1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <stddef.h>
3
4 /*
5 * Override the "basic" built-in string helpers so that they can be used in
6 * guest code. KVM selftests don't support dynamic loading in guest code and
7 * will jump into the weeds if the compiler decides to insert an out-of-line
8 * call via the PLT.
9 */
memcmp(const void * cs,const void * ct,size_t count)10 int memcmp(const void *cs, const void *ct, size_t count)
11 {
12 const unsigned char *su1, *su2;
13 int res = 0;
14
15 for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) {
16 if ((res = *su1 - *su2) != 0)
17 break;
18 }
19 return res;
20 }
21
memcpy(void * dest,const void * src,size_t count)22 void *memcpy(void *dest, const void *src, size_t count)
23 {
24 char *tmp = dest;
25 const char *s = src;
26
27 while (count--)
28 *tmp++ = *s++;
29 return dest;
30 }
31
memset(void * s,int c,size_t count)32 void *memset(void *s, int c, size_t count)
33 {
34 char *xs = s;
35
36 while (count--)
37 *xs++ = c;
38 return s;
39 }
40
strnlen(const char * s,size_t count)41 size_t strnlen(const char *s, size_t count)
42 {
43 const char *sc;
44
45 for (sc = s; count-- && *sc != '\0'; ++sc)
46 /* nothing */;
47 return sc - s;
48 }
49