Merged revisions 266142 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r266142 | tilghman | 2010-05-26 16:11:44 -0500 (Wed, 26 May 2010) | 14 lines
  
  Use sigaction for signals which should persist past the initial trigger, not signal.
  
  If you call signal() in a Solaris signal handler, instead of just resetting
  the signal handler, it causes the signal to refire, because the signal is not
  marked as handled prior to the signal handler being called.  This effectively
  causes Solaris to immediately exceed the threadstack in recursive signal
  handlers and crash.
  
  (closes issue #17000)
   Reported by: rmcgilvr
   Patches: 
         20100526__issue17000.diff.txt uploaded by tilghman (license 14)
   Tested by: rmcgilvr
........


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@266146 f38db490-d61c-443f-a65b-d21fe96a405b

2 files changed, 44 insertions, 22 deletions

diff --git a/main/asterisk.c b/main/asterisk.c
index a9844de96..e69f2ce03 100644
--- a/main/asterisk.c
+++ b/main/asterisk.c
@@ -970,16 +970,24 @@ static int fdprint(int fd, const char *s)
 }
 
 /*! \brief NULL handler so we can collect the child exit status */
-static void null_sig_handler(int sig)
+static void _null_sig_handler(int sig)
 {
 
 }
 
+static struct sigaction null_sig_handler = {
+	.sa_handler = _null_sig_handler,
+};
+
+static struct sigaction ignore_sig_handler = {
+	.sa_handler = SIG_IGN,
+};
+
 AST_MUTEX_DEFINE_STATIC(safe_system_lock);
 /*! \brief Keep track of how many threads are currently trying to wait*() on
  *  a child process */
 static unsigned int safe_system_level = 0;
-static void *safe_system_prev_handler;
+static struct sigaction safe_system_prev_handler;
 
 void ast_replace_sigchld(void)
 {
@@ -989,8 +997,9 @@ void ast_replace_sigchld(void)
 	level = safe_system_level++;
 
 	/* only replace the handler if it has not already been done */
-	if (level == 0)
-		safe_system_prev_handler = signal(SIGCHLD, null_sig_handler);
+	if (level == 0) {
+		sigaction(SIGCHLD, &null_sig_handler, &safe_system_prev_handler);
+	}
 
 	ast_mutex_unlock(&safe_system_lock);
 }
@@ -1003,8 +1012,9 @@ void ast_unreplace_sigchld(void)
 	level = --safe_system_level;
 
 	/* only restore the handler if we are the last one */
-	if (level == 0)
-		signal(SIGCHLD, safe_system_prev_handler);
+	if (level == 0) {
+		sigaction(SIGCHLD, &safe_system_prev_handler, NULL);
+	}
 
 	ast_mutex_unlock(&safe_system_lock);
 }
@@ -1437,13 +1447,16 @@ static int ast_tryconnect(void)
  system call.  We don't actually need to do anything though.  
  Remember: Cannot EVER ast_log from within a signal handler 
  */
-static void urg_handler(int num)
+static void _urg_handler(int num)
 {
-	signal(num, urg_handler);
 	return;
 }
 
-static void hup_handler(int num)
+static struct sigaction urg_handler = {
+	.sa_handler = _urg_handler,
+};
+
+static void _hup_handler(int num)
 {
 	int a = 0;
 	if (option_verbose > 1) 
@@ -1456,10 +1469,13 @@ static void hup_handler(int num)
 			fprintf(stderr, "hup_handler: write() failed: %s\n", strerror(errno));
 		}
 	}
-	signal(num, hup_handler);
 }
 
-static void child_handler(int sig)
+static struct sigaction hup_handler = {
+	.sa_handler = _hup_handler,
+};
+
+static void _child_handler(int sig)
 {
 	/* Must not ever ast_log or ast_verbose within signal handler */
 	int n, status;
@@ -1471,9 +1487,12 @@ static void child_handler(int sig)
 		;
 	if (n == 0 && option_debug)	
 		printf("Huh?  Child handler, but nobody there?\n");
-	signal(sig, child_handler);
 }
 
