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/* Copyright (C) 1994, 1995 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <signal.h>
#include <stddef.h>
static __sighandler_t user_handlers[NSIG];
extern int __context_syscall (int, struct sigcontext *);
extern int __sigaction_syscall (int,
const struct sigaction *, struct sigaction *);
static void
trampoline (int sig, int code, struct sigcontext *context)
{
(*(void (*) (int, int, struct sigcontext *)) user_handlers[sig])
(sig, code, context);
__context_syscall (1, context);
}
/* If ACT is not NULL, change the action for SIG to *ACT.
If OACT is not NULL, put the old action for SIG in *OACT. */
int
DEFUN(__sigaction, (sig, act, oact),
int sig AND CONST struct sigaction *act AND struct sigaction *oact)
{
struct sigaction myact;
__sighandler_t ohandler;
if (sig <= 0 || sig >= NSIG)
{
errno = EINVAL;
return -1;
}
ohandler = user_handlers[sig];
if (act != NULL)
{
user_handlers[sig] = act->sa_handler;
if (act->sa_handler != SIG_DFL && act->sa_handler != SIG_IGN)
{
myact = *act;
act = &myact;
act->sa_handler = (__sighandler_t) trampoline;
}
}
if (__sigaction_syscall (sig, act, oact) < 0)
{
/* The syscall got an error. Restore the old handler and return -1. */
user_handlers[sig] = ohandler;
return -1;
}
if (oact != NULL && oact->sa_handler == (__sighandler_t) trampoline)
oact->sa_handler = ohandler;
return 0;
}
weak_alias (__sigaction, sigaction)
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