ACK: [SRU][Trusty][PATCH 1/1] x86/mm: Fix slow_virt_to_phys() for X86_PAE again

[Tim Gardner]

On 03/10/2016 05:36 AM, Tim Gardner wrote:
> On 03/09/2016 10:50 AM, Joseph Salisbury wrote:
>> From: Dexuan Cui <decui at microsoft.com>
>>
>> BugLink: http://bugs.launchpad.net/bugs/1549601
>>
>> "d1cd12108346: x86, pageattr: Prevent overflow in slow_virt_to_phys() for
>> X86_PAE" was unintentionally removed by the recent "34437e67a672: x86/mm: Fix
>> slow_virt_to_phys() to handle large PAT bit".
>>
>> And, the variable 'phys_addr' was defined as "unsigned long" by mistake -- it should
>> be "phys_addr_t".
>>
>> As a result, Hyper-V network driver in 32-PAE Linux guest can't work again.
>>
>> Fixes: commit 34437e67a672: "x86/mm: Fix slow_virt_to_phys() to handle large PAT bit"
>> Signed-off-by: Dexuan Cui <decui at microsoft.com>
>> Reviewed-by: Toshi Kani <toshi.kani at hpe.com>
>> Cc: olaf at aepfle.de
>> Cc: gregkh at linuxfoundation.org
>> Cc: jasowang at redhat.com
>> Cc: driverdev-devel at linuxdriverproject.org
>> Cc: linux-mm at kvack.org
>> Cc: apw at canonical.com
>> Cc: Andrew Morton <akpm at linux-foundation.org>
>> Cc: K. Y. Srinivasan <kys at microsoft.com>
>> Cc: Haiyang Zhang <haiyangz at microsoft.com>
>> Link: http://lkml.kernel.org/r/1456394292-9030-1-git-send-email-decui@microsoft.com
>> Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
>> (backported from commit bf70e5513dfea29c3682e7eb3dbb45f0723bac09)
>> Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
>> ---
>>  arch/x86/include/asm/page_types.h |  9 ++++++---
>>  arch/x86/mm/pageattr.c            | 26 +++++++++++++++++++++-----
>>  2 files changed, 27 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
>> index f97fbe3..53193b7 100644
>> --- a/arch/x86/include/asm/page_types.h
>> +++ b/arch/x86/include/asm/page_types.h
>> @@ -9,6 +9,12 @@
>>  #define PAGE_SIZE	(_AC(1,UL) << PAGE_SHIFT)
>>  #define PAGE_MASK	(~(PAGE_SIZE-1))
>>  
>> +#define PMD_PAGE_SIZE		(_AC(1, UL) << PMD_SHIFT)
>> +#define PMD_PAGE_MASK		(~(PMD_PAGE_SIZE-1))
>> +
>> +#define PUD_PAGE_SIZE           (_AC(1, UL) << PUD_SHIFT)
>> +#define PUD_PAGE_MASK           (~(PUD_PAGE_SIZE-1))
>> +
>>  #define __PHYSICAL_MASK		((phys_addr_t)((1ULL << __PHYSICAL_MASK_SHIFT) - 1))
>>  #define __VIRTUAL_MASK		((1UL << __VIRTUAL_MASK_SHIFT) - 1)
>>  
>> @@ -17,9 +23,6 @@
>>     (ie, 32-bit PAE). */
>>  #define PHYSICAL_PAGE_MASK	(((signed long)PAGE_MASK) & __PHYSICAL_MASK)
>>  
>> -#define PMD_PAGE_SIZE		(_AC(1, UL) << PMD_SHIFT)
>> -#define PMD_PAGE_MASK		(~(PMD_PAGE_SIZE-1))
>> -
>>  #define HPAGE_SHIFT		PMD_SHIFT
>>  #define HPAGE_SIZE		(_AC(1,UL) << HPAGE_SHIFT)
>>  #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
> 
> Why the changes to these macros ? They are not part of the upstream
> commit, which is an otherwise clean cherry-pick except for some minor
> whitespace differences.
> 
> rtg
> 

Never mind, I see why you've done this. You probably should have
mentioned the partial backports from prerequisite commits and why this
is much simpler.

rtg
-- 
Tim Gardner tim.gardner at canonical.com