From: Jakub Jelinek <jakub@redhat.com>
To: Jamie Lokier <jamie@shareable.org>
Cc: "Keith M. Wesolowski" <wesolows@foobazco.org>,
sparclinux@vger.kernel.org, "David S. Miller" <davem@redhat.com>,
ultralinux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: A question about PROT_NONE on Sparc and Sparc64
Date: Wed, 30 Jun 2004 08:28:05 +0000 [thread overview]
Message-ID: <20040630082804.GS21264@devserv.devel.redhat.com> (raw)
In-Reply-To: <20040630030503.GA25149@mail.shareable.org>
On Wed, Jun 30, 2004 at 04:05:03AM +0100, Jamie Lokier wrote:
> I'm doing a survey of the different architectural implementations of
> PROT_* flags for mmap() and mprotect(). I'm looking at linux-2.6.5.
>
> The Sparc and Sparc64 implementations are very similar to plain x86:
> read implies exec, exec implies read and write implies read.
>
> (Aside: A comment in include/asm-sparc/pgtsrmmu.h says that finer-grained
> access is possible. Quite a few other architectures do implement
> finer-grained access, and even x86 is getting it now, so you may want
> to revisit that. The code is already available, and tested, if you
> cut that part out of the PaX security patch).
I believe R!X and X!R pages ought to be possible on sparc64 too, just use a
different bit as "read" in the fast ITLB miss handler from the one fast DTLB
miss uses.
Jakub
WARNING: multiple messages have this Message-ID (diff)
From: Jakub Jelinek <jakub@redhat.com>
To: Jamie Lokier <jamie@shareable.org>
Cc: "Keith M. Wesolowski" <wesolows@foobazco.org>,
sparclinux@vger.kernel.org, "David S. Miller" <davem@redhat.com>,
ultralinux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: A question about PROT_NONE on Sparc and Sparc64
Date: Wed, 30 Jun 2004 04:28:05 -0400 [thread overview]
Message-ID: <20040630082804.GS21264@devserv.devel.redhat.com> (raw)
In-Reply-To: <20040630030503.GA25149@mail.shareable.org>
On Wed, Jun 30, 2004 at 04:05:03AM +0100, Jamie Lokier wrote:
> I'm doing a survey of the different architectural implementations of
> PROT_* flags for mmap() and mprotect(). I'm looking at linux-2.6.5.
>
> The Sparc and Sparc64 implementations are very similar to plain x86:
> read implies exec, exec implies read and write implies read.
>
> (Aside: A comment in include/asm-sparc/pgtsrmmu.h says that finer-grained
> access is possible. Quite a few other architectures do implement
> finer-grained access, and even x86 is getting it now, so you may want
> to revisit that. The code is already available, and tested, if you
> cut that part out of the PaX security patch).
I believe R!X and X!R pages ought to be possible on sparc64 too, just use a
different bit as "read" in the fast ITLB miss handler from the one fast DTLB
miss uses.
Jakub
next prev parent reply other threads:[~2004-06-30 8:28 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-06-30 3:05 A question about PROT_NONE on Sparc and Sparc64 Jamie Lokier
2004-06-30 3:05 ` Jamie Lokier
2004-06-30 5:17 ` David S. Miller
2004-06-30 5:17 ` David S. Miller
2004-06-30 5:17 ` David S. Miller
2004-06-30 15:21 ` wesolows
2004-06-30 15:21 ` wesolows
2004-06-30 8:28 ` Jakub Jelinek [this message]
2004-06-30 8:28 ` Jakub Jelinek
2004-06-30 20:54 ` David S. Miller
2004-06-30 20:54 ` David S. Miller
2004-06-30 22:52 ` Jamie Lokier
2004-06-30 22:52 ` Jamie Lokier
2004-07-01 5:25 ` David S. Miller
2004-07-01 5:25 ` David S. Miller
2004-07-01 7:47 ` David S. Miller
2004-07-01 7:47 ` David S. Miller
2004-07-02 1:03 ` A question about PROT_NONE on Sun4c 32-bit Sparc Jamie Lokier
2004-07-02 1:03 ` Jamie Lokier
2004-07-02 4:11 ` Keith M. Wesolowski
2004-07-02 4:11 ` Keith M. Wesolowski
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=20040630082804.GS21264@devserv.devel.redhat.com \
--to=jakub@redhat.com \
--cc=davem@redhat.com \
--cc=jamie@shareable.org \
--cc=linux-kernel@vger.kernel.org \
--cc=sparclinux@vger.kernel.org \
--cc=ultralinux@vger.kernel.org \
--cc=wesolows@foobazco.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.