[lib] Put symbolic backtrace on system log

When BGP crashes, sometimes all we get to see is syslog.

diff --git a/lib/log.c b/lib/log.c
index 407904d5df4342c19dcedb63882d36593181fdd6..f7a36851395700b06768b9fca37fe28a6da2a519 100644 (file)
--- a/lib/log.c
+++ b/lib/log.c
@@ -435,10 +435,10 @@ zlog_backtrace_sigsafe(int priority, void *program_counter)
 {
 #ifdef HAVE_STACK_TRACE
   static const char pclabel[] = "Program counter: ";
-  void *array[20];
+  void *array[64];
   int size;
   char buf[100];
-  char *s;
+  char *s, **bt = NULL;
 #define LOC s,buf+sizeof(buf)-s
 
 #ifdef HAVE_GLIBC_BACKTRACE
@@ -485,20 +485,29 @@ zlog_backtrace_sigsafe(int priority, void *program_counter)
        syslog_sigsafe(priority|zlog_default->facility,buf,s-buf);
       {
        int i;
+#ifdef HAVE_GLIBC_BACKTRACE
+        bt = backtrace_symbols(array, size);
+#endif
        /* Just print the function addresses. */
        for (i = 0; i < size; i++)
          {
            s = buf;
-           s = str_append(LOC,"[bt ");
-           s = num_append(LOC,i);
-           s = str_append(LOC,"] 0x");
-           s = hex_append(LOC,(u_long)(array[i]));
+           if (bt) 
+             s = str_append(LOC, bt[i]);
+           else {
+             s = str_append(LOC,"[bt ");
+             s = num_append(LOC,i);
+             s = str_append(LOC,"] 0x");
+             s = hex_append(LOC,(u_long)(array[i]));
+           }
            *s = '\0';
            if (priority <= zlog_default->maxlvl[ZLOG_DEST_MONITOR])
              vty_log_fixed(buf,s-buf);
            if (priority <= zlog_default->maxlvl[ZLOG_DEST_SYSLOG])
              syslog_sigsafe(priority|zlog_default->facility,buf,s-buf);
          }
+         if (bt)
+           free(bt);
       }
     }
 #undef DUMP