linux/samples/bpf
Jakub Kicinski 4b2765ae41 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-02-29

We've added 119 non-merge commits during the last 32 day(s) which contain
a total of 150 files changed, 3589 insertions(+), 995 deletions(-).

The main changes are:

1) Extend the BPF verifier to enable static subprog calls in spin lock
   critical sections, from Kumar Kartikeya Dwivedi.

2) Fix confusing and incorrect inference of PTR_TO_CTX argument type
   in BPF global subprogs, from Andrii Nakryiko.

3) Larger batch of riscv BPF JIT improvements and enabling inlining
   of the bpf_kptr_xchg() for RV64, from Pu Lehui.

4) Allow skeleton users to change the values of the fields in struct_ops
   maps at runtime, from Kui-Feng Lee.

5) Extend the verifier's capabilities of tracking scalars when they
   are spilled to stack, especially when the spill or fill is narrowing,
   from Maxim Mikityanskiy & Eduard Zingerman.

6) Various BPF selftest improvements to fix errors under gcc BPF backend,
   from Jose E. Marchesi.

7) Avoid module loading failure when the module trying to register
   a struct_ops has its BTF section stripped, from Geliang Tang.

8) Annotate all kfuncs in .BTF_ids section which eventually allows
   for automatic kfunc prototype generation from bpftool, from Daniel Xu.

9) Several updates to the instruction-set.rst IETF standardization
   document, from Dave Thaler.

10) Shrink the size of struct bpf_map resp. bpf_array,
    from Alexei Starovoitov.

11) Initial small subset of BPF verifier prepwork for sleepable bpf_timer,
    from Benjamin Tissoires.

12) Fix bpftool to be more portable to musl libc by using POSIX's
    basename(), from Arnaldo Carvalho de Melo.

13) Add libbpf support to gcc in CORE macro definitions,
    from Cupertino Miranda.

14) Remove a duplicate type check in perf_event_bpf_event,
    from Florian Lehner.

15) Fix bpf_spin_{un,}lock BPF helpers to actually annotate them
    with notrace correctly, from Yonghong Song.

16) Replace the deprecated bpf_lpm_trie_key 0-length array with flexible
    array to fix build warnings, from Kees Cook.

17) Fix resolve_btfids cross-compilation to non host-native endianness,
    from Viktor Malik.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
  selftests/bpf: Test if shadow types work correctly.
  bpftool: Add an example for struct_ops map and shadow type.
  bpftool: Generated shadow variables for struct_ops maps.
  libbpf: Convert st_ops->data to shadow type.
  libbpf: Set btf_value_type_id of struct bpf_map for struct_ops.
  bpf: Replace bpf_lpm_trie_key 0-length array with flexible array
  bpf, arm64: use bpf_prog_pack for memory management
  arm64: patching: implement text_poke API
  bpf, arm64: support exceptions
  arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT
  bpf: add is_async_callback_calling_insn() helper
  bpf: introduce in_sleepable() helper
  bpf: allow more maps in sleepable bpf programs
  selftests/bpf: Test case for lacking CFI stub functions.
  bpf: Check cfi_stubs before registering a struct_ops type.
  bpf: Clarify batch lookup/lookup_and_delete semantics
  bpf, docs: specify which BPF_ABS and BPF_IND fields were zero
  bpf, docs: Fix typos in instruction-set.rst
  selftests/bpf: update tcp_custom_syncookie to use scalar packet offset
  bpf: Shrink size of struct bpf_map/bpf_array.
  ...
====================

