.gitignore
Makefile
README.rst
asm_goto_workaround.h
bpf_insn.h
bpf_load.c
bpf_load.h
cookie_uid_helper_example.c
cpustat_kern.c
cpustat_user.c
fds_example.c
hash_func01.h
hbm.c
hbm.h
hbm_edt_kern.c
hbm_kern.h
hbm_out_kern.c
lathist_kern.c
lathist_user.c
lwt_len_hist.sh
lwt_len_hist_kern.c
lwt_len_hist_user.c
map_perf_test_kern.c
map_perf_test_user.c
offwaketime_kern.c
offwaketime_user.c
parse_ldabs.c
parse_simple.c
parse_varlen.c
sampleip_kern.c
sampleip_user.c
sock_example.c
sock_example.h
sock_flags_kern.c
sockex1_kern.c
sockex1_user.c
sockex2_kern.c
sockex2_user.c
sockex3_kern.c
sockex3_user.c
spintest_kern.c
spintest_user.c
syscall_nrs.c
syscall_tp_kern.c
syscall_tp_user.c
task_fd_query_kern.c
task_fd_query_user.c
tc_l2_redirect_kern.c
tc_l2_redirect_user.c
tcbpf1_kern.c
tcp_basertt_kern.c
tcp_bpf.readme
tcp_bufs_kern.c
tcp_clamp_kern.c
tcp_cong_kern.c
tcp_dumpstats_kern.c
tcp_iw_kern.c
tcp_rwnd_kern.c
tcp_synrto_kern.c
tcp_tos_reflect_kern.c
test_cgrp2_array_pin.c
test_cgrp2_attach.c
test_cgrp2_sock.c
test_cgrp2_sock2.c
test_cgrp2_tc_kern.c
test_current_task_under_cgroup_kern.c
test_current_task_under_cgroup_user.c
test_lru_dist.c
test_lwt_bpf.c
test_lwt_bpf.sh
test_map_in_map_kern.c
test_map_in_map_user.c
test_overhead_kprobe_kern.c
test_overhead_raw_tp_kern.c
test_overhead_tp_kern.c
test_overhead_user.c
test_probe_write_user_kern.c
test_probe_write_user_user.c
trace_event_kern.c
trace_event_user.c
trace_output_kern.c
trace_output_user.c
tracex1_kern.c
tracex1_user.c
tracex2_kern.c
tracex2_user.c
tracex3_kern.c
tracex3_user.c
tracex4_kern.c
tracex4_user.c
tracex5_kern.c
tracex5_user.c
tracex6_kern.c
tracex6_user.c
tracex7_kern.c
tracex7_user.c
xdp1_kern.c
xdp1_user.c
xdp2_kern.c
xdp2skb_meta_kern.c
xdp_adjust_tail_kern.c
xdp_adjust_tail_user.c
xdp_fwd_kern.c
xdp_fwd_user.c
xdp_monitor_kern.c
xdp_monitor_user.c
xdp_redirect_cpu_kern.c
xdp_redirect_cpu_user.c
xdp_redirect_kern.c
xdp_redirect_map_kern.c
xdp_redirect_map_user.c
xdp_redirect_user.c
xdp_router_ipv4_kern.c
xdp_router_ipv4_user.c
xdp_rxq_info_kern.c
xdp_rxq_info_user.c
xdp_sample_pkts_kern.c
xdp_sample_pkts_user.c
xdp_tx_iptunnel_common.h
xdp_tx_iptunnel_kern.c
xdp_tx_iptunnel_user.c
xdpsock_user.c
do_hbm_test.sh
run_cookie_uid_helper_example.sh
tc_l2_redirect.sh
test_cgrp2_sock.sh
test_cgrp2_sock2.sh
test_cgrp2_tc.sh
test_cls_bpf.sh
test_ipip.sh
test_override_return.sh
xdp2skb_meta.sh
README.rst

eBPF sample programs

This directory contains a test stubs, verifier test-suite and examples for using eBPF. The examples use libbpf from tools/lib/bpf.

Build dependencies

Compiling requires having installed:
  • clang >= version 3.4.0
  • llvm >= version 3.7.1

Note that LLVM's tool 'llc' must support target 'bpf', list version and supported targets with command: llc --version

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 building the BPF samples, issue the below command from the kernel top level directory:

make samples/bpf/

Do notice the "/" slash after the directory name.

It is also possible to call make from this directory. This will just hide the the invocation of make as above with the appended "/".

Manually compiling LLVM with 'bpf' support

Since version 3.7.0, LLVM adds a proper LLVM backend target for the BPF bytecode architecture.

By default llvm will build all non-experimental backends including bpf. To generate a smaller llc binary one can use:

-DLLVM_TARGETS_TO_BUILD="BPF"

Quick sniplet for manually compiling LLVM and clang (build dependencies are cmake and gcc-c++):

$ git clone http://llvm.org/git/llvm.git
$ cd llvm/tools
$ git clone --depth 1 http://llvm.org/git/clang.git
$ cd ..; mkdir build; cd build
$ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
$ make -j $(getconf _NPROCESSORS_ONLN)

It is also possible to point make to the newly compiled 'llc' or 'clang' command via redefining LLC or CLANG on the make command line:

make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang

Cross compiling samples

In order to cross-compile, say for arm64 targets, export CROSS_COMPILE and ARCH environment variables before calling make. This will direct make to build samples for the cross target.

export ARCH=arm64 export CROSS_COMPILE="aarch64-linux-gnu-" make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang