glibc/sysdeps/unix/sysv/linux/i386/sigaction.c

/* POSIX.1 `sigaction' call for Linux/i386.
Copyright (C) 1991, 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 <sysdep.h>
#include <errno.h>
#include <stddef.h>
#include <signal.h>


/* 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 sigaction newact;
  int result;

  if (act)
    {
      newact = *act;
      newact.sa_restorer = ((act->sa_flags & SA_NOMASK)
			    ? &&restore_nomask : &&restore);
      act = &newact;
    }

  asm volatile ("pushl %%ebx\n"
		"movl %2, %%ebx\n"
		"int $0x80\n"
		"popl %%ebx"
		: "=a" (result)
		: "0" (SYS_ify (sigaction)), "r" (sig), "c" (act), "d" (oact));

  if (result < 0)
    {
      errno = -result;
      return -1;
    }
  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)