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#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include "dynlink.h"
static size_t mal0_clear(char *p, size_t n)
{
const size_t pagesz = 4096; /* arbitrary */
if (n < pagesz) return n;
#ifdef __GNUC__
typedef uint64_t __attribute__((__may_alias__)) T;
#else
typedef unsigned char T;
#endif
char *pp = p + n;
size_t i = (uintptr_t)pp & (pagesz - 1);
for (;;) {
pp = memset(pp - i, 0, i);
if (pp - p < pagesz) return pp - p;
for (i = pagesz; i; i -= 2*sizeof(T), pp -= 2*sizeof(T))
if (((T *)pp)[-1] | ((T *)pp)[-2])
break;
}
}
static int allzerop(void *p)
{
return 0;
}
weak_alias(allzerop, __malloc_allzerop);
void *calloc(size_t m, size_t n)
{
if (n && m > (size_t)-1/n) {
errno = ENOMEM;
return 0;
}
n *= m;
void *p = malloc(n);
if (!p || (!__malloc_replaced && __malloc_allzerop(p)))
return p;
n = mal0_clear(p, n);
return memset(p, 0, n);
}
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