mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
6f7d0cb1c3
This makes breaking changes to add underscores to many non-standard function names provided by the c library. MODE=tiny is now tinier and we now use smaller locks that are better for tiny apps in this mode. Some headers have been renamed to be in the same folder as the build package, so it'll be easier to know which build dependency is needed. Certain old misguided interfaces have been removed. Intel intrinsics headers are now listed in libc/isystem (but not in the amalgamation) to help further improve open source compatibility. Header complexity has also been reduced. Lastly, more shell scripts are now available.
120 lines
4.7 KiB
C
120 lines
4.7 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 2021 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/intrin/strace.internal.h"
|
|
#include "libc/calls/struct/metasigaltstack.h"
|
|
#include "libc/calls/struct/sigaltstack.h"
|
|
#include "libc/calls/struct/sigaltstack.internal.h"
|
|
#include "libc/calls/syscall-sysv.internal.h"
|
|
#include "libc/dce.h"
|
|
#include "libc/intrin/asan.internal.h"
|
|
#include "libc/intrin/describeflags.internal.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
|
|
static void sigaltstack2bsd(struct sigaltstack_bsd *bsd,
|
|
const struct sigaltstack *linux) {
|
|
void *sp;
|
|
int flags;
|
|
size_t size;
|
|
sp = linux->ss_sp;
|
|
flags = linux->ss_flags;
|
|
size = linux->ss_size;
|
|
bsd->ss_sp = sp;
|
|
bsd->ss_flags = flags;
|
|
bsd->ss_size = size;
|
|
}
|
|
|
|
static void sigaltstack2linux(struct sigaltstack *linux,
|
|
const struct sigaltstack_bsd *bsd) {
|
|
void *sp;
|
|
int flags;
|
|
size_t size;
|
|
sp = bsd->ss_sp;
|
|
flags = bsd->ss_flags;
|
|
size = bsd->ss_size;
|
|
linux->ss_sp = sp;
|
|
linux->ss_flags = flags;
|
|
linux->ss_size = size;
|
|
}
|
|
|
|
/**
|
|
* Sets and/or gets alternate signal stack, e.g.
|
|
*
|
|
* struct sigaction sa;
|
|
* struct sigaltstack ss;
|
|
* ss.ss_flags = 0;
|
|
* ss.ss_size = GetStackSize();
|
|
* ss.ss_sp = mmap(0, GetStackSize(), PROT_READ | PROT_WRITE,
|
|
* MAP_STACK | MAP_ANONYMOUS, -1, 0);
|
|
* sa.sa_flags = SA_ONSTACK;
|
|
* sa.sa_handler = OnStackOverflow;
|
|
* __cxa_atexit(free, ss[0].ss_sp, 0);
|
|
* sigemptyset(&sa.ss_mask);
|
|
* sigaltstack(&ss, 0);
|
|
* sigaction(SIGSEGV, &sa, 0);
|
|
*
|
|
* It's strongly recommended that you allocate a stack with the same
|
|
* size as GetStackSize() and that it have GetStackSize() alignment.
|
|
* Otherwise some of your runtime support code (e.g. ftrace stack use
|
|
* logging, kprintf() memory safety) won't be able to work as well.
|
|
*
|
|
* @param neu if non-null will install new signal alt stack
|
|
* @param old if non-null will receive current signal alt stack
|
|
* @return 0 on success, or -1 w/ errno
|
|
*/
|
|
int sigaltstack(const struct sigaltstack *neu, struct sigaltstack *old) {
|
|
int rc;
|
|
void *b;
|
|
const void *a;
|
|
struct sigaltstack_bsd bsd;
|
|
if (IsAsan() && ((old && __asan_check(old, sizeof(*old)).kind) ||
|
|
(neu && (__asan_check(neu, sizeof(*neu)).kind ||
|
|
__asan_check(neu->ss_sp, neu->ss_size).kind)))) {
|
|
rc = efault();
|
|
} else if (IsLinux() || IsBsd()) {
|
|
if (IsLinux()) {
|
|
a = neu;
|
|
b = old;
|
|
} else {
|
|
if (neu) {
|
|
sigaltstack2bsd(&bsd, neu);
|
|
a = &bsd;
|
|
} else {
|
|
a = 0;
|
|
}
|
|
if (old) {
|
|
b = &bsd;
|
|
} else {
|
|
b = 0;
|
|
}
|
|
}
|
|
if ((rc = sys_sigaltstack(a, b)) != -1) {
|
|
if (IsBsd() && old) {
|
|
sigaltstack2linux(old, &bsd);
|
|
}
|
|
rc = 0;
|
|
} else {
|
|
rc = -1;
|
|
}
|
|
} else {
|
|
rc = enosys();
|
|
}
|
|
STRACE("sigaltstack(%s, [%s]) → %d% m", DescribeSigaltstk(0, neu),
|
|
DescribeSigaltstk(0, old), rc);
|
|
return rc;
|
|
}
|