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![]() Daniel Borkmann says:
====================
pull-request: bpf-next 2017-12-18
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Allow arbitrary function calls from one BPF function to another BPF function.
As of today when writing BPF programs, __always_inline had to be used in
the BPF C programs for all functions, unnecessarily causing LLVM to inflate
code size. Handle this more naturally with support for BPF to BPF calls
such that this __always_inline restriction can be overcome. As a result,
it allows for better optimized code and finally enables to introduce core
BPF libraries in the future that can be reused out of different projects.
x86 and arm64 JIT support was added as well, from Alexei.
2) Add infrastructure for tagging functions as error injectable and allow for
BPF to return arbitrary error values when BPF is attached via kprobes on
those. This way of injecting errors generically eases testing and debugging
without having to recompile or restart the kernel. Tags for opting-in for
this facility are added with BPF_ALLOW_ERROR_INJECTION(), from Josef.
3) For BPF offload via nfp JIT, add support for bpf_xdp_adjust_head() helper
call for XDP programs. First part of this work adds handling of BPF
capabilities included in the firmware, and the later patches add support
to the nfp verifier part and JIT as well as some small optimizations,
from Jakub.
4) The bpftool now also gets support for basic cgroup BPF operations such
as attaching, detaching and listing current BPF programs. As a requirement
for the attach part, bpftool can now also load object files through
'bpftool prog load'. This reuses libbpf which we have in the kernel tree
as well. bpftool-cgroup man page is added along with it, from Roman.
5) Back then commit
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.. | ||
bpf_load.c | ||
bpf_load.h | ||
cookie_uid_helper_example.c | ||
fds_example.c | ||
lathist_kern.c | ||
lathist_user.c | ||
libbpf.h | ||
load_sock_ops.c | ||
lwt_len_hist.sh | ||
lwt_len_hist_kern.c | ||
lwt_len_hist_user.c | ||
Makefile | ||
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 | ||
README.rst | ||
run_cookie_uid_helper_example.sh | ||
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 | ||
tc_l2_redirect.sh | ||
tc_l2_redirect_kern.c | ||
tc_l2_redirect_user.c | ||
tcbpf1_kern.c | ||
tcbpf2_kern.c | ||
tcp_basertt_kern.c | ||
tcp_bpf.readme | ||
tcp_bufs_kern.c | ||
tcp_clamp_kern.c | ||
tcp_cong_kern.c | ||
tcp_iw_kern.c | ||
tcp_rwnd_kern.c | ||
tcp_synrto_kern.c | ||
test_cgrp2_array_pin.c | ||
test_cgrp2_attach.c | ||
test_cgrp2_attach2.c | ||
test_cgrp2_sock.c | ||
test_cgrp2_sock.sh | ||
test_cgrp2_sock2.c | ||
test_cgrp2_sock2.sh | ||
test_cgrp2_tc.sh | ||
test_cgrp2_tc_kern.c | ||
test_cls_bpf.sh | ||
test_current_task_under_cgroup_kern.c | ||
test_current_task_under_cgroup_user.c | ||
test_ipip.sh | ||
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_tp_kern.c | ||
test_overhead_user.c | ||
test_override_return.sh | ||
test_probe_write_user_kern.c | ||
test_probe_write_user_user.c | ||
test_tunnel_bpf.sh | ||
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 | ||
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_tx_iptunnel_common.h | ||
xdp_tx_iptunnel_kern.c | ||
xdp_tx_iptunnel_user.c |
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