49 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2#include <stddef.h>3 4/*5 * Override the "basic" built-in string helpers so that they can be used in6 * guest code. KVM selftests don't support dynamic loading in guest code and7 * will jump into the weeds if the compiler decides to insert an out-of-line8 * call via the PLT.9 */10int 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 22void *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 32void *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 41size_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