Re: Possible regression in next-20150323 due to "ARM, arm64: kvm: get rid of the bounce page"

[Simon Horman <horms@verge.net.au>]

On Fri, Mar 27, 2015 at 10:06:12AM +0000, Will Deacon wrote:
> On Fri, Mar 27, 2015 at 12:25:54AM +0000, Simon Horman wrote:
> > On Thu, Mar 26, 2015 at 08:29:21AM -0700, Tyler Baker wrote:
> > > On 26 March 2015 at 06:36, Will Deacon <will.deacon@arm.com> wrote:
> > > > On Thu, Mar 26, 2015 at 12:39:39AM +0000, Simon Horman wrote:
> > > >> On Tue, Mar 24, 2015 at 11:13:58AM -0500, Nishanth Menon wrote:
> > > >> > I think we now have a new error: (seen with omap2plus_defconfig)
> > > >> > on next-20150324 :
> > > >> > ./arch/arm/kernel/vmlinux.lds:677: undefined symbol `__hyp_idmap_size'
> > > >> > referenced in expression
> > > >> > make: *** [vmlinux] Error 1
> > > >>
> > > >> Thanks, I am seeing that too.
> > > >>
> > > >> My armchair suggestion is that the following should be reverted.
> > > >>
> > > >> e60a1fec44a2f ("ARM: kvm: implement replacement for ld's LOG2CEIL()")
> > > >> 06f75a1f62000 ("ARM, arm64: kvm: get rid of the bounce page")
> > > >
> > > > Can you try again with the latest -next please? We've merged an additional
> > > > patch aimed at sorting this out. Reverting isn't really an option, as
> > > > there's an awful lot of code that depends on the bounce page removal.
> > > 
> > > Here are the kernelci.org -next results[1], if you click the build
> > > status you can dig down into the build failures. next-20150326 has now
> > > hit a compiler bug, Arnd mentioned he was looking into this issue.
> > 
> > I have confirmed that next-20150326 does not compile without
> > the following reverted:
> > 
> > 12eb3e833961 ("ARM: kvm: assert on HYP section boundaries not actual code size")
> > e60a1fec44a2 ("ARM: kvm: implement replacement for ld's LOG2CEIL()")
> > 06f75a1f6200 ("ARM, arm64: kvm: get rid of the bounce page")
> 
> Thanks for testing this and sorry for the continued breakage. Which
> toolchain did you say you were using? Ard has some more patches trying to
> fix this, but none of our toolchains seem to tickle the issue.

It seems that a fix has emerged (thanks! local testing looks good so far)
but for the record I am using the arm (32) tool chain for x86_84
on kernel.org.

https://www.kernel.org/pub/tools/crosstool/files/bin/x86_64/4.6.3/

# arm-unknown-linux-gnueabi-gcc --version
arm-unknown-linux-gnueabi-gcc (GCC) 4.6.3
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

# arm-unknown-linux-gnueabi-ld --version
GNU ld (GNU Binutils) 2.22
Copyright 2011 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.