Re: [PATCH V2] selftests: Fix build when $(O) points to a relative path

[Muhammad Usama Anjum <usama.anjum@collabora.com>]

On 2/26/22 2:13 AM, Shuah Khan wrote:
> On 2/25/22 11:01 AM, Shuah Khan wrote:
>> On 2/25/22 10:22 AM, Muhammad Usama Anjum wrote:
>>> Any thoughts about it?
>>>
>>
>> No to post please.
>>
>>> On 2/17/22 3:38 AM, Muhammad Usama Anjum wrote:
>>>> Build of bpf and tc-testing selftests fails when the relative path of
>>>> the build directory is specified.
>>>>
>>>> make -C tools/testing/selftests O=build0
>>>> make[1]: Entering directory
>>>> '/linux_mainline/tools/testing/selftests/bpf'
>>>> ../../../scripts/Makefile.include:4: *** O=build0 does not exist. 
>>>> Stop.
>>>> make[1]: Entering directory
>>>> '/linux_mainline/tools/testing/selftests/tc-testing'
>>>> ../../../scripts/Makefile.include:4: *** O=build0 does not exist. 
>>>> Stop.
>>>>
>>>> Makefiles of bpf and tc-testing include scripts/Makefile.include file.
>>>> This file has sanity checking inside it which checks the output path.
>>>> The output path is not relative to the bpf or tc-testing. The sanity
>>>> check fails. Expand the output path to get rid of this error. The
>>>> fix is
>>>> the same as mentioned in commit 150a27328b68 ("bpf, preload: Fix build
>>>> when $(O) points to a relative path").
>>>>
>>>> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
>>>> ---
>>>> Changes in V2:
>>>> Add more explaination to the commit message.
>>>> Support make install as well.
>>
> 
> Does the same happen when you use make kselftest-all?
No, this problem doesn't appear when using make kselftest-all.

As separate output directory build was broken in kernel's top most
Makefile i.e., make kselftest-all O=dir. (I've sent separate patch to
fix this:
https://lore.kernel.org/lkml/20220223191016.1658728-1-usama.anjum@collabora.com/)
So people must have been using kselftest's internal Makefile directly to
keep object files in separate directory i.e., make -C
tools/testing/selftests O=dir and in this way the build of these tests
(bpf, tc-testing) fail. This patch is fixing those build errors.

> 
> I am unable to reproduce what you are seeing?
make -C tools/testing/selftests O=dir should reproduce this problem.

> 
> thanks,
> -- Shuah
>