1 | /* Copyright (C) 1991-2024 Free Software Foundation, Inc. |
2 | |
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 | #include <errno.h> |
20 | #include <signal.h> |
21 | #include <hurd.h> |
22 | #include <hurd/signal.h> |
23 | |
24 | /* If ACT is not NULL, change the action for SIG to *ACT. |
25 | If OACT is not NULL, put the old action for SIG in *OACT. */ |
26 | int |
27 | __libc_sigaction (int sig, const struct sigaction *act, |
28 | struct sigaction *oact) |
29 | { |
30 | struct hurd_sigstate *ss; |
31 | struct sigaction a, old; |
32 | sigset_t pending; |
33 | |
34 | if (act != NULL && act->sa_handler != SIG_DFL |
35 | && ((__sigmask (sig) & _SIG_CANT_MASK) || act->sa_handler == SIG_ERR)) |
36 | return __hurd_fail (EINVAL); |
37 | |
38 | /* Copy so we fault before taking locks. */ |
39 | if (act != NULL) |
40 | a = *act; |
41 | |
42 | ss = _hurd_self_sigstate (); |
43 | |
44 | __spin_lock (&ss->critical_section_lock); |
45 | _hurd_sigstate_lock (ss); |
46 | old = _hurd_sigstate_actions (ss) [sig]; |
47 | if (act != NULL) |
48 | _hurd_sigstate_actions (ss) [sig] = a; |
49 | |
50 | if (act != NULL && sig == SIGCHLD |
51 | && (a.sa_flags & SA_NOCLDSTOP) != (old.sa_flags & SA_NOCLDSTOP)) |
52 | { |
53 | _hurd_sigstate_unlock (ss); |
54 | |
55 | /* Inform the proc server whether or not it should send us SIGCHLD for |
56 | stopped children. We do this in a critical section so that no |
57 | SIGCHLD can arrive in the middle and be of indeterminate status. */ |
58 | __USEPORT (PROC, |
59 | __proc_mod_stopchild (port, !(a.sa_flags & SA_NOCLDSTOP))); |
60 | |
61 | _hurd_sigstate_lock (ss); |
62 | pending = _hurd_sigstate_pending (ss) & ~ss->blocked; |
63 | } |
64 | else if (act != NULL && (a.sa_handler == SIG_IGN || a.sa_handler == SIG_DFL)) |
65 | /* We are changing to an action that might be to ignore SIG signals. |
66 | If SIG is blocked and pending and the new action is to ignore it, we |
67 | must remove it from the pending set now; if the action is changed |
68 | back and then SIG is unblocked, the signal pending now should not |
69 | arrive. So wake up the signal thread to check the new state and do |
70 | the right thing. */ |
71 | pending = _hurd_sigstate_pending (ss) & __sigmask (sig); |
72 | else |
73 | pending = 0; |
74 | |
75 | _hurd_sigstate_unlock (ss); |
76 | __spin_unlock (&ss->critical_section_lock); |
77 | |
78 | if (pending) |
79 | __msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ()); |
80 | |
81 | if (oact != NULL) |
82 | *oact = old; |
83 | |
84 | return 0; |
85 | } |
86 | libc_hidden_def (__libc_sigaction) |
87 | |