gdbserver(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | COPYRIGHT | COLOPHON

GDBSERVER(1)              GNU Development Tools             GDBSERVER(1)

NAME         top

       gdbserver - Remote Server for the GNU Debugger

SYNOPSIS         top

       gdbserver comm prog [args...]

       gdbserver --attach comm pid

       gdbserver --multi comm

DESCRIPTION         top

       gdbserver is a program that allows you to run GDB on a different
       machine than the one which is running the program being debugged.

       Usage (server (target) side):

       First, you need to have a copy of the program you want to debug
       put onto the target system.  The program can be stripped to save
       space if needed, as gdbserver doesn't care about symbols.  All
       symbol handling is taken care of by the GDB running on the host
       system.

       To use the server, you log on to the target system, and run the
       gdbserver program.  You must tell it (a) how to communicate with
       GDB, (b) the name of your program, and (c) its arguments.  The
       general syntax is:

               target> gdbserver <comm> <program> [<args> ...]

       For example, using a serial port, you might say:

               target> gdbserver /dev/com1 emacs foo.txt

       This tells gdbserver to debug emacs with an argument of foo.txt,
       and to communicate with GDB via /dev/com1.  gdbserver now waits
       patiently for the host GDB to communicate with it.

       To use a TCP connection, you could say:

               target> gdbserver host:2345 emacs foo.txt

       This says pretty much the same thing as the last example, except
       that we are going to communicate with the "host" GDB via TCP.
       The "host:2345" argument means that we are expecting to see a TCP
       connection from "host" to local TCP port 2345.  (Currently, the
       "host" part is ignored.)  You can choose any number you want for
       the port number as long as it does not conflict with any existing
       TCP ports on the target system.  This same port number must be
       used in the host GDBs "target remote" command, which will be
       described shortly.  Note that if you chose a port number that
       conflicts with another service, gdbserver will print an error
       message and exit.

       gdbserver can also attach to running programs.  This is
       accomplished via the --attach argument.  The syntax is:

               target> gdbserver --attach <comm> <pid>

       pid is the process ID of a currently running process.  It isn't
       necessary to point gdbserver at a binary for the running process.

       To start "gdbserver" without supplying an initial command to run
       or process ID to attach, use the --multi command line option.  In
       such case you should connect using "target extended-remote" to
       start the program you want to debug.

               target> gdbserver --multi <comm>

       Usage (host side):

       You need an unstripped copy of the target program on your host
       system, since GDB needs to examine its symbol tables and such.
       Start up GDB as you normally would, with the target program as
       the first argument.  (You may need to use the --baud option if
       the serial line is running at anything except 9600 baud.)  That
       is "gdb TARGET-PROG", or "gdb --baud BAUD TARGET-PROG".  After
       that, the only new command you need to know about is "target
       remote" (or "target extended-remote").  Its argument is either a
       device name (usually a serial device, like /dev/ttyb), or a
       "HOST:PORT" descriptor.  For example:

               (gdb) target remote /dev/ttyb

       communicates with the server via serial line /dev/ttyb, and:

               (gdb) target remote the-target:2345

       communicates via a TCP connection to port 2345 on host
       `the-target', where you previously started up gdbserver with the
       same port number.  Note that for TCP connections, you must start
       up gdbserver prior to using the `target remote' command,
       otherwise you may get an error that looks something like
       `Connection refused'.

       gdbserver can also debug multiple inferiors at once, described in
       the GDB manual in node "Inferiors Connections and Programs" --
       shell command "info -f gdb -n 'Inferiors Connections and
       Programs'".  In such case use the "extended-remote" GDB command
       variant:

               (gdb) target extended-remote the-target:2345

       The gdbserver option --multi may or may not be used in such case.

OPTIONS         top

       There are three different modes for invoking gdbserver:

       •   Debug a specific program specified by its program name:

                   gdbserver <comm> <prog> [<args>...]

           The comm parameter specifies how should the server
           communicate with GDB; it is either a device name (to use a
           serial line), a TCP port number (":1234"), or "-" or "stdio"
           to use stdin/stdout of "gdbserver".  Specify the name of the
           program to debug in prog.  Any remaining arguments will be
           passed to the program verbatim.  When the program exits, GDB
           will close the connection, and "gdbserver" will exit.

       •   Debug a specific program by specifying the process ID of a
           running program:

                   gdbserver --attach <comm> <pid>

           The comm parameter is as described above.  Supply the process
           ID of a running program in pid; GDB will do everything else.
           Like with the previous mode, when the process pid exits, GDB
           will close the connection, and "gdbserver" will exit.

       •   Multi-process mode -- debug more than one program/process:

                   gdbserver --multi <comm>

           In this mode, GDB can instruct gdbserver which command(s) to
           run.  Unlike the other 2 modes, GDB will not close the
           connection when a process being debugged exits, so you can
           debug several processes in the same session.

       In each of the modes you may specify these options:

       --help
           List all options, with brief explanations.

       --version
           This option causes gdbserver to print its version number and
           exit.

       --attach
           gdbserver will attach to a running program.  The syntax is:

                   target> gdbserver --attach <comm> <pid>

           pid is the process ID of a currently running process.  It
           isn't necessary to point gdbserver at a binary for the
           running process.

       --multi
           To start "gdbserver" without supplying an initial command to
           run or process ID to attach, use this command line option.
           Then you can connect using "target extended-remote" and start
           the program you want to debug.  The syntax is:

                   target> gdbserver --multi <comm>

       --debug
           Instruct "gdbserver" to display extra status information
           about the debugging process.  This option is intended for
           "gdbserver" development and for bug reports to the
           developers.

       --remote-debug
           Instruct "gdbserver" to display remote protocol debug output.
           This option is intended for "gdbserver" development and for
           bug reports to the developers.

       --debug-file=filename
           Instruct "gdbserver" to send any debug output to the given
           filename.  This option is intended for "gdbserver"
           development and for bug reports to the developers.

       --debug-format=option1[,option2,...]
           Instruct "gdbserver" to include extra information in each
           line of debugging output.

       --wrapper
           Specify a wrapper to launch programs for debugging.  The
           option should be followed by the name of the wrapper, then
           any command-line arguments to pass to the wrapper, then "--"
           indicating the end of the wrapper arguments.

       --once
           By default, gdbserver keeps the listening TCP port open, so
           that additional connections are possible.  However, if you
           start "gdbserver" with the --once option, it will stop
           listening for any further connection attempts after
           connecting to the first GDB session.

SEE ALSO         top

       The full documentation for GDB is maintained as a Texinfo manual.
       If the "info" and "gdb" programs and GDB's Texinfo documentation
       are properly installed at your site, the command

               info gdb

       should give you access to the complete manual.

       Using GDB: A Guide to the GNU Source-Level Debugger, Richard M.
       Stallman and Roland H. Pesch, July 1991.

COPYRIGHT         top

       Copyright (c) 1988-2020 Free Software Foundation, Inc.

       Permission is granted to copy, distribute and/or modify this
       document under the terms of the GNU Free Documentation License,
       Version 1.3 or any later version published by the Free Software
       Foundation; with the Invariant Sections being "Free Software" and
       "Free Software Needs Free Documentation", with the Front-Cover
       Texts being "A GNU Manual," and with the Back-Cover Texts as in
       (a) below.

       (a) The FSF's Back-Cover Text is: "You are free to copy and
       modify this GNU Manual.  Buying copies from GNU Press supports
       the FSF in developing GNU and promoting software freedom."

COLOPHON         top

       This page is part of the gdb (GNU debugger) project.  Information
       about the project can be found at 
       ⟨http://www.gnu.org/software/gdb/⟩.  If you have a bug report for
       this manual page, see ⟨http://www.gnu.org/software/gdb/bugs/⟩.
       This page was obtained from the tarball gdb-10.1.tar.gz fetched
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gdb-10.1                       2020-10-24                   GDBSERVER(1)