fill_canary
fill_canary(p, size, B2SIZE(bucket));
fill_canary(p, sz - mopts.malloc_guard,
fill_canary(p, newsz,
fill_canary(p, newsz, PAGEROUND(newsz));
fill_canary(p, newsz, PAGEROUND(newsz));
fill_canary(p, newsz, B2SIZE(info->bucket));
fill_canary(p, sz - mopts.malloc_guard,