a44116bb1f
Syncing latest libbpf commits from kernel repository. Baseline bpf-next commit: 06a4ec1d9dc652e17ee3ac2ceb6c7cf6c2b75cdd Checkpoint bpf-next commit: dca5612f8eb9d0cf1dc254eb2adff1f16a588a7d Baseline bpf commit: 3fb1a96a91120877488071a167d26d76be4be977 Checkpoint bpf commit: 4af7b32f84aa4cd60e39b355bc8a1eab6cd8d8a4 Andrii Nakryiko (17): libbpf: Make kernel feature probing lazy libbpf: Factor out common logic of testing and closing FD libbpf: Sanitize BPF program code for bpf_probe_read_{kernel, user}[_str] libbpf: Switch tracing and CO-RE helper macros to bpf_probe_read_kernel() libbpf: Detect minimal BTF support and skip BTF loading, if missing libbpf: Improve error logging for mismatched BTF kind cases libbpf: Clean up and improve CO-RE reloc logging libbpf: Improve relocation ambiguity detection libbpf: Remove any use of reallocarray() in libbpf tools/bpftool: Remove libbpf_internal.h usage in bpftool libbpf: Centralize poisoning and poison reallocarray() tools: Remove feature-libelf-mmap feature detection libbpf: Implement type-based CO-RE relocations support libbpf: Implement enum value-based CO-RE relocations libbpf: Fix detection of BPF helper call instruction libbpf: Fix libbpf build on compilers missing __builtin_mul_overflow libbpf: Add perf_buffer APIs for better integration with outside epoll loop Tobias Klauser (1): bpf: Fix two typos in uapi/linux/bpf.h Toke Høiland-Jørgensen (1): libbpf: Fix map index used in error message Xu Wang (2): libbpf: Convert comma to semicolon libbpf: Simplify the return expression of build_map_pin_path() Yonghong Song (1): bpf: Implement link_query for bpf iterators include/uapi/linux/bpf.h | 17 +- src/bpf.c | 3 - src/bpf_core_read.h | 120 +++- src/bpf_prog_linfo.c | 3 - src/bpf_tracing.h | 4 +- src/btf.c | 31 +- src/btf.h | 38 -- src/btf_dump.c | 9 +- src/hashmap.c | 3 + src/libbpf.c | 1177 ++++++++++++++++++++++++++++---------- src/libbpf.h | 4 + src/libbpf.map | 8 + src/libbpf_internal.h | 138 ++++- src/libbpf_probes.c | 3 - src/netlink.c | 128 +---- src/nlattr.c | 9 +- src/ringbuf.c | 8 +- src/xsk.c | 3 - 18 files changed, 1149 insertions(+), 557 deletions(-) -- 2.24.1 |
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include | ||
scripts | ||
src | ||
travis-ci | ||
.lgtm.yml | ||
.travis.yml | ||
BPF-CHECKPOINT-COMMIT | ||
CHECKPOINT-COMMIT | ||
LICENSE | ||
LICENSE.BSD-2-Clause | ||
LICENSE.LPGL-2.1 | ||
README.md |
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:
pahole
1.16+ tool (part ofdwarves
package), which performs DWARF to BTF conversion;- kernel built with
CONFIG_DEBUG_INFO_BTF=y
option; - you can check if your kernel has BTF built-in by looking for
/sys/kernel/btf/vmlinux
file:
$ 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