libbb: introduce and use sigprocmask_allsigs and sigaction_set.

libbb: rename sig_pause to wait_for_any_sig.

include/libbb.h

@@ -311,13 +311,14 @@ void bb_signals_recursive(int sigs, void (*f)(int));
 void signal_no_SA_RESTART_empty_mask(int sig, void (*handler)(int));
 /* syscalls like read() won't be interrupted (though select/poll will be): */
 void signal_SA_RESTART_empty_mask(int sig, void (*handler)(int));
-/* Will do sigaction(signum, act, NULL): */
+void wait_for_any_sig(void);
-int sigaction_set(int signum, const struct sigaction *act);
-void sig_block(int);
-void sig_unblock(int);
-/* UNUSED: void sig_blocknone(void); */
-void sig_pause(void);
 void kill_myself_with_sig(int sig) ATTRIBUTE_NORETURN;
+void sig_block(int sig);
+void sig_unblock(int sig);
+/* Will do sigaction(signum, act, NULL): */
+int sigaction_set(int sig, const struct sigaction *act);
+/* SIG_BLOCK/SIG_UNBLOCK all signals: */
+int sigprocmask_allsigs(int how);
 
 
 void xsetgid(gid_t gid);

init/init.c

@@ -526,27 +526,13 @@ static void init_reboot(unsigned long magic)
 
 static void kill_all_processes(void)
 {
-	sigset_t block_signals;
-
 	/* run everything to be run at "shutdown".  This is done _prior_
 	 * to killing everything, in case people wish to use scripts to
 	 * shut things down gracefully... */
 	run_actions(SHUTDOWN);
 
 	/* first disable all our signals */
-	sigfillset(&block_signals);
+	sigprocmask_allsigs(SIG_BLOCK);
-	/*sigemptyset(&block_signals);
-	sigaddset(&block_signals, SIGHUP);
-	sigaddset(&block_signals, SIGQUIT);
-	sigaddset(&block_signals, SIGCHLD);
-	sigaddset(&block_signals, SIGUSR1);
-	sigaddset(&block_signals, SIGUSR2);
-	sigaddset(&block_signals, SIGINT);
-	sigaddset(&block_signals, SIGTERM);
-	sigaddset(&block_signals, SIGCONT);
-	sigaddset(&block_signals, SIGSTOP);
-	sigaddset(&block_signals, SIGTSTP);*/
-	sigprocmask(SIG_BLOCK, &block_signals, NULL);
 
 	message(L_CONSOLE | L_LOG, "The system is going down NOW!");
 
@@ -593,26 +579,13 @@ static void halt_reboot_pwoff(int sig)
 static void exec_restart_action(int sig ATTRIBUTE_UNUSED)
 {
 	struct init_action *a;
-	sigset_t unblock_signals;
 
 	for (a = init_action_list; a; a = a->next) {
 		if (a->action_type & RESTART) {
 			kill_all_processes();
 
 			/* unblock all signals (blocked in kill_all_processes()) */
-			sigfillset(&unblock_signals);
+			sigprocmask_allsigs(SIG_UNBLOCK);
-			/*sigemptyset(&unblock_signals);
-			sigaddset(&unblock_signals, SIGHUP);
-			sigaddset(&unblock_signals, SIGQUIT);
-			sigaddset(&unblock_signals, SIGCHLD);
-			sigaddset(&unblock_signals, SIGUSR1);
-			sigaddset(&unblock_signals, SIGUSR2);
-			sigaddset(&unblock_signals, SIGINT);
-			sigaddset(&unblock_signals, SIGTERM);
-			sigaddset(&unblock_signals, SIGCONT);
-			sigaddset(&unblock_signals, SIGSTOP);
-			sigaddset(&unblock_signals, SIGTSTP);*/
-			sigprocmask(SIG_UNBLOCK, &unblock_signals, NULL);
 
 			/* Open the new terminal device */
 			open_stdio_to_tty(a->terminal, 0 /* - halt if open fails */);

ipsvd/tcpudp.c

@@ -290,7 +290,7 @@ int tcpudpsvd_main(int argc, char **argv)
 	hccp = NULL;
 
 	while (cnum >= cmax)
-		sig_pause(); /* wait for any signal (expecting SIGCHLD) */
+		wait_for_any_sig(); /* expecting SIGCHLD */
 
 	/* Accept a connection to fd #0 */
  again1:

libbb/signals.c

@@ -17,6 +17,13 @@ int sigaction_set(int signum, const struct sigaction *act)
 	return sigaction(signum, act, NULL);
 }
 
+int sigprocmask_allsigs(int how)
+{
+	sigset_t set;
+	sigfillset(&set);
+	return sigprocmask(how, &set, NULL);
+}
+
 void bb_signals(int sigs, void (*f)(int))
 {
 	int sig_no = 0;
@@ -69,16 +76,7 @@ void sig_unblock(int sig)
 	sigprocmask(SIG_UNBLOCK, &ss, NULL);
 }
 
