Basic backtrace ability

On platforms with the backtrace/backtrace_symbols_fd interface, Tor
can now dump stack traces on assertion failure.  By default, I log
them to DataDir/stack_dump and to stderr.

2 files changed, 20 insertions, 3 deletions

diff --git a/src/or/config.c b/src/or/config.c
index ad6689ceef..af5bf41d24 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -12,6 +12,7 @@
 #define CONFIG_PRIVATE
 #include "or.h"
 #include "addressmap.h"
+#include "backtrace.h"
 #include "channel.h"
 #include "circuitbuild.h"
 #include "circuitlist.h"
@@ -1113,6 +1114,19 @@ options_act_reversible(const or_options_t *old_options, char **msg)
     /* No need to roll back, since you can't change the value. */
   }
 
+  /* Enable crash logging to files */
+  {
+    /* XXXX we might want to set this up earlier, if possible! */
+    char *backtrace_fname = NULL;
+    char *progname = NULL;
+    tor_asprintf(&backtrace_fname, "%s"PATH_SEPARATOR"stack_dump",
+                 options->DataDirectory);
+    tor_asprintf(&progname, "Tor %s", get_version());
+    configure_backtrace_handler(backtrace_fname, progname);
+    tor_free(backtrace_fname);
+    tor_free(progname);
+  }
+
   /* Write control ports to disk as appropriate */
   control_ports_write_to_file();
 
diff --git a/src/or/main.c b/src/or/main.c
index d1728250a4..ea86df0738 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -12,6 +12,7 @@
 
 #include "or.h"
 #include "addressmap.h"
+#include "backtrace.h"
 #include "buffers.h"
 #include "channel.h"
 #include "channeltls.h"
@@ -2304,7 +2305,7 @@ handle_signals(int is_parent)
 int
 tor_init(int argc, char *argv[])
 {
-  char buf[256];
+  char progname[256];
   int i, quiet = 0;
   time_of_process_start = time(NULL);
   if (!connection_array)
@@ -2314,8 +2315,8 @@ tor_init(int argc, char *argv[])
   if (!active_linked_connection_lst)
     active_linked_connection_lst = smartlist_new();
   /* Have the log set up with our application name. */
-  tor_snprintf(buf, sizeof(buf), "Tor %s", get_version());
-  log_set_application_name(buf);
+  tor_snprintf(progname, sizeof(progname), "Tor %s", get_version());
+  log_set_application_name(progname);
   /* Initialize the history structures. */
   rep_hist_init();
   /* Initialize the service cache. */
@@ -2684,6 +2685,8 @@ tor_main(int argc, char *argv[])
   }
 #endif
 
+  configure_backtrace_handler(NULL, get_version());
+
   update_approx_time(time(NULL));
   tor_threads_init();
   init_logging();