libbpf: fix using uninitialized ioctl results
'channels.max_combined' initialized only on ioctl success and
errno is only valid on ioctl failure.
The code doesn't produce any runtime issues, but makes memory
sanitizers angry:
Conditional jump or move depends on uninitialised value(s)
at 0x55C056F: xsk_get_max_queues (xsk.c:336)
by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
by 0x55C0E57: xsk_socket__create (xsk.c:601)
Uninitialised value was created by a stack allocation
at 0x55C04CD: xsk_get_max_queues (xsk.c:318)
Additionally fixed warning on uninitialized bytes in ioctl arguments:
Syscall param ioctl(SIOCETHTOOL) points to uninitialised byte(s)
at 0x648D45B: ioctl (in /usr/lib64/libc-2.28.so)
by 0x55C0546: xsk_get_max_queues (xsk.c:330)
by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
by 0x55C0E57: xsk_socket__create (xsk.c:601)
Address 0x1ffefff378 is on thread 1's stack
in frame #1, created by xsk_get_max_queues (xsk.c:318)
Uninitialised value was created by a stack allocation
at 0x55C04CD: xsk_get_max_queues (xsk.c:318)
CC: Magnus Karlsson <magnus.karlsson@intel.com>
Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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