Subject: Re: linux-next: Tree for Mar 31 (build failures and culprits)

From: Michael Ellerman <[email-masked]>
Date: Wed, 01 Apr 2015 14:01:31 +1100

On Tue, 2015-03-31 at 19:18 -0700, Guenter Roeck wrote:
> On 03/31/2015 04:24 PM, Michael Ellerman wrote:
> > On Wed, 2015-04-01 at 01:07 +0200, Greg Kroah-Hartman wrote:
> >> On Tue, Mar 31, 2015 at 09:16:40AM -0700, Guenter Roeck wrote:
> >>> alpha:allmodconfig
> >>> mips:allmodconfig
> >>>
> >>> samples/kdbus/kdbus-workers.c: In function ‘prime_new’:
> >>> samples/kdbus/kdbus-workers.c:930:18: error: ‘__NR_memfd_create’ undeclared
> >>> (first use in this function)
> >>>    p->fd = syscall(__NR_memfd_create, "prime-area", MFD_CLOEXEC);
> >>>
> >>> Looks like the kdbus example never worked for the affected architectures.
> >>> I don't build allmodconfig for all architectures, so other architectures
> >>> may be affected as well.
> >>
> >> You need 3.17 kernel headers to have memfd_create, not much the kdbus
> >> test code can do about that.  You might want to update the kernel
> >> headers for these build boxes.
> >
> > Or just 'make headers_install' before building the samples should do it.
> >
> 
> Sure, that works so well in a cross build environment.

Well yeah it does, I do it all the time.

But what you mean is that the samples are built with HOSTCC, so having the
cross headers doesn't help.

The real problem here is samples, they shouldn't be built with the kernel, they
should be a separate thing, like the selftests.

cheers