On Tue, 26 Apr 2016 13:44:06 +0200 Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: > On 04/26/2016 01:09 PM, Jesper Dangaard Brouer wrote: > > Getting started with using examples in samples/bpf/ is not > > straightforward. There are several dependencies, and specific > > versions of these dependencies. > > > > Just compiling the example tool is also slightly obscure, e.g. one > > need to call make like: > > > > make samples/bpf/ > > > > Do notice the "/" slash after the directory name. > > > > Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> > > --- > > samples/bpf/README.rst | 67 ++++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 67 insertions(+) > > create mode 100644 samples/bpf/README.rst > > > > diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst > > new file mode 100644 > > index 000000000000..3e1ac05d8e7c > > --- /dev/null > > +++ b/samples/bpf/README.rst > > @@ -0,0 +1,67 @@ > > +eBPF sample programs > > +==================== > > + > > +This kernel samples/bpf directory contains a mini eBPF library, test > > +stubs, verifier test-suite and examples for using eBPF. > > + > > +Build dependencies > > +================== > > + > > +Compiling requires having installed: > > + * clang > > + * llvm >= version 3.7.0 > > + > > +Note that LLVM's tool 'llc' must support target 'bpf', list with command:: > > + > > + $ llc --version > > + LLVM (http://llvm.org/): > > + LLVM version 3.x.y > > + [...] > > + Host CPU: xxx > > + > > + Registered Targets: > > + [...] > > + bpf - BPF (host endian) > > + bpfeb - BPF (big endian) > > + bpfel - BPF (little endian) > > + [...] > > + > > +Kernel headers > > +-------------- > > + > > +There are usually dependencies to header files of the current kernel. > > +To avoid installing devel kernel headers system wide, as a normal > > +user, simply call:: > > + > > + make headers_install > > + > > +This will creates a local "usr/include" directory in the git/build top > > +level directory, that the make system automatically pickup first. > > + > > +Compiling > > +========= > > + > > +For compiling goto kernel top level build directory and run make like:: > > + > > + make samples/bpf/ > > + > > +Do notice the "/" slash after the directory name. > > + > > +Manually compiling LLVM with 'bpf' support > > +------------------------------------------ > > + > > +In some LLVM versions the BPF target were marked experimental. To > > +compile LLVM manually and enable BPF target run (build dependencies > > +are cmake and gcc-c++):: > > + > > + $ git clone http://llvm.org/git/llvm.git > > + $ cd llvm > > + $ mkdir build; cd build > > + $ cmake .. -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=BPF > > + $ make > > That's perhaps a bit misleading in the sense that when you clone the > tree from git, you'd nowadays invoke cmake normally with LLVM_TARGETS_TO_BUILD > instead of LLVM_EXPERIMENTAL_TARGETS_TO_BUILD for BPF, as BPF is not an > experimental target anymore. It's probably also recommended to clone > clang into tools/ dir as well under your llvm/ repo when you compile > from scratch anyways. Can you come up with a formulation/desc I can use instead then? -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
