cosmopolitan/libc/runtime/isheap.c

40 lines
2.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/runtime/memtrack.h"
#include "libc/runtime/runtime.h"
/**
* Returns true if address isn't stack and was malloc'd or mmap'd.
*
* @assume stack addresses are always greater than heap addresses
* @assume stack memory isn't stored beneath %rsp (-mno-red-zone)
*/
bool isheap(void *p) {
int x, i;
#if 1
register intptr_t rsp asm("rsp");
if ((intptr_t)p >= rsp) return false;
#endif
if ((intptr_t)p <= (intptr_t)_end) return false;
x = (intptr_t)p >> 16;
i = FindMemoryInterval(&_mmi, x);
return i < _mmi.i && x >= _mmi.p[i].x && x <= _mmi.p[i].y;
}