Re: [PATCH 1/2] [stable-4.9] x86: fix build without CONFIG_X86_VSYSCALL_EMULATION

[Greg Kroah-Hartman]

On Thu, Feb 15, 2018 at 11:18:21AM -0800, Hugh Dickins wrote:
> On Thu, 15 Feb 2018, Greg Kroah-Hartman wrote:
> > On Thu, Feb 15, 2018 at 04:16:56PM +0100, Arnd Bergmann wrote:
> > > I ran into a 4.9 build regression in randconfig testing, starting with the
> > > KAISER patches:
> > > 
> > > arch/x86/mm/kaiser.c: In function 'kaiser_init':
> > > arch/x86/mm/kaiser.c:347:8: error: 'vsyscall_pgprot' undeclared (first use in this function); did you mean 'massage_pgprot'?
> > > 
> > > This is easy enough to fix, we just need to make the declaration visible
> > > outside of the #ifdef. This works because the code using it is optimized
> > > away when vsyscall_enabled() returns false at compile time.
> > > 
> > > Fixes: 9a0be5afbfbb ("vsyscall: Fix permissions for emulate mode with KAISER/PTI")
> > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > > ---
> > >  arch/x86/include/asm/vsyscall.h | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > Thanks for these, I'll queue them up in the next round after these
> > kernels get released in a few days.
> 
> Thanks to Arnd, but please drop this vsyscall one Greg: it duplicates
> my/Tobias's "kaiser: fix compile error without vsyscall" that you just
> sent out for 4.4 and 4.9 review.
> 
> Arnd's PAE one looks good for 4.4 and 4.9 (well, in another context I'd
> object to using a different prototype in the stub, but I'm pretty sure
> Arnd feels the same way, but has made the appropriate choice for our
> Kaiser backports context): so please do take his 2/2 "x86: fix build
> warnign with 32-bit PAE" for both 4.4 and 4.9.

I've now taken the 2/2 patch here, thanks for the review.  Arnd, thanks
for the patch.

greg k-h