From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751761AbdBNDHP (ORCPT ); Mon, 13 Feb 2017 22:07:15 -0500 Received: from mail-it0-f46.google.com ([209.85.214.46]:37624 "EHLO mail-it0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751480AbdBNDHN (ORCPT ); Mon, 13 Feb 2017 22:07:13 -0500 MIME-Version: 1.0 In-Reply-To: <1486630590-9410-2-git-send-email-mpe@ellerman.id.au> References: <1486630590-9410-1-git-send-email-mpe@ellerman.id.au> <1486630590-9410-2-git-send-email-mpe@ellerman.id.au> From: Bamvor Zhang Jian Date: Tue, 14 Feb 2017 11:07:12 +0800 Message-ID: Subject: Re: [PATCH 2/5] selftests: Fix the .c linking rule To: Michael Ellerman Cc: Shuah Khan , "Zhang Jian(Bamvor)" , lkml , linuxppc-dev@ozlabs.org, linux-kselftest@vger.kernel.org, linux-api Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tested-by: Bamvor Jian Zhang On 9 February 2017 at 16:56, Michael Ellerman wrote: > Currently we can't build some tests, for example: > > $ make -C tools/testing/selftests/ TARGETS=vm > ... > gcc -Wall -I ../../../../usr/include -lrt -lpthread ../../../../usr/include/linux/kernel.h userfaultfd.c -o tools/testing/selftests/vm/userfaultfd > /tmp/ccmOkQSM.o: In function `stress': > userfaultfd.c:(.text+0xc60): undefined reference to `pthread_create' > userfaultfd.c:(.text+0xca5): undefined reference to `pthread_create' > userfaultfd.c:(.text+0xcee): undefined reference to `pthread_create' > userfaultfd.c:(.text+0xd30): undefined reference to `pthread_create' > userfaultfd.c:(.text+0xd77): undefined reference to `pthread_join' > userfaultfd.c:(.text+0xe7d): undefined reference to `pthread_join' > userfaultfd.c:(.text+0xe9f): undefined reference to `pthread_cancel' > userfaultfd.c:(.text+0xec6): undefined reference to `pthread_join' > userfaultfd.c:(.text+0xf14): undefined reference to `pthread_join' > /tmp/ccmOkQSM.o: In function `userfaultfd_stress': > userfaultfd.c:(.text+0x13e2): undefined reference to `pthread_attr_setstacksize' > collect2: error: ld returned 1 exit status > > This is because the rule for linking .c files to binaries is incorrect. > > The first bug is that it uses $< (first prerequisite) instead of $^ (all > preqrequisites), fix it by using ^$. > > Secondly the ordering of the prerequisites vs $(LDLIBS) is wrong, > meaning on toolchains that use --as-needed we fail to link (as above). > Fix that by placing $(LDLIBS) *after* ^$. > > Finally switch to using the default rule $(LINK.c), so that we get > $(CPPFLAGS) etc. included. > > Fixes: a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT") > Signed-off-by: Michael Ellerman > --- > tools/testing/selftests/lib.mk | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk > index 17ed4bbe3963..98841c54763a 100644 > --- a/tools/testing/selftests/lib.mk > +++ b/tools/testing/selftests/lib.mk > @@ -51,7 +51,7 @@ clean: > $(RM) -r $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES) $(EXTRA_CLEAN) > > $(OUTPUT)/%:%.c > - $(CC) $(CFLAGS) $(LDFLAGS) $(LDLIBS) $< -o $@ > + $(LINK.c) $^ $(LDLIBS) -o $@ > > $(OUTPUT)/%.o:%.S > $(CC) $(ASFLAGS) -c $< -o $@ > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-api" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bamvor Zhang Jian Subject: Re: [PATCH 2/5] selftests: Fix the .c linking rule Date: Tue, 14 Feb 2017 11:07:12 +0800 Message-ID: References: <1486630590-9410-1-git-send-email-mpe@ellerman.id.au> <1486630590-9410-2-git-send-email-mpe@ellerman.id.au> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <1486630590-9410-2-git-send-email-mpe-Gsx/Oe8HsFggBc27wqDAHg@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Michael Ellerman Cc: Shuah Khan , "Zhang Jian(Bamvor)" , lkml , linuxppc-dev-mnsaURCQ41sdnm+yROfE0A@public.gmane.org, linux-kselftest-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api List-Id: linux-api@vger.kernel.org Tested-by: Bamvor Jian Zhang On 9 February 2017 at 16:56, Michael Ellerman wrote: > Currently we can't build some tests, for example: > > $ make -C tools/testing/selftests/ TARGETS=vm > ... > gcc -Wall -I ../../../../usr/include -lrt -lpthread ../../../../usr/include/linux/kernel.h userfaultfd.c -o tools/testing/selftests/vm/userfaultfd > /tmp/ccmOkQSM.o: In function `stress': > userfaultfd.c:(.text+0xc60): undefined reference to `pthread_create' > userfaultfd.c:(.text+0xca5): undefined reference to `pthread_create' > userfaultfd.c:(.text+0xcee): undefined reference to `pthread_create' > userfaultfd.c:(.text+0xd30): undefined reference to `pthread_create' > userfaultfd.c:(.text+0xd77): undefined reference to `pthread_join' > userfaultfd.c:(.text+0xe7d): undefined reference to `pthread_join' > userfaultfd.c:(.text+0xe9f): undefined reference to `pthread_cancel' > userfaultfd.c:(.text+0xec6): undefined reference to `pthread_join' > userfaultfd.c:(.text+0xf14): undefined reference to `pthread_join' > /tmp/ccmOkQSM.o: In function `userfaultfd_stress': > userfaultfd.c:(.text+0x13e2): undefined reference to `pthread_attr_setstacksize' > collect2: error: ld returned 1 exit status > > This is because the rule for linking .c files to binaries is incorrect. > > The first bug is that it uses $< (first prerequisite) instead of $^ (all > preqrequisites), fix it by using ^$. > > Secondly the ordering of the prerequisites vs $(LDLIBS) is wrong, > meaning on toolchains that use --as-needed we fail to link (as above). > Fix that by placing $(LDLIBS) *after* ^$. > > Finally switch to using the default rule $(LINK.c), so that we get > $(CPPFLAGS) etc. included. > > Fixes: a8ba798bc8ec ("selftests: enable O and KBUILD_OUTPUT") > Signed-off-by: Michael Ellerman > --- > tools/testing/selftests/lib.mk | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk > index 17ed4bbe3963..98841c54763a 100644 > --- a/tools/testing/selftests/lib.mk > +++ b/tools/testing/selftests/lib.mk > @@ -51,7 +51,7 @@ clean: > $(RM) -r $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES) $(EXTRA_CLEAN) > > $(OUTPUT)/%:%.c > - $(CC) $(CFLAGS) $(LDFLAGS) $(LDLIBS) $< -o $@ > + $(LINK.c) $^ $(LDLIBS) -o $@ > > $(OUTPUT)/%.o:%.S > $(CC) $(ASFLAGS) -c $< -o $@ > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-api" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html