cosmopolitan/libc/runtime/mapstack.c
Justine Tunney 369aebfc48
Make improvements
- Let OpenMP be usable via cosmocc
- Let libunwind be usable via cosmocc
- Make X86_HAVE(AVXVNNI) work correctly
- Avoid using MAP_GROWSDOWN on qemu-aarch64
- Introduce in6addr_any and in6addr_loopback
- Have thread stacks use MAP_GROWSDOWN by default
- Ask OpenMP to not use filesystem to manage threads
- Make NI_MAXHOST and NI_MAXSERV available w/o _GNU_SOURCE
2024-01-29 16:31:58 -08:00

67 lines
3.2 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/asancodes.h"
#include "libc/runtime/memtrack.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/stack.h"
#include "libc/sysv/consts/auxv.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/prot.h"
/**
* Allocates stack.
*
* The size of your returned stack is always GetStackSize().
*
* The bottom 4096 bytes of your stack can't be used, since it's always
* reserved for a read-only guard page. With ASAN it'll be poisoned too.
*
* The top 16 bytes of a stack can't be used due to openbsd:stackbound
* and those bytes are also poisoned under ASAN build modes.
*
* @return stack bottom address on success, or null w/ errno
*/
void *NewCosmoStack(void) {
char *p;
if ((p = mmap(0, GetStackSize(), PROT_READ | PROT_WRITE,
MAP_ANONYMOUS |
(IsAarch64() && IsLinux() && IsQemuUser() ? MAP_PRIVATE
: MAP_STACK),
-1, 0)) != MAP_FAILED) {
if (IsAsan()) {
__asan_poison(p + GetStackSize() - 16, 16, kAsanStackOverflow);
__asan_poison(p, getauxval(AT_PAGESZ), kAsanStackOverflow);
}
return p;
} else {
return 0;
}
}
/**
* Frees stack.
*
* @param stk was allocated by NewCosmoStack()
*/
int FreeCosmoStack(void *stk) {
return munmap(stk, GetStackSize());
}