// SPDX-License-Identifier: GPL-2.0-only
#include <stddef.h>

/*
 * Override the "basic" built-in string helpers so that they can be used in
 * guest code.  KVM selftests don't support dynamic loading in guest code and
 * will jump into the weeds if the compiler decides to insert an out-of-line
 * call via the PLT.
 */
int memcmp(const void *cs, const void *ct, size_t count)
{
        const unsigned char *su1, *su2;
        int res = 0;

        for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) {
                if ((res = *su1 - *su2) != 0)
                        break;
        }
        return res;
}

void *memcpy(void *dest, const void *src, size_t count)
{
        char *tmp = dest;
        const char *s = src;

        while (count--)
                *tmp++ = *s++;
        return dest;
}

void *memset(void *s, int c, size_t count)
{
        char *xs = s;

        while (count--)
                *xs++ = c;
        return s;
}

size_t strnlen(const char *s, size_t count)
{
        const char *sc;

        for (sc = s; count-- && *sc != '\0'; ++sc)
                /* nothing */;
        return sc - s;
}