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. */ |
36 | static 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. */ |
43 | static 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. */ |
55 | static 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). */ |
64 | static 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. */ |
75 | static 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. */ |
84 | extern struct xid_command *__xidcmd attribute_hidden; |
85 | |