1/* Special use of signals in NPTL internals. Linux version.
2 Copyright (C) 2014-2017 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 <http://www.gnu.org/licenses/>. */
18
19#include <signal.h>
20
21/* The signal used for asynchronous cancelation. */
22#define SIGCANCEL __SIGRTMIN
23
24
25/* Signal needed for the kernel-supported POSIX timer implementation.
26 We can reuse the cancellation signal since we can distinguish
27 cancellation from timer expirations. */
28#define SIGTIMER SIGCANCEL
29
30
31/* Signal used to implement the setuid et.al. functions. */
32#define SIGSETXID (__SIGRTMIN + 1)
33
34
35/* Return is sig is used internally. */
36static inline int
37__nptl_is_internal_signal (int sig)
38{
39 return (sig == SIGCANCEL) || (sig == SIGTIMER) || (sig == SIGSETXID);
40}
41
42/* Remove internal glibc signal from the mask. */
43static inline void
44__nptl_clear_internal_signals (sigset_t *set)
45{
46 __sigdelset (set, SIGCANCEL);
47 __sigdelset (set, SIGTIMER);
48 __sigdelset (set, SIGSETXID);
49}
50
51#define SIGALL_SET \
52 ((__sigset_t) { .__val = {[0 ... _SIGSET_NWORDS-1 ] = -1 } })
53
54/* Block all signals, including internal glibc ones. */
55static inline int
56__libc_signal_block_all (sigset_t *set)
57{
58 INTERNAL_SYSCALL_DECL (err);
59 return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_BLOCK, &SIGALL_SET,
60 set, _NSIG / 8);
61}
62
63/* Block all application signals (excluding internal glibc ones). */
64static inline int
65__libc_signal_block_app (sigset_t *set)
66{
67 sigset_t allset = SIGALL_SET;
68 __nptl_clear_internal_signals (&allset);
69 INTERNAL_SYSCALL_DECL (err);
70 return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_BLOCK, &allset, set,
71 _NSIG / 8);
72}
73
74/* Restore current process signal mask. */
75static inline int
76__libc_signal_restore_set (const sigset_t *set)
77{
78 INTERNAL_SYSCALL_DECL (err);
79 return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, set, NULL,
80 _NSIG / 8);
81}
82
83/* Used to communicate with signal handler. */
84extern struct xid_command *__xidcmd attribute_hidden;
85