mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
7e0d92f002
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>
372 lines
8 KiB
C
372 lines
8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Optimized string functions
|
|
*
|
|
* S390 version
|
|
* Copyright IBM Corp. 2004
|
|
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
|
|
*/
|
|
|
|
#define IN_ARCH_STRING_C 1
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/string.h>
|
|
#include <linux/export.h>
|
|
|
|
/*
|
|
* Helper functions to find the end of a string
|
|
*/
|
|
static inline char *__strend(const char *s)
|
|
{
|
|
register unsigned long r0 asm("0") = 0;
|
|
|
|
asm volatile ("0: srst %0,%1\n"
|
|
" jo 0b"
|
|
: "+d" (r0), "+a" (s) : : "cc", "memory");
|
|
return (char *) r0;
|
|
}
|
|
|
|
static inline char *__strnend(const char *s, size_t n)
|
|
{
|
|
register unsigned long r0 asm("0") = 0;
|
|
const char *p = s + n;
|
|
|
|
asm volatile ("0: srst %0,%1\n"
|
|
" jo 0b"
|
|
: "+d" (p), "+a" (s) : "d" (r0) : "cc", "memory");
|
|
return (char *) p;
|
|
}
|
|
|
|
/**
|
|
* strlen - Find the length of a string
|
|
* @s: The string to be sized
|
|
*
|
|
* 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
|
|
* @s: The string to be sized
|
|
* @n: The maximum number of bytes to search
|
|
*
|
|
* 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
|
|
* @dest: Where to copy the string to
|
|
* @src: Where to copy the string from
|
|
*
|
|
* returns a pointer to @dest
|
|
*/
|
|
#ifdef __HAVE_ARCH_STRCPY
|
|
char *strcpy(char *dest, const char *src)
|
|
{
|
|
register int r0 asm("0") = 0;
|
|
char *ret = dest;
|
|
|
|
asm volatile ("0: mvst %0,%1\n"
|
|
" jo 0b"
|
|
: "+&a" (dest), "+&a" (src) : "d" (r0)
|
|
: "cc", "memory" );
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(strcpy);
|
|
#endif
|
|
|
|
/**
|
|
* strlcpy - Copy a %NUL terminated string into a sized buffer
|
|
* @dest: Where to copy the string to
|
|
* @src: Where to copy the string from
|
|
* @size: size of destination buffer
|
|
*
|
|
* Compatible with *BSD: the result is always a valid
|
|
* NUL-terminated string that fits in the buffer (unless,
|
|
* 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;
|
|
|
|
if (size) {
|
|
size_t len = (ret >= size) ? size-1 : ret;
|
|
dest[len] = '\0';
|
|
memcpy(dest, src, len);
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(strlcpy);
|
|
#endif
|
|
|
|
/**
|
|
* strncpy - Copy a length-limited, %NUL-terminated string
|
|
* @dest: Where to copy the string to
|
|
* @src: Where to copy the string from
|
|
* @n: The maximum number of bytes to copy
|
|
*
|
|
* 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;
|
|
memset(dest + len, 0, n - len);
|
|
memcpy(dest, src, len);
|
|
return dest;
|
|
}
|
|
EXPORT_SYMBOL(strncpy);
|
|
#endif
|
|
|
|
/**
|
|
* strcat - Append one %NUL-terminated string to another
|
|
* @dest: The string to be appended to
|
|
* @src: The string to append to it
|
|
*
|
|
* returns a pointer to @dest
|
|
*/
|
|
#ifdef __HAVE_ARCH_STRCAT
|
|
char *strcat(char *dest, const char *src)
|
|
{
|
|
register int r0 asm("0") = 0;
|
|
unsigned long dummy;
|
|
char *ret = dest;
|
|
|
|
asm volatile ("0: srst %0,%1\n"
|
|
" jo 0b\n"
|
|
"1: mvst %0,%2\n"
|
|
" jo 1b"
|
|
: "=&a" (dummy), "+a" (dest), "+a" (src)
|
|
: "d" (r0), "0" (0UL) : "cc", "memory" );
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(strcat);
|
|
#endif
|
|
|
|
/**
|
|
* strlcat - Append a length-limited, %NUL-terminated string to another
|
|
* @dest: The string to be appended to
|
|
* @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;
|
|
size_t len = __strend(src) - src;