Link: https://lore.kernel.org/r/20240301001625.8800-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-02 20:50:59 -08:00
..
gnu bpf: Replace deprecated -target with --target= for Clang 2023-06-29 15:46:17 +02:00
.gitignore samples/bpf: Cleanup .gitignore 2023-08-24 08:43:50 -07:00
asm_goto_workaround.h work around gcc bugs with 'asm goto' with outputs 2024-02-09 15:57:48 -08:00
bpf_insn.h samples/bpf: Relicense bpf_insn.h as GPL-2.0-only OR BSD-2-Clause 2021-09-29 16:03:55 +02:00
cookie_uid_helper_example.c samples/bpf: Get rid of deprecated libbpf API uses 2021-12-02 15:23:40 -08:00
cpustat_kern.c bpf: use canonical ftrace path 2023-03-13 21:51:30 -07:00
cpustat_user.c samples/bpf: Use %lu format specifier for unsigned long values 2023-12-20 15:28:59 +01:00
do_hbm_test.sh samples: bpf: Fix a spelling typo in do_hbm_test.sh 2021-03-15 22:17:35 -07:00
fds_example.c samples: bpf: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE 2022-07-13 21:43:52 -07:00
hash_func01.h
hbm_edt_kern.c samples/bpf: Fix double word in comments 2022-10-19 11:21:49 -07:00
hbm_kern.h samples/bpf: Clean up samples/bpf build failes 2021-12-02 15:23:40 -08:00
hbm_out_kern.c
hbm.c samples/bpf: Drop unnecessary fallthrough 2023-05-16 19:44:05 +02:00
hbm.h
ibumad_kern.c bpf: use canonical ftrace path 2023-03-13 21:51:30 -07:00
ibumad_user.c samples/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK 2022-04-10 20:17:15 -07:00
lathist_kern.c
lathist_user.c
lwt_len_hist_user.c
lwt_len_hist.bpf.c samples/bpf: change _kern suffix to .bpf with BPF test programs 2023-01-15 13:32:45 -08:00
lwt_len_hist.sh bpf: use canonical ftrace path 2023-03-13 21:51:30 -07:00
Makefile samples/bpf: Allow building with custom bpftool 2023-10-26 15:32:13 +02:00
Makefile.target samples/bpf: Clean up samples/bpf build failes 2021-12-02 15:23:40 -08:00
map_perf_test_user.c bpf: Replace bpf_lpm_trie_key 0-length array with flexible array 2024-02-29 22:52:43 +01:00
map_perf_test.bpf.c samples/bpf: Use BPF_KSYSCALL macro in syscall tracing programs 2022-12-29 14:22:34 -08:00
net_shared.h samples/bpf: convert to vmlinux.h with tracing programs 2023-08-21 15:39:09 -07:00
offwaketime_user.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
offwaketime.bpf.c samples/bpf: make tracing programs to be more CO-RE centric 2023-08-21 15:39:09 -07:00
parse_ldabs.c
parse_simple.c
parse_varlen.c
README.rst samples/bpf: Add note to README about the XDP utilities moved to xdp-tools 2023-08-24 08:43:50 -07:00
run_cookie_uid_helper_example.sh
sampleip_kern.c bpf: Remove unused headers 2021-03-25 22:03:46 -07:00
sampleip_user.c samples/bpf: sampleip: Replace PAGE_OFFSET with _text address 2023-04-13 21:57:11 -07:00
sock_example.c samples: bpf: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE 2022-07-13 21:43:52 -07:00
sock_example.h
sock_flags.bpf.c samples/bpf: change _kern suffix to .bpf with BPF test programs 2023-01-15 13:32:45 -08:00
sockex1_kern.c
sockex1_user.c samples/bpf: Get rid of deprecated libbpf API uses 2021-12-02 15:23:40 -08:00
sockex2_kern.c
sockex2_user.c samples/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK 2022-04-10 20:17:15 -07:00
sockex3_kern.c samples/bpf: Fix sockex3 error: Missing BPF prog type 2022-11-07 17:13:35 -08:00
sockex3_user.c samples/bpf: Fix sockex3 error: Missing BPF prog type 2022-11-07 17:13:35 -08:00
spintest_user.c samples/bpf: simplify spintest with kprobe.multi 2023-08-21 15:39:10 -07:00
spintest.bpf.c samples/bpf: simplify spintest with kprobe.multi 2023-08-21 15:39:10 -07:00
syscall_nrs.c
syscall_tp_kern.c samples: bpf: Fix syscall_tp openat argument 2023-10-23 09:58:15 -07:00
syscall_tp_user.c samples/bpf: syscall_tp_user: Fix array out-of-bound access 2023-09-21 14:32:47 -07:00
task_fd_query_kern.c samples/bpf: Replace blk_account_io_done() with __blk_account_io_done() 2022-09-20 17:25:59 -07:00
task_fd_query_user.c bpf: use canonical ftrace path 2023-03-13 21:51:30 -07:00
tc_l2_redirect_kern.c
tc_l2_redirect_user.c
tc_l2_redirect.sh samples/bpf: ensure ipv6 is enabled before running tests 2023-01-15 13:32:45 -08:00
tcbpf1_kern.c
tcp_basertt_kern.c samples/bpf: Fix buffer overflow in tcp_basertt 2023-05-05 08:37:48 -07:00
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 samples/bpf: Get rid of deprecated libbpf API uses 2021-12-02 15:23:40 -08:00
test_cgrp2_attach.c samples: bpf: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE 2022-07-13 21:43:52 -07:00
test_cgrp2_sock2.c samples: bpf: Refactor test_cgrp2_sock2 program with libbpf 2020-11-26 19:33:35 -08:00
test_cgrp2_sock2.sh samples/bpf: change _kern suffix to .bpf with BPF test programs 2023-01-15 13:32:45 -08:00
test_cgrp2_sock.c samples/bpf: Get rid of deprecated libbpf API uses 2021-12-02 15:23:40 -08:00
test_cgrp2_sock.sh samples/bpf: refactor BPF functionality testing scripts 2023-01-15 13:32:45 -08:00
