sway

commit 7d8413d9628ed493790454410a28b9f0c41444e6
parent d6095588a143710d25be47577ea65517770e7a74
Author: Marien Zwart <marienz@google.com>
Date:   Wed,  1 Aug 2018 23:21:29 +1000

Reset signal mask after fork

wlroots uses wl_event_loop_add_signal to handle SIGUSR1 from Xwayland.
wl_event_loop_add_signal works by masking the signal and receiving it from a
signalfd. The signal mask is preserved across fork and exec, so subprocesses
spawned by Sway start with SIGUSR1 masked. Most subprocesses do not expect this
and never unmask the signal, resulting in missing functionality or unexpected
behavior for processes that use SIGUSR1 (such as i3status).

Fix this by unmasking all signals between fork and exec.

Diffstat:
M
sway/commands/exec_always.c
 | 
4
++++
M
sway/config/bar.c
 | 
4
++++

2 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/sway/commands/exec_always.c b/sway/commands/exec_always.c
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <sys/wait.h>
 #include <unistd.h>
+#include <signal.h>
 #include "sway/commands.h"
 #include "sway/config.h"
 #include "sway/tree/container.h"
@@ -47,6 +48,9 @@ struct cmd_results *cmd_exec_always(int argc, char **argv) {
 	if ((pid = fork()) == 0) {
 		// Fork child process again
 		setsid();
+		sigset_t set;
+		sigemptyset(&set);
+		sigprocmask(SIG_SETMASK, &set, NULL);
 		close(fd[0]);
 		if ((child = fork()) == 0) {
 			close(fd[1]);
diff --git a/sway/config/bar.c b/sway/config/bar.c
@@ -10,6 +10,7 @@
 #include <sys/stat.h>
 #include <signal.h>
 #include <strings.h>
+#include <signal.h>
 #include "sway/config.h"
 #include "stringop.h"
 #include "list.h"
@@ -175,6 +176,9 @@ void invoke_swaybar(struct bar_config *bar) {
 	if (bar->pid == 0) {
 		setpgid(0, 0);
 		close(filedes[0]);
+		sigset_t set;
+		sigemptyset(&set);
+		sigprocmask(SIG_SETMASK, &set, NULL);
 
 		// run custom swaybar
 		size_t len = snprintf(NULL, 0, "%s -b %s",