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/* POSIX.1 `sigaction' call for Linux/i386.
Copyright (C) 1991, 95, 96, 97, 98, 99 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 <sysdep.h>
#include <errno.h>
#include <stddef.h>
#include <signal.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>
/* We do not globally define the SA_RESTORER flag so do it here. */
#define SA_RESTORER 0x04000000
extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *,
struct kernel_sigaction *, size_t);
#if __ASSUME_REALTIME_SIGNALS == 0
/* The variable is shared between all wrappers around signal handling
functions which have RT equivalents. */
int __libc_missing_rt_sigs;
#endif
#ifdef __NR_rt_sigaction
static void restore_rt (void) asm ("__restore_rt");
#endif
static void restore (void) asm ("__restore");
/* 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 (int sig, const struct sigaction *act, struct sigaction *oact)
{
#if __ASSUME_REALTIME_SIGNALS == 0
struct old_kernel_sigaction k_newact, k_oldact;
#endif
int result;
#ifdef __NR_rt_sigaction
/* First try the RT signals. */
# if __ASSUME_REALTIME_SIGNALS == 0
if (!__libc_missing_rt_sigs)
# endif
{
struct kernel_sigaction kact, koact;
# 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 | SA_RESTORER;
kact.sa_restorer = ((act->sa_flags & SA_SIGINFO)
? &restore_rt : &restore);
}
/* 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;
oact->sa_restorer = koact.sa_restorer;
}
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_newact.k_sa_handler = act->sa_handler;
k_newact.sa_mask = act->sa_mask.__val[0];
k_newact.sa_flags = act->sa_flags | SA_RESTORER;
k_newact.sa_restorer = &restore;
}
asm volatile ("pushl %%ebx\n"
"movl %2, %%ebx\n"
"int $0x80\n"
"popl %%ebx"
: "=a" (result)
: "0" (SYS_ify (sigaction)), "r" (sig),
"c" (act ? &k_newact : 0), "d" (oact ? &k_oldact : 0));
if (result < 0)
{
__set_errno (-result);
return -1;
}
if (oact)
{
oact->sa_handler = k_oldact.k_sa_handler;
oact->sa_mask.__val[0] = k_oldact.sa_mask;
oact->sa_flags = k_oldact.sa_flags;
oact->sa_restorer = k_oldact.sa_restorer;
}
return 0;
#endif
}
weak_alias (__sigaction, sigaction)
#define RESTORE(name, syscall) RESTORE2 (name, syscall)
#define RESTORE2(name, syscall) \
asm \
( \
".align 16\n" \
"__" #name ":\n" \
" movl $" #syscall ", %eax\n" \
" int $0x80" \
);
#ifdef __NR_rt_sigaction
/* The return code for realtime-signals. */
RESTORE (restore_rt, __NR_rt_sigreturn)
#endif
/* For the boring old signals. */
# undef RESTORE2
# define RESTORE2(name, syscall) \
asm \
( \
".align 8\n" \
"__" #name ":\n" \
" popl %eax\n" \
" movl $" #syscall ", %eax\n" \
" int $0x80" \
);
RESTORE (restore, __NR_sigreturn)
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