malloc/page_begin/page_begin.c


1
2
3
4
5
6
7
8
9
10

#include "page_begin.h"

void *page_begin(void *ptr, size_t page_size)
{
    char *a = ptr;
    char *p = NULL;
    size_t test = a - p;
    void *res = (void *)(test & ~(page_size - 1));
    return res;
}