Re: [GIT PULL -tip v3] fix 39 'make headers_check' warnings

On Mon, Jan 19, 2009 at 5:23 PM, Avi Kivity <avi@xxxxxxxxxx> wrote:
Sam Ravnborg wrote:

They are. This bits advertise to userspace what features kvm supports,
both compile- and run-time.


This is wrong...
The headers does not change with the kernel configuration and advertising
the
kvm features via a .h file like this is simply plain broken.


Ok. Don't know why I thought unifdef was supplied with the full
configuration.

You cannot assume that the header files are generated with the exact same
config
as used by the running kernel.


This is just for arch specific defines. I'll move these to asm/kvm.h.

And userspace has in no way access to the CONFIG_ namespace which is
purely kernel-internal.

I cannot see how you have ever seen kcm advertise that for example
KVM_CAP_USER_NMI
equals to 22 because CONFIG_X86 is never (supposed to be) defined in
userspace -
except if you did so yourself by some means.


We did, we ship a hacked-up kvm.h (generated by unifdef) with our userspace.


latest -tip is still giving 'make headers_check' warnings:
usr/include/linux/kvm.h:61: leaks CONFIG_X86 to userspace where it is not valid
usr/include/linux/kvm.h:64: leaks CONFIG_X86 to userspace where it is not valid
usr/include/linux/kvm.h:387: leaks CONFIG_X86 to userspace where it
is not valid
usr/include/linux/kvm.h:391: leaks CONFIG_X86 to userspace where it
is not valid
usr/include/linux/kvm.h:396: leaks CONFIG_X86 to userspace where it
is not valid

So should I resend my patch or you are going to move this stuff

--
JSR
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