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android/platform/external/libbpf/3cd9cac
commit
3cd9cac8fb898382f5f6e80e04a4773da29201b5
[log]
author
Andrey Ignatov <rdna@fb.com>
Wed May 13 18:50:27 2020 -0700
committer
Andrii Nakryiko <andrii.nakryiko@gmail.com>
Wed May 20 01:00:06 2020 -0700
tree
89aed679c9c67144e5a57ae6ea445a7e46e12e4e
parent
70e6075d1d60c9320cc450ff5b52b76f6bd6a7ee [diff]
bpf: Support narrow loads from bpf_sock_addr.user_port

bpf_sock_addr.user_port supports only 4-byte load and it leads to ugly
code in BPF programs, like:

	volatile __u32 user_port = ctx->user_port;
	__u16 port = bpf_ntohs(user_port);

Since otherwise clang may optimize the load to be 2-byte and it's
rejected by verifier.

Add support for 1- and 2-byte loads same way as it's supported for other
fields in bpf_sock_addr like user_ip4, msg_src_ip4, etc.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/c1e983f4c17573032601d0b2b1f9d1274f24bc16.1589420814.git.rdna@fb.com
1 file changed
tree: 89aed679c9c67144e5a57ae6ea445a7e46e12e4e
  1. include/
  2. scripts/
  3. src/
  4. travis-ci/
  5. .lgtm.yml
  6. .travis.yml
  7. BPF-CHECKPOINT-COMMIT
  8. CHECKPOINT-COMMIT
  9. LICENSE
  10. LICENSE.BSD-2-Clause
  11. LICENSE.LPGL-2.1
  12. README.md
README.md

This is a mirror of bpf-next linux tree's tools/lib/bpf directory plus its supporting header files.

The following files will by sync'ed with bpf-next repo:

  • src/ <-> bpf-next/tools/lib/bpf/
  • include/uapi/linux/bpf_common.h <-> bpf-next/tools/include/uapi/linux/bpf_common.h
  • include/uapi/linux/bpf.h <-> bpf-next/tools/include/uapi/linux/bpf.h
  • include/uapi/linux/btf.h <-> bpf-next/tools/include/uapi/linux/btf.h
  • include/uapi/linux/if_link.h <-> bpf-next/tools/include/uapi/linux/if_link.h
  • include/uapi/linux/if_xdp.h <-> bpf-next/tools/include/uapi/linux/if_xdp.h
  • include/uapi/linux/netlink.h <-> bpf-next/tools/include/uapi/linux/netlink.h
  • include/tools/libc_compat.h <-> bpf-next/tools/include/tools/libc_compat.h

Other header files at this repo (include/linux/*.h) are reduced versions of their counterpart files at bpf-next's tools/include/linux/*.h to make compilation successful.

Build Build Status Total alerts Coverity

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

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