From df5d691c39b0ff41d3d98a01db078f7157eb0250 Mon Sep 17 00:00:00 2001
From: Marcel Holtmann <marcel@holtmann.org>
Date: Fri, 20 Aug 2010 14:44:54 +0200
Subject: [PATCH] Add support for simple glibc based backtrace

---
 Makefile.am    |  3 ++-
 src/log.c      | 51 ++++++++++++++++++++++++++++++++++++++++++++
 test/backtrace | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 110 insertions(+), 1 deletion(-)
 create mode 100755 test/backtrace

diff --git a/Makefile.am b/Makefile.am
index 3aa2aef0..3164f9be 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -310,8 +310,9 @@ doc_files = doc/overview.txt doc/ofono-paper.txt \
 			doc/supplementaryservices-api.txt \
 			doc/connman-api.txt
 
-test_scripts = test/activate-context \
+test_scripts = test/backtrace \
 		test/create-context \
+		test/activate-context \
 		test/deactivate-context \
 		test/dial-number \
 		test/disable-modem \
diff --git a/src/log.c b/src/log.c
index 25ccd12f..51d1b0d0 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 <stdlib.h>
+#include <execinfo.h>
+#include <dlfcn.h>
 
 #include "ofono.h"
 
@@ -103,6 +107,49 @@ void ofono_debug(const char *format, ...)
 	va_end(ap);
 }
 
+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) {
+		ofono_error("No backtrace symbols");
+		exit(1);
+	}
+
+	ofono_error("Aborting (signal %d)", signo);
+	ofono_error("++++++++ backtrace ++++++++");
+
+	for (i = 1; i < n_ptrs; i++)
+		ofono_error("[%d]: %s", i - 1, symbols[i]);
+
+	ofono_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);
+}
+
 extern struct ofono_debug_desc __start___debug[];
 extern struct ofono_debug_desc __stop___debug[];
 
@@ -152,6 +199,8 @@ int __ofono_log_init(const char *debug, ofono_bool_t detach)
 	if (detach == FALSE)
 		option |= LOG_PERROR;
 
+	signal_setup(signal_handler);
+
 	openlog("ofonod", option, LOG_DAEMON);
 
 	syslog(LOG_INFO, "oFono version %s", VERSION);
@@ -165,5 +214,7 @@ void __ofono_log_cleanup(void)
 
 	closelog();
 
+	signal_setup(SIG_DFL);
+
 	g_strfreev(enabled);
 }
diff --git a/test/backtrace b/test/backtrace
new file mode 100755
index 00000000..c906f369
--- /dev/null
+++ b/test/backtrace
@@ -0,0 +1,57 @@
+#!/usr/bin/python
+
+import os
+import re
+import sys
+import subprocess
+
+if (len(sys.argv) < 3):
+	print "Usage: %s [binary] [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 "-------- backtrace --------"
+while count < frame_count:
+	print "[%d]: %s() [%s]" % (count/2, frames[count], frames[count + 1])
+	count = count + 2
+print "---------------------------"