ref: f596580cba7c5b7bae84ee7cd83d2b2a438a1e9b
dir: /sys/src/libc/port/calloc.c/
#include <u.h>
#include <libc.h>
void*
calloc(ulong n, ulong s)
{
void *v;
if(n > 1 && ((ulong)-1)/n < s)
return nil;
if(v = mallocz(n*s, 1))
setmalloctag(v, getcallerpc(&n));
return v;
}