93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
/* Copyright (C) 1998, 2000, 2005, 2006 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#define __need_NULL
|
|
#include <stddef.h>
|
|
#include <signal.h>
|
|
#include <string.h> /* For the real memset prototype. */
|
|
|
|
|
|
/* Set the disposition for SIG. */
|
|
__sighandler_t
|
|
sigset (sig, disp)
|
|
int sig;
|
|
__sighandler_t disp;
|
|
{
|
|
struct sigaction act;
|
|
struct sigaction oact;
|
|
sigset_t set;
|
|
sigset_t oset;
|
|
|
|
#ifdef SIG_HOLD
|
|
/* Handle SIG_HOLD first. */
|
|
if (disp == SIG_HOLD)
|
|
{
|
|
/* Create an empty signal set. */
|
|
if (__sigemptyset (&set) < 0)
|
|
return SIG_ERR;
|
|
|
|
/* Add the specified signal. */
|
|
if (__sigaddset (&set, sig) < 0)
|
|
return SIG_ERR;
|
|
|
|
/* Add the signal set to the current signal mask. */
|
|
if (__sigprocmask (SIG_BLOCK, &set, &oset) < 0)
|
|
return SIG_ERR;
|
|
|
|
/* If the signal was already blocked signal this to the caller. */
|
|
if (__sigismember (&oset, sig))
|
|
return SIG_HOLD;
|
|
|
|
/* We need to determine whether a specific handler is installed. */
|
|
if (__sigaction (sig, NULL, &oact) < 0)
|
|
return SIG_ERR;
|
|
|
|
return oact.sa_handler;
|
|
}
|
|
#endif /* SIG_HOLD */
|
|
|
|
/* Check signal extents to protect __sigismember. */
|
|
if (disp == SIG_ERR || sig < 1 || sig >= NSIG)
|
|
{
|
|
__set_errno (EINVAL);
|
|
return SIG_ERR;
|
|
}
|
|
|
|
act.sa_handler = disp;
|
|
if (__sigemptyset (&act.sa_mask) < 0)
|
|
return SIG_ERR;
|
|
act.sa_flags = 0;
|
|
if (__sigaction (sig, &act, &oact) < 0)
|
|
return SIG_ERR;
|
|
|
|
/* Create an empty signal set. */
|
|
if (__sigemptyset (&set) < 0)
|
|
return SIG_ERR;
|
|
|
|
/* Add the specified signal. */
|
|
if (__sigaddset (&set, sig) < 0)
|
|
return SIG_ERR;
|
|
|
|
/* Remove the signal set from the current signal mask. */
|
|
if (__sigprocmask (SIG_UNBLOCK, &set, &oset) < 0)
|
|
return SIG_ERR;
|
|
|
|
/* If the signal was already blocked return SIG_HOLD. */
|
|
return __sigismember (&oset, sig) ? SIG_HOLD : oact.sa_handler;
|
|
}
|