test_cgrp2_tc.bpf.c samples/bpf: change _kern suffix to .bpf with BPF test programs 2023-01-15 13:32:45 -08:00
test_cgrp2_tc.sh samples/bpf: change _kern suffix to .bpf with BPF test programs 2023-01-15 13:32:45 -08:00
test_cls_bpf.sh
test_current_task_under_cgroup_user.c samples/bpf: Change _kern suffix to .bpf with syscall tracing program 2022-12-29 14:22:34 -08:00
test_current_task_under_cgroup.bpf.c samples/bpf: Use BPF_KSYSCALL macro in syscall tracing programs 2022-12-29 14:22:34 -08:00
test_lru_dist.c samples/bpf: remove unused function with test_lru_dist 2022-12-19 14:21:05 -08:00
test_lwt_bpf.c samples/bpf: use vmlinux.h instead of implicit headers in BPF test program 2023-01-15 13:32:45 -08:00
test_lwt_bpf.sh bpf: Replace deprecated -target with --target= for Clang 2023-06-29 15:46:17 +02:00
test_map_in_map_user.c samples/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd() 2023-02-16 15:32:45 -08:00
test_map_in_map.bpf.c samples/bpf: refactor syscall tracing programs using BPF_KSYSCALL macro 2023-08-21 15:39:10 -07:00
test_overhead_kprobe.bpf.c samples/bpf: make tracing programs to be more CO-RE centric 2023-08-21 15:39:09 -07:00
test_overhead_raw_tp.bpf.c samples/bpf: change _kern suffix to .bpf with BPF test programs 2023-01-15 13:32:45 -08:00
test_overhead_tp.bpf.c samples/bpf: convert to vmlinux.h with tracing programs 2023-08-21 15:39:09 -07:00
test_overhead_user.c samples/bpf: change _kern suffix to .bpf with BPF test programs 2023-01-15 13:32:45 -08:00
test_override_return.sh samples: bpf: Fix tracex7 error raised on the missing argument 2021-07-27 11:15:09 -07:00
test_probe_write_user_user.c samples/bpf: Change _kern suffix to .bpf with syscall tracing program 2022-12-29 14:22:34 -08:00
test_probe_write_user.bpf.c samples/bpf: Use BPF_KSYSCALL macro in syscall tracing programs 2022-12-29 14:22:34 -08:00
trace_event_kern.c bpf: Remove unused headers 2021-03-25 22:03:46 -07:00
trace_event_user.c bpf: samples: Do not touch RLIMIT_MEMLOCK 2020-12-02 18:32:47 -08:00
trace_output_user.c samples/bpf: Change _kern suffix to .bpf with syscall tracing program 2022-12-29 14:22:34 -08:00
trace_output.bpf.c samples/bpf: Change _kern suffix to .bpf with syscall tracing program 2022-12-29 14:22:34 -08:00
tracex1_user.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
tracex1.bpf.c samples/bpf: make tracing programs to be more CO-RE centric 2023-08-21 15:39:09 -07:00
tracex2_user.c samples/bpf: Change _kern suffix to .bpf with syscall tracing program 2022-12-29 14:22:34 -08:00
tracex2.bpf.c samples/bpf: Fix tracex2 by using BPF_KSYSCALL macro 2022-12-29 14:22:34 -08:00
tracex3_user.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
tracex3.bpf.c samples/bpf: fix bio latency check with tracepoint 2023-08-21 15:39:09 -07:00
tracex4_user.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
tracex4.bpf.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
tracex5_user.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
tracex5.bpf.c samples/bpf: make tracing programs to be more CO-RE centric 2023-08-21 15:39:09 -07:00
tracex6_user.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
tracex6.bpf.c samples/bpf: fix broken map lookup probe 2023-08-21 15:39:09 -07:00
tracex7_user.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
tracex7.bpf.c samples/bpf: unify bpf program suffix to .bpf with tracing programs 2023-08-21 15:39:09 -07:00
xdp2skb_meta_kern.c samples: bpf: Remove bpf_load loader completely 2020-11-26 19:33:36 -08:00
xdp2skb_meta.sh
xdp_adjust_tail_kern.c
xdp_adjust_tail_user.c samples/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd() 2023-02-16 15:32:45 -08:00
xdp_fwd_kern.c
xdp_fwd_user.c samples/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd() 2023-02-16 15:32:45 -08:00
xdp_router_ipv4_user.c bpf: Replace bpf_lpm_trie_key 0-length array with flexible array 2024-02-29 22:52:43 +01:00
xdp_router_ipv4.bpf.c sample: bpf: xdp_router_ipv4: Allow the kernel to send arp requests 2022-06-02 16:26:54 -07:00
xdp_sample_shared.h samples: bpf: Add basic infrastructure for XDP samples 2021-08-24 14:48:40 -07:00
xdp_sample_user.c samples/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK 2022-04-10 20:17:15 -07:00
xdp_sample_user.h samples/bpf: use preferred getters/setters instead of deprecated ones 2022-01-25 17:59:07 -08:00
xdp_sample.bpf.c samples: bpf: Add BPF support for devmap_xmit tracepoint 2021-08-24 14:48:41 -07:00
xdp_sample.bpf.h samples/bpf: split common macros to net_shared.h 2023-01-15 13:32:45 -08:00
xdp_tx_iptunnel_common.h
xdp_tx_iptunnel_kern.c samples/bpf: fixup some tools to be able to support xdp multibuffer 2022-06-21 18:55:53 -07:00
xdp_tx_iptunnel_user.c samples/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd() 2023-02-16 15:32:45 -08:00