+static struct sigaction child_handler = {
+	.sa_handler = _child_handler,
+};
+
 /*! \brief Set maximum open files */
 static void set_ulimit(int value)
 {
@@ -1672,7 +1691,7 @@ static void __quit_handler(int num)
 	sig_flags.need_quit = 1;
 	if (sig_alert_pipe[1] != -1) {
 		if (write(sig_alert_pipe[1], &a, sizeof(a)) < 0) {
-			fprintf(stderr, "hup_handler: write() failed: %s\n", strerror(errno));
+			fprintf(stderr, "quit_handler: write() failed: %s\n", strerror(errno));
 		}
 	}
 	/* There is no need to restore the signal handler here, since the app
@@ -3322,7 +3341,7 @@ int main(int argc, char *argv[])
 	/* Must install this signal handler up here to ensure that if the canary
 	 * fails to execute that it doesn't kill the Asterisk process.
 	 */
-	signal(SIGCHLD, child_handler);
+	sigaction(SIGCHLD, &child_handler, NULL);
 
 	/* It's common on some platforms to clear /var/run at boot.  Create the
 	 * socket file directory before we drop privileges. */
@@ -3521,7 +3540,7 @@ int main(int argc, char *argv[])
 		snprintf(canary_filename, sizeof(canary_filename), "%s/alt.asterisk.canary.tweet.tweet.tweet", ast_config_AST_RUN_DIR);
 
 		/* Don't let the canary child kill Asterisk, if it dies immediately */
-		signal(SIGPIPE, SIG_IGN);
+		sigaction(SIGPIPE, &ignore_sig_handler, NULL);
 
 		canary_pid = fork();
 		if (canary_pid == 0) {
@@ -3575,11 +3594,11 @@ int main(int argc, char *argv[])
 	sigaddset(&sigs, SIGPIPE);
 	sigaddset(&sigs, SIGWINCH);
 	pthread_sigmask(SIG_BLOCK, &sigs, NULL);
-	signal(SIGURG, urg_handler);
+	sigaction(SIGURG, &urg_handler, NULL);
 	signal(SIGINT, __quit_handler);
 	signal(SIGTERM, __quit_handler);
-	signal(SIGHUP, hup_handler);
-	signal(SIGPIPE, SIG_IGN);
+	sigaction(SIGHUP, &hup_handler, NULL);
+	sigaction(SIGPIPE, &ignore_sig_handler, NULL);
 
 	/* ensure that the random number generators are seeded with a different value every time
 	   Asterisk is started
diff --git a/main/logger.c b/main/logger.c
index 698e782eb..fa57a0563 100644
--- a/main/logger.c
+++ b/main/logger.c
@@ -738,7 +738,7 @@ static char *handle_logger_show_channels(struct ast_cli_entry *e, int cmd, struc
 	}
 	AST_RWLIST_UNLOCK(&logchannels);
 	ast_cli(a->fd, "\n");
- 		
+
 	return CLI_SUCCESS;
 }
 
@@ -756,13 +756,16 @@ static struct ast_cli_entry cli_logger[] = {
 	AST_CLI_DEFINE(handle_logger_set_level, "Enables/Disables a specific logging level for this console")
 };
 
-static int handle_SIGXFSZ(int sig) 
+static void _handle_SIGXFSZ(int sig)
 {
 	/* Indicate need to reload */
 	filesize_reload_needed = 1;
-	return 0;
 }
 
+static struct sigaction handle_SIGXFSZ = {
+	.sa_handler = _handle_SIGXFSZ,
+};
+
 static void ast_log_vsyslog(struct logmsg *msg)
 {
 	char buf[BUFSIZ];
@@ -929,7 +932,7 @@ int init_logger(void)
 	int res = 0;
 
 	/* auto rotate if sig SIGXFSZ comes a-knockin */
-	(void) signal(SIGXFSZ, (void *) handle_SIGXFSZ);
+	sigaction(SIGXFSZ, &handle_SIGXFSZ, NULL);
 
 	/* start logger thread */
 	ast_cond_init(&logcond, NULL);