kernel/tools/lib/bpf/Makefile, branch linux-5.1.y

bpf, libbpf: fix quiet install_headers

2019-03-28T16:01:37Z

Both btf.h and xsk.h headers are not installed quietly due to missing '\' for the call to QUIET_INSTALL. Lets fix it. Before: # make install_headers INSTALL headers if [ ! -d '''/usr/local/include/bpf' ]; then install -d -m 755 '''/usr/local/include/bpf'; fi; install btf.h -m 644 '''/usr/local/include/bpf'; if [ ! -d '''/usr/local/include/bpf' ]; then install -d -m 755 '''/usr/local/include/bpf'; fi; install xsk.h -m 644 '''/usr/local/include/bpf'; # ls /usr/local/include/bpf/ bpf.h btf.h libbpf.h xsk.h After: # make install_headers INSTALL headers # ls /usr/local/include/bpf/ bpf.h btf.h libbpf.h xsk.h Fixes: a493f5f9d8c2 ("libbpf: Install btf.h with libbpf") Fixes: 379e2014c95b ("libbpf: add xsk.h to install_headers target") Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Acked-by: Andrii Nakryiko

libbpf: add libelf dependency to shared library build

2019-03-28T15:24:52Z

The DPDK project is moving forward with its AF_XDP PMD, and during that process some libbpf issues surfaced [1]: When libbpf was built as a shared library, libelf was not included in the linking phase. Since libelf is an internal depedency to libbpf, libelf should be included. This patch adds '-lelf' to resolve that. [1] https://patches.dpdk.org/patch/50704/#93571 Fixes: 1b76c13e4b36 ("bpf tools: Introduce 'bpf' library and add bpf feature check") Suggested-by: Luca Boccassi Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann

libbpf: add xsk.h to install_headers target

2019-03-28T15:24:21Z

The xsk.h header file was missing from the install_headers target in the Makefile. This patch simply adds xsk.h to the set of installed headers. Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Reported-by: Bruce Richardson Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann

bpf, libbpf: fix version info and add it to shared object

2019-03-25T02:49:04Z

Even though libbpf's versioning script for the linker (libbpf.map) is pointing to 0.0.2, the BPF_EXTRAVERSION in the Makefile has not been updated along with it and is therefore still on 0.0.1. While fixing up, I also noticed that the generated shared object versioning information is missing, typical convention is to have a linker name (libbpf.so), soname (libbpf.so.0) and real name (libbpf.so.0.0.2) for library management. This is based upon the LIBBPF_VERSION as well. The build will then produce the following bpf libraries: # ll libbpf* libbpf.a libbpf.so -> libbpf.so.0.0.2 libbpf.so.0 -> libbpf.so.0.0.2 libbpf.so.0.0.2 # readelf -d libbpf.so.0.0.2 | grep SONAME 0x000000000000000e (SONAME) Library soname: [libbpf.so.0] And install them accordingly: # rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld install Auto-detecting system features: ... libelf: [ on ] ... bpf: [ on ] CC /tmp/bld/libbpf.o CC /tmp/bld/bpf.o CC /tmp/bld/nlattr.o CC /tmp/bld/btf.o CC /tmp/bld/libbpf_errno.o CC /tmp/bld/str_error.o CC /tmp/bld/netlink.o CC /tmp/bld/bpf_prog_linfo.o CC /tmp/bld/libbpf_probes.o CC /tmp/bld/xsk.o LD /tmp/bld/libbpf-in.o LINK /tmp/bld/libbpf.a LINK /tmp/bld/libbpf.so.0.0.2 LINK /tmp/bld/test_libbpf INSTALL /tmp/bld/libbpf.a INSTALL /tmp/bld/libbpf.so.0.0.2 # ll /usr/local/lib64/libbpf.* /usr/local/lib64/libbpf.a /usr/local/lib64/libbpf.so -> libbpf.so.0.0.2 /usr/local/lib64/libbpf.so.0 -> libbpf.so.0.0.2 /usr/local/lib64/libbpf.so.0.0.2 Fixes: 1bf4b05810fe ("tools: bpftool: add probes for eBPF program types") Fixes: 1b76c13e4b36 ("bpf tools: Introduce 'bpf' library and add bpf feature check") Reported-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov

libbpf: force fixdep compilation at the start of the build

2019-03-07T09:44:41Z

libbpf targets don't explicitly depend on fixdep target, so when we do 'make -j$(nproc)', there is a high probability, that some objects will be built before fixdep binary is available. Fix this by running sub-make; this makes sure that fixdep dependency is properly accounted for. For the same issue in perf, see commit abb26210a395 ("perf tools: Force fixdep compilation at the start of the build"). Before: $ rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld -C tools/lib/bpf/ Auto-detecting system features: ... libelf: [ on ] ... bpf: [ on ] HOSTCC /tmp/bld/fixdep.o CC /tmp/bld/libbpf.o CC /tmp/bld/bpf.o CC /tmp/bld/btf.o CC /tmp/bld/nlattr.o CC /tmp/bld/libbpf_errno.o CC /tmp/bld/str_error.o CC /tmp/bld/netlink.o CC /tmp/bld/bpf_prog_linfo.o CC /tmp/bld/libbpf_probes.o CC /tmp/bld/xsk.o HOSTLD /tmp/bld/fixdep-in.o LINK /tmp/bld/fixdep LD /tmp/bld/libbpf-in.o LINK /tmp/bld/libbpf.a LINK /tmp/bld/libbpf.so LINK /tmp/bld/test_libbpf $ head /tmp/bld/.libbpf.o.cmd # cannot find fixdep (/usr/local/google/home/sdf/src/linux/xxx//fixdep) # using basic dep data /tmp/bld/libbpf.o: libbpf.c /usr/include/stdc-predef.h \ /usr/include/stdlib.h /usr/include/features.h \ /usr/include/x86_64-linux-gnu/sys/cdefs.h \ /usr/include/x86_64-linux-gnu/bits/wordsize.h \ /usr/include/x86_64-linux-gnu/gnu/stubs.h \ /usr/include/x86_64-linux-gnu/gnu/stubs-64.h \ /usr/lib/gcc/x86_64-linux-gnu/7/include/stddef.h \ After: $ rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld -C tools/lib/bpf/ Auto-detecting system features: ... libelf: [ on ] ... bpf: [ on ] HOSTCC /tmp/bld/fixdep.o HOSTLD /tmp/bld/fixdep-in.o LINK /tmp/bld/fixdep CC /tmp/bld/libbpf.o CC /tmp/bld/bpf.o CC /tmp/bld/nlattr.o CC /tmp/bld/btf.o CC /tmp/bld/libbpf_errno.o CC /tmp/bld/str_error.o CC /tmp/bld/netlink.o CC /tmp/bld/bpf_prog_linfo.o CC /tmp/bld/libbpf_probes.o CC /tmp/bld/xsk.o LD /tmp/bld/libbpf-in.o LINK /tmp/bld/libbpf.a LINK /tmp/bld/libbpf.so LINK /tmp/bld/test_libbpf $ head /tmp/bld/.libbpf.o.cmd cmd_/tmp/bld/libbpf.o := gcc -Wp,-MD,/tmp/bld/.libbpf.o.d -Wp,-MT,/tmp/bld/libbpf.o -g -Wall -DHAVE_LIBELF_MMAP_SUPPORT -DCOMPAT_NEED_REALLOCARRAY -Wbad-function-cast -Wdeclaration-after-statement -Wformat-security -Wformat-y2k -Winit-self -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wno-system-headers -Wold-style-definition -Wpacked -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wundef -Wwrite-strings -Wformat -Wstrict-aliasing=3 -Werror -Wall -fPIC -I. -I/usr/local/google/home/sdf/src/linux/tools/include -I/usr/local/google/home/sdf/src/linux/tools/arch/x86/include/uapi -I/usr/local/google/home/sdf/src/linux/tools/include/uapi -fvisibility=hidden -D"BUILD_STR(s)=$(pound)s" -c -o /tmp/bld/libbpf.o libbpf.c source_/tmp/bld/libbpf.o := libbpf.c deps_/tmp/bld/libbpf.o := \ /usr/include/stdc-predef.h \ /usr/include/stdlib.h \ /usr/include/features.h \ /usr/include/x86_64-linux-gnu/sys/cdefs.h \ /usr/include/x86_64-linux-gnu/bits/wordsize.h \ Fixes: 7c422f557266 ("tools build: Build fixdep helper from perf and basic libs") Reported-by: Eric Dumazet Signed-off-by: Stanislav Fomichev Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann

tools: libbpf: make sure readelf shows full names in build checks

2019-02-28T23:53:46Z

readelf truncates its output by default to attempt to make it more readable. This can lead to function names getting aliased if they differ late in the string. Use --wide parameter to avoid truncation. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Acked-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann

libbpf: add support for using AF_XDP sockets

2019-02-25T22:21:42Z

This commit adds AF_XDP support to libbpf. The main reason for this is to facilitate writing applications that use AF_XDP by offering higher-level APIs that hide many of the details of the AF_XDP uapi. This is in the same vein as libbpf facilitates XDP adoption by offering easy-to-use higher level interfaces of XDP functionality. Hopefully this will facilitate adoption of AF_XDP, make applications using it simpler and smaller, and finally also make it possible for applications to benefit from optimizations in the AF_XDP user space access code. Previously, people just copied and pasted the code from the sample application into their application, which is not desirable. The interface is composed of two parts: * Low-level access interface to the four rings and the packet * High-level control plane interface for creating and setting up umems and af_xdp sockets as well as a simple XDP program. Tested-by: Björn Töpel Signed-off-by: Magnus Karlsson Signed-off-by: Daniel Borkmann

libbpf: don't define CC and AR

2019-01-16T21:47:43Z

We are already including tools/scripts/Makefile.include which correctly handles CROSS_COMPILE, no need to define our own vars. See related commit 7ed1c1901fe5 ("tools: fix cross-compile var clobbering") for more details. Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

libbpf: Verify versioned symbols

2018-11-27T02:57:14Z

Since ABI versioning info is kept separately from the code it's easy to forget to update it while adding a new API. Add simple verification that all global symbols exported with LIBBPF_API are versioned in libbpf.map version script. The idea is to check that number of global symbols in libbpf-in.o, that is the input to the linker, matches with number of unique versioned symbols in libbpf.so, that is the output of the linker. If these numbers don't match, it may mean some symbol was not versioned and make will fail. "Unique" means that if a symbol is present in more than one version of ABI due to ABI changes, it'll be counted once. Another option to calculate number of global symbols in the "input" could be to count number of LIBBPF_ABI entries in C headers but it seems to be fragile. Example of output when a symbol is missing in version script: ... LD libbpf-in.o LINK libbpf.a LINK libbpf.so Warning: Num of global symbols in libbpf-in.o (115) does NOT match with num of versioned symbols in libbpf.so (114). Please make sure all LIBBPF_API symbols are versioned in libbpf.map. make: *** [check_abi] Error 1 Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov

libbpf: Add version script for DSO

2018-11-27T02:57:14Z

More and more projects use libbpf and one day it'll likely be packaged and distributed as DSO and that requires ABI versioning so that both compatible and incompatible changes to ABI can be introduced in a safe way in the future without breaking executables dynamically linked with a previous version of the library. Usual way to do ABI versioning is version script for the linker. Add such a script for libbpf. All global symbols currently exported via LIBBPF_API macro are added to the version script libbpf.map. The version name LIBBPF_0.0.1 is constructed from the name of the library + version specified by $(LIBBPF_VERSION) in Makefile. Version script does not duplicate the work done by LIBBPF_API macro, it rather complements it. The macro is used at compile time and can be used by compiler to do optimization that can't be done at link time, it is purely about global symbol visibility. The version script, in turn, is used at link time and takes care of ABI versioning. Both techniques are described in details in [1]. Whenever ABI is changed in the future, version script should be changed appropriately. [1] https://www.akkadia.org/drepper/dsohowto.pdf Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov