Re: [PATCH v4 RESEND 4/11] x86/asm: Fix pud/pmd interfaces to handle large PAT bit

[Boris Ostrovsky]

On 11/09/2015 02:16 PM, Toshi Kani wrote:
> On Mon, 2015-11-09 at 13:06 -0500, Boris Ostrovsky wrote:
> > On 09/17/2015 02:24 PM, Toshi Kani wrote:
> > > Now that we have pud/pmd mask interfaces, which handle pfn & flags
> > > mask properly for the large PAT bit.
> > >
> > > Fix pud/pmd pfn & flags interfaces by replacing PTE_PFN_MASK and
> > > PTE_FLAGS_MASK with the pud/pmd mask interfaces.
> > >
> > > Suggested-by: Juergen Gross <jgross@xxxxxxxx>
> > > Signed-off-by: Toshi Kani <toshi.kani@xxxxxxx>
> > > Cc: Juergen Gross <jgross@xxxxxxxx>
> > > Cc: Konrad Wilk <konrad.wilk@xxxxxxxxxx>
> > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > > Cc: H. Peter Anvin <hpa@xxxxxxxxx>
> > > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > > Cc: Borislav Petkov <bp@xxxxxxxxx>
> > > ---
> > >    arch/x86/include/asm/pgtable.h       |   14 ++++++++------
> > >    arch/x86/include/asm/pgtable_types.h |    4 ++--
> > >    2 files changed, 10 insertions(+), 8 deletions(-)
> >
> > Looks like this commit is causing this splat for 32-bit kernels. I am
> > attaching my config file, just in case.
> Thanks for the report!  I'd like to reproduce the issue since I am not sure how
> this change caused it...
>
> I tried to build a kernel with the attached config file, and got the following
> error.  Not sure what I am missing.
>
> ----
> $ make -j24 ARCH=i386
>     :
>    LD      drivers/built-in.o
>    LINK    vmlinux
> ./.config: line 44: $'\r': command not found

I wonder whether my email client added ^Ms to the file that I send. It 
shouldn't have.

> Makefile:929: recipe for target 'vmlinux' failed
> make: *** [vmlinux] Error 127
> ----
>
> Do you have steps to reproduce the issue?  Or do you see it during boot-time?

This always happens just after system has booted, it may still be going 
over init scripts. I am booting with ramdisk, don't know whether it has 
anything to do with this problem.

FWIW, it looks like pmd_pfn_mask() inline is causing this. Reverting it 
alone makes this crash go away.


-boris
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