[PATCH] selftests: use LDLIBS for libraries instead of LDFLAGS

[PATCH] selftests: use LDLIBS for libraries instead of LDFLAGS

[Dmitry Safonov]

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
-- 
2.25.0

Re: [PATCH] selftests: use LDLIBS for libraries instead of LDFLAGS

[shuah]

On 2/12/20 7:00 AM, Dmitry Safonov wrote:
> 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(-)
> 


Looks good. Thanks for fixing it quickly.

Please split these into 4 patches and send one for each test.

For timens:

Tested-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah

Re: [PATCH] selftests: use LDLIBS for libraries instead of LDFLAGS

[shuah]

On 2/12/20 11:15 AM, shuah wrote:
> On 2/12/20 7:00 AM, Dmitry Safonov wrote:
>> 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(-)
>>
> 
> 
> Looks good. Thanks for fixing it quickly.
> 
> Please split these into 4 patches and send one for each test.
> 
> For timens:
> 
> Tested-by: Shuah Khan <skhan@linuxfoundation.org>
> 

In the interest of getting this fix in, I applied it to

git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git 
fixes branch.

No need to do anything.

thanks,
-- Shuah

Re: [PATCH] selftests: use LDLIBS for libraries instead of LDFLAGS

[Dmitry Safonov]

On 2/13/20 8:24 PM, shuah wrote:
> In the interest of getting this fix in, I applied it to
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git
> fixes branch.
> 
> No need to do anything.

Ah, thank you!
I was on other issues - sorry for the delay.

Thanks,
          Dmitry