80 lines
2.2 KiB
C
80 lines
2.2 KiB
C
/* Copyright (C) 1994, 1995 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA. */
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#include <ansidecl.h>
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#include <errno.h>
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#include <signal.h>
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#include <stddef.h>
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static __sighandler_t user_handlers[NSIG];
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extern int __context_syscall (int, struct sigcontext *);
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extern int __sigaction_syscall (int,
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const struct sigaction *, struct sigaction *);
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static void
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trampoline (int sig, int code, struct sigcontext *context)
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{
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(*(void (*) (int, int, struct sigcontext *)) user_handlers[sig])
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(sig, code, context);
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__context_syscall (1, context);
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}
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/* If ACT is not NULL, change the action for SIG to *ACT.
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If OACT is not NULL, put the old action for SIG in *OACT. */
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int
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DEFUN(__sigaction, (sig, act, oact),
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int sig AND CONST struct sigaction *act AND struct sigaction *oact)
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{
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struct sigaction myact;
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__sighandler_t ohandler;
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if (sig <= 0 || sig >= NSIG)
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{
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errno = EINVAL;
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return -1;
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}
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ohandler = user_handlers[sig];
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if (act != NULL)
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{
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user_handlers[sig] = act->sa_handler;
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if (act->sa_handler != SIG_DFL && act->sa_handler != SIG_IGN)
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{
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myact = *act;
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act = &myact;
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act->sa_handler = (__sighandler_t) trampoline;
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}
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}
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if (__sigaction_syscall (sig, act, oact) < 0)
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{
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/* The syscall got an error. Restore the old handler and return -1. */
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user_handlers[sig] = ohandler;
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return -1;
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}
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if (oact != NULL && oact->sa_handler == (__sighandler_t) trampoline)
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oact->sa_handler = ohandler;
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return 0;
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}
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weak_alias (__sigaction, sigaction)
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