Re: [PATCH 17/34] selftests: net: Fix incorrect kernel headers search path

[Mathieu Desnoyers]

On 2023-01-27 11:21, Matthieu Baerts wrote:
> Hi Mathieu,
>
> On 27/01/2023 14:57, Mathieu Desnoyers wrote:
> > Use $(KHDR_INCLUDES) as lookup path for kernel headers. This prevents
> > building against kernel headers from the build environment in scenarios
> > where kernel headers are installed into a specific output directory
> > (O=...).
>
> Thank you for the patch!

You're welcome :)

> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> > Cc: Shuah Khan <shuah@xxxxxxxxxx>
> > Cc: linux-kselftest@xxxxxxxxxxxxxxx
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: <stable@xxxxxxxxxxxxxxx>    [5.18+]
>
> (It might be useful to add a "Fixes" tag as well to clearly indicate the
> dependence with a specific commit and better understand the fix.)

Just a bit of context: I found this problematic pattern in my own 
selftests (rseq and membarrier), and figured that it was an issue all 
across the board. I did an initial single-patch fix, and then split it 
up in 34 patches based on feedback from Shuah Khan.

I know it should have a Fixed ... tag, but I simply don't have time to 
do the historical investigation work for all the 34 patches form this 
patchset. Perhaps someone else is up to the task ?

> (and add all the individual maintainers of the files you modify -- feel
> free to use 'b4' to help you for this task ;-) )

If this can be automated, then perhaps Shuah can use it to append the 
relevant information ?

> (...)
>
> > diff --git a/tools/testing/selftests/net/mptcp/Makefile b/tools/testing/selftests/net/mptcp/Makefile
> > index 43a723626126..06bba013bcef 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 $(KHDR_INCLUDES)
>
> I only looked at the modification here with MPTCP selftests and it looks
> good to me. It makes sense because if KHDR_INCLUDES is not set, it will
> be set later by lib.mk I suppose.
>
> Just one small thing: I guess you can also remove "top_srcdir" variable
> that is no longer used, right? I see that "lib.mk" uses a variable with
> the same name but it overrides its value anyway. But it is likely I
> missed something there :)
>
> If indeed it is no longer needed, I guess a few Makefile can be adapted
> according to:
>
>    git grep top_srcdir -- tools/testing/selftests/*/

Yes, this should perhaps come as additional fixes on top of my series. I 
don't have time to do it myself though.

Anyone willing to contribute it ?

> I guess most of these Makefile are very similar, no? For MPTCP, we
> simply looked at what was done elsewhere :)

Yes, I did likewise.

Thanks for the feedback,

Mathieu

> Cheers,
> Matt

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com