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

[Hugh Dickins <hughd@google.com>]

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@arndb.de>
> > ---
> >  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.

Thanks,
Hugh