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/* POSIX.1 `sigaction' call for Linux/i386.
Copyright (C) 1991, 1995, 1996, 1997, 1998 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>
/* 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>
extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *,
struct kernel_sigaction *, size_t);
/* The variable is shared between all wrappers around signal handling
functions which have RT equivalents. */
int __libc_missing_rt_sigs;
/* 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)
{
struct old_kernel_sigaction k_newact, k_oldact;
int result;
/* First try the RT signals. */
if (!__libc_missing_rt_sigs)
{
struct kernel_sigaction kact, koact;
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;
kact.sa_restorer = ((act->sa_flags & SA_NOMASK)
? &&restore_nomask : &&restore);
}
/* XXX The size argument hopefully will have to be changed to the
real size of the user-level sigset_t. */
result = __syscall_rt_sigaction (sig, act ? &kact : NULL,
oact ? &koact : NULL, _NSIG / 8);
if (result >= 0 || errno != ENOSYS)
{
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;
}
__libc_missing_rt_sigs = 1;
}
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;
k_newact.sa_restorer = ((act->sa_flags & SA_NOMASK)
? &&restore_nomask : &&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;
restore:
asm (
#ifdef PIC
" pushl %%ebx\n"
" call 0f\n"
"0: popl %%ebx\n"
" addl $_GLOBAL_OFFSET_TABLE_+[.-0b], %%ebx\n"
" addl $8, %%esp\n"
" call __sigsetmask@PLT\n"
" addl $8, %%esp\n"
" popl %%ebx\n"
#else
" addl $4, %%esp\n"
" call __sigsetmask\n"
" addl $4, %%esp\n"
#endif
" popl %%eax\n"
" popl %%ecx\n"
" popl %%edx\n"
" popf\n"
" ret"
: : );
restore_nomask:
asm (" addl $4, %%esp\n"
" popl %%eax\n"
" popl %%ecx\n"
" popl %%edx\n"
" popf\n"
" ret"
: : );
/* NOTREACHED */
return -1;
}
weak_alias (__sigaction, sigaction)
|
