3fa2c28d2c
Syncing latest libbpf commits from kernel repository. Baseline bpf-next commit: b0d93b44641a83c28014ca38001e85bf6dc8501e Checkpoint bpf-next commit: 71930846b36f8e4e68267f8a3d47e33435c3657a Baseline bpf commit: d28b25a62a47a8c8aa19bd543863aab6717e68c9 Checkpoint bpf commit: f946964a9f79f8dcb5a6329265281eebfc23aee5 Andrii Nakryiko (7): libbpf: add bpf_core_type_matches() helper macro libbpf: Remove unnecessary usdt_rel_ip assignments libbpf: generalize virtual __kconfig externs and use it for USDT libbpf: improve BPF_KPROBE_SYSCALL macro and rename it to BPF_KSYSCALL libbpf: add ksyscall/kretsyscall sections support for syscall kprobes libbpf: fallback to tracefs mount point if debugfs is not mounted libbpf: make RINGBUF map size adjustments more eagerly Anquan Wu (1): libbpf: Fix the name of a reused map Chuang Wang (3): libbpf: Cleanup the legacy kprobe_event on failed add/attach_event() libbpf: Fix wrong variable used in perf_event_uprobe_open_legacy() libbpf: Cleanup the legacy uprobe_event on failed add/attach_event() Dan Carpenter (3): libbpf: fix an snprintf() overflow check libbpf: Fix sign expansion bug in btf_dump_get_enum_value() libbpf: Fix str_has_sfx()'s return value Daniel Müller (4): bpf: Introduce TYPE_MATCH related constants/macros bpf, libbpf: Add type match support bpf: Correctly propagate errors up from bpf_core_composites_match libbpf: Support PPC in arch_specific_syscall_pfx Hangbin Liu (1): Bonding: add per-port priority for failover re-selection Hengqi Chen (1): libbpf: Error out when binary_path is NULL for uprobe and USDT Ilya Leoshkevich (1): libbpf: Extend BPF_KSYSCALL documentation James Hilliard (1): libbpf: Disable SEC pragma macro on GCC Joanne Koong (2): bpf: Add flags arg to bpf_dynptr_read and bpf_dynptr_write APIs bpf: fix bpf_skb_pull_data documentation Joe Burton (1): libbpf: Add bpf_obj_get_opts() Jon Doron (1): libbpf: perfbuf: Add API to get the ring buffer Pu Lehui (1): bpf, docs: Remove deprecated xsk libbpf APIs description Yixun Lan (1): libbpf, riscv: Use a0 for RC register docs/libbpf_naming_convention.rst | 13 +- include/uapi/linux/bpf.h | 15 +- include/uapi/linux/if_link.h | 1 + src/bpf.c | 9 + src/bpf.h | 11 + src/bpf_core_read.h | 11 + src/bpf_helpers.h | 13 + src/bpf_tracing.h | 60 +++- src/btf_dump.c | 2 +- src/gen_loader.c | 2 +- src/libbpf.c | 440 ++++++++++++++++++++++-------- src/libbpf.h | 62 +++++ src/libbpf.map | 3 + src/libbpf_internal.h | 8 +- src/relo_core.c | 286 ++++++++++++++++++- src/relo_core.h | 4 + src/usdt.bpf.h | 16 +- src/usdt.c | 6 +- 18 files changed, 793 insertions(+), 169 deletions(-) -- 2.30.2
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/libbpf usage and questions
Please check out libbpf-bootstrap and the companion blog post for the examples of building BPF applications with libbpf. libbpf-tools are also a good source of the real-world libbpf-based tracing tools.
See also "BPF CO-RE reference guide" for the coverage of practical aspects of building BPF CO-RE applications and "BPF CO-RE" for general introduction into BPF portability issues and BPF CO-RE origins.
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
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)
- Manjaro (from kernel 5.4 if compiled after 2021-06-18)
- Ubuntu 20.10
- Debian 11 (amd64/arm64)
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
- Ubuntu 20.10 (LLVM 11)
- Debian 11 (LLVM 11)
- Alpine 3.13+
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 CO-RE reference guide
- 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.
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 GitHub Actions.
- Static code analysis via LGTM and Coverity.
Package dependencies of libbpf, package names may vary across distros:
- zlib
- libelf
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