glibc/sysdeps/mach/hurd/sigstack.c

/* Copyright (C) 1992-2023 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 Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <signal.h>
#include <hurd.h>

/* Run signals handlers on the stack specified by SS (if not NULL).
   If OSS is not NULL, it is filled in with the old signal stack status.  */
int
sigstack (struct sigstack *ss, struct sigstack *oss)
{
  stack_t as, oas;

  as.ss_sp = ss->ss_sp;
  as.ss_size = 0;
  as.ss_flags = 0;

  if (__sigaltstack (&as, &oas) < 0)
    return -1;

  if (oss != NULL)
    {
      oss->ss_sp = oas.ss_sp;
      oss->ss_onstack = oas.ss_flags & SS_ONSTACK;
    }

  return 0;
}