Re: [PATCH v2 0/4] vDSO fixes, on top of tip/x86/vdso

From: Andy Lutomirski
Date: Fri Feb 28 2014 - 15:16:07 EST


On Thu, Feb 27, 2014 at 11:33 PM, Stefani Seibold <stefani@xxxxxxxxxxx> wrote:
> Am Donnerstag, den 27.02.2014, 16:18 -0800 schrieb Andy Lutomirski:
>> I'd still like someone else to confirm that the 32-bit vDSO is working
>> on all common configurations before I'm happy with it, but this should
>> be a considerable improvement.
>>
>> Someone who maintains the clock code should review the changes in:
>>
>> commit 0fc8a237cbe98a06962f5ea37d24fc2369e23c74
>> Author: Stefani Seibold <stefani@xxxxxxxxxxx>
>> Date: Wed Feb 19 10:09:10 2014 +0100
>>
>> x86, vdso: Add 32-bit VDSO time support for the 64-bit kernel
>>
>> very carefully.
>>
>> There's still something extremely questionable about VDSO_PAGES in the
>> 32-bit vDSO code. It appears to be terminally screwed up, and AFAICS it
>> only works at all because none of the 32-bit vDSO images ever exceed
>> 4096 bytes.
>>
>
> The 4096 bytes limit was not introduced by the patch set. It is still
> there for compatibility reason.

Compatibility with what? And it doesn't look like there's a sane 4k
"limit". It looks like the code with confuse itself and crash if the
image exceeds 4k.

But yes, this issue predates your code.

--Andy
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