NAME

       stapbpf - systemtap bpf runtime

SYNOPSIS

       stapbpf [ OPTIONS ] MODULE

DESCRIPTION

       The stapbpf program is the BPF back-end of the Systemtap tool.  It expects a bpf-elf file produced by the
       front-end stap tool, when run with --runtime=bpf.

       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  needed  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 # (for Fedora/RHEL)
        $ apt-get -v systemtap # (for Ubuntu)

OPTIONS

       The stapbpf 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.

       -h     Print help message.

       -x PID The '_stp_target' variable will be set to PID.

       -o FILE
              Send output to FILE.

ARGUMENTS

       MODULE is the path of a bpf-elf file produced by the front-end stap tool, when run with --runtime=bpf.

EXAMPLES

       Here is a very basic example of how to generate a stapbpf module.  First, use stap to compile  a  script.
       The stap program will report the name of the resulting module in the current working directory.

        $ stap --runtime=bpf -p4 -e 'probe begin { printf("Hello World!\n"); exit() }'
        stap_28784.bo

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

        $ stapbpf ./stap_28784.bo
        Hello World!

       If the -p4 option is omitted, stap will invoke stapbpf automatically.

LIMITATIONS

       This  runtime is in an early stage of development and it currently lacks support for a number of features
       available in the default runtime.  A subset of the following probe points is supported:

              begin
              end
              kernel.*
              process.*
              timer.*
              perf.*
              procfs.*

       In general, probes based on the kprobes, uprobes, tracepoint and perf infrastructures are supported.  See
       stapprobes(3stap)  for  more  information  on the probe points and which tracing infrastructures they are
       based on.

       for loops, foreach loops and while loops are usable only in begin and end probes.  try statements are not
       supported.

       There is limited support for string operations. String variables and literals are limited to  64  charac‐
       ters, except for printf format strings, which are limited to 256 characters.

       A  subset  of  the  statistical aggregate functionality is available, with support only for the @count(),
       @sum(), @avg() extractor functions.

       The name of the bpf-elf file produced by the front-end stap tool should not be changed.

SAFETY AND SECURITY

       See the stap(1) manual page for additional information on safety and security.

SEE ALSO

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

BUGS

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

                                                                                                      STAPBPF(8)