From: Kirill Korotaev <dev@sw.ru>
To: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Linus Torvalds <torvalds@osdl.org>, Ingo Molnar <mingo@elte.hu>,
"Saxena, Sunil" <sunil.saxena@intel.com>,
"Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>,
Andrey Savochkin <saw@sawoct.com>,
linux-kernel@vger.kernel.org
Subject: Re: possible CPU bug and request for Intel contacts
Date: Tue, 25 Jan 2005 17:12:12 +0300 [thread overview]
Message-ID: <41F653BC.20809@sw.ru> (raw)
In-Reply-To: <01EF044AAEE12F4BAAD955CB7506494302E61BA0@scsmsx401.amr.corp.intel.com>
Hello Rohit,
>>BTW, can you explain why making pages non-global is the cure? Is it
>> safe workaround for this bug?
> There is a boundary condition that can have non-global pages containing
> the CR3 load to also hit this issue on affected PIII. Though for this
> to happen, mov to cr3 has to be the very last instruction on a page.
> And the page following that page (containing CR3 load) has to have
> different mapping between user and kernel spaces.
but in our case "mov %edx, %cr3" is not the last instruction on a page.
It is in the middle of it.
Well, another remark is that after cr3 load there are only few
instructions before the "call system_call_table(%edx)" which references
the page with different user and kernel mappings.
also, this bug can be cured via inserting about 20 simple operations
between cr3 load and call to the page with overlapping mappings.
I'm just trying to understand is it the bug referenced in E80 or not and
is it safe to use non-global mappings as a cure.
Kirill
next prev parent reply other threads:[~2005-01-25 14:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-25 7:22 possible CPU bug and request for Intel contacts Seth, Rohit
2005-01-25 14:12 ` Kirill Korotaev [this message]
-- strict thread matches above, loose matches on Subject: below --
2005-02-14 16:55 Pallipadi, Venkatesh
2005-01-26 1:38 Seth, Rohit
2005-02-13 20:10 ` Ingo Molnar
2005-01-25 7:15 Seth, Rohit
2005-01-22 3:02 Seth, Rohit
2005-01-24 9:51 ` Kirill Korotaev
[not found] <01EF044AAEE12F4BAAD955CB7506494302DFE109@scsmsx401.amr.corp.intel.com>
2005-01-21 12:46 ` Kirill Korotaev
2005-01-22 10:03 ` Pavel Machek
2005-01-19 16:07 Kirill Korotaev
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