|
|
size_t res = dsize + len;
|
|
|
|
if (dsize < n) {
|
|
dest += dsize;
|
|
n -= dsize;
|
|
if (len >= n)
|
|
len = n - 1;
|
|
dest[len] = '\0';
|
|
memcpy(dest, src, len);
|
|
}
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(strlcat);
|
|
#endif
|
|
|
|
/**
|
|
* strncat - Append a length-limited, %NUL-terminated string to another
|
|
* @dest: The string to be appended to
|
|
* @src: The string to append to it
|
|
* @n: The maximum numbers of bytes to copy
|
|
*
|
|
* returns a pointer to @dest
|
|
*
|
|
* 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;
|
|
char *p = __strend(dest);
|
|
|
|
p[len] = '\0';
|
|
memcpy(p, src, len);
|
|
return dest;
|
|
}
|
|
EXPORT_SYMBOL(strncat);
|
|
#endif
|
|
|
|
/**
|
|
* strcmp - Compare two strings
|
|
* @s1: One string
|
|
* @s2: Another string
|
|
*
|
|
* returns 0 if @s1 and @s2 are equal,
|
|
* < 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;
|
|
int ret = 0;
|
|
|
|
asm volatile ("0: clst %2,%3\n"
|
|
" jo 0b\n"
|
|
" je 1f\n"
|
|
" ic %0,0(%2)\n"
|
|
" ic %1,0(%3)\n"
|
|
" sr %0,%1\n"
|
|
"1:"
|
|
: "+d" (ret), "+d" (r0), "+a" (s1), "+a" (s2)
|
|
: : "cc", "memory");
|
|
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;
|
|
|
|
if (len)
|
|
do {
|
|
if (s[len] == (char) c)
|
|
return (char *) s + len;
|
|
} while (--len > 0);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(strrchr);
|
|
#endif
|
|
|
|
static inline int clcle(const char *s1, unsigned long l1,
|
|
const char *s2, unsigned long l2)
|
|
{
|
|
register unsigned long r2 asm("2") = (unsigned long) s1;
|
|
register unsigned long r3 asm("3") = (unsigned long) l1;
|
|
register unsigned long r4 asm("4") = (unsigned long) s2;
|
|
register unsigned long r5 asm("5") = (unsigned long) l2;
|
|
int cc;
|
|
|
|
asm volatile ("0: clcle %1,%3,0\n"
|
|
" jo 0b\n"
|
|
" ipm %0\n"
|
|
" srl %0,28"
|
|
: "=&d" (cc), "+a" (r2), "+a" (r3),
|
|
"+a" (r4), "+a" (r5) : : "cc", "memory");
|
|
return cc;
|
|
}
|
|
|
|
/**
|
|
* strstr - Find the first substring in a %NUL terminated string
|
|
* @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;
|
|
|
|
l2 = __strend(s2) - s2;
|
|
if (!l2)
|
|
return (char *) s1;
|
|
l1 = __strend(s1) - s1;
|
|
while (l1-- >= l2) {
|
|
int cc;
|
|
|
|
cc = clcle(s1, l2, s2, l2);
|
|
if (!cc)
|
|
return (char *) s1;
|
|
s1++;
|
|
}
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(strstr);
|
|
#endif
|
|
|
|
/**
|
|
* memchr - Find a character in an area of memory.
|
|
* @s: The memory area
|
|
* @c: The byte to search for
|
|
* @n: The size of the area.
|
|
*
|
|
* 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;
|
|
const void *ret = s + n;
|
|
|
|
asm volatile ("0: srst %0,%1\n"
|
|
" jo 0b\n"
|
|
" jl 1f\n"
|
|
" la %0,0\n"
|
|
"1:"
|
|
: "+a" (ret), "+&a" (s) : "d" (r0) : "cc", "memory");
|
|
return (void *) ret;
|
|
}
|
|
EXPORT_SYMBOL(memchr);
|
|
#endif
|
|
|
|
/**
|
|
* memcmp - Compare two areas of memory
|
|
* @s1: One area of memory
|
|
* @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;
|
|
|
|
ret = clcle(s1, n, s2, n);
|
|
if (ret)
|
|
ret = ret == 1 ? -1 : 1;
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(memcmp);
|
|
#endif
|
|
|
|
/**
|
|
* memscan - Find a character in an area of memory.
|
|
* @s: The memory area
|
|
* @c: The byte to search for
|
|
* @n: The size of the area.
|
|
*
|
|
* 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;
|
|
const void *ret = s + n;
|
|
|
|
asm volatile ("0: srst %0,%1\n"
|
|
" jo 0b\n"
|
|
: "+a" (ret), "+&a" (s) : "d" (r0) : "cc", "memory");
|
|
return (void *) ret;
|
|
}
|
|
EXPORT_SYMBOL(memscan);
|
|
#endif
|