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.

Note that the XDP-specific samples have been removed from this directory and
moved to the xdp-tools repository: https://github.com/xdp-project/xdp-tools
See the commit messages removing each tool from this directory for how to
convert specific command invocations between the old samples and the utilities
in xdp-tools.

Build dependencies
==================

Compiling requires having installed:
 * clang
 * llvm
 * pahole

Consult :ref:`Documentation/process/changes.rst <changes>` for the minimum
version numbers required and how to update them. Note that LLVM's tool
'llc' must support target 'bpf', list version and supported targets with
command: ``llc --version``

Clean and configuration
-----------------------

It can be needed to clean tools, samples or kernel before trying new arch or
after some changes (on demand)::

 make -C tools clean
 make -C samples/bpf clean
 make clean

Configure kernel, defconfig for instance
(see "tools/testing/selftests/bpf/config" for a reference config)::

 make defconfig

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 create a local "usr/include" directory in the git/build top
level directory, that the make system will automatically pick up first.

Compiling
=========

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

 make M=samples/bpf

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

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"

We recommend that developers who want the fastest incremental builds
use the Ninja build system, you can find it in your system's package
manager, usually the package is ninja or ninja-build.

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

 $ git clone https://github.com/llvm/llvm-project.git
 $ mkdir -p llvm-project/llvm/build
 $ cd llvm-project/llvm/build
 $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
            -DLLVM_ENABLE_PROJECTS="clang"    \
            -DCMAKE_BUILD_TYPE=Release        \
            -DLLVM_BUILD_RUNTIME=OFF
 $ ninja

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 M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/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. But do this before clean,
configuration and header install steps described above. This will direct make to
build samples for the cross target::

 export ARCH=arm64
 export CROSS_COMPILE="aarch64-linux-gnu-"

Headers can be also installed on RFS of target board if need to keep them in
sync (not necessarily and it creates a local "usr/include" directory also)::

 make INSTALL_HDR_PATH=~/some_sysroot/usr headers_install

Pointing LLC and CLANG is not necessarily if it's installed on HOST and have
in its targets appropriate arm64 arch (usually it has several arches).
Build samples::

 make M=samples/bpf

Or build samples with SYSROOT if some header or library is absent in toolchain,
say libelf, providing address to file system containing headers and libs,
can be RFS of target board::

 make M=samples/bpf SYSROOT=~/some_sysroot