linux-zen-desktop/tools/testing/selftests/kvm/lib/string_override.c

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2023-08-30 17:31:07 +02:00
// 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;
}