gcc generates extremely bad code (7 byte immediate mov) for the old
null pointer write approach. it should be generating something like
"xor %eax,%eax ; mov %al,(%eax)". in any case, using a dedicated
crashing opcode accomplishes the same thing in one byte.
size_t oldlen = n0 + extra;
size_t newlen = n + extra;
/* Crash on realloc of freed chunk */
- if (extra & 1) *(volatile char *)0=0;
+ if (extra & 1) a_crash();
if (newlen < PAGE_SIZE && (new = malloc(n))) {
memcpy(new, p, n-OVERHEAD);
free(p);
char *base = (char *)self - extra;
size_t len = CHUNK_SIZE(self) + extra;
/* Crash on double free */
- if (extra & 1) *(volatile char *)0=0;
+ if (extra & 1) a_crash();
__munmap(base, len);
return;
}