| commit | c438cecc546fde76d1017a8eede9c8b483fca15f | [log] [tgz] |
|---|---|---|
| author | Daniel T. Lee <danieltimlee@gmail.com> | Wed Apr 24 05:24:56 2019 +0900 |
| committer | Andrii Nakryiko <andrii.nakryiko@gmail.com> | Thu May 16 09:40:04 2019 -0700 |
| tree | e6dce665f2b4762ec266347ed1f5a83e8053b9e6 | |
| parent | 72ef206260dbd22da8f042202c32b9e7c8b0d2bd [diff] |
libbpf: fix samples/bpf build failure due to undefined UINT32_MAX
Currently, building bpf samples will cause the following error.
./tools/lib/bpf/bpf.h:132:27: error: 'UINT32_MAX' undeclared here (not in a function) ..
#define BPF_LOG_BUF_SIZE (UINT32_MAX >> 8) /* verifier maximum in kernels <= 5.1 */
^
./samples/bpf/bpf_load.h:31:25: note: in expansion of macro 'BPF_LOG_BUF_SIZE'
extern char bpf_log_buf[BPF_LOG_BUF_SIZE];
^~~~~~~~~~~~~~~~
Due to commit 4519efa6f8ea ("libbpf: fix BPF_LOG_BUF_SIZE off-by-one error")
hard-coded size of BPF_LOG_BUF_SIZE has been replaced with UINT32_MAX which is
defined in <stdint.h> header.
Even with this change, bpf selftests are running fine since these are built
with clang and it includes header(-idirafter) from clang/6.0.0/include.
(it has <stdint.h>)
clang -I. -I./include/uapi -I../../../include/uapi -idirafter /usr/local/include -idirafter /usr/include \
-idirafter /usr/lib/llvm-6.0/lib/clang/6.0.0/include -idirafter /usr/include/x86_64-linux-gnu \
-Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm -c progs/test_sysctl_prog.c -o - | \
llc -march=bpf -mcpu=generic -filetype=obj -o /linux/tools/testing/selftests/bpf/test_sysctl_prog.o
But bpf samples are compiled with GCC, and it only searches and includes
headers declared at the target file. As '#include <stdint.h>' hasn't been
declared in tools/lib/bpf/bpf.h, it causes build failure of bpf samples.
gcc -Wp,-MD,./samples/bpf/.sockex3_user.o.d -Wall -Wmissing-prototypes -Wstrict-prototypes \
-O2 -fomit-frame-pointer -std=gnu89 -I./usr/include -I./tools/lib/ -I./tools/testing/selftests/bpf/ \
-I./tools/ lib/ -I./tools/include -I./tools/perf -c -o ./samples/bpf/sockex3_user.o ./samples/bpf/sockex3_user.c;
This commit add declaration of '#include <stdint.h>' to tools/lib/bpf/bpf.h
to fix this problem.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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.hinclude/uapi/linux/bpf.h <-> bpf-next/tools/include/uapi/linux/bpf.hinclude/uapi/linux/btf.h <-> bpf-next/tools/include/uapi/linux/btf.hinclude/uapi/linux/if_link.h <-> bpf-next/tools/include/uapi/linux/if_link.hinclude/uapi/linux/if_xdp.h <-> bpf-next/tools/include/uapi/linux/if_xdp.hinclude/uapi/linux/netlink.h <-> bpf-next/tools/include/uapi/linux/netlink.hinclude/tools/libc_compat.h <-> bpf-next/tools/include/tools/libc_compat.hOther 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.
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
To integrate libbpf into a project which uses Meson building system define [wrap-git] file in subprojects folder. To add libbpf dependency to the parent parent project, e.g. for libbpf_static_dep:
libbpf_obj = subproject('libbpf', required : true)
libbpf_static_dep = libbpf_proj.get_variable('libbpf_static_dep')
To validate changes to meson.build
$ python3 meson.py build $ ninja -C build/
To install headers, libs and pkgconfig
$ cd build
$ ninja install