osmo-nitb: 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: I3371783e04c7bce12d11d6f9cc7021bf290489ea
Fixes: OS#4865

1 files changed, 14 insertions, 5 deletions

diff --git a/openbsc/src/osmo-nitb/bsc_hack.c b/openbsc/src/osmo-nitb/bsc_hack.c
index 2aeaa8fef..4950f4ca9 100644
--- a/openbsc/src/osmo-nitb/bsc_hack.c
+++ b/openbsc/src/osmo-nitb/bsc_hack.c
@@ -196,11 +196,11 @@ static void handle_options(int argc, char **argv)
 }
 
 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:
 		bsc_shutdown_net(bsc_gsmnet);
@@ -210,8 +210,17 @@ static void signal_handler(int signal)
 		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_bsc_ctx, stderr);
+		signal(SIGABRT, SIG_DFL);
+		raise(SIGABRT);
+		break;
 	case SIGUSR1:
 		talloc_report(tall_vty_ctx, stderr);
 		talloc_report_full(tall_bsc_ctx, stderr);