STAPRUN(8) STAPRUN(8)
NAME
staprun - systemtap runtime
SYNOPSIS
staprun [ OPTIONS ] MODULE [ MODULE-OPTIONS ]
DESCRIPTION
The staprun program is the back-end of the Systemtap tool. It expects
a kernel module produced by the front-end stap tool.
Splitting the systemtap tool into a front-end and a back-end allows a
user to compile a systemtap script on a development machine that has
the kernel debugging information (need to compile the script) and then
transfer the resulting kernel module to a production machine that
doesn’t have any development tools or kernel debugging information
installed.
This manual corresponds to version 0.6.2.
OPTIONS
The staprun program supports the following options. Any other option
prints a list of supported options.
-v Verbose mode.
-c CMD Command CMD will be run and the staprun program will exit when
CMD does. The ’_stp_target’ variable will contain the pid for
CMD.
-x PID The ’_stp_target’ variable will be set to PID.
-o FILE
Send output to FILE. If the module uses bulk mode, the output
will be in percpu files FILE_x where ’x’ is the cpu number.
-b BUFFER_SIZE
The systemtap module will specify a buffer size. Setting one
here will override that value. The value should be an integer
between 1 and 64 which be assumed to be the buffer size in MB.
That value will be per-cpu if bulk mode is used.
-L Load module and start probes, then detach from the module leav-
ing the probes running. The module can be attached to later by
using the -A option.
-A Attach to loaded systemtap module.
ARGUMENTS
MODULE is either a module path or a module name. If it is a module
name, the module will be looked for in the following directory (where
’VERSION’ is the output of "uname -r"):
/lib/modules/VERSION/systemtap
Any additional arguments on the command line are passed to the module.
EXAMPLES
See the stapex(5) manual page for a collection of sample scripts.
Here is a very basic example of how to use staprun. First, use stap to
compile a script. The stap program will report the pathname to the
resulting module.
$ stap -p4 -e ’probe begin { printf("Hello World!\n"); exit() }’
/home/user/.systemtap/cache/85/stap_8553d83f78c_265.ko
Run staprun with the pathname to the module as an argument.
$ staprun /home/user/.systemtap/cache/85/stap_8553d83f78c_265.ko
Hello World!
MODULE DETACHING AND ATTACHING
After the staprun program installs a Systemtap kernel module, users can
detach from the kernel module and reattach to it later. The -L option
loads the module and automatically detaches. Users can also detach
from the kernel module interactively by sending the SIGQUIT signal from
the keyboard (typically by typing Ctrl-\).
To reattach to a kernel module, the staprun -A option would be used.
SAFETY AND SECURITY
Systemtap is an administrative tool. It exposes kernel internal data
structures and potentially private user information. See the stap(1)
manual page for additional information on safety and security.
To increase system security, only the root user and members of the
stapdev group can use staprun to insert systemtap modules (or attach to
existing ones). Members of the stapusr group can use staprun to insert
systemtap modules (or attach to existing systemtap modules) that are
located in the /lib/modules/VERSION/systemtap directory.
FILES
/lib/modules/VERSION/systemtap
If MODULE is a module name, the module will be looked for in
this directory. Users who are only in the ’stapusr’ group can
only install modules located in this directory. This directory
should be owned by the root user and not be world writable.
SEE ALSO
stap(1), stapprobes(5), stapfuncs(5), stapex(5),
BUGS
Use the Bugzilla link off of the project web page or our mailing list.
http://sources.redhat.com/systemtap/,<systemtap@sources.redhat.com>.
Red Hat 2008-11-04 STAPRUN(8)
