From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: Stop irqsoff tracing if return to user with interrupts enabled
Date: Sat, 13 Nov 2010 09:38:39 +0000 [thread overview]
Message-ID: <20101113093839.GC10125@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20101113084802.GB10125@n2100.arm.linux.org.uk>
On Sat, Nov 13, 2010 at 08:48:02AM +0000, Russell King - ARM Linux wrote:
> On Fri, Nov 12, 2010 at 07:40:48PM -0800, Todd Poynor wrote:
> > Signed-off-by: Todd Poynor <toddpoynor@google.com>
>
> NAK. Firstly, you're not explaining why. Secondly, we purposely leave
> IRQs off when returning to userspace to avoid race conditions. Thirdly,
> we purposely leave lockdep believing that IRQs are off while userspace
> is running, even though IRQs are not.
Forthly, we never