While building selftests, the following errors were observed:
tools/testing/selftests/timens' gcc -Wall -Werror -pthread -lrt -ldl timens.c -o tools/testing/selftests/timens/timens /usr/bin/ld: /tmp/ccGy5CST.o: in function `check_config_posix_timers': timens.c:(.text+0x65a): undefined reference to `timer_create' collect2: error: ld returned 1 exit status
Quoting commit 870f193d48c2 ("selftests: net: use LDLIBS instead of LDFLAGS"):
The default Makefile rule looks like:
$(CC) $(CFLAGS) $(LDFLAGS) $@ $^ $(LDLIBS)
When linking is done by gcc itself, no issue, but when it needs to be passed to proper ld, only LDLIBS follows and then ld cannot know what libs to link with.
More detail: https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html
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.
While at here, correct other selftests, not only timens ones.
Reported-by: Shuah Khan skhan@kernel.org Signed-off-by: Dmitry Safonov dima@arista.com --- tools/testing/selftests/futex/functional/Makefile | 2 +- tools/testing/selftests/net/Makefile | 4 ++-- tools/testing/selftests/rtc/Makefile | 2 +- tools/testing/selftests/timens/Makefile | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile index 30996306cabc..23207829ec75 100644 --- a/tools/testing/selftests/futex/functional/Makefile +++ b/tools/testing/selftests/futex/functional/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 INCLUDES := -I../include -I../../ CFLAGS := $(CFLAGS) -g -O2 -Wall -D_GNU_SOURCE -pthread $(INCLUDES) -LDFLAGS := $(LDFLAGS) -pthread -lrt +LDLIBS := -lpthread -lrt
HEADERS := \ ../include/futextest.h \ diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index b5694196430a..287ae916ec0b 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -27,5 +27,5 @@ KSFT_KHDR_INSTALL := 1 include ../lib.mk
$(OUTPUT)/reuseport_bpf_numa: LDLIBS += -lnuma -$(OUTPUT)/tcp_mmap: LDFLAGS += -lpthread -$(OUTPUT)/tcp_inq: LDFLAGS += -lpthread +$(OUTPUT)/tcp_mmap: LDLIBS += -lpthread +$(OUTPUT)/tcp_inq: LDLIBS += -lpthread diff --git a/tools/testing/selftests/rtc/Makefile b/tools/testing/selftests/rtc/Makefile index de9c8566672a..2d93d65723c9 100644 --- a/tools/testing/selftests/rtc/Makefile +++ b/tools/testing/selftests/rtc/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 CFLAGS += -O3 -Wl,-no-as-needed -Wall -LDFLAGS += -lrt -lpthread -lm +LDLIBS += -lrt -lpthread -lm
TEST_GEN_PROGS = rtctest
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile index e9fb30bd8aeb..b4fd9a934654 100644 --- a/tools/testing/selftests/timens/Makefile +++ b/tools/testing/selftests/timens/Makefile @@ -2,6 +2,6 @@ TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec TEST_GEN_PROGS_EXTENDED := gettime_perf
CFLAGS := -Wall -Werror -pthread -LDFLAGS := -lrt -ldl +LDLIBS := -lrt -ldl
include ../lib.mk