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https://github.com/netdata/libbpf.git
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ac2254d0ea
Reported in [1].
With gcc 8.3.0 the following error is issued:
cc -Ibpf@sta -I. -I.. -I.././include -I.././include/uapi
-fdiagnostics-color=always -fsanitize=address,undefined -fno-omit-frame-pointer
-pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Werror -g -fPIC -g -O2
-Werror -Wall -Wno-pointer-arith -Wno-sign-compare -MD -MQ
'bpf@sta/src_libbpf.c.o' -MF 'bpf@sta/src_libbpf.c.o.d' -o
'bpf@sta/src_libbpf.c.o' -c ../src/libbpf.c
../src/libbpf.c: In function 'bpf_object__elf_collect':
../src/libbpf.c:947:18: error: 'map_def_sz' may be used uninitialized in this
function [-Werror=maybe-uninitialized]
if (map_def_sz <= sizeof(struct bpf_map_def)) {
~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/libbpf.c:827:18: note: 'map_def_sz' was declared here
int i, map_idx, map_def_sz, nr_syms, nr_maps = 0, nr_maps_glob = 0;
^~~~~~~~~~
According to [2] -Wmaybe-uninitialized is enabled by -Wall.
Same error is generated by clang's -Wconditional-uninitialized.
[1] https://github.com/libbpf/libbpf/pull/29#issuecomment-481902601
[2] https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
Fixes: d859900c4c56 ("bpf, libbpf: support global data/bss/rodata sections")
Reported-by: Evgeny Vereshchagin <evvers@ya.ru>
Signed-off-by: Andrey Ignatov <rdna@fb.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 (https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next) bpf-next/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/tools/include/linux/*.h to make compilation successful. 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