On 10/15/23 3:39 PM, Akihiko Odaki wrote:

When linking statically, libraries may require other dependencies to be included to ld flags. In particular, libelf may require libzstd. Use pkg-config to determine such dependencies.

Is this not covered via -lz or is it that the name differs?

Anyway, this change breaks selftest build for BPF CI (see below), could this either be made optional or detected differently?

https://github.com/kernel-patches/bpf/actions/runs/6524480596/job/1771617002...

[...] make: pkg-config: Command not found CC bench.o make: pkg-config: Command not found make: pkg-config: Command not found CC bench_count.o make: pkg-config: Command not found BINARY xdp_redirect_multi HOSTLD /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/fixdep-in.o LINK /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/fixdep CC veristat.o INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/exec-cmd.h CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/exec-cmd.o make: pkg-config: Command not found INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/help.h CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/help.o INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/pager.h make: pkg-config: Command not found BINARY test_verifier CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/pager.o BINARY test_tag CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/parse-options.o make: pkg-config: Command not found CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/run-command.o INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/parse-options.h make: pkg-config: Command not found INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/run-command.h CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/sigchain.o BINARY flow_dissector_load CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/subcmd-config.o make: pkg-config: Command not found BINARY test_lirc_mode2_user INSTALL libsubcmd_headers BINARY xdping make: pkg-config: Command not found

tools/testing/selftests/bpf/Makefile | 3 ++- tools/testing/selftests/bpf/README.rst | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index caede9b574cb..833134aa2eda 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -4,6 +4,7 @@ include ../../../scripts/Makefile.arch include ../../../scripts/Makefile.include CXX ?= $(CROSS_COMPILE)g++ +PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config CURDIR := $(abspath .) TOOLSDIR := $(abspath ../../..) @@ -31,7 +32,7 @@ CFLAGS += -g -O0 -rdynamic -Wall -Werror $(GENFLAGS) $(SAN_CFLAGS) \ -I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \ -I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT) LDFLAGS += $(SAN_LDFLAGS) -LDLIBS += -lelf -lz -lrt -lpthread +LDLIBS += $(shell $(PKG_CONFIG) --libs libelf zlib) -lrt -lpthread ifneq ($(LLVM),) # Silence some warnings when compiled with clang diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst index cb9b95702ac6..9af79c7a9b58 100644 --- a/tools/testing/selftests/bpf/README.rst +++ b/tools/testing/selftests/bpf/README.rst @@ -77,7 +77,7 @@ In case of linker errors when running selftests, try using static linking: .. code-block:: console

• $ LDLIBS=-static vmtest.sh

• $ LDLIBS=-static PKG_CONFIG='pkg-config --static' vmtest.sh

.. note:: Some distros may not support static linking.