From: Daniel Wagner <[email protected]>
It's unsafe to call syslog in the terminat signal handler
because syslog takes an lock. So when the signal handler
kicks in and we were already in syslog, we have a nice
deadlock.
---
src/main.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 69 insertions(+), 13 deletions(-)
diff --git a/src/main.c b/src/main.c
index da98d0e..2e9ae47 100644
--- a/src/main.c
+++ b/src/main.c
@@ -28,6 +28,7 @@
#include <unistd.h>
#include <string.h>
#include <signal.h>
+#include <sys/signalfd.h>
#include <gdbus.h>
@@ -39,18 +40,74 @@
static GMainLoop *main_loop = NULL;
-static volatile sig_atomic_t __terminated = 0;
+static unsigned int __terminated = 0;
-static void sig_term(int sig)
+static gboolean signal_handler(GIOChannel *channel, GIOCondition cond,
+ gpointer user_data)
{
- if (__terminated > 0)
- return;
+ struct signalfd_siginfo si;
+ ssize_t result;
+ int fd;
- __terminated = 1;
+ if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP))
+ return FALSE;
- pacrunner_info("Terminating");
+ fd = g_io_channel_unix_get_fd(channel);
- g_main_loop_quit(main_loop);
+ result = read(fd, &si, sizeof(si));
+ if (result != sizeof(si))
+ return FALSE;
+
+ switch (si.ssi_signo) {
+ case SIGINT:
+ case SIGTERM:
+ if (__terminated == 0) {
+ pacrunner_info("Terminating");
+ g_main_loop_quit(main_loop);
+ }
+
+ __terminated = 1;
+ break;
+ }
+
+ return TRUE;
+}
+
+static guint setup_signalfd(void)
+{
+ GIOChannel *channel;
+ guint source;
+ sigset_t mask;
+ int fd;
+
+ sigemptyset(&mask);
+ sigaddset(&mask, SIGINT);
+ sigaddset(&mask, SIGTERM);
+
+ if (sigprocmask(SIG_BLOCK, &mask, NULL) < 0) {
+ perror("Failed to set signal mask");
+ return 0;
+ }
+
+ fd = signalfd(-1, &mask, 0);
+ if (fd < 0) {
+ perror("Failed to create signal descriptor");
+ return 0;
+ }
+
+ channel = g_io_channel_unix_new(fd);
+
+ g_io_channel_set_close_on_unref(channel, TRUE);
+ g_io_channel_set_encoding(channel, NULL, NULL);
+ g_io_channel_set_buffered(channel, FALSE);
+
+ source = g_io_add_watch(channel,
+ G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL,
+ signal_handler, NULL);
+
+ g_io_channel_unref(channel);
+
+ return source;
}
static void disconnect_callback(DBusConnection *conn, void *user_data)
@@ -99,7 +156,7 @@ int main(int argc, char *argv[])
GError *error = NULL;
DBusConnection *conn;
DBusError err;
- struct sigaction sa;
+ guint signal;
#ifdef HAVE_CAPNG
/* Drop capabilities */
@@ -143,6 +200,8 @@ int main(int argc, char *argv[])
exit(1);
}
+ signal = setup_signalfd();
+
dbus_error_init(&err);
conn = g_dbus_setup_bus(DBUS_BUS_SYSTEM, PACRUNNER_SERVICE, &err);
@@ -170,13 +229,10 @@ int main(int argc, char *argv[])
g_free(option_plugin);
g_free(option_noplugin);
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = sig_term;
- sigaction(SIGINT, &sa, NULL);
- sigaction(SIGTERM, &sa, NULL);
-
g_main_loop_run(main_loop);
+ g_source_remove(signal);
+
__pacrunner_plugin_cleanup();
__pacrunner_manual_cleanup();
__pacrunner_client_cleanup();
--
1.7.4.4
_______________________________________________
connman mailing list
[email protected]
http://lists.connman.net/listinfo/connman
