From: r.sricharan@ti•com (R Sricharan)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v4] ARM: LPAE: Fix mapping in alloc_init_pte for unaligned addresses
Date: Wed, 6 Feb 2013 19:29:20 +0530 [thread overview]
Message-ID: <511261B8.3010403@ti.com> (raw)
In-Reply-To: <20130206123307.GE26454@arm.com>
On Wednesday 06 February 2013 06:03 PM, Catalin Marinas wrote:
> On Wed, Feb 06, 2013 at 12:22:13PM +0000, Russell King - ARM Linux wrote:
>> On Wed, Feb 06, 2013 at 12:15:23PM +0000, Catalin Marinas wrote:
>>> The problem with the classic MMU is that if we have a 1MB range we can
>>> end up with just page mappings. The code is currently buggy since if we
>>> have create_mapping() for a 1MB range and later create_mapping() for a
>>> 4KB in the next MB, the first 1MB is removed.
>>
>> And that is where we rely on people calling create_mapping() - who
>> will be the SoC porters - not to be idiotic and do that kind of thing.
>> That's worked fine for the last 10+ years so there's no need to make
>> the code any more complex by trying to fix something that really isn't
>> a problem.
>>
>> I wouldn't be surprised if we have some mappings which are created by
>> 4K page tables, and then one half of the page table is overwritten by
>> a section mapping - so trying to fix this _may_ be risky.
>
> If the 4K is called first, it should be fine. But some WARN_ON() calls
> wouldn't hurt, just to be sure. It's not a fast path anyway.
>
Just to understand, wont we hit pmd_bad already in this case ?
Regards,
Sricharan
next prev parent reply other threads:[~2013-02-06 13:59 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-29 15:07 [PATCH v4] ARM: LPAE: Fix mapping in alloc_init_pte for unaligned addresses R Sricharan
2013-02-01 6:21 ` Santosh Shilimkar
2013-02-01 16:26 ` Catalin Marinas
2013-02-01 16:32 ` Christoffer Dall
2013-02-01 16:37 ` Catalin Marinas
2013-02-01 16:40 ` Christoffer Dall
2013-02-01 17:42 ` Catalin Marinas
2013-02-01 18:37 ` Christoffer Dall
2013-02-04 4:40 ` R Sricharan
2013-02-04 4:44 ` R Sricharan
2013-02-04 11:10 ` R Sricharan
2013-02-06 12:15 ` Catalin Marinas
2013-02-06 12:22 ` Russell King - ARM Linux
2013-02-06 12:33 ` Catalin Marinas
2013-02-06 13:59 ` R Sricharan [this message]
2013-02-06 13:56 ` R Sricharan
2013-02-06 15:16 ` Catalin Marinas
2013-02-06 15:25 ` R Sricharan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=511261B8.3010403@ti.com \
--to=r.sricharan@ti$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox