| Message ID | 20241217031052.69744-1-lizhijian@fujitsu.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC] Makefile: Export absolute srctree path for out-of-tree builds | expand |
2024-12-17 11:10 UTC+0800 ~ Li Zhijian <lizhijian@fujitsu.com> > Fixes an issue where out-of-tree kselftest builds fail when building > the BPF and bpftools components. The failure occurs because the top-level > Makefile passes a relative srctree path ('..') to its sub-Makefiles, which > leads to errors in locating necessary files. > > For example, the following error is encountered: > > ``` > $ make V=1 O=$build/ TARGETS=hid kselftest-all > ... > make -C ../tools/testing/selftests all > make[4]: Entering directory '/path/to/linux/tools/testing/selftests/hid' > make -C /path/to/linux/tools/testing/selftests/../../../tools/lib/bpf OUTPUT=/path/to/linux/O/kselftest/hid/tools/build/libbpf/ \ > EXTRA_CFLAGS='-g -O0' \ > DESTDIR=/path/to/linux/O/kselftest/hid/tools prefix= all install_headers > make[5]: Entering directory '/path/to/linux/tools/lib/bpf' > ... > make[5]: Entering directory '/path/to/linux/tools/bpf/bpftool' > Makefile:127: ../tools/build/Makefile.feature: No such file or directory > make[5]: *** No rule to make target '../tools/build/Makefile.feature'. Stop. > ``` Another condition to reproduce the failure above is to have have $(srcroot) in the Makefile set to "." or "..", for example when your $build is located right under the root of the repo [0]. [0] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Makefile?h=v6.13-rc3#n273 > To resolve this, the srctree is exported as an absolute path (abs_srctree) > when performing an out-of-tree build. This ensures that all sub-Makefiles > have the correct path to the source tree, preventing directory resolution > errors. > > Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> > --- > Request for Additional Testing > > We welcome all contributors and CI systems to test this change thoroughly. > In theory, this change should not affect in-tree builds. However, to ensure > stability and compatibility, we encourage testing across different > configurations. > > What has been tested? > - out-of-tree kernel build > - out-of-tree kselftest-all > --- > Makefile | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/Makefile b/Makefile > index e5b8a8832c0c..36e65806bb5e 100644 > --- a/Makefile > +++ b/Makefile > @@ -275,7 +275,8 @@ else ifeq ($(srcroot)/,$(dir $(CURDIR))) > srcroot := .. > endif > > -export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) > +srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) > +export srctree := $(if $(building_out_of_srctree),$(abs_srctree),$(srctree)) > > ifdef building_out_of_srctree > export VPATH := $(srcroot) The patch does fix the issue in the case you reported. Maybe I'd write the change differently, though; rather than potentially overwriting $(srctree) before exporting it, let's unroll with ifdef's to make it clearer? ifdef building_out_of_srctree srctree := $(abs_srctree) else ifdef KBUILD_EXTMOD srctree := $(abs_srctree) else srctree := $(srcroot) endif export srctree (not tested) Thanks, Quentin
On Tue, Dec 17, 2024 at 12:10 PM Li Zhijian <lizhijian@fujitsu.com> wrote: > > Fixes an issue where out-of-tree kselftest builds fail when building > the BPF and bpftools components. The failure occurs because the top-level > Makefile passes a relative srctree path ('..') to its sub-Makefiles, which > leads to errors in locating necessary files. > > For example, the following error is encountered: > > ``` > $ make V=1 O=$build/ TARGETS=hid kselftest-all > ... > make -C ../tools/testing/selftests all > make[4]: Entering directory '/path/to/linux/tools/testing/selftests/hid' > make -C /path/to/linux/tools/testing/selftests/../../../tools/lib/bpf OUTPUT=/path/to/linux/O/kselftest/hid/tools/build/libbpf/ \ > EXTRA_CFLAGS='-g -O0' \ > DESTDIR=/path/to/linux/O/kselftest/hid/tools prefix= all install_headers > make[5]: Entering directory '/path/to/linux/tools/lib/bpf' > ... > make[5]: Entering directory '/path/to/linux/tools/bpf/bpftool' > Makefile:127: ../tools/build/Makefile.feature: No such file or directory > make[5]: *** No rule to make target '../tools/build/Makefile.feature'. Stop. > ``` > > To resolve this, the srctree is exported as an absolute path (abs_srctree) > when performing an out-of-tree build. This ensures that all sub-Makefiles > have the correct path to the source tree, preventing directory resolution > errors. NACK. This negates 9da0763bdd82572be243fcf5161734f11568960f This is a recurring topic [1] because kselftest adopts a completely different build system. If kselftest cannot do this correctly, please do not hook it to the top-Makefile. [1] https://lore.kernel.org/linux-kbuild/cover.1657614127.git.guillaume.tucker@collabora.com/ > Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> > --- > Request for Additional Testing > > We welcome all contributors and CI systems to test this change thoroughly. This is NACKed. I recommend not wasting CI system resources. > In theory, this change should not affect in-tree builds. However, to ensure > stability and compatibility, we encourage testing across different > configurations. > > What has been tested? > - out-of-tree kernel build > - out-of-tree kselftest-all > --- > Makefile | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/Makefile b/Makefile > index e5b8a8832c0c..36e65806bb5e 100644 > --- a/Makefile > +++ b/Makefile > @@ -275,7 +275,8 @@ else ifeq ($(srcroot)/,$(dir $(CURDIR))) > srcroot := .. > endif > > -export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) > +srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) > +export srctree := $(if $(building_out_of_srctree),$(abs_srctree),$(srctree)) > > ifdef building_out_of_srctree > export VPATH := $(srcroot) > -- > 2.44.0 > >
On 21/12/2024 11:41, Masahiro Yamada wrote: > On Tue, Dec 17, 2024 at 12:10 PM Li Zhijian <lizhijian@fujitsu.com> wrote: >> >> Fixes an issue where out-of-tree kselftest builds fail when building >> the BPF and bpftools components. The failure occurs because the top-level >> Makefile passes a relative srctree path ('..') to its sub-Makefiles, which >> leads to errors in locating necessary files. >> >> For example, the following error is encountered: >> >> ``` >> $ make V=1 O=$build/ TARGETS=hid kselftest-all >> ... >> make -C ../tools/testing/selftests all >> make[4]: Entering directory '/path/to/linux/tools/testing/selftests/hid' >> make -C /path/to/linux/tools/testing/selftests/../../../tools/lib/bpf OUTPUT=/path/to/linux/O/kselftest/hid/tools/build/libbpf/ \ >> EXTRA_CFLAGS='-g -O0' \ >> DESTDIR=/path/to/linux/O/kselftest/hid/tools prefix= all install_headers >> make[5]: Entering directory '/path/to/linux/tools/lib/bpf' >> ... >> make[5]: Entering directory '/path/to/linux/tools/bpf/bpftool' >> Makefile:127: ../tools/build/Makefile.feature: No such file or directory >> make[5]: *** No rule to make target '../tools/build/Makefile.feature'. Stop. >> ``` >> >> To resolve this, the srctree is exported as an absolute path (abs_srctree) >> when performing an out-of-tree build. This ensures that all sub-Makefiles >> have the correct path to the source tree, preventing directory resolution >> errors. > > NACK. > This negates 9da0763bdd82572be243fcf5161734f11568960f > > This is a recurring topic [1] because kselftest adopts a completely > different build system. > If kselftest cannot do this correctly, please do not hook it to the > top-Makefile. > Hi Masahiro, Thank you for your feedback I understand and agree with your points, thanks again for these information. > [1] https://lore.kernel.org/linux-kbuild/cover.1657614127.git.guillaume.tucker@collabora.com/ > > > >> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> >> --- >> Request for Additional Testing >> >> We welcome all contributors and CI systems to test this change thoroughly. > > This is NACKed. I recommend not wasting CI system resources. It sounds reasonable. It makes sense to avoid using CI resources on this patch given the current circumstances. Thanks Zhijian > > > > > > >> In theory, this change should not affect in-tree builds. However, to ensure >> stability and compatibility, we encourage testing across different >> configurations. >> >> What has been tested? >> - out-of-tree kernel build >> - out-of-tree kselftest-all >> --- >> Makefile | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/Makefile b/Makefile >> index e5b8a8832c0c..36e65806bb5e 100644 >> --- a/Makefile >> +++ b/Makefile >> @@ -275,7 +275,8 @@ else ifeq ($(srcroot)/,$(dir $(CURDIR))) >> srcroot := .. >> endif >> >> -export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) >> +srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) >> +export srctree := $(if $(building_out_of_srctree),$(abs_srctree),$(srctree)) >> >> ifdef building_out_of_srctree >> export VPATH := $(srcroot) >> -- >> 2.44.0 >> >> > >
On 21/12/2024 01:14, Quentin Monnet wrote: > 2024-12-17 11:10 UTC+0800 ~ Li Zhijian <lizhijian@fujitsu.com> >> Fixes an issue where out-of-tree kselftest builds fail when building >> the BPF and bpftools components. The failure occurs because the top-level >> Makefile passes a relative srctree path ('..') to its sub-Makefiles, which >> leads to errors in locating necessary files. >> >> For example, the following error is encountered: >> >> ``` >> $ make V=1 O=$build/ TARGETS=hid kselftest-all >> ... >> make -C ../tools/testing/selftests all >> make[4]: Entering directory '/path/to/linux/tools/testing/selftests/hid' >> make -C /path/to/linux/tools/testing/selftests/../../../tools/lib/bpf OUTPUT=/path/to/linux/O/kselftest/hid/tools/build/libbpf/ \ >> EXTRA_CFLAGS='-g -O0' \ >> DESTDIR=/path/to/linux/O/kselftest/hid/tools prefix= all install_headers >> make[5]: Entering directory '/path/to/linux/tools/lib/bpf' >> ... >> make[5]: Entering directory '/path/to/linux/tools/bpf/bpftool' >> Makefile:127: ../tools/build/Makefile.feature: No such file or directory >> make[5]: *** No rule to make target '../tools/build/Makefile.feature'. Stop. >> ``` > > > Another condition to reproduce the failure above is to have have > $(srcroot) in the Makefile set to "." or "..", for example when your > $build is located right under the root of the repo [0]. > > [0] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Makefile?h=v6.13-rc3#n273 > > >> To resolve this, the srctree is exported as an absolute path (abs_srctree) >> when performing an out-of-tree build. This ensures that all sub-Makefiles >> have the correct path to the source tree, preventing directory resolution >> errors. >> >> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> >> --- >> Request for Additional Testing >> >> We welcome all contributors and CI systems to test this change thoroughly. >> In theory, this change should not affect in-tree builds. However, to ensure >> stability and compatibility, we encourage testing across different >> configurations. >> >> What has been tested? >> - out-of-tree kernel build >> - out-of-tree kselftest-all >> --- >> Makefile | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/Makefile b/Makefile >> index e5b8a8832c0c..36e65806bb5e 100644 >> --- a/Makefile >> +++ b/Makefile >> @@ -275,7 +275,8 @@ else ifeq ($(srcroot)/,$(dir $(CURDIR))) >> srcroot := .. >> endif >> >> -export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) >> +srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) >> +export srctree := $(if $(building_out_of_srctree),$(abs_srctree),$(srctree)) >> >> ifdef building_out_of_srctree >> export VPATH := $(srcroot) > > > The patch does fix the issue in the case you reported. > > Maybe I'd write the change differently, though; rather than potentially > overwriting $(srctree) before exporting it, let's unroll with ifdef's to > make it clearer? Yes, your code looks better. However, this "absolute source tree" approach was not approved.:) Thank you!! > > ifdef building_out_of_srctree > srctree := $(abs_srctree) > else ifdef KBUILD_EXTMOD > srctree := $(abs_srctree) > else > srctree := $(srcroot) > endif > export srctree > > (not tested) > > Thanks, > Quentin
diff --git a/Makefile b/Makefile index e5b8a8832c0c..36e65806bb5e 100644 --- a/Makefile +++ b/Makefile @@ -275,7 +275,8 @@ else ifeq ($(srcroot)/,$(dir $(CURDIR))) srcroot := .. endif -export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) +srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot)) +export srctree := $(if $(building_out_of_srctree),$(abs_srctree),$(srctree)) ifdef building_out_of_srctree export VPATH := $(srcroot)
Fixes an issue where out-of-tree kselftest builds fail when building the BPF and bpftools components. The failure occurs because the top-level Makefile passes a relative srctree path ('..') to its sub-Makefiles, which leads to errors in locating necessary files. For example, the following error is encountered: ``` $ make V=1 O=$build/ TARGETS=hid kselftest-all ... make -C ../tools/testing/selftests all make[4]: Entering directory '/path/to/linux/tools/testing/selftests/hid' make -C /path/to/linux/tools/testing/selftests/../../../tools/lib/bpf OUTPUT=/path/to/linux/O/kselftest/hid/tools/build/libbpf/ \ EXTRA_CFLAGS='-g -O0' \ DESTDIR=/path/to/linux/O/kselftest/hid/tools prefix= all install_headers make[5]: Entering directory '/path/to/linux/tools/lib/bpf' ... make[5]: Entering directory '/path/to/linux/tools/bpf/bpftool' Makefile:127: ../tools/build/Makefile.feature: No such file or directory make[5]: *** No rule to make target '../tools/build/Makefile.feature'. Stop. ``` To resolve this, the srctree is exported as an absolute path (abs_srctree) when performing an out-of-tree build. This ensures that all sub-Makefiles have the correct path to the source tree, preventing directory resolution errors. Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> --- Request for Additional Testing We welcome all contributors and CI systems to test this change thoroughly. In theory, this change should not affect in-tree builds. However, to ensure stability and compatibility, we encourage testing across different configurations. What has been tested? - out-of-tree kernel build - out-of-tree kselftest-all --- Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)