Re: [PATCH v2 3/5] kbuild: Use relative path for $(objtree)

From: Michal Marek <mmarek@suse.cz>
To: Richard Weinberger <richard.weinberger@gmail.com>
Cc: linux-kbuild@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Sam Ravnborg <sam@ravnborg.org>,
	rdunlap@infradead.org
Subject: Re: [PATCH v2 3/5] kbuild: Use relative path for $(objtree)
Date: Wed, 04 Jun 2014 11:43:25 +0200	[thread overview]
Message-ID: <538EEA3D.1080105@suse.cz> (raw)
In-Reply-To: <CAFLxGvyz-aX8rTveo9W3mqsQxPeg8cb7Oq59UiC1kMz4qTiYwg@mail.gmail.com>

On 2014-06-04 11:03, Richard Weinberger wrote:
> On Fri, May 9, 2014 at 2:52 PM, Michal Marek <mmarek@suse.cz> wrote:
>> The main Makefile sets its working directory to the object tree and
>> never changes it again. Therefore, we can use '.' instead of the
>> absolute path. The only case where we need the absolute path is when
>> creating the 'build' symlink in /lib/modules.
>>
>> Acked-by: Sam Ravnborg <sam@ravnborg.org>
>> Signed-off-by: Michal Marek <mmarek@suse.cz>
>> ---
>> v1->v2: Fix the 'build' symlink
>>
>>  Makefile | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/Makefile b/Makefile
>> index 60ccbfe..480503a 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -154,7 +154,7 @@ _all: modules
>>  endif
>>
>>  srctree                := $(if $(KBUILD_SRC),$(KBUILD_SRC),$(CURDIR))
>> -objtree                := $(CURDIR)
>> +objtree                := .
>>  src            := $(srctree)
>>  obj            := $(objtree)
>>
>> @@ -1057,7 +1057,7 @@ _modinst_:
>>         @ln -s $(srctree) $(MODLIB)/source
>>         @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
>>                 rm -f $(MODLIB)/build ; \
>> -               ln -s $(objtree) $(MODLIB)/build ; \
>> +               ln -s $(CURDIR) $(MODLIB)/build ; \
>>         fi
>>         @cp -f $(objtree)/modules.order $(MODLIB)/
>>         @cp -f $(objtree)/modules.builtin $(MODLIB)/
> 
> This commit breaks the of-of-tree build of UML.
> 
>   CC      arch/x86/um/user-offsets.s
> /home/rw/linux-next/arch/x86/um/user-offsets.c:21:29: fatal error:
> asm/syscalls_64.h: No such file or directory
> compilation terminated.
> make[2]: *** [arch/x86/um/user-offsets.s] Error 1
> make[1]: *** [arch/x86/um/user-offsets.s] Error 2
> make: *** [sub-make] Error 2
> 
> To reproduce run:
> make defconfig ARCH=um O=/mnt/o && make linux ARCH=um O=/mnt/
> 
> If there is anything in UML which needs fixing, please tell. :-)

I'll have a look, thanks for the report.

Michal