WWW-www.enlightenment.org pushed a commit to branch master. http://git.enlightenment.org/website/www-content.git/commit/?id=9d9cb47292b32e91eca3e04e358919ed7f912e89
commit 9d9cb47292b32e91eca3e04e358919ed7f912e89 Author: Gareth Halfacree <[email protected]> Date: Thu Nov 30 07:00:31 2017 -0800 Wiki page remote-debug.md changed with summary [created] by Gareth Halfacree --- pages/develop/debug/c/remote-debug.md.txt | 134 ++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) diff --git a/pages/develop/debug/c/remote-debug.md.txt b/pages/develop/debug/c/remote-debug.md.txt new file mode 100644 index 000000000..e1fd663f2 --- /dev/null +++ b/pages/develop/debug/c/remote-debug.md.txt @@ -0,0 +1,134 @@ +--- +~~Title: Remote Debugging~~ +--- + +# Remote Debugging # + +The debugging tools [GDB](gdb.md) and [Clouseau](clouseau.md) are most commonly used to debug an application locally, but can also be used remotely in order to debug a program running on one system using a different system entirely. This can be vital for debugging issues which result in display corruption or loss of user input capabilities on the host device. + +This document aims to provide a brief overview of the server capabilities available for remote debugging using these two tools. You will need an SSH server running on the system to be debugged, and an SSH client on the system you are controlling. + +## GDB Server ## + +Information on debugging local programs with the GNU Debugger (GDB) can be found in [Debugging with GDB](gdb.md). The GNU Debugger Server ``gdbserver`` is a control program for Unix-like systems which allows you to connect your program with a remote ``gdb`` via ``target remote`` but without linking in the usual debugging stub. + +``gdbserver`` is not a complete replacement for the debugging stubs because it requires essentially the same operating-system facilities that ``gdb`` itself does. In fact, a system that can run ``gdbserver`` to connect to a remote ``gdb`` could also run ``gdb`` locally. ``gdbserver`` is nevertheless sometimes useful because it is a much smaller program than ``gdb`` itself. It is also easier to port than all of ``gdb``, so you may be able to get started more quickly on a new system by usi [...] + +``gdb`` and ``gdbserver`` communicate via either a serial line or a TCP connection, using the standard GDB remote serial protocol. + +> **NOTE:** +> ``gdbserver`` does not have any security built-in. Do not run ``gdbserver`` while connected to any public network. A ``gdb`` connection to ``gdbserver`` provides access to the target system with the same privileges as the user running ``gdbserver``. + +### Remote Debugging with GDB ### + +Install ``gdbserver`` on your target system, then create and compile the "helloworld.c" program from [Debugging with GDB](gdb.md#Debugging_a_Callback_Function). + +Run the "helloworld" binary through ``gdbserver``: + +```bash +#target +gdbserver localhost:2000 helloworld + +$ Process hello created; pid = 2763 +$ Listening on port 2000 +``` + +At this point ``gdbserver`` is waiting for a connection on port 2000 of the target system. + +> **NOTE:** +> The GNU Debugger can be launched as multiple processes using ``gdbserver --multi localhost:2000``. + +On the client side, with a run ``gdb``: + +```gdb +#client +gdb hello +``` +```bash +... +$ Type "apropos word" to search for commands related to "word"... +$ Reading symbols from test...(no debugging symbols found)...done. +``` + +Use ``target remote`` to connect to the target system, replacing ``[target-ip]`` with the IP address of the target system. + +```gdb +#client +gdb +(gdb) target remote [target-ip]:2000 +$ Remote debugging using [target-ip]:2000 +$ Reading symbols from /lib64/ld-linux-x86-64.so.2...Reading symbols from +$ /usr/lib/debug//lib/x86_64-linux-gnu/ld-2.19.so...done. +$ done. +$ Loaded symbols for /lib64/ld-linux-x86-64.so.2 +$ 0x00007ffff7ddb2d0 in _start () from /lib64/ld-linux-x86-64.so.2 +``` + +At this point you can add breakpoints or carry out other debugging tasks. Note, however, that if you continue the program's execution the output will display on the target system, not your local client. + +```gdb +#client +(gdb) continue +``` + +Return to the target system and click