From: tixy@linaro.org (Jon Medhurst (Tixy))
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] ARM: mm: make text and rodata read-only
Date: Wed, 09 Apr 2014 11:29:38 +0100 [thread overview]
Message-ID: <1397039378.3537.32.camel@linaro1.home> (raw)
In-Reply-To: <20140408194815.GA6188@debian>
On Tue, 2014-04-08 at 21:48 +0200, Rabin Vincent wrote:
[...]
> For any other CPU to pull in the writable entry it would have to get a
> TLB miss inside the loop in multi_cpu_stop(), after the state transition
> to MULTI_STOP_RUN and before the state transition to MULTI_STOP_EXIT.
> This is unlikely, but theoretically possible, for example if
> multi_cpu_stop() straddles sections.
With speculative execution it is also possible for the CPU to fill the
TLB with entries for a memory address that the program would never
actually access. Basically, whatever is in the MMU registers and page
tables at any given time, the CPU can speculatively use that address
translation and read that memory. And if it's marked cacheable, pull it
into the cache. Oh, and if there is a dirty cacheline in another
CPU/clusters cache, move that dirty entry over into it's own cache (I
believe).
--
Tixy
prev parent reply other threads:[~2014-04-09 10:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-04 2:15 [RFC PATCH] ARM: mm: implement CONFIG_DEBUG_RODATA Kees Cook
2014-04-04 2:15 ` [PATCH 1/2] ARM: mm: mark non-text sections non-executable Kees Cook
2014-04-04 2:15 ` [PATCH 2/2] ARM: mm: make text and rodata read-only Kees Cook
2014-04-04 19:58 ` Rabin Vincent
2014-04-05 0:07 ` Kees Cook
2014-04-08 12:41 ` Jon Medhurst (Tixy)
2014-04-08 16:01 ` Kees Cook
2014-04-08 16:12 ` Jon Medhurst (Tixy)
2014-04-08 16:59 ` Kees Cook
2014-04-08 19:48 ` Rabin Vincent
2014-04-08 20:19 ` Kees Cook
2014-04-14 21:08 ` Rabin Vincent
2014-04-09 10:29 ` Jon Medhurst (Tixy) [this message]
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=1397039378.3537.32.camel@linaro1.home \
--to=tixy@linaro.org \
--cc=linux-arm-kernel@lists.infradead.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;
as well as URLs for NNTP newsgroup(s).