1 | /* Special use of signals in NPTL internals. Linux version. |
2 | Copyright (C) 2014-2018 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 | #include <sigsetops.h> |
21 | |
22 | /* The signal used for asynchronous cancelation. */ |
23 | #define SIGCANCEL __SIGRTMIN |
24 | |
25 | |
26 | /* Signal needed for the kernel-supported POSIX timer implementation. |
27 | We can reuse the cancellation signal since we can distinguish |
28 | cancellation from timer expirations. */ |
29 | #define SIGTIMER SIGCANCEL |
30 | |
31 | |
32 | /* Signal used to implement the setuid et.al. functions. */ |
33 | #define SIGSETXID (__SIGRTMIN + 1) |
34 | |
35 | |
36 | /* Return is sig is used internally. */ |
37 | static inline int |
38 | __nptl_is_internal_signal (int sig) |
39 | { |
40 | return (sig == SIGCANCEL) || (sig == SIGTIMER) || (sig == SIGSETXID); |
41 | } |
42 | |
43 | /* Remove internal glibc signal from the mask. */ |
44 | static inline void |
45 | __nptl_clear_internal_signals (sigset_t *set) |
46 | { |
47 | __sigdelset (set, SIGCANCEL); |
48 | __sigdelset (set, SIGTIMER); |
49 | __sigdelset (set, SIGSETXID); |
50 | } |
51 | |
52 | #define SIGALL_SET \ |
53 | ((__sigset_t) { .__val = {[0 ... _SIGSET_NWORDS-1 ] = -1 } }) |
54 | |
55 | /* Block all signals, including internal glibc ones. */ |
56 | static inline int |
57 | __libc_signal_block_all (sigset_t *set) |
58 | { |
59 | INTERNAL_SYSCALL_DECL (err); |
60 | return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_BLOCK, &SIGALL_SET, |
61 | set, _NSIG / 8); |
62 | } |
63 | |
64 | /* Block all application signals (excluding internal glibc ones). */ |
65 | static inline int |
66 | __libc_signal_block_app (sigset_t *set) |
67 | { |
68 | sigset_t allset = SIGALL_SET; |
69 | __nptl_clear_internal_signals (&allset); |
70 | INTERNAL_SYSCALL_DECL (err); |
71 | return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_BLOCK, &allset, set, |
72 | _NSIG / 8); |
73 | } |
74 | |
75 | /* Restore current process signal mask. */ |
76 | static inline int |
77 | __libc_signal_restore_set (const sigset_t *set) |
78 | { |
79 | INTERNAL_SYSCALL_DECL (err); |
80 | return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, set, NULL, |
81 | _NSIG / 8); |
82 | } |
83 | |
84 | /* Used to communicate with signal handler. */ |
85 | extern struct xid_command *__xidcmd attribute_hidden; |
86 | |