From: "H. Peter Anvin" <hpa@zytor.com>
To: Yinghai Lu <yinghai@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Ingo Molnar <mingo@elte.hu>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC] x86: add brk allocation for very, very early allocations
Date: Fri, 27 Feb 2009 13:05:59 -0800 [thread overview]
Message-ID: <49A855B7.4090204@zytor.com> (raw)
In-Reply-To: <49A84C5A.3020304@kernel.org>
Yinghai Lu wrote:
>
> it seems reserve _brk_end is some late?
>
> init_memory_mapping(0,...) could get some for direct mapping page table. and it could start from _end...
>
That would make sense. init_memory_mapping() needs to know what not to
step on, and that would include the brk at this stage. For 64-bit mode,
Xen is the only user of !PSE, and so may be particularly vulnerable to
this issue (because of massively larger direct mapping tables.)
This reminds me... is your intent that the BRK is permanent (unless
explicitly freed on a page by page basis) or part of the init memory
that is flushed?
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2009-02-27 21:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-27 17:58 [PATCH RFC] x86: add brk allocation for very, very early allocations Jeremy Fitzhardinge
2009-02-27 18:43 ` H. Peter Anvin
2009-02-27 19:17 ` H. Peter Anvin
2009-02-27 19:26 ` Jeremy Fitzhardinge
2009-02-27 20:26 ` Yinghai Lu
2009-02-27 21:02 ` Jeremy Fitzhardinge
2009-02-27 21:05 ` H. Peter Anvin [this message]
2009-02-27 21:19 ` Jeremy Fitzhardinge
2009-02-27 21:28 ` H. Peter Anvin
2009-02-27 21:41 ` Jeremy Fitzhardinge
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=49A855B7.4090204@zytor.com \
--to=hpa@zytor.com \
--cc=jeremy@goop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=x86@kernel.org \
--cc=yinghai@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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