-#if 0
+void wait_for_any_sig(void)
-void sig_blocknone(void)
-{
-	sigset_t ss;
-	sigemptyset(&ss);
-	sigprocmask(SIG_SETMASK, &ss, NULL);
-}
-#endif
-
-void sig_pause(void)
 {
 	sigset_t ss;
 	sigemptyset(&ss);

networking/inetd.c

@@ -378,12 +378,12 @@ static void block_CHLD_HUP_ALRM(sigset_t *m)
 	sigaddset(m, SIGCHLD);
 	sigaddset(m, SIGHUP);
 	sigaddset(m, SIGALRM);
-	sigprocmask(SIG_BLOCK, m, NULL);
+	sigprocmask(SIG_BLOCK, m, m); /* old sigmask is stored in m */
 }
 
-static void unblock_sigs(sigset_t *m)
+static void restore_sigmask(sigset_t *m)
 {
-	sigprocmask(SIG_UNBLOCK, m, NULL);
+	sigprocmask(SIG_SETMASK, m, NULL);
 }
 
 #if ENABLE_FEATURE_INETD_RPC
@@ -870,7 +870,7 @@ static servtab_t *insert_in_servlist(servtab_t *cp)
 	block_CHLD_HUP_ALRM(&omask);
 	sep->se_next = serv_list;
 	serv_list = sep;
-	unblock_sigs(&omask);
+	restore_sigmask(&omask);
 	return sep;
 }
 
@@ -941,7 +941,7 @@ static void reread_config_file(int sig ATTRIBUTE_UNUSED)
 			for (i = 0; i < MAXARGV; i++)
 				SWAP(char*, sep->se_argv[i], cp->se_argv[i]);
 #undef SWAP
-			unblock_sigs(&omask);
+			restore_sigmask(&omask);
 			free_servtab_strings(cp);
 		}
  after_check:
@@ -1052,7 +1052,7 @@ static void reread_config_file(int sig ATTRIBUTE_UNUSED)
 		free_servtab_strings(sep);
 		free(sep);
 	}
-	unblock_sigs(&omask);
+	restore_sigmask(&omask);
 }
 
 static void reap_child(int sig ATTRIBUTE_UNUSED)
@@ -1252,7 +1252,7 @@ int inetd_main(int argc, char **argv)
 							sep->se_fd = -1;
 							sep->se_count = 0;
 							rearm_alarm(); /* will revive it in RETRYTIME sec */
-							unblock_sigs(&omask);
+							restore_sigmask(&omask);
 							maybe_close(accepted_fd);
 							continue; /* -> check next fd in fd set */
 						}
@@ -1272,7 +1272,7 @@ int inetd_main(int argc, char **argv)
 				if (pid < 0) { /* fork error */
 					bb_perror_msg("fork");
 					sleep(1);
-					unblock_sigs(&omask);
+					restore_sigmask(&omask);
 					maybe_close(accepted_fd);
 					continue; /* -> check next fd in fd set */
 				}
@@ -1288,7 +1288,7 @@ int inetd_main(int argc, char **argv)
 					/* we passed listening socket to child,
 					 * will wait for child to terminate */
 				}
-				unblock_sigs(&omask);
+				restore_sigmask(&omask);
 				maybe_close(accepted_fd);
 				continue; /* -> check next fd in fd set */
 			}
@@ -1300,7 +1300,7 @@ int inetd_main(int argc, char **argv)
 					close(sep->se_fd); /* listening socket */
 					logmode = 0; /* make xwrite etc silent */
 				}
-				unblock_sigs(&omask);
+				restore_sigmask(&omask);
 				if (sep->se_socktype == SOCK_STREAM)
 					sep->se_builtin->bi_stream_fn(ctrl, sep);
 				else
@@ -1383,7 +1383,7 @@ int inetd_main(int argc, char **argv)
 			for (sep2 = serv_list; sep2; sep2 = sep2->se_next)
 				maybe_close(sep2->se_fd);
 			sigaction_set(SIGPIPE, &saved_pipe_handler);
-			unblock_sigs(&omask);
+			restore_sigmask(&omask);
 			BB_EXECVP(sep->se_program, sep->se_argv);
 			bb_perror_msg("exec %s", sep->se_program);
  do_exit1:

shell/ash.c

@@ -273,13 +273,11 @@ static void
 raise_interrupt(void)
 {
 	int i;
-	sigset_t mask;
 
 	intpending = 0;
 	/* Signal is not automatically unmasked after it is raised,
 	 * do it ourself - unmask all signals */
-	sigemptyset(&mask);
+	sigprocmask_allsigs(SIG_UNBLOCK);
-	sigprocmask(SIG_SETMASK, &mask, NULL);
 	/* pendingsig = 0; - now done in onsig() */
 
 	i = EXSIG;

shell/hush.c

@@ -788,11 +788,8 @@ static void handler_ctrl_z(int sig)
 static void sigexit(int sig) ATTRIBUTE_NORETURN;
 static void sigexit(int sig)
 {
-	sigset_t block_all;
-
 	/* Disable all signals: job control, SIGPIPE, etc. */
-	sigfillset(&block_all);
+	sigprocmask_allsigs(SIG_BLOCK);
-	sigprocmask(SIG_SETMASK, &block_all, NULL);
 
 	if (interactive_fd)
 		tcsetpgrp(interactive_fd, saved_tty_pgrp);