From ff4679178975cede4a4173bcf03447f1c0058d73 Mon Sep 17 00:00:00 2001
From: Samuel Ortiz <sameo@linux.intel.com>
Date: Tue, 17 Aug 2010 17:10:46 +0200
Subject: [PATCH] ConnMan backtrace support

Add a generic signal handler in order to dump ConnMan backtrace when
crashing. The implementation is based on glibc backtrace() routines and
thus can not resolve static function names. A little python wrapper over
addr2line fixes that by taking a full backtrace from a complete connman
log file.
---
 Makefile.am    |  2 +-
 src/log.c      | 51 ++++++++++++++++++++++++++++++++++++++++++++++
 test/backtrace | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 107 insertions(+), 1 deletion(-)
 create mode 100644 test/backtrace

diff --git a/Makefile.am b/Makefile.am
index ed4689c9..1bf72074 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -179,7 +179,7 @@ test_scripts = test/get-state test/list-profiles test/list-services \
 		test/monitor-manager test/test-counter test/set-ip-method \
 		test/set-nameservers test/set-domains test/find-service \
 		test/get-services test/get-proxy-autoconfig \
-		test/enable-tethering test/disable-tethering
+		test/enable-tethering test/disable-tethering test/backtrace
 
 if TEST
 testdir = $(pkglibdir)/test
diff --git a/src/log.c b/src/log.c
index 327731f2..4dee0031 100644
--- a/src/log.c
+++ b/src/log.c
@@ -23,8 +23,12 @@
 #include <config.h>
 #endif
 
+#define _GNU_SOURCE
 #include <stdarg.h>
 #include <syslog.h>
+#include <execinfo.h>
+#include <dlfcn.h>
+#include <stdlib.h>
 
 #include "connman.h"
 
@@ -148,6 +152,49 @@ static connman_bool_t is_enabled(struct connman_debug_desc *desc)
 	return FALSE;
 }
 
+static void signal_handler(int signo)
+{
+	void *frames[64];
+	char **symbols;
+	size_t n_ptrs;
+	unsigned int i;
+
+	n_ptrs = backtrace(frames, G_N_ELEMENTS(frames));
+	symbols = backtrace_symbols(frames, n_ptrs);
+	if (symbols == NULL) {
+		connman_error("No backtrace symbols");
+		exit(1);
+	}
+
+	connman_error("Aborting (signal %d)", signo);
+	connman_error("++++++++ ConnMan backtrace ++++++++");
+
+	for (i = 1; i < n_ptrs; i++)
+		connman_error("[%d]: %s", i - 1, symbols[i]);
+
+	connman_error("++++++++++++++++++++++++++++++++++++");
+
+	g_free(symbols);
+	exit(1);
+}
+
+static void signal_setup(sighandler_t handler)
+{
+	struct sigaction sa;
+	sigset_t mask;
+
+	sigemptyset(&mask);
+	sa.sa_handler = handler;
+	sa.sa_mask = mask;
+	sa.sa_flags = 0;
+	sigaction(SIGBUS, &sa, NULL);
+	sigaction(SIGILL, &sa, NULL);
+	sigaction(SIGFPE, &sa, NULL);
+	sigaction(SIGSEGV, &sa, NULL);
+	sigaction(SIGABRT, &sa, NULL);
+	sigaction(SIGPIPE, &sa, NULL);
+}
+
 int __connman_log_init(const char *debug, connman_bool_t detach)
 {
 	int option = LOG_NDELAY | LOG_PID;
@@ -179,6 +226,8 @@ int __connman_log_init(const char *debug, connman_bool_t detach)
 	if (detach == FALSE)
 		option |= LOG_PERROR;
 
+	signal_setup(signal_handler);
+
 	openlog("connmand", option, LOG_DAEMON);
 
 	syslog(LOG_INFO, "Connection Manager version %s", VERSION);
@@ -193,4 +242,6 @@ void __connman_log_cleanup(void)
 	closelog();
 
 	g_strfreev(enabled);
+
+	signal_setup(SIG_DFL);
 }
diff --git a/test/backtrace b/test/backtrace
new file mode 100644
index 00000000..d33bcb18
--- /dev/null
+++ b/test/backtrace
@@ -0,0 +1,55 @@
+#!/usr/bin/python
+
+import os
+import re
+import sys
+import subprocess
+
+if (len(sys.argv) < 3):
+	print "Usage: %s [connman binary] [connman log]" % (sys.argv[0])
+	sys.exit(1)
+
+binary = sys.argv[1]
+count = 0
+frames = []
+addrs = []
+
+log_file = open(sys.argv[2], 'r')
+
+# Extract addresses
+for line in log_file:
+    matchobj = re.compile(r'\[(0x[0-9a-f]+)\]$').search(line)
+    if matchobj:
+        addrs.append(matchobj.group(1))
+
+log_file.close()
+
+# Feed into addr2line
+command = ['addr2line', '--demangle', '--functions', '--basename', '-e', binary]
+command.extend(addrs)
+
+p = subprocess.Popen(command, shell=False, bufsize=0,
+          stdin=subprocess.PIPE, stdout=subprocess.PIPE, close_fds=True)
+(child_stdin, child_stdout) = (p.stdin, p.stdout)
+
+child_stdin.close()
+
+# Backtrace display
+for line in child_stdout:
+
+    if line.startswith("??"): continue
+
+    line = line.strip()
+
+    frames.append(line)
+
+child_stdout.close()
+
+frame_count = len(frames);
+
+count = 0
+print "-------- ConnMan backtrace --------"
+while count < frame_count:
+    print "[%d]: %s() [%s]" % (count/2, frames[count], frames[count + 1])
+    count = count + 2
+print "-----------------------------------"
-- 
2.34.1