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

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

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@suse.com>
>>> Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
>>> Cc: Juergen Gross <jgross@suse.com>
>>> Cc: Konrad Wilk <konrad.wilk@oracle.com>
>>> Cc: Thomas Gleixner <tglx@linutronix.de>
>>> Cc: H. Peter Anvin <hpa@zytor.com>
>>> Cc: Ingo Molnar <mingo@redhat.com>
>>> Cc: Borislav Petkov <bp@alien8.de>
>>> ---
>>>    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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