Re: [PATCH] selftests: mptcp: extend CFLAGS to keep options from environment

[Matthieu Baerts <matttbe@kernel.org>]

Hi Jan, Hangbin,

(-cc <eliang@kernel.org>: wrong address apparently)

On 23/01/2025 09:43, Hangbin Liu wrote:
> On Thu, Jan 23, 2025 at 08:39:53AM +0000, Hangbin Liu wrote:
>> On Thu, Jan 23, 2025 at 09:35:42AM +0100, Jan Stancek wrote:
>>> Package build environments like Fedora rpmbuild introduced hardening
>>> options (e.g. -pie -Wl,-z,now) by passing a -spec option to CFLAGS
>>> and LDFLAGS.
>>>
>>> mptcp Makefile currently overrides CFLAGS but not LDFLAGS, which leads
>>> to a mismatch and build failure, for example:
>>>   make[1]: *** [../../lib.mk:222: tools/testing/selftests/net/mptcp/mptcp_sockopt] Error 1
>>>   /usr/bin/ld: /tmp/ccqyMVdb.o: relocation R_X86_64_32 against `.rodata.str1.8' can not be used when making a PIE object; recompile with -fPIE
>>>   /usr/bin/ld: failed to set dynamic section sizes: bad value
>>>   collect2: error: ld returned 1 exit status
>>>
>>> Signed-off-by: Jan Stancek <jstancek@redhat.com>
>>> ---
>>>  tools/testing/selftests/net/mptcp/Makefile | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/tools/testing/selftests/net/mptcp/Makefile b/tools/testing/selftests/net/mptcp/Makefile
>>> index 8e3fc05a5397..9706bc73809f 100644
>>> --- a/tools/testing/selftests/net/mptcp/Makefile
>>> +++ b/tools/testing/selftests/net/mptcp/Makefile
>>> @@ -2,7 +2,7 @@
>>>  
>>>  top_srcdir = ../../../../..
>>>  
>>> -CFLAGS =  -Wall -Wl,--no-as-needed -O2 -g -I$(top_srcdir)/usr/include $(KHDR_INCLUDES)
>>> +CFLAGS +=  -Wall -Wl,--no-as-needed -O2 -g -I$(top_srcdir)/usr/include $(KHDR_INCLUDES)

Thank you for the fix, it looks good to me too:

Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

>>>  
>>>  TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh diag.sh \
>>>  	      simult_flows.sh mptcp_sockopt.sh userspace_pm.sh
>>> -- 
>>> 2.43.0
>>>
>>
>> Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
> 
> Hmm, net-next is closed. Not sure if we can target this to net since it fixes
> the build errors.

I think this should target -net. It should then have a Fixes tag (and cc
Stable). Not sure if we need to backport that all along. Maybe enough to
use the following one, because I see it fixed the same issue in net and
tcp_ao:

Fixes: cc937dad85ae ("selftests: centralize -D_GNU_SOURCE= to CFLAGS in
lib.mk")

BTW, I guess you will need the same fix in
tools/testing/selftests/net/lib/Makefile and
tools/testing/selftests/net/openvswitch/Makefile.

@Jan: Do you mind fixing them too please? Also, please next time add the
target in the subject, e.g. [PATCH net], see:

  https://docs.kernel.org/process/maintainer-netdev.html

@Netdev maintainers: this can be applied directly in -net, no need to go
through the MPTCP tree first. But it can if you prefer me adding the
Fixes tag.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.