1  /* Support functionality for using signals.
       2     Copyright (C) 2016-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef SUPPORT_SIGNAL_H
      20  #define SUPPORT_SIGNAL_H
      21  
      22  #include <signal.h>
      23  #include <sys/cdefs.h>
      24  
      25  __BEGIN_DECLS
      26  
      27  /* The following functions call the corresponding libc functions and
      28     terminate the process on error.  */
      29  
      30  void xraise (int sig);
      31  #ifdef _GNU_SOURCE
      32  sighandler_t xsignal (int sig, sighandler_t handler);
      33  #endif
      34  void xsigaction (int sig, const struct sigaction *newact,
      35                   struct sigaction *oldact);
      36  
      37  /* The following functions call the corresponding libpthread functions
      38     and terminate the process on error.  */
      39  
      40  void xpthread_sigmask (int how, const sigset_t *set, sigset_t *oldset);
      41  
      42  /* Allocate and activate an alternate signal stack.  This stack will
      43     have SIZE + MINSIGSTKSZ bytes of space, rounded up to a whole
      44     number of pages.  There will be large (at least 1 MiB) inaccessible
      45     guard bands on either side of it.  The return value is a cookie
      46     that can be passed to xfree_sigstack to deactivate and deallocate
      47     the stack again.  It is not necessary to call sigaltstack after
      48     calling this function.  Terminates the process on error.  */
      49  void *xalloc_sigstack (size_t size);
      50  
      51  /* Deactivate and deallocate a signal stack created by xalloc_sigstack.  */
      52  void xfree_sigstack (void *stack);
      53  
      54  /* Extract the actual address and size of the alternate signal stack from
      55     the cookie returned by xalloc_sigstack.  */
      56  void xget_sigstack_location (const void *stack, unsigned char **addrp,
      57                               size_t *sizep);
      58  
      59  __END_DECLS
      60  
      61  #endif /* SUPPORT_SIGNAL_H */