From 35ea6a5a054d61cbcd1db680439f03d152e5a5b4 Mon Sep 17 00:00:00 2001
From: Marcel Holtmann <marcel@holtmann.org>
Date: Wed, 5 Oct 2011 19:41:40 -0700
Subject: [PATCH] log: Add support for backtrace symbole resolving

---
 src/log.c   | 125 ++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 src/main.c  |   2 +-
 src/ofono.h |   2 +-
 3 files changed, 112 insertions(+), 17 deletions(-)

diff --git a/src/log.c b/src/log.c
index c31a76c..84710f0 100644
--- a/src/log.c
+++ b/src/log.c
@@ -24,14 +24,20 @@
 #endif
 
 #define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
 #include <stdarg.h>
-#include <syslog.h>
 #include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
 #include <execinfo.h>
 #include <dlfcn.h>
 
 #include "ofono.h"
 
+static const char *program_exec;
+static const char *program_path;
+
 /**
  * ofono_info:
  * @format: format string
@@ -107,30 +113,115 @@ void ofono_debug(const char *format, ...)
 	va_end(ap);
 }
 
-static void signal_handler(int signo)
+static void print_backtrace(unsigned int offset)
 {
-	void *frames[64];
-	char **symbols;
+	void *frames[99];
 	size_t n_ptrs;
 	unsigned int i;
+	int outfd[2], infd[2];
+	int pathlen;
+	pid_t pid;
+
+	if (program_exec == NULL)
+		return;
+
+	pathlen = strlen(program_path);
 
 	n_ptrs = backtrace(frames, G_N_ELEMENTS(frames));
-	symbols = backtrace_symbols(frames, n_ptrs);
-	if (symbols == NULL) {
-		ofono_error("No backtrace symbols");
-		exit(1);
+	if (n_ptrs < offset)
+		return;
+
+	if (pipe(outfd) < 0)
+		return;
+
+	if (pipe(infd) < 0) {
+		close(outfd[0]);
+		close(outfd[1]);
+		return;
+	}
+
+	pid = fork();
+	if (pid < 0) {
+		close(outfd[0]);
+		close(outfd[1]);
+		close(infd[0]);
+		close(infd[1]);
+		return;
+	}
+
+	if (pid == 0) {
+		close(outfd[1]);
+		close(infd[0]);
+
+		dup2(outfd[0], STDIN_FILENO);
+		dup2(infd[1], STDOUT_FILENO);
+
+		execlp("addr2line", "-C", "-f", "-e", program_exec, NULL);
+
+		exit(EXIT_FAILURE);
 	}
 
-	ofono_error("Aborting (signal %d)", signo);
+	close(outfd[0]);
+	close(infd[1]);
+
 	ofono_error("++++++++ backtrace ++++++++");
 
-	for (i = 1; i < n_ptrs; i++)
-		ofono_error("[%d]: %s", i - 1, symbols[i]);
+	for (i = offset; i < n_ptrs - 1; i++) {
+		Dl_info info;
+		char addr[20], buf[PATH_MAX * 2];
+		int len, written;
+		char *ptr, *pos;
+
+		dladdr(frames[i], &info);
+
+		len = snprintf(addr, sizeof(addr), "%p\n", frames[i]);
+		if (len < 0)
+			break;
+
+		written = write(outfd[1], addr, len);
+		if (written < 0)
+			break;
+
+		len = read(infd[0], buf, sizeof(buf));
+		if (len < 0)
+			break;
+
+		buf[len] = '\0';
+
+		pos = strchr(buf, '\n');
+		*pos++ = '\0';
+
+		if (strcmp(buf, "??") == 0) {
+			ofono_error("#%-2u %p in %s", i - offset,
+						frames[i], info.dli_fname);
+			continue;
+		}
+
+		ptr = strchr(pos, '\n');
+		*ptr++ = '\0';
+
+		if (strncmp(pos, program_path, pathlen) == 0)
+			pos += pathlen + 1;
+
+		ofono_error("#%-2u %p in %s() at %s", i - offset,
+						frames[i], buf, pos);
+	}
 
 	ofono_error("+++++++++++++++++++++++++++");
 
-	g_free(symbols);
-	exit(1);
+	kill(pid, SIGTERM);
+
+	close(outfd[1]);
+	close(infd[0]);
+}
+
+static void signal_handler(int signo)
+{
+	ofono_error("Aborting (signal %d) [%s]", signo, program_exec);
+
+	print_backtrace(2);
+
+	exit(EXIT_FAILURE);
 }
 
 static void signal_setup(sighandler_t handler)
@@ -197,10 +288,14 @@ void __ofono_log_enable(struct ofono_debug_desc *start,
 	}
 }
 
-int __ofono_log_init(const char *debug, ofono_bool_t detach)
+int __ofono_log_init(const char *exe, const char *debug, ofono_bool_t detach)
 {
+	static char path[PATH_MAX];
 	int option = LOG_NDELAY | LOG_PID;
 
+	program_exec = exe;
+	program_path = getcwd(path, sizeof(path));
+
 	if (debug != NULL)
 		enabled = g_strsplit_set(debug, ":, ", 0);
 
@@ -211,7 +306,7 @@ int __ofono_log_init(const char *debug, ofono_bool_t detach)
 
 	signal_setup(signal_handler);
 
-	openlog("ofonod", option, LOG_DAEMON);
+	openlog(basename(exe), option, LOG_DAEMON);
 
 	syslog(LOG_INFO, "oFono version %s", VERSION);
 
diff --git a/src/main.c b/src/main.c
index e6233f0..b88b538 100644
--- a/src/main.c
+++ b/src/main.c
@@ -226,7 +226,7 @@ int main(int argc, char **argv)
 
 	signal = setup_signalfd();
 
-	__ofono_log_init(option_debug, option_detach);
+	__ofono_log_init(argv[0], option_debug, option_detach);
 
 	dbus_error_init(&error);
 
diff --git a/src/ofono.h b/src/ofono.h
index a5995b0..a25299d 100644
--- a/src/ofono.h
+++ b/src/ofono.h
@@ -34,7 +34,7 @@ void __ofono_modem_shutdown(void);
 
 #include <ofono/log.h>
 
-int __ofono_log_init(const char *debug, ofono_bool_t detach);
+int __ofono_log_init(const char *exe, const char *debug, ofono_bool_t detach);
 void __ofono_log_cleanup(void);
 void __ofono_log_enable(struct ofono_debug_desc *start,
 					struct ofono_debug_desc *stop);
-- 
2.7.4