21ea184818
Syncing latest libbpf commits from kernel repository.
Baseline bpf-next commit: 2f7de9865ba3cbfcf8b504f07154fdb6124176a4
Checkpoint bpf-next commit: b0efc216f577997bf563d76d51673ed79c3d5f71
Baseline bpf commit: 87f92ac4c12758c4da3bbe4393f1d884b610b8a6
Checkpoint bpf commit: 9cf51446e68607136e42a4e531a30c888c472463
Alan Maguire (2):
bpf: Add bpf_snprintf_btf helper
bpf: Add bpf_seq_printf_btf helper
Andrii Nakryiko (11):
libbpf: Refactor internals of BTF type index
libbpf: Remove assumption of single contiguous memory for BTF data
libbpf: Generalize common logic for managing dynamically-sized arrays
libbpf: Extract generic string hashing function for reuse
libbpf: Allow modification of BTF and add btf__add_str API
libbpf: Add btf__new_empty() to create an empty BTF object
libbpf: Add BTF writing APIs
libbpf: Add btf__str_by_offset() as a more generic variant of
name_by_offset
selftests/bpf: Test BTF writing APIs
libbpf: Support BTF loading and raw data output in both endianness
libbpf: Fix uninitialized variable in btf_parse_type_sec
Martin KaFai Lau (4):
bpf: Change bpf_sk_release and bpf_sk_*cgroup_id to accept
ARG_PTR_TO_BTF_ID_SOCK_COMMON
bpf: Change bpf_sk_storage_*() to accept ARG_PTR_TO_BTF_ID_SOCK_COMMON
bpf: Change bpf_tcp_*_syncookie to accept
ARG_PTR_TO_BTF_ID_SOCK_COMMON
bpf: Change bpf_sk_assign to accept ARG_PTR_TO_BTF_ID_SOCK_COMMON
Song Liu (3):
bpf: Fix comment for helper bpf_current_task_under_cgroup()
bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint
libbpf: Support test run of raw tracepoint programs
Toke Høiland-Jørgensen (2):
bpf: Support attaching freplace programs to multiple attach points
libbpf: Add support for freplace attachment in bpf_link_create
YiFei Zhu (2):
bpf: Add BPF_PROG_BIND_MAP syscall
libbpf: Add BPF_PROG_BIND_MAP syscall and use it on .rodata section
Yonghong Song (1):
libbpf: Fix a compilation error with xsk.c for ubuntu 16.04
include/uapi/linux/bpf.h | 118 ++-
src/bpf.c | 67 +-
src/bpf.h | 39 +-
src/btf.c | 1851 ++++++++++++++++++++++++++++++++------
src/btf.h | 51 ++
src/btf_dump.c | 9 +-
src/hashmap.h | 12 +
src/libbpf.c | 113 ++-
src/libbpf.h | 3 +
src/libbpf.map | 28 +
src/libbpf_internal.h | 8 +
src/xsk.c | 1 +
12 files changed, 1997 insertions(+), 303 deletions(-)
--
2.24.1
This is a mirror of bpf-next Linux source
tree's
tools/lib/bpf directory plus its supporting header files.
All the gory details of syncing can be found in scripts/sync-kernel.sh
script.
Some header files in this repo (include/linux/*.h) are reduced versions of
their counterpart files at
bpf-next's
tools/include/linux/*.h to make compilation successful.
BPF questions
All general BPF questions, including kernel functionality, libbpf APIs and their application, should be sent to bpf@vger.kernel.org mailing list. You can subscribe to it here and search its archive here. Please search the archive before asking new questions. It very well might be that this was already addressed or answered before.
bpf@vger.kernel.org is monitored by many more people and they will happily try to help you with whatever issue you have. This repository's PRs and issues should be opened only for dealing with issues pertaining to specific way this libbpf mirror repo is set up and organized.
Build
libelf is an internal dependency of libbpf and thus it is required to link
against and must be installed on the system for applications to work.
pkg-config is used by default to find libelf, and the program called can be
overridden with PKG_CONFIG.
If using pkg-config at build time is not desired, it can be disabled by
setting NO_PKG_CONFIG=1 when calling make.
To build both static libbpf.a and shared libbpf.so:
$ cd src
$ make
To build only static libbpf.a library in directory build/ and install them together with libbpf headers in a staging directory root/:
$ cd src
$ mkdir build root
$ BUILD_STATIC_ONLY=y OBJDIR=build DESTDIR=root make install
To build both static libbpf.a and shared libbpf.so against a custom libelf dependency installed in /build/root/ and install them together with libbpf headers in a build directory /build/root/:
$ cd src
$ PKG_CONFIG_PATH=/build/root/lib64/pkgconfig DESTDIR=/build/root make install
Distributions
Distributions packaging libbpf from this mirror:
Benefits of packaging from the mirror over packaging from kernel sources:
- Consistent versioning across distributions.
- No ties to any specific kernel, transparent handling of older kernels. Libbpf is designed to be kernel-agnostic and work across multitude of kernel versions. It has built-in mechanisms to gracefully handle older kernels, that are missing some of the features, by working around or gracefully degrading functionality. Thus libbpf is not tied to a specific kernel version and can/should be packaged and versioned independently.
- Continuous integration testing via TravisCI.
- Static code analysis via LGTM and Coverity.
Package dependencies of libbpf, package names may vary across distros:
- zlib
- libelf
BPF CO-RE (Compile Once – Run Everywhere)
Libbpf supports building BPF CO-RE-enabled applications, which, in contrast to BCC, do not require Clang/LLVM runtime being deployed to target servers and doesn't rely on kernel-devel headers being available.
It does rely on kernel to be built with BTF type information, though. Some major Linux distributions come with kernel BTF already built in:
- Fedora 31+
- RHEL 8.2+
- OpenSUSE Tumbleweed (in the next release, as of 2020-06-04)
- Arch Linux (from kernel 5.7.1.arch1-1)
If your kernel doesn't come with BTF built-in, you'll need to build custom kernel. You'll need:
pahole1.16+ tool (part ofdwarvespackage), which performs DWARF to BTF conversion;- kernel built with
CONFIG_DEBUG_INFO_BTF=yoption; - you can check if your kernel has BTF built-in by looking for
/sys/kernel/btf/vmlinuxfile:
$ ls -la /sys/kernel/btf/vmlinux
-r--r--r--. 1 root root 3541561 Jun 2 18:16 /sys/kernel/btf/vmlinux
To develop and build BPF programs, you'll need Clang/LLVM 10+. The following distributions have Clang/LLVM 10+ packaged by default:
- Fedora 32+
- Ubuntu 20.04+
- Arch Linux
Otherwise, please make sure to update it on your system.
The following resources are useful to understand what BPF CO-RE is and how to use it:
- BPF Portability and CO-RE
- HOWTO: BCC to libbpf conversion
- libbpf-tools in BCC repo contain lots of real-world tools converted from BCC to BPF CO-RE. Consider converting some more to both contribute to the BPF community and gain some more experience with it.
License
This work is dual-licensed under BSD 2-clause license and GNU LGPL v2.1 license. You can choose between one of them if you use this work.
SPDX-License-Identifier: BSD-2-Clause OR LGPL-2.1