X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=server.c;h=a4115eb65734391128481f6fa421d548aba78e20;hp=9c06991378512172e95b70165118ae1ea873bdb1;hb=ad81d625737e1c096c154aedd8a1d161d3ee592e;hpb=26d662890f5e1c29c0b09d1cac94b8b4acb065ed

diff --git a/server.c b/server.c
index 9c069913..a4115eb6 100644
--- a/server.c
+++ b/server.c
@@ -300,6 +300,9 @@ static void signal_post_select(struct sched *s, struct task *t)
 		PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
 genocide:
 		kill(0, SIGTERM);
+		free(mmd->afd.afhi.chunk_table);
+		free(mmd->afd.afhi.info_string);
+		close_listed_fds();
 		mutex_destroy(mmd_mutex);
 		shm_detach(mmd);
 		exit(EXIT_FAILURE);
@@ -349,6 +352,8 @@ static void command_post_select(struct sched *s, struct task *t)
 	int new_fd, ret, i;
 	char *peer_name;
 	pid_t child_pid;
+	uint32_t *chunk_table;
+	char *info_string;
 
 	if (!FD_ISSET(sct->listen_fd, &s->rfds))
 		return;
@@ -361,6 +366,16 @@ static void command_post_select(struct sched *s, struct task *t)
 	mmd->num_connects++;
 	mmd->active_connections++;
 	random();
+	/* The chunk table and the info_string are pointers located in the
+	 * mmd struct that point to dynamically allocated memory that must be
+	 * freed by the parent and the child. However, as the mmd struct is in
+	 * a shared memory area, there's no guarantee that after the fork these
+	 * pointers are still valid in child context. As these two pointers are
+	 * not used in the child anyway, we save them to local variables and
+	 * free the memory via that copy in the child.
+	 */
+	info_string = mmd->afd.afhi.info_string;
+	chunk_table = mmd->afd.afhi.chunk_table;
 	child_pid = fork();
 	if (child_pid < 0) {
 		ret = -ERRNO_TO_PARA_ERROR(errno);
@@ -371,6 +386,9 @@ static void command_post_select(struct sched *s, struct task *t)
 		/* parent keeps accepting connections */
 		return;
 	}
+	/* mmd might already have changed at this point */
+	free(info_string);
+	free(chunk_table);
 	alarm(ALARM_TIMEOUT);
 	close_listed_fds();
 	para_signal_shutdown();
@@ -467,6 +485,12 @@ static int init_afs(void)
 	return afs_server_socket[0];
 }
 
+__noreturn static void tmp_sigchld_handler(__a_unused int s)
+{
+	PARA_EMERG_LOG("caught early SIGCHLD\n");
+	exit(EXIT_FAILURE);
+}
+
 static void server_init(int argc, char **argv)
 {
 	struct server_cmdline_parser_params params = {
@@ -509,6 +533,15 @@ static void server_init(int argc, char **argv)
 		PARA_EMERG_LOG("failed to ignore SIGUSR1\n");
 		exit(EXIT_FAILURE);
 	}
+	/*
+	 * We have to install a SIGCHLD handler before the afs process is being
+	 * forked off. Otherwise, para_server does not notice if afs dies before
+	 * the SIGCHLD handler has been installed by init_signal_task() below.
+	 */
+	if (signal(SIGCHLD, tmp_sigchld_handler) == SIG_ERR) {
+		PARA_EMERG_LOG("failed to install temporary SIGCHLD handler\n");
+		exit(EXIT_FAILURE);
+	}
 	PARA_NOTICE_LOG("initializing the audio file selector\n");
 	afs_socket = init_afs();
 	init_signal_task();