glibc/sysdeps/unix/sysv/linux/sigaction.c

136 lines
4.0 KiB
C

/* Copyright (C) 1997, 1998, 1999 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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sysdep.h>
#include <sys/syscall.h>
#include "kernel-features.h"
/* The difference here is that the sigaction structure used in the
kernel is not the same as we use in the libc. Therefore we must
translate it here. */
#include <kernel_sigaction.h>
#if __ASSUME_REALTIME_SIGNALS == 0
/* The variable is shared between all wrappers around signal handling
functions which have RT equivalents. This is the definition. */
int __libc_missing_rt_sigs;
extern int __syscall_sigaction (int, const struct old_kernel_sigaction *,
struct old_kernel_sigaction *);
# define rtsignals_guaranteed 0
#else
# define rtsignals_guaranteed 1
#endif
extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *,
struct kernel_sigaction *, size_t);
/* 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
__sigaction (sig, act, oact)
int sig;
const struct sigaction *act;
struct sigaction *oact;
{
struct old_kernel_sigaction k_sigact, k_osigact;
int result;
#if defiend __NR_rt_sigaction || __ASSUME_REALTIME_SIGNALS > 0
/* First try the RT signals. */
# if __ASSUME_REALTIME_SIGNALS == 0
if (!__libc_missing_rt_sigs)
# endif
{
struct kernel_sigaction kact, koact;
/* Save the current error value for later. We need not do this
if we are guaranteed to have realtime signals. */
# if __ASSUME_REALTIME_SIGNALS == 0
int saved_errno = errno;
# endif
if (act)
{
kact.k_sa_handler = act->sa_handler;
memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
kact.sa_flags = act->sa_flags;
# ifdef HAVE_SA_RESTORER
kact.sa_restorer = act->sa_restorer;
# endif
}
/* XXX The size argument hopefully will have to be changed to the
real size of the user-level sigset_t. */
result = INLINE_SYSCALL (rt_sigaction, 4, sig, act ? &kact : NULL,
oact ? &koact : NULL, _NSIG / 8);
# if __ASSUME_REALTIME_SIGNALS == 0
if (result >= 0 || errno != ENOSYS)
# endif
{
if (oact && result >= 0)
{
oact->sa_handler = koact.k_sa_handler;
memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
oact->sa_flags = koact.sa_flags;
# ifdef HAVE_SA_RESTORER
oact->sa_restorer = koact.sa_restorer;
# endif
}
return result;
}
# if __ASSUME_REALTIME_SIGNALS == 0
__set_errno (saved_errno);
__libc_missing_rt_sigs = 1;
# endif
}
#endif
#if __ASSUME_REALTIME_SIGNALS == 0
if (act)
{
k_sigact.k_sa_handler = act->sa_handler;
k_sigact.sa_mask = act->sa_mask.__val[0];
k_sigact.sa_flags = act->sa_flags;
# ifdef HAVE_SA_RESTORER
k_sigact.sa_restorer = act->sa_restorer;
# endif
}
result = INLINE_SYSCALL (sigaction, 3, sig, act ? &k_sigact : NULL,
oact ? &k_osigact : NULL);
if (oact && result >= 0)
{
oact->sa_handler = k_osigact.k_sa_handler;
oact->sa_mask.__val[0] = k_osigact.sa_mask;
oact->sa_flags = k_osigact.sa_flags;
# ifdef HAVE_SA_RESTORER
oact->sa_restorer = k_osigact.sa_restorer;
# endif
}
return result;
#endif
}
weak_alias (__sigaction, sigaction)