_SYMBOL(strlcat);

#endif



/**

 * strncat - Append a length-limited, %NUL-terminated string to another
@@ -182,6 +196,7 @@ EXPORT_SYMBOL(strlcat); 
 * Note that in contrast to strncpy, strncat ensures the result is

 * terminated.

 */

#ifdef __HAVE_ARCH_STRNCAT

char *strncat(char *dest, const char *src, size_t n)

{

	size_t len = __strnend(src, n) - src;
@@ -192,6 +207,7 @@ char *strncat(char *dest, const char *src, size_t n) 
	return dest;

}

EXPORT_SYMBOL(strncat);

#endif



/**

 * strcmp - Compare two strings
@@ -202,6 +218,7 @@ EXPORT_SYMBOL(strncat); 
 *	   < 0 if @s1 is less than @s2

 *	   > 0 if @s1 is greater than @s2

 */

#ifdef __HAVE_ARCH_STRCMP

int strcmp(const char *s1, const char *s2)

{

	register int r0 asm("0") = 0;
@@ -219,12 +236,14 @@ int strcmp(const char *s1, const char *s2) 
	return ret;

}

EXPORT_SYMBOL(strcmp);

#endif



/**

 * strrchr - Find the last occurrence of a character in a string

 * @s: The string to be searched

 * @c: The character to search for

 */

#ifdef __HAVE_ARCH_STRRCHR

char *strrchr(const char *s, int c)

{

       size_t len = __strend(s) - s;
@@ -237,6 +256,7 @@ char *strrchr(const char *s, int c) 
       return NULL;

}

EXPORT_SYMBOL(strrchr);

#endif



static inline int clcle(const char *s1, unsigned long l1,

			const char *s2, unsigned long l2)
@@ -261,6 +281,7 @@ static inline int clcle(const char *s1, unsigned long l1, 
 * @s1: The string to be searched

 * @s2: The string to search for

 */

#ifdef __HAVE_ARCH_STRSTR

char *strstr(const char *s1, const char *s2)

{

	int l1, l2;
@@ -280,6 +301,7 @@ char *strstr(const char *s1, const char *s2) 
	return NULL;

}

EXPORT_SYMBOL(strstr);

#endif



/**

 * memchr - Find a character in an area of memory.
@@ -290,6 +312,7 @@ EXPORT_SYMBOL(strstr); 
 * returns the address of the first occurrence of @c, or %NULL

 * if @c is not found

 */

#ifdef __HAVE_ARCH_MEMCHR

void *memchr(const void *s, int c, size_t n)

{

	register int r0 asm("0") = (char) c;
@@ -304,6 +327,7 @@ void *memchr(const void *s, int c, size_t n) 
	return (void *) ret;

}

EXPORT_SYMBOL(memchr);

#endif



/**

 * memcmp - Compare two areas of memory
@@ -311,6 +335,7 @@ EXPORT_SYMBOL(memchr); 
 * @s2: Another area of memory

 * @count: The size of the area.

 */

#ifdef __HAVE_ARCH_MEMCMP

int memcmp(const void *s1, const void *s2, size_t n)

{

	int ret;
@@ -321,6 +346,7 @@ int memcmp(const void *s1, const void *s2, size_t n) 
	return ret;

}

EXPORT_SYMBOL(memcmp);

#endif



/**

 * memscan - Find a character in an area of memory.
@@ -331,6 +357,7 @@ EXPORT_SYMBOL(memcmp); 
 * returns the address of the first occurrence of @c, or 1 byte past

 * the area if @c is not found

 */

#ifdef __HAVE_ARCH_MEMSCAN

void *memscan(void *s, int c, size_t n)

{

	register int r0 asm("0") = (char) c;
@@ -342,3 +369,4 @@ void *memscan(void *s, int c, size_t n) 
	return (void *) ret;

}

EXPORT_SYMBOL(memscan);

#endif