Re: [asm-generic:master 2/6] arch/x86//mm/mpx.c:57:26: error: 'MAP_PRIVATE' undeclared; did you mean 'DQF_PRIVATE'?

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Feb 18, 2019 at 05:52:09PM +0100, Arnd Bergmann wrote:
> On Mon, Feb 18, 2019 at 5:44 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > On Tue, Feb 19, 2019 at 12:28:55AM +0800, kbuild test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git master
> > > head:   3c4fcc2648569c3fe573849f9254c8c3499ec648
> > > commit: 9ac483109d19095e22414e46d38a6817520883b9 [2/6] arch: move common mmap flags to linux/mman.h
> > > config: x86_64-kexec (attached as .config)
> > > compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
> > > reproduce:
> > >         git checkout 9ac483109d19095e22414e46d38a6817520883b9
> > >         # save the attached .config to linux build tree
> > >         make ARCH=x86_64
> > >
> > > All errors (new ones prefixed by >>):
> > >
> > >    arch/x86//mm/mpx.c: In function 'mpx_mmap':
> > > >> arch/x86//mm/mpx.c:57:26: error: 'MAP_PRIVATE' undeclared (first use in this function); did you mean 'DQF_PRIVATE'?
> > >              MAP_ANONYMOUS | MAP_PRIVATE, VM_MPX, 0, &populate, NULL);
> > >                              ^~~~~~~~~~~
> > >                              DQF_PRIVATE
> > >    arch/x86//mm/mpx.c:57:26: note: each undeclared identifier is reported only once for each function it appears in
> >
> > Arnd I think you are missing:
> >     x86/mpx: tweak header name
> >
> > The whole file is going away eventually:
> > https://lkml.kernel.org/r/7de5232f-4bc1-5c85-00d5-cb646462577f@intel.com
> >
> > but to avoid breaking bisect I think it's needed.
> 
> Right, I misunderstood the earlier mails and assumed it wasn't really
> needed even for building the current tree. Added it in now as well. I see that
> there are various other files including asm/mman.h:

I did my best to check the rest, yes. I don't think any of them are broken.

> arch/arm/mm/hugetlbpage.c:#include <asm/mman.h>
> arch/arm64/mm/hugetlbpage.c:#include <asm/mman.h>
> arch/c6x/include/asm/cacheflush.h:#include <asm/mman.h>
> arch/ia64/include/asm/pgtable.h:#include <asm/mman.h>
> arch/ia64/mm/hugetlbpage.c:#include <asm/mman.h>
> arch/mips/kernel/linux32.c:#include <asm/mman.h>
> arch/mips/mm/hugetlbpage.c:#include <asm/mman.h>
> arch/parisc/mm/hugetlbpage.c:#include <asm/mman.h>
> arch/powerpc/include/asm/mman.h:#include <uapi/asm/mman.h>
> arch/powerpc/mm/hugetlbpage-radix.c:#include <asm/mman.h>
> arch/powerpc/mm/pkeys.c:#include <asm/mman.h>
> arch/powerpc/mm/slice.c:#include <asm/mman.h>
> arch/sh/mm/hugetlbpage.c:#include <asm/mman.h>
> arch/sparc/include/asm/mman.h:#include <uapi/asm/mman.h>
> arch/sparc/mm/hugetlbpage.c:#include <asm/mman.h>
> arch/um/kernel/syscall.c:#include <asm/mman.h>
> arch/x86/ia32/sys_ia32.c:#include <asm/mman.h>
> arch/x86/mm/hugetlbpage.c:#include <asm/mman.h>
> arch/x86/um/shared/sysdep/kernel-offsets.h:#include <asm/mman.h>
> fs/eventpoll.c:#include <asm/mman.h>
> include/uapi/linux/mman.h:#include <asm/mman.h>
> mm/filemap.c:#include <asm/mman.h>
> tools/include/uapi/linux/mman.h:#include <asm/mman.h>
> virt/kvm/arm/arm.c:#include <asm/mman.h>
> 
> Did you check if we need to do the same change on any of the
> other files? A lot of them are architecture specific and might not be
> caught by the regular build testing.
> 
>       Arnd


First let's check for direct issues:

$ git grep -e MAP_SHARED -e MAP_PRIVATE `git grep -l asm/mman.h`
arch/ia64/include/asm/pgtable.h: * version gets used for a shared memory segment with MAP_SHARED on.
include/uapi/linux/mman.h:#define MAP_SHARED    0x01            /* Share changes */
include/uapi/linux/mman.h:#define MAP_PRIVATE   0x02            /* Changes are private */
include/uapi/linux/mman.h:#define MAP_SHARED_VALIDATE 0x03      /* share + validate extension flags */

Now it's possible that there's an indirect include. Let's find headers -
but note that any asm/mman.h header itself is not a problem.

$git grep -l asm/mman.h|fgrep -e .h|grep -v mman.h
arch/c6x/include/asm/cacheflush.h
arch/ia64/include/asm/pgtable.h
arch/x86/um/shared/sysdep/kernel-offsets.h


Analysis (only looking at arch specific files):
$ git grep -e MAP_SHARED -e MAP_PRIVATE `git grep -l asm/cacheflush.h arch/c6x/`
$ git grep -e MAP_SHARED -e MAP_PRIVATE `git grep -l asm/pgtable.h arch/ia64/`
$ git grep MAP_ `git grep -l kernel-offsets.h`

Having said that, once these patches are in I think the
next step would be to:
- patch CodingStyle to document the rule (already enforced by checkpatch.pl) that everyone
  should include linux/foo.h in preference to asm/foo.h
- write a script to find and fix violations - they are probably not limited
  to mman.h

-- 
MST