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

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

Hi Nishanth,

On Tue, Mar 24, 2015 at 11:13:58AM -0500, Nishanth Menon wrote:
> On 09:31-20150324, Ard Biesheuvel wrote:
> > On 24 March 2015 at 01:45, Simon Horman <horms@verge.net.au> wrote:
> > > Hi Ard,
> > >
> > > I have observe what appears to be a build regression in next-20150323
> > > caused by 06f75a1f62000 ("ARM, arm64: kvm: get rid of the bounce page").
> > >
> > > # make
> > > ...
> > > arm-unknown-linux-gnueabi-ld:./arch/arm/kernel/vmlinux.lds:546: syntax error
> > >
> > > I have observed this using the cross-compiler that is available 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.
> > >
> > 
> > Hi all,
> > 
> > This is fixed now in next-20150324.
> > Sorry for the trouble
> 
> 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")

> cross compiler (from ubuntu 12.04):
> $ arm-linux-gnueabi-ld --version
> GNU ld (GNU Binutils for Ubuntu) 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.
> $ arm-linux-gnueabi-gcc --version
> arm-linux-gnueabi-gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 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.
> 
> next-20150320 was the last kernel which was successfully built

I have also confirmed that.