the "seg" button to trigger the segmentation fault condition. When the program crashes, the traces will appear on the local client system: + +```gdb +$ Program received signal SIGSEGV, Segmentation fault. +$ 0x0000000000400b71 in ?? () +``` + +You can now use ``gdb`` as it is explaines in [[apps_efl_debugging#Segfault in +callback function]], for example print the backtrace: + +```gdb +(gdb) bt +$ 0 0x0000000000400b71 in ?? () +$ 1 0x000000000073a9a0 in ?? () +$ 2 0x00007ffff74e4f6c in _eo_evas_smart_cb (data=<optimized out>, eo_obj=<optimized out>, desc=<optimized out>, event_info=<optimized out>) at lib/evas/canvas/evas_object_smart.c:65 +$ 3 0x00007ffff561a8b7 in _eo_base_event_callback_call (obj_id=0x80000007e0000040, pd=0x73a3f0, desc=0x85d4c0, event_info=0x0) at lib/eo/eo_base_class.c:712 +$ 4 0x00007ffff5619648 in eo_event_callback_call (desc=desc@entry=0x85d4c0, event_info=event_info@entry=0x0) at lib/eo/eo_base.eo.c:94 +$ 5 0x00007ffff74e6f6e in evas_object_smart_callback_call (eo_obj=eo_obj@entry=0x80000007e0000040, event=event@entry=0x7ffff7af501f <SIG_CLICKED> "clicked", event_info=event_info@entry=0x0) at lib/evas/canvas/evas_object_smart.c:784 +$ 6 0x00007ffff7995baf in _activate (obj=0x80000007e0000040) at elm_button.c:69 +$ 7 0x00007ffff7995be5 in _on_clicked_signal (data=<optimized out>, obj=<optimized out>, emission=<optimized out>, source=<optimized out>) at elm_button.c:191 +$ 8 0x00007ffff58b0507 in edje_match_callback_exec_check_finals (prop=<optimized out>, ed=0xaaaaaaaaaaaaaaab, source=0x7245b0 "elm", sig=0x73af9c "elm,action,click", source_states=<optimized out>, signal_states=<optimized out>, matches=0x73b0c0, ssp=0x7594e0) at lib/edje/edje_match.c:556 +$ 9 edje_match_callback_exec (ssp=ssp@entry=0x7594e0, matches=0x73b0c0, sig=sig@entry=0x73af9c "elm,action,click", source=source@entry=0x7245b0 "elm", ed=ed@entry=0x73a9a0, prop=prop@entry=0 '\000') at lib/edje/edje_match.c:711 +$ 10 0x00007ffff58b6a3d in _edje_emit_cb (prop=0 '\000', data=0x0, src=0x7245b0 "elm", sig=0x73af9c "elm,action,click", ed=0x73a9a0) at lib/edje/edje_program.c:1423 +$ 11 _edje_emit_handle (ed=0x73a9a0, sig=0x73af9c "elm,action,click", src=0x7245b0 "elm", sdata=0x0, prop=0 '\000') at lib/edje/edje_program.c:1376 +$ 12 0x00007ffff58b13a1 in _edje_message_process (em=0x667830) at lib/edje/edje_message_queue.c:684 +$ 13 0x00007ffff58b18b3 in _edje_message_queue_process () at lib/edje/edje_message_queue.c:787 +$ 14 0x00007ffff58b1a14 in _edje_job (data=<optimized out>) at lib/edje/edje_message_queue.c:154 +$ 15 0x00007ffff7235a32 in _ecore_job_event_handler (data=<optimized out>, type=<optimized out>, ev=<optimized out>) at lib/ecore/ecore_job.c:121 +$ 16 0x00007ffff7230463 in _ecore_call_handler_cb (event=<optimized out>, type=<optimized out>, data=<optimized out>, func=<optimized out>) at lib/ecore/ecore_private.h:386 +$ 17 _ecore_event_call () at lib/ecore/ecore_events.c:565 +$ 18 0x00007ffff7237e05 in _ecore_main_loop_iterate_internal (once_only=once_only@entry=0) at lib/ecore/ecore_main.c:1927 +$ 19 0x00007ffff7237f14 in ecore_main_loop_begin () at lib/ecore/ecore_main.c:983 +$ 20 0x00007ffff7a47e59 in elm_run () at elm_main.c:1097 +``` + +## Clouseau Server ## + +Designed for inspecting EFL user interfaces, Clouseau can be used locally as well as remotely. Information on using Clouseau locally can be found in [Debugging with Clouseau](clouseau.md). + +Clouseau consists of a client, ``clouseau_client``, and launcher, ``clouseau_server``. This design means you can run the application requiring debugging on one device and the ``clouseau_client`` itself on another. In this it is very similar to ``gdbserver``. + +### Remote Debugging with Clouseau ### + +On your target system, launch the Clouseau server with the application to be debugged: + +```bash +clouseau_start ./your_application +``` + +On your local client connect to the target system with the following command, replacing ``[target-ip]`` with its IP address: + + +```bash +clouseau_client [target-ip] +``` + +Alternatively, you can connect via Clouseau's user interface as demonstrated in the following screenshot: + + + +From here use Clouseau as per [Debugging with Clouseau](clouseau.md). \ No newline at end of file --
