This is the official Linux port of the DTrace tracing tool.
The source is posted here on github.com in the hope that it increases the visibility for our work and to make it even easier for people to access the source. We also use this repository to work with developers in the Linux community.
The main development branch is devel.
We provide prebuilt x86_64 and aarch64 DTrace userspace packages for Oracle Linux 9 (UEK7 kernel), Oracle Linux 8 (UEK7 or UEK6 kernel), and Oracle Linux 7 (UEK6 kernel). These packages are based on the Oracle Linux specific release branch 2.0-branch.
The latest packages can be obtained from the following Oracle Linux yum server repositories:
- Oracle Linux 9 (x86_64) UEK Release 7: https://yum.oracle.com/repo/OracleLinux/OL9/UEKR7/x86_64/
- Oracle Linux 9 (aarch64) BaseOS Latest: https://yum.oracle.com/repo/OracleLinux/OL9/baseos/latest/aarch64/
- Oracle Linux 8 (x86_64) UEK Release 7: https://yum.oracle.com/repo/OracleLinux/OL8/UEKR7/x86_64/
- Oracle Linux 8 (aarch64) UEK Release 7: https://yum.oracle.com/repo/OracleLinux/OL8/UEKR7/aarch64/
- Oracle Linux 8 (x86_64) UEK Release 6: https://yum.oracle.com/repo/OracleLinux/OL8/UEKR6/x86_64/
- Oracle Linux 8 (aarch64) BaseOS Latest: https://yum.oracle.com/repo/OracleLinux/OL8/baseos/latest/aarch64/
- Oracle Linux 7 (x86_64) UEK Release 6: https://yum.oracle.com/repo/OracleLinux/OL7/UEKR6/x86_64/
- Oracle Linux 7 (aarch64) UEK Release 6: https://yum.oracle.com/repo/OracleLinux/OL7/UEKR6/aarch64/
Source code for the UEK kernel is available on github in the linux-uek repo.
- 1. License
- 2. How to Build DTrace
- 3. Testing
- 4. How to Run DTrace
- 5. Questions
- 6. Pull Requests and Support
- 7. Building Previous Releases of DTrace
DTrace is licensed under the UPL 1.0 (Universal Permissive License). A copy is included in this repository as the LICENSE file.
The build instructions focus on building DTrace for the upstream Linux kernel. We will use the 5.14.9 release, but the instructions apply to most recent Linux kernel versions.
Please read this section carefully before moving over to the build documentation to ensure your environment is properly configured.
DTrace uses a type introspection system called CTF. This is supported by upstream GCC and GNU Binutils. Make sure you have binutils 2.36 or later installed.
If your distro provides libctf.so in a binutils development package, you need to install that too.
If your distro provides binutils 2.36 or later, you should install it. If not, you can build your own local copy (which can be configured with a --prefix specific to itself to avoid disturbing the distro version).
A few other packages are required, either for building or at runtime. They should be part of most Linux distributions today and can be installed via the package manager of your distro. The table below gives package names for Debian and Oracle Linux.
For building:
Prerequisite | Debian | Oracle Linux |
---|---|---|
glibc headers | libc6-dev | glibc-headers |
glibc (static) | (in libc6-dev) | glibc-static |
glibc (32-bit dev) | libc6-dev-i386 | glibc-devel.i686 |
bison | bison | bison |
flex | flex | flex |
BPF gcc | gcc-bpf | gcc-bpf-unknown-none |
BPF binutils | binutils-bpf | binutils-bpf-unknown-none |
libpcap dev | libpcap-dev | libpcap-devel |
wireshark | wireshark | wireshark |
valgrind | valgrind | valgrind-devel |
fuse3 or fuse | libfuse3-dev or libfuse-dev | fuse3-devel or fuse-devel |
kernel headers | linux-headers-- | kernel-uek-devel- |
linux-headers--common |
At runtime:
Prerequisite | Debian | Oracle Linux |
---|---|---|
wireshark | wireshark | wireshark |
fuse3 or fuse | libfuse3-3 or libfuse2 | fuse3-devel or fuse-devel |
The simplest way of building DTrace is done by issuing the following commands from the DTrace source tree:
make
sudo make install
Some distributions install the BPF gcc and binutils under different names. You can specify the executables to use using the BPFC and BPFLD variables. E.g. on Debian you would use:
make BPFC=bpf-gcc BPFLD=bpf-ld
sudo make install
In this scenario the build system expects that kernel sources can be found at
/lib/modules/$(uname -r)/build
. It is also expected that the kernel used for
userspace build is compatible with the utils (the exported userspace headers in
the include/uapi/linux/dtrace
are compatible with the utils version being
built).
