From 142325a93c6ad70f851f43434acfdf75e12dfe03 Mon Sep 17 00:00:00 2001
From: Tobias Girstmair <t-osmocom@girst.at>
Date: Fri, 18 Nov 2022 16:20:14 +0100
Subject: [PATCH] Fix signal handler from getting stuck in an endless loop

The signal handler for SIGINT/TERM/QUIT and, importantly, SIGPIPE tries
to write an informational message to stderr. When however stderr is
redirected to a closed pipe, this will cause (another) SIGPIPE, and in
turn the signal handler will get called again, and again and again.

Since we intend to exit rtl_fm anyways, we can just ignore this signal.
---
 src/rtl_adsb.c  | 1 +
 src/rtl_fm.c    | 1 +
 src/rtl_power.c | 1 +
 src/rtl_sdr.c   | 1 +
 src/rtl_tcp.c   | 1 +
 src/rtl_test.c  | 1 +
 6 files changed, 6 insertions(+)

diff --git a/src/rtl_adsb.c b/src/rtl_adsb.c
index 7aea8dd..8119ac8 100644
--- a/src/rtl_adsb.c
+++ b/src/rtl_adsb.c
@@ -123,6 +123,7 @@ sighandler(int signum)
 #else
 static void sighandler(int signum)
 {
+	signal(SIGPIPE, SIG_IGN);
 	fprintf(stderr, "Signal caught, exiting!\n");
 	do_exit = 1;
 	rtlsdr_cancel_async(dev);
diff --git a/src/rtl_fm.c b/src/rtl_fm.c
index 7c84332..037793c 100644
--- a/src/rtl_fm.c
+++ b/src/rtl_fm.c
@@ -246,6 +246,7 @@ sighandler(int signum)
 #else
 static void sighandler(int signum)
 {
+	signal(SIGPIPE, SIG_IGN);
 	fprintf(stderr, "Signal caught, exiting!\n");
 	do_exit = 1;
 	rtlsdr_cancel_async(dongle.dev);
diff --git a/src/rtl_power.c b/src/rtl_power.c
index 6204de2..df3ceb7 100644
--- a/src/rtl_power.c
+++ b/src/rtl_power.c
@@ -195,6 +195,7 @@ sighandler(int signum)
 #else
 static void sighandler(int signum)
 {
+	signal(SIGPIPE, SIG_IGN);
 	do_exit++;
 	multi_bail();
 }
diff --git a/src/rtl_sdr.c b/src/rtl_sdr.c
index e6537ca..2c93b57 100644
--- a/src/rtl_sdr.c
+++ b/src/rtl_sdr.c
@@ -74,6 +74,7 @@ sighandler(int signum)
 #else
 static void sighandler(int signum)
 {
+	signal(SIGPIPE, SIG_IGN);
 	fprintf(stderr, "Signal caught, exiting!\n");
 	do_exit = 1;
 	rtlsdr_cancel_async(dev);
diff --git a/src/rtl_tcp.c b/src/rtl_tcp.c
index 84f5591..8781ba9 100644
--- a/src/rtl_tcp.c
+++ b/src/rtl_tcp.c
@@ -144,6 +144,7 @@ sighandler(int signum)
 #else
 static void sighandler(int signum)
 {
+	signal(SIGPIPE, SIG_IGN);
 	fprintf(stderr, "Signal caught, exiting!\n");
 	rtlsdr_cancel_async(dev);
 	do_exit = 1;
diff --git a/src/rtl_test.c b/src/rtl_test.c
index 9b44097..b7f46ea 100644
--- a/src/rtl_test.c
+++ b/src/rtl_test.c
@@ -115,6 +115,7 @@ sighandler(int signum)
 #else
 static void sighandler(int signum)
 {
+	signal(SIGPIPE, SIG_IGN);
 	fprintf(stderr, "Signal caught, exiting!\n");
 	do_exit = 1;
 	rtlsdr_cancel_async(dev);