cosmopolitan/libc/calls/sigprocmask.c
Justine Tunney ccbae7799e
Improve docs of more system calls
This change also found a few POSIX compliance bugs with errnos. Another
bug was discovered where, on Windows, pread() and pwrite() could modify
the file position in cases where ReadFile() returned an error e.g. when
seeking past the end of file. We also have more tests!
2022-10-02 22:14:33 -07:00

71 lines
3.5 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 │
│ │
│ 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/calls/internal.h"
#include "libc/calls/sig.internal.h"
#include "libc/calls/struct/sigset.h"
#include "libc/calls/struct/sigset.internal.h"
#include "libc/dce.h"
#include "libc/fmt/itoa.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/log/log.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/sig.h"
#include "libc/sysv/errfuns.h"
/**
* Changes signal blocking state of calling thread, e.g.:
*
* sigset_t neu,old;
* sigfillset(&neu);
* sigprocmask(SIG_BLOCK, &neu, &old);
* sigprocmask(SIG_SETMASK, &old, NULL);
*
* @param how can be SIG_BLOCK (U), SIG_UNBLOCK (/), SIG_SETMASK (=)
* @param set is the new mask content (optional)
* @param oldset will receive the old mask (optional) and can't overlap
* @return 0 on success, or -1 w/ errno
* @asyncsignalsafe
* @restartable
* @vforksafe
*/
int sigprocmask(int how, const sigset_t *opt_set, sigset_t *opt_out_oldset) {
int res, rc, arg1;
sigset_t old = {0};
const sigset_t *arg2;
if (IsAsan() &&
((opt_set && !__asan_is_valid(opt_set, sizeof(*opt_set))) ||
(opt_out_oldset &&
!__asan_is_valid(opt_out_oldset, sizeof(*opt_out_oldset))))) {
rc = efault();
} else if (IsMetal() || IsWindows()) {
rc = __sig_mask(how, opt_set, &old);
_check_interrupts(false, 0);
} else {
rc = sys_sigprocmask(how, opt_set, opt_out_oldset ? &old : 0);
}
if (rc != -1 && opt_out_oldset) {
*opt_out_oldset = old;
}
STRACE("sigprocmask(%s, %s, [%s]) → %d% m", DescribeHow(how),
DescribeSigset(0, opt_set), DescribeSigset(rc, opt_out_oldset), rc);
return rc;
}