systemtap: a linux trace/probe tool

Visit the project web site at <http://sources.redhat.com/systemtap>,
for documentation and mailing lists for developers and users.

This is free software.
See the COPYING file for redistribution/modification terms.
See the INSTALL file for generic build instructions.

Prerequisites:

- linux kernel with kprobes (mainline 2.6.11+ or backport)
- kernel module build environment (kernel-devel or kernel-smp-devel rpm)
- kernel debugging information (kernel-debuginfo rpm)
- C compiler (same as what kernel was compiled with)
- elfutils with libdwfl for debugging informatin parsing
- root privileges

Installation steps:

- Install the kernel-debuginfo, kernel-devel, gcc packages.
- Install the systemtap package, if one already exists.

Build steps:

- Install the kernel-debuginfo, kernel-[smp-]devel, gcc and libcap-devel
  packages (or see below if you are building your own kernels from source).
  If avaialable, install your distribution's copy of elfutils and its
  development headers/libraries.

- Or if desired, download an elfutils source release to build in
  "bundled mode" (below), and untar it into some new directory.
  Or if desired, build elfutils separately one time, and install
  it to /usr/local.
  See http://fedorahosted.org/elfutils/

- Download systemtap sources:
  http://sources.redhat.com/systemtap/ftp/releases/
  http://sources.redhat.com/systemtap/ftp/snapshots/
  (or)
  git clone git://sources.redhat.com/git/systemtap.git
      (or) http://sources.redhat.com/git/systemtap.git

- Build systemtap normally:
  % .../configure [other autoconf options]
  Or, with build it with a bundled internal copy of elfutils:
  % .../configure --with-elfutils=ELFUTILS-SOURCE-DIR [other autoconf options]
  Consider configuring with "--enable-dejazilla" to automatically
  contribute to our public test result database.

  % make all check
  % sudo make install
  % sudo make installcheck

Tips:

- Systemtap looks for the debug info in these locations:
  /boot/vmlinux-`uname -r`
  /usr/lib/debug/lib/modules/`uname -r`/vmlinux
  /lib/modules/`uname -r`/vmlinux
  /lib/modules/`uname -r`/build/vmlinux

Building a kernel.org kernel:

- Build the kernel using your normal procedures.  Enable
  CONFIG_DEBUG_INFO, CONFIG_KPROBES, and optionally CONFIG_RELAY and
  CONFIG_DEBUG_FS.
- Boot into the kernel.
- Make sure the large unstripped kernel image 'vmlinux' from your
  build can be found by systemtap (see above)  You can just symlink
  it to one of these locations.
- Symlink your source directory to these two places, though systemtap
  does not at present use such source code. 
  - /usr/src/kernels/`uname -r`
  - /lib/modules/`uname -r`/source
- Symlink your build directory to here:
  - /lib/modules/`uname -r`/build
- For example, if your kernel source is in /home/me/linux/2.6.17-rc6
  and you build your kernel in the source directory, you would do
  this (be sure you are running the right kernel or `uname -r`
  will be wrong:)
     ln -s /home/me/linux/2.6.17-rc6/vmlinux /boot/vmlinux-`uname -r`
     mkdir /usr/src/kernels  (if needed)
     ln -s /home/me/linux/2.6.17-rc6 /usr/src/kernels/`uname -r`
     mkdir /lib/modules/`uname -r`  (if needed)
     ln -s /home/me/linux/2.6.17-rc6 /lib/modules/`uname -r`/build
     ln -s /home/me/linux/2.6.17-rc6 /lib/modules/`uname -r`/source