You can point at a different kernel version with the KERNELS variable, e.g.
make KERNELS="5.16.8"
as long as the source tree that kernel was built with remains where it was when that kernel was installed.
See the GNUmakefile for more options (building translators against multiple different kernels at once, building against kernel sources found in different places, building against a kernel built with O=, etc.)
'make help' might also be of interest.
A testsuite is provided in the source tree. It is run using make in conjunction with one of the following targets:
target | description |
---|---|
check-verbose |
Tests binaries from build directory. Prints result of every tests. |
check-installed-verbose |
Tests binaries installed in the system. Prints result of every tests. |
Example:
sudo make check-verbose
Logs from test runs are stored in test/log/<run_number>/
.
The most recent logs are also available by via the test/log/current/
symbolic link.
The testsuite itself has more dependencies that need to be installed. The full list is available in the dtrace.spec file.
The dtrace
binary is installed in /usr/sbin/dtrace.
Currently, you can only run dtrace with root privileges.
Be careful not to confuse the utility with SystemTap's dtrace script,
which is installed in /usr/bin/dtrace.
For questions, please check the dtrace-devel mailing list.
NEW: We have a #linux-dtrace IRC channel on irc.libera.chat, you can ask questions there as well.
We currently do not accept pull requests via GitHub, please contact us via the mailing list or IRC channel listed above.
The source code for DTrace is published here without support. Compiled binaries are provided as part of Oracle Linux, which is free to download, distribute and use. Support for DTrace is included in Oracle Linux support subscriptions. Individual packages and updates are available on the Oracle Linux yum server.
For versions of DTrace prior to 2.0.0-1.13.2 a small number of kernel patches patches are needed, which are here. Branches named starting v2/* are suitable.
To build such versions of dtrace follow the steps below.
See above.
At this point, you will need an additional step:
DTrace 2.0.0-1.13.1 and earlier depend on a few extra kernel features that are not available in the upstream kernel:
- CTF type information extraction
- /proc/kallmodsyms
- New system call: waitfd()
As noted above, patches that implement these features are available from the v2/* branches in our Linux kernel repository for features that DTrace uses: https://github.com/oracle/dtrace-linux-kernel
The customary way to obtain these patches is to clone an appropriate upstream kernel version (5.8.1 or later) and to merge our updated tree into it. The patch set is quite small, but may need some tweaking if it is being merged into a newer tree. We occasionally push a new patched tree to our github repo, so do look around the repo to see if there is a branch with better match.
Oracle Linux's UEK7 provides a simple alternative if you don't want to patch your own kernel.
Building of a patched kernel from sources is also straightforward.
Please consult Documentation/process/changes.rst
in the kernel source tree
to ensure all required dependencies are installed first. The following steps
should build and install the kernel.
# Start with your preferred .config options. Features DTrace needs should
# enable themselves automatically.
make olddefconfig
make
# This step will produce vmlinux.ctfa, which holds all CTF data for the kernel
# and its modules. If it doesn't work, you don't have a toolchain that is
# recent enough.
make ctf
# Install with root privileges.
sudo make INSTALL_MOD_STRIP=1 modules_install
sudo make install
It is preferred (but not required) to reboot into your new kernel before trying to build DTrace. (If you don't reboot into it, you need to specify some extra options when running make.)
See above.