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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | AUTHOR | NOTES | COLOPHON |
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VGDB(1) vgdb VGDB(1)
vgdb - intermediary between Valgrind and GDB or a shell
vgdb [options]
vgdb ("Valgrind to GDB") is used as an intermediary between
Valgrind and GDB or a shell. It has three 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 given.
3. In the --multi mode, vgdb uses the extended remote protocol
to communicate with GDB. This allows you to view output from
both valgrind and GDB in the GDB session. This is
accomplished via the "target extended-remote | vgdb --multi".
In this mode you no longer need to start valgrind yourself.
vgdb will start up valgrind when gdb tells it to run a new
program. For this usage, the vgdb OPTIONS(s) can also include
--valgrind and --vargs to describe how valgrind should be
started.
--pid=<number>
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.
--vgdb-prefix
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.
--wait=<number>
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.
--max-invoke-ms=<number>
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
--cmd-time-out=<number>
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.
--port=<portnr>
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
computer.
--vgdb-multi
Makes vgdb start in extended-remote mode and to wait for gdb
to tell us what to run.
--valgrind
The path to valgrind to use, in extended-remote mode. If not
specified, the system valgrind will be launched.
--vargs
Options to run valgrind with, in extended-remote mode. For
example -q. Everything following --vargs will be provided as
arguments to valgrind as is.
-c
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
-l
Instructs a standalone vgdb to report the list of the
Valgrind gdbserver processes running and then exit.
-T
Instructs vgdb to add timestamps to vgdb information
messages.
-D
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.
-d
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.
valgrind(1), $INSTALL/share/doc/valgrind/html/index.html or
http://www.valgrind.org/docs/manual/index.html,
Debugging your program using Valgrind's gdbserver and GDB[1]
vgdb[2], Valgrind monitor commands[3].
Philippe Waroquiers.
1. Debugging your program using Valgrind's gdbserver and GDB
http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.gdbserver
2. vgdb
http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.vgdb
3. Valgrind monitor commands
http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.valgrind-monitor-commands
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 Git repository
⟨http://sourceware.org/git/valgrind.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-10.) 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
man-pages@man7.org
Release 3.24.0.GIT 06/14/2024 VGDB(1)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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