1 /* Support functionality for using signals.
2    Copyright (C) 2016-2021 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 sighandler_t xsignal (int sig, sighandler_t handler);
32 void xsigaction (int sig, const struct sigaction *newact,
33                  struct sigaction *oldact);
34 
35 /* The following functions call the corresponding libpthread functions
36    and terminate the process on error.  */
37 
38 void xpthread_sigmask (int how, const sigset_t *set, sigset_t *oldset);
39 
40 /* Allocate and activate an alternate signal stack.  This stack will
41    have SIZE + MINSIGSTKSZ bytes of space, rounded up to a whole
42    number of pages.  There will be large (at least 1 MiB) inaccessible
43    guard bands on either side of it.  The return value is a cookie
44    that can be passed to xfree_sigstack to deactivate and deallocate
45    the stack again.  It is not necessary to call sigaltstack after
46    calling this function.  Terminates the process on error.  */
47 void *xalloc_sigstack (size_t size);
48 
49 /* Deactivate and deallocate a signal stack created by xalloc_sigstack.  */
50 void xfree_sigstack (void *stack);
51 
52 /* Extract the actual address and size of the alternate signal stack from
53    the cookie returned by xalloc_sigstack.  */
54 void xget_sigstack_location (const void *stack, unsigned char **addrp,
55                              size_t *sizep);
56 
57 __END_DECLS
58 
59 #endif /* SUPPORT_SIGNAL_H */
60