Defects - A reminder

[Arran Cudbard-Bell]

The following can be found bundled with the server in doc/bugs and at
https://github.com/FreeRADIUS/freeradius-server/blob/master/doc/bugs.

1.YOU FOUND A BUG

  Where the server terminates ungracefully due to a bus error, 
  segmentation violation, or other memory error, you should create 
  a new issue in the issue tracker <URL: http://bugs.freeradius.org>,
  including information from sections 4 and 5.

  For other issues, you should first discuss them on the users list, 
  to see if anyone can reproduce them. Often there's a simple explanation 
  of why the server behaves as it does, and it's not necessarily a bug in
  the code, so browse the lists' archives of the last two months, and if 
  you don't see messages about it, ask!

  If the behavior is correct but confusing, we think that's a bug too, and
  you should file a bug against our documentation.

  For more information about the users list, the lists' archives and the
  faq, please visit http://www.freeradius.org/list/users.html
  Please make sure to READ and RESPECT the house-rules. You will get much
  better response and much faster if you do!

2.CORE DUMPS

  If the server, or one of the accompyaning programs core dumps, then
  you should rebuild the server as follows:

  $ ./configure --enable-developer
  $ make
  $ make install

  and then run the program again. You may have to to enable core
  dumps, via:

  $ ulimit -c unlimited

  When it core dumps, do:

  $ gdb /path/to/executable /path/to/core/file

  Enable logging in gdb via the following commands:

  (gdb) set logging file gdb-radiusd.log
  (gdb) set logging on

  and follow the instructions in section 4, below.

3. DEBUGGING A LIVE SERVER

  If you can't get a core dump, or the problem doesn't result in a
  core dump, you may have to run the server under gdb.  To do this,
  ensure that you have symbols in the binaries (i.e. a non-stripped
  binary) by re-building the server as described in the previous
  section.  Then, run the server under gdb as follows:

  $ gdb radiusd

  Enable logging in gdb via the following commands:

  (gdb) set logging file gdb-radiusd.log
  (gdb) set logging on

  Tell gdb to pass any necessary command-line arguments to the
  server:

  (gdb) set args ...

  Where the "..." are the command-line arguments you normally pass to
  radiusd.  Fo debugging, you probably want to do:

  (gdb) set args -f

  Then, do:

  (gdb) run

  When something interesting happens, you can hit CTRL-C in the
  window, and you should be back at the gdb prompt:

  (gdb)

  And follow the instructions in section 4, below.

4. OBTAINING USEFUL INFORMATION

  Once you have a core dump loaded into gdb, or FreeRADIUS running under
  gdb, you may use the commands below to get useful information about 
  the state of the server.

  If the server was built with threads, you can do:

  (gdb) info threads

  Which will give you information about the threads.  If the server
  isn't threaded, that command-line will print a message saying so.

  Then, do:

  (gdb) thread apply all bt full

  If the server isn't threaded, the "thread apply" section isn't necessary

  The output should be printed to the screen, and also sent to the
  gdb-radiusd.log file.  
  
  You should then submit the information from the log file, along with 
  any server output, the output of radiusd -xv, and information about your
  operating system to:
  
    http://bugs.freeradius.org/

  Submitting it to the bug database ensures that the bug report won't
  get forgotten, and that it will be dealt with in due course.

  You should provide the issue number in any mail sent to the user's list.

5. VALGRIND

  On Linux systems, "valgrind" is a useful tool that can catch certain
  classes of bugs.  To use it, run the server via:

$ valgrind --tool=memcheck --leak-check=full radiusd -Xm

  It will print out certain kinds of errors to the screen.  There may
  be a number of errors related to OpenSSL, dlopen(), or libtldl.  We
  cannot do anything about those problems.  However, any errors that are
  inside of the FreeRADIUS source should be brought to our attention.


6. Running with "screen"

  If the bug is a crash of the server, and it takes a long time for the
  crash to happen, perform the following steps:

 * log in as root
 * open a screen session (http://blogamundo.net/code/screen/)
   $ screen bash
 * make sure FreeRADIUS is not running
 * make sure you have all the debug symbols about, or a debugable
   version of the server installed
 * configure screen to log to a file; 'Ctrl-A H'
 * type 'gdb /path/to/radius'  (or /path/to/freeradius on Debian)
 * at the (gdb) prompt, type 'run -X'
 * detach from screen 'Ctrl-A D'
 * when you notice FreeRADIUS has died, reconnect to your screen session
   $ screen -D -r
 * at the (gdb) prompt type 'where' or for *lots* of info try
   'thread apply all bt full'
 * tell screen to stop logging, 'Ctrl-A H'
 * logout from screen

--

FreeRADIUS Project, copyright 2014


Arran Cudbard-Bell <a.cudbardb at freeradius.org>
FreeRADIUS Development Team

FD31 3077 42EC 7FCD 32FE 5EE2 56CF 27F9 30A8 CAA2

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