main: generate coredump and exit upon SIGABRT received

Previous code relied on abort() switching sigaction to SIG_FDL +
retriggering SIGABRT in case the signal handler returns, which would
then generate the coredump + terminate the process.
However, if a SIGABRT is received from somewhere else (kill -SIGABRT),
then the process would print the talloc report and continue running,
which is not desired.

Change-Id: Iff66eea9ee70850a4d038ece1d8473457023e1ee
Fixes: OS#4865

1 files changed, 15 insertions, 6 deletions

diff --git a/src/osmo-msc/msc_main.c b/src/osmo-msc/msc_main.c
index aefdcbfea..fcca101b6 100644
--- a/src/osmo-msc/msc_main.c
+++ b/src/osmo-msc/msc_main.c
@@ -273,20 +273,29 @@ void msc_network_shutdown(struct gsm_network *net)
 static struct gsm_network *msc_network = NULL;
 
 extern void *tall_vty_ctx;
-static void signal_handler(int signal)
+static void signal_handler(int signum)
 {
-	fprintf(stdout, "signal %u received\n", signal);
+	fprintf(stdout, "signal %u received\n", signum);
 
-	switch (signal) {
+	switch (signum) {
 	case SIGINT:
 	case SIGTERM:
-		LOGP(DMSC, LOGL_NOTICE, "Terminating due to signal %d\n", signal);
+		LOGP(DMSC, LOGL_NOTICE, "Terminating due to signal %d\n", signum);
 		quit++;
 		break;
 	case SIGABRT:
 		osmo_generate_backtrace();
-		/* in case of abort, we want to obtain a talloc report
-		 * and then return to the caller, who will abort the process */
+		/* in case of abort, we want to obtain a talloc report and
+		 * then run default SIGABRT handler, who will generate coredump
+		 * and abort the process. abort() should do this for us after we
+		 * return, but program wouldn't exit if an external SIGABRT is
+		 * received.
+		 */
+		talloc_report(tall_vty_ctx, stderr);
+		talloc_report_full(tall_msc_ctx, stderr);
+		signal(SIGABRT, SIG_DFL);
+		raise(SIGABRT);
+		break;
 	case SIGUSR1:
 		talloc_report(tall_vty_ctx, stderr);
 		talloc_report_full(tall_msc_ctx, stderr);