From: Joe.Buck@synopsys.COM (Joe Buck)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: Convert BUG() to use unreachable()
Date: Thu, 17 Dec 2009 11:14:01 -0800 [thread overview]
Message-ID: <20091217191401.GD10707@synopsys.com> (raw)
In-Reply-To: <20091217190613.GB4440@n2100.arm.linux.org.uk>
On Thu, Dec 17, 2009 at 11:06:13AM -0800, Russell King - ARM Linux wrote:
> On Thu, Dec 17, 2009 at 10:35:17AM -0800, Joe Buck wrote:
> > Besides, didn't I see a whole bunch of kernel security patches related
> > to null pointer dereferences lately? If page 0 can be mapped, you
> > suddenly won't get your trap.
>
> Page 0 can not be mapped on ARM kernels since the late 1990s, and this
> protection is independent of the generic kernel.
>
> Milage may vary on other architectures, but that's not a concern here.
I don't understand, though, why you would want to implement a generally
useful facility (make the kernel trap so you can do a post-mortem
analysis) in a way that's only safe for the ARM port.
WARNING: multiple messages have this Message-ID (diff)
From: Joe Buck <Joe.Buck@synopsys.COM>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: "Richard Guenther" <richard.guenther@gmail.com>,
"David Daney" <ddaney@caviumnetworks.com>,
"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>,
"Jamie Lokier" <jamie@shareable.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Subject: Re: [PATCH] ARM: Convert BUG() to use unreachable()
Date: Thu, 17 Dec 2009 11:14:01 -0800 [thread overview]
Message-ID: <20091217191401.GD10707@synopsys.com> (raw)
In-Reply-To: <20091217190613.GB4440@n2100.arm.linux.org.uk>
On Thu, Dec 17, 2009 at 11:06:13AM -0800, Russell King - ARM Linux wrote:
> On Thu, Dec 17, 2009 at 10:35:17AM -0800, Joe Buck wrote:
> > Besides, didn't I see a whole bunch of kernel security patches related
> > to null pointer dereferences lately? If page 0 can be mapped, you
> > suddenly won't get your trap.
>
> Page 0 can not be mapped on ARM kernels since the late 1990s, and this
> protection is independent of the generic kernel.
>
> Milage may vary on other architectures, but that's not a concern here.
I don't understand, though, why you would want to implement a generally
useful facility (make the kernel trap so you can do a post-mortem
analysis) in a way that's only safe for the ARM port.
next prev parent reply other threads:[~2009-12-17 19:14 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-08 9:55 [PATCH] ARM: Convert BUG() to use unreachable() Uwe Kleine-König
2009-12-08 9:55 ` Uwe Kleine-König
2009-12-08 17:07 ` David Daney
2009-12-10 17:50 ` Russell King - ARM Linux
2009-12-10 17:50 ` Russell King - ARM Linux
2009-12-10 17:55 ` David Daney
2009-12-16 13:58 ` Uwe Kleine-König
2009-12-16 13:58 ` Uwe Kleine-König
2009-12-17 15:01 ` Jamie Lokier
2009-12-17 15:01 ` Jamie Lokier
2009-12-17 17:09 ` David Daney
2009-12-17 17:17 ` Richard Guenther
2009-12-17 17:17 ` Richard Guenther
2009-12-17 18:17 ` Russell King - ARM Linux
2009-12-17 18:17 ` Russell King - ARM Linux
2009-12-17 18:35 ` Joe Buck
2009-12-17 18:35 ` Joe Buck
2009-12-17 19:06 ` Russell King - ARM Linux
2009-12-17 19:06 ` Russell King - ARM Linux
2009-12-17 19:14 ` Joe Buck [this message]
2009-12-17 19:14 ` Joe Buck
2009-12-17 19:33 ` David Daney
2009-12-17 19:33 ` Russell King - ARM Linux
2009-12-17 19:33 ` Russell King - ARM Linux
2009-12-17 19:38 ` Jamie Lokier
2009-12-17 19:38 ` Jamie Lokier
2009-12-17 19:48 ` Russell King - ARM Linux
2009-12-17 19:48 ` Russell King - ARM Linux
2009-12-17 19:58 ` Russell King - ARM Linux
2009-12-17 19:58 ` Russell King - ARM Linux
2009-12-17 19:04 ` Jamie Lokier
2009-12-17 19:04 ` Jamie Lokier
2009-12-21 19:30 ` Richard Henderson
2009-12-21 19:30 ` Richard Henderson
2009-12-21 20:10 ` Russell King - ARM Linux
2009-12-21 20:10 ` Russell King - ARM Linux
2009-12-22 14:09 ` Dave Korn
2009-12-22 14:09 ` Dave Korn
2009-12-22 14:12 ` Russell King - ARM Linux
2009-12-22 14:12 ` Russell King - ARM Linux
2009-12-22 14:49 ` Dave Korn
2009-12-22 14:49 ` Dave Korn
2009-12-22 11:33 ` Paolo Bonzini
2009-12-22 11:33 ` Paolo Bonzini
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=20091217191401.GD10707@synopsys.com \
--to=joe.buck@synopsys.com \
--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 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.