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
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:
On the computer which hosts GDB, execute the command:
(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.
This page is part of the valgrind (a system for debugging and
profiling Linux programs) project. Information about the project can
be found at ⟨http://www.valgrind.org/⟩. If you have a bug report for
this manual page, see
⟨http://www.valgrind.org/support/bug_reports.html⟩. This page was
obtained from the project's upstream Subversion repository
⟨svn://svn.valgrind.org/valgrind/trunk⟩ on 2017-03-13. If you dis‐
cover 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
Release 3.13.0.SVN 03/13/2017 VGDB(1)