stapdyn(8) — Linux manual page

STAPDYN(8)               System Manager's Manual               STAPDYN(8)

NAME         top

       stapdyn - systemtap dyninst runtime

SYNOPSIS         top

       stapdyn [ OPTIONS ] MODULE [ MODULE-OPTIONS ]

DESCRIPTION         top

       The stapdyn program is the dyninst back-end of the Systemtap tool.
       It expects a shared library produced by the front-end stap tool,
       when run with --dyninst.

       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 debugging information (need to compile the
       script) and then transfer the resulting shared object to a
       production machine that doesn't have any development tools or
       debugging information installed.

       Please refer to stappaths (7) for the version number, or run rpm
       -q systemtap (fedora/red hat) apt-get -v systemtap (ubuntu)

OPTIONS         top

       The stapdyn program supports the following options.  Any other
       option prints a list of supported options.

       -v     Verbose mode.

       -V     Print version number and exit.

       -w     Suppress warnings from the script.

       -c CMD Command CMD will be run and the stapdyn 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(FILE_cpux in
              background and bulk mode) where 'x' is the cpu number. This
              supports strftime(3) formats for FILE.

       -C WHEN
              Control coloring of error messages. WHEN must be either
              "never", "always", or "auto" (i.e. enable only if at a ter‐
              minal). If the option is missing, then "auto" is assumed.
              Colors can be modified using the SYSTEMTAP_COLORS environ‐
              ment variable. See the stap(1) manual page for more infor‐
              mation on syntax and behaviour.

       var1=val
              Sets the value of global variable var1 to val. Global vari‐
              ables contained within a script are treated as options and
              can be set from the stapdyn command line.

ARGUMENTS         top

       MODULE is either a module path or a module name.  If it is a mod‐
       ule name, the module will be looked for in the following directory
       (where 'VERSION' is the output of "uname -r"):

              /lib/modules/VERSION/systemtap

        $ stap --dyninst -p4 -m mod1 -e 'global var1="foo"; probe be‐
       gin{printf("%s\n", var1); exit()}'

       Running this with an additional module argument:

        $ stapdyn mod1.so var1="HelloWorld"
        HelloWorld

       Spaces and exclamation marks currently cannot be passed into glob‐
       al variables this way.

EXAMPLES         top

       See the stapex(3stap) manual page for a collection of sample
       scripts.

       Here is a very basic example of how to use stapdyn.  First, use
       stap to compile a script.  The stap program will report the path‐
       name to the resulting module.

        $ stap --dyninst -p4 -e 'probe begin { printf("Hello World!\n");
       exit() }'
        /home/user/.systemtap/cache/85/stap_8553d83f78c_265.so

       Run stapdyn with the pathname to the module as an argument.

        $ stapdyn /home/user/.systemtap/cache/85/stap_8553d83f78c_265.so
        Hello World!

SAFETY AND SECURITY         top

       Systemtap, in DynInst mode, is a developer tool, and runs com‐
       pletely unprivileged.  The Linux kernel will only permit one's own
       processes to be accessed, which is enforced by the ptrace(2) sys‐
       tem call.  See the stap(1) manual page for additional information
       on safety and security.

SEE ALSO         top

       stap(1), stapprobes(3stap), stap-server(8), staprun(8),
       stapex(3stap)

BUGS         top

       Use the Bugzilla link of the project web page or our mailing list.
       http://sourceware.org/systemtap/ , <systemtap@sourceware.org>.

COLOPHON         top

       This page is part of the systemtap (a tracing and live-system
       analysis tool) project.  Information about the project can be
       found at ⟨https://sourceware.org/systemtap/⟩.  If you have a bug
       report for this manual page, send it to systemtap@sourceware.org.
       This page was obtained from the project's upstream Git repository
       ⟨git://sourceware.org/git/systemtap.git⟩ on 2025-02-02.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2025-01-28.)  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
       man-pages@man7.org

                                                               STAPDYN(8)

Pages that refer to this page: stap(1),  staprun(8)

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