asm/kvm_para.h from asm-generic (was: Re: linux-next: triage forApril 19, 2012)

[Geert Uytterhoeven]

On Wed, May 30, 2012 at 10:52 AM, Geert Uytterhoeven
<geert@xxxxxxxxxxxxxx> wrote:
> On Mon, May 28, 2012 at 5:04 PM, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> wrote:
>> On Mon, May 28, 2012 at 4:37 PM, Avi Kivity <avi@xxxxxxxxxx> wrote:
>>> On 05/25/2012 11:59 PM, Geert Uytterhoeven wrote:
>>>> On Fri, Apr 20, 2012 at 4:00 AM, Paul Gortmaker
>>>> <paul.gortmaker@xxxxxxxxxxxxx> wrote:
>>>>> The parisc got borked by some kvm header shuffle it seems?
>>>>> Now complaining about "file 'asm-generic/kvm_para.h' is not exported"
>>>>> [ http://kisskb.ellerman.id.au/kisskb/buildresult/6137786/ ]
>>>>
>>>> Not only parisc.
>>>>
>>>> This breakage has now entered mainline:
>>>>
>>>> parisc deconfig http://kisskb.ellerman.id.au/kisskb/buildresult/6365677/
>>>> m68k allmodconfig: http://kisskb.ellerman.id.au/kisskb/buildresult/6365681/
>>>
>>>
>>> Does the following patch help?
>>
>> Thanks, that fixes it!
>>
>> Tested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
>>
>>> From: Avi Kivity <avi@xxxxxxxxxx>
>>> Date: Mon, 28 May 2012 17:35:22 +0300
>>> Subject: [PATCH] KVM: Export asm-generic/kvm_para.h
>>>
>>> Prevents build failures on non-KVM archs.
>>>
>>> Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
>>> ---
>>> Âinclude/asm-generic/Kbuild | Â Â1 +
>>> Â1 file changed, 1 insertion(+)
>>>
>>> diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild
>>> index 53f91b1..2c85a0f 100644
>>> --- a/include/asm-generic/Kbuild
>>> +++ b/include/asm-generic/Kbuild
>>> @@ -8,6 +8,7 @@ header-y += int-ll64.h
>>> Âheader-y += ioctl.h
>>> Âheader-y += ioctls.h
>>> Âheader-y += ipcbuf.h
>>> +header-y += kvm_para.h
>>> Âheader-y += mman-common.h
>>> Âheader-y += mman.h
>>> Âheader-y += msgbuf.h
>
> I just noticed include/asm-generic/Kbuild.asm already had
>
> ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/kvm_para.h \
> Â Â Â Â Â Â Â Â Â$(srctree)/include/asm-$(SRCARCH)/kvm_para.h),)
> header-y Â+= kvm_para.h
> endif
>
> but this doesn't seem to work.
>
> Kbuild people: which one is correct?

Oops...

After linux-next commit 2bbc89a8e9c652ee71c6c3b2e0679b7ecedb1a09
("m68k: Use Kbuild logic to import asm-generic headers"), which does:
  - remove arch/m68k/include/asm/kvm_para.h, which just included the
    asm-generic version,
  - add "generic-y += kvm_para.h" to arch/m68k/include/asm/Kbuild,
it fails again:

$ make ARCH=m68k headers_check
  CHK     include/linux/version.h
  INSTALL include/asm-generic (35 files)
  INSTALL include/linux (372 files)
  CHECK   include/asm-generic (35 files)
  CHECK   include/linux (372 files)
usr/include/linux/kexec.h:49: userspace cannot reference function or
variable defined in the kernel
usr/include/linux/kvm_para.h:26: included file 'asm-m68k/kvm_para.h'
is not exported
usr/include/linux/soundcard.h:1054: userspace cannot reference
function or variable defined in the kernel
make[2]: *** [usr/include/linux/.check] Error 123
make[1]: *** [linux] Error 2
make: *** [headers_check] Error 2
$

After reverting Avi's fix (commit
7beb8e723c8d7da7decbbe217b79525aef73fccb. ("KVM:
Export asm-generic/kvm_para.h")) it works again. Note that it now _removes_
kvm_para.h:

$ make ARCH=m68k headers_check
  CHK     include/linux/version.h
  REMOVE  kvm_para.h
  INSTALL include/asm-generic (34 files)
  REMOVE  kvm_para.h
  INSTALL include/linux (371 files)
  CHECK   include/asm-generic (34 files)
  CHECK   include/linux (371 files)
usr/include/linux/kexec.h:49: userspace cannot reference function or
variable defined in the kernel
usr/include/linux/soundcard.h:1054: userspace cannot reference
function or variable defined in the kernel
$

What's the proper way to get this working in both cases??
  1. arch has it's own asm/kvm_para.h (cfr. m68k and all other arches
in mainline)
  2. arch includes asm-generic/kvm_para.h via Kbuild logic (cfr.
(only) m68k in -next)
Or is this not possible, and should I create arch/m68k/include/asm/kvm_para.h
again, like all other arches seem to do?

Gr{oetje,eeting}s,

            Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
             Â Â -- Linus Torvalds
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