VGDB(1)                      Release 3.15.0.GIT                      VGDB(1)

NAME         top

       vgdb - intermediary between Valgrind and GDB or a shell

SYNOPSIS         top

       vgdb [options]

DESCRIPTION         top

       vgdb ("Valgrind to GDB") is used as an intermediary between Valgrind
       and GDB or a shell. It has two usage modes:

        1. As a standalone utility, it is used from a shell command line to
           send monitor commands to a process running under Valgrind. For
           this usage, the vgdb OPTION(s) must be followed by the monitor
           command to send. To send more than one command, separate them
           with the -c option.

        2. In combination with GDB "target remote |" command, it is used as
           the relay application between GDB and the Valgrind gdbserver. For
           this usage, only OPTION(s) can be given, but no COMMAND can be

OPTIONS         top

           Specifies the PID of the process to which vgdb must connect to.
           This option is useful in case more than one Valgrind gdbserver
           can be connected to. If the --pid argument is not given and
           multiple Valgrind gdbserver processes are running, vgdb will
           report the list of such processes and then exit.

           Must be given to both Valgrind and vgdb if you want to change the
           default prefix for the FIFOs (named pipes) used for communication
           between the Valgrind gdbserver and vgdb.

           Instructs vgdb to search for available Valgrind gdbservers for
           the specified number of seconds. This makes it possible start a
           vgdb process before starting the Valgrind gdbserver with which
           you intend the vgdb to communicate. This option is useful when
           used in conjunction with a --vgdb-prefix that is unique to the
           process you want to wait for. Also, if you use the --wait
           argument in the GDB "target remote" command, you must set the GDB
           remotetimeout to a value bigger than the --wait argument value.
           See option --max-invoke-ms (just below) for an example of setting
           the remotetimeout value.

           Gives the number of milliseconds after which vgdb will force the
           invocation of gdbserver embedded in Valgrind. The default value
           is 100 milliseconds. A value of 0 disables forced invocation. The
           forced invocation is used when vgdb is connected to a Valgrind
           gdbserver, and the Valgrind process has all its threads blocked
           in a system call.

           If you specify a large value, you might need to increase the GDB
           "remotetimeout" value from its default value of 2 seconds. You
           should ensure that the timeout (in seconds) is bigger than the
           --max-invoke-ms value. For example, for --max-invoke-ms=5000, the
           following GDB command is suitable:

                   (gdb) set remotetimeout 6

           Instructs a standalone vgdb to exit if the Valgrind gdbserver it
           is connected to does not process a command in the specified
           number of seconds. The default value is to never time out.

           Instructs vgdb to use tcp/ip and listen for GDB on the specified
           port nr rather than to use a pipe to communicate with GDB. Using
           tcp/ip allows to have GDB running on one computer and debugging a
           Valgrind process running on another target computer. Example:

               # On the target computer, start your program under valgrind using
               valgrind --vgdb-error=0 prog
               # and then in another shell, run:
               vgdb --port=1234

           On the computer which hosts GDB, execute the command:

               gdb prog
               (gdb) target remote targetip:1234

           where targetip is the ip address or hostname of the target

           To give more than one command to a standalone vgdb, separate the
           commands by an option -c. Example:

               vgdb v.set log_output -c leak_check any

           Instructs a standalone vgdb to report the list of the Valgrind
           gdbserver processes running and then exit.

           Instructs a standalone vgdb to show the state of the shared
           memory used by the Valgrind gdbserver. vgdb will exit after
           having shown the Valgrind gdbserver shared memory state.

           Instructs vgdb to produce debugging output. Give multiple -d args
           to increase the verbosity. When giving -d to a relay vgdb, you
           better redirect the standard error (stderr) of vgdb to a file to
           avoid interaction between GDB and vgdb debugging output.

SEE ALSO         top

       valgrind(1), $INSTALL/share/doc/valgrind/html/index.html or, Debugging your
       program using Valgrind's gdbserver and GDB[1] vgdb[2], Valgrind
       monitor commands[3].

AUTHOR         top

       Philippe Waroquiers.

NOTES         top

        1. Debugging your program using Valgrind's gdbserver and GDB

        2. vgdb

        3. Valgrind monitor commands

COLOPHON         top

       This page is part of the valgrind (a system for debugging and
       profiling Linux programs) project.  Information about the project can
       be found at ⟨⟩.  If you have a bug report for
       this manual page, see
       ⟨⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨⟩ on 2018-10-29.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2018-10-28.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to

Release 3.15.0.GIT               10/29/2018                          VGDB(1)