On Wed, 2024-01-10 at 21:34 +0000, Dmitry Safonov wrote:
The rules to link selftests are:
$(OUTPUT)/%_ipv4: %.c $(LINK.c) $^ $(LDLIBS) -o $@
$(OUTPUT)/%_ipv6: %.c $(LINK.c) -DIPV6_TEST $^ $(LDLIBS) -o $@
The intel test robot uses only selftest's Makefile, not the top linux Makefile:
make W=1 O=/tmp/kselftest -C tools/testing/selftests
So, $(LINK.c) is determined by environment, rather than by kernel Makefiles. On my machine (as well as other people that ran tcp-ao selftests) GNU/Make implicit definition does use $(LDFLAGS):
[dima@Mindolluin ~]$ make -p -f/dev/null | grep '^LINK.c>' make: *** No targets. Stop. LINK.c = $(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $(TARGET_ARCH)
But, according to build robot report, it's not the case for them. While I could just avoid using pre-defined $(LINK.c), it's also used by selftests/lib.mk by default.
Anyways, according to GNU/Make documentation [1], I should have used $(LDLIBS) instead of $(LDFLAGS) in the first place, so let's just do it:
LDFLAGS Extra flags to give to compilers when they are supposed to invoke the linker, ‘ld’, such as -L. Libraries (-lfoo) should be added to the LDLIBS variable instead. LDLIBS Library flags or names given to compilers when they are supposed to invoke the linker, ‘ld’. LOADLIBES is a deprecated (but still supported) alternative to LDLIBS. Non-library linker flags, such as -L, should go in the LDFLAGS variable.
Fixes: cfbab37b3da0 ("selftests/net: Add TCP-AO library") Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202401011151.veyYTJzq-lkp@intel.com/ Signed-off-by: Dmitry Safonov dima@arista.com
Acked-by: Paolo Abeni pabeni@redhat.com