use pthread_sigmask instead of sigprocmask

pthread is already in our vmem due to our dependencies so link to it
explicitly and use pthread_sigmask to avoid buggy sigprocmask in
multi-threaded applications.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

Makefile.am

@@ -97,7 +97,8 @@ libkmscon_core_la_LIBADD = \
 	$(FREETYPE2_LIBS) \
 	$(XPROTO_LIBS) \
 	$(XKBCOMMON_LIBS) \
-	$(GLIB_LIBS)
+	$(GLIB_LIBS) \
+	-lpthread
 
 kmscon_SOURCES = src/main.c
 kmscon_LDADD = libkmscon-core.la

src/eloop.c

@@ -32,6 +32,7 @@
  */
 
 #include <errno.h>
+#include <pthread.h>
 #include <signal.h>
 #include <stdbool.h>
 #include <stdlib.h>
@@ -540,7 +541,7 @@ int ev_eloop_add_signal(struct ev_eloop *loop, struct ev_signal *sig,
 		return ret;
 	}
 
-	sigprocmask(SIG_BLOCK, &mask, NULL);
+	pthread_sigmask(SIG_BLOCK, &mask, NULL);
 	sig->cb = cb;
 	sig->data = data;
 	ev_signal_ref(sig);
@@ -617,7 +618,7 @@ static int signal_new(struct ev_signal_shared **out, struct ev_eloop *loop,
 	if (ret)
 		goto err_sig;
 
-	sigprocmask(SIG_BLOCK, &mask, NULL);
+	pthread_sigmask(SIG_BLOCK, &mask, NULL);
 	sig->next = loop->sig_list;
 	loop->sig_list = sig;
 

src/pty.c

@@ -25,6 +25,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <pthread.h>
 #include <pty.h>
 #include <signal.h>
 #include <stdlib.h>
@@ -131,7 +132,7 @@ static int setup_child(int master, struct winsize *ws)
 
 	/* The child should not inherit our signal mask. */
 	sigemptyset(&sigset);
-	ret = sigprocmask(SIG_SETMASK, &sigset, NULL);
+	ret = pthread_sigmask(SIG_SETMASK, &sigset, NULL);
 	if (ret)
 		log_warn("cannot reset blocked signals: %m");