1 /* vi: set sw=4 ts=4: */
2 /*
3  * Utility routines.
4  *
5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6  * Copyright (C) 2006 Rob Landley
7  * Copyright (C) 2006 Denys Vlasenko
8  *
9  * Licensed under GPLv2, see file LICENSE in this source tree.
10  */
11 #include "libbb.h"
12 
13 /* All known arches use small ints for signals */
14 smallint bb_got_signal;
15 
record_signo(int signo)16 void record_signo(int signo)
17 {
18 	bb_got_signal = signo;
19 }
20 
21 /* Saves 2 bytes on x86! Oh my... */
sigaction_set(int signum,const struct sigaction * act)22 int FAST_FUNC sigaction_set(int signum, const struct sigaction *act)
23 {
24 	return sigaction(signum, act, NULL);
25 }
26 
sigprocmask_allsigs(int how)27 int FAST_FUNC sigprocmask_allsigs(int how)
28 {
29 	sigset_t set;
30 	sigfillset(&set);
31 	return sigprocmask(how, &set, NULL);
32 }
33 
sigprocmask2(int how,sigset_t * set)34 int FAST_FUNC sigprocmask2(int how, sigset_t *set)
35 {
36 	// Grr... gcc 8.1.1:
37 	// "passing argument 3 to restrict-qualified parameter aliases with argument 2"
38 	// dance around that...
39 	sigset_t *oset FIX_ALIASING;
40 	oset = set;
41 	return sigprocmask(how, set, oset);
42 }
43 
bb_signals(int sigs,void (* f)(int))44 void FAST_FUNC bb_signals(int sigs, void (*f)(int))
45 {
46 	int sig_no = 0;
47 	int bit = 1;
48 
49 	while (sigs) {
50 		if (sigs & bit) {
51 			sigs -= bit;
52 			signal(sig_no, f);
53 		}
54 		sig_no++;
55 		bit <<= 1;
56 	}
57 }
58 
bb_signals_norestart(int sigs,void (* f)(int))59 void FAST_FUNC bb_signals_norestart(int sigs, void (*f)(int))
60 {
61 	int sig_no = 0;
62 	int bit = 1;
63 	struct sigaction sa;
64 
65 	memset(&sa, 0, sizeof(sa));
66 	sa.sa_handler = f;
67 	/*sa.sa_flags = 0;*/
68 	/*sigemptyset(&sa.sa_mask); - hope memset did it*/
69 
70 	while (sigs) {
71 		if (sigs & bit) {
72 			sigs -= bit;
73 			sigaction_set(sig_no, &sa);
74 		}
75 		sig_no++;
76 		bit <<= 1;
77 	}
78 }
79 
sig_block(int sig)80 void FAST_FUNC sig_block(int sig)
81 {
82 	sigset_t ss;
83 	sigemptyset(&ss);
84 	sigaddset(&ss, sig);
85 	sigprocmask(SIG_BLOCK, &ss, NULL);
86 }
87 
sig_unblock(int sig)88 void FAST_FUNC sig_unblock(int sig)
89 {
90 	sigset_t ss;
91 	sigemptyset(&ss);
92 	sigaddset(&ss, sig);
93 	sigprocmask(SIG_UNBLOCK, &ss, NULL);
94 }
95 
wait_for_any_sig(void)96 void FAST_FUNC wait_for_any_sig(void)
97 {
98 	sigset_t ss;
99 	sigemptyset(&ss);
100 	sigsuspend(&ss);
101 }
102 
103 /* Assuming the sig is fatal */
kill_myself_with_sig(int sig)104 void FAST_FUNC kill_myself_with_sig(int sig)
105 {
106 	signal(sig, SIG_DFL);
107 	sig_unblock(sig);
108 	raise(sig);
109 	_exit(sig | 128); /* Should not reach it */
110 }
111 
signal_SA_RESTART_empty_mask(int sig,void (* handler)(int))112 void FAST_FUNC signal_SA_RESTART_empty_mask(int sig, void (*handler)(int))
113 {
114 	struct sigaction sa;
115 	memset(&sa, 0, sizeof(sa));
116 	/*sigemptyset(&sa.sa_mask);*/
117 	sa.sa_flags = SA_RESTART;
118 	sa.sa_handler = handler;
119 	sigaction_set(sig, &sa);
120 }
121 
signal_no_SA_RESTART_empty_mask(int sig,void (* handler)(int))122 void FAST_FUNC signal_no_SA_RESTART_empty_mask(int sig, void (*handler)(int))
123 {
124 	struct sigaction sa;
125 	memset(&sa, 0, sizeof(sa));
126 	/*sigemptyset(&sa.sa_mask);*/
127 	/*sa.sa_flags = 0;*/
128 	sa.sa_handler = handler;
129 	sigaction_set(sig, &sa);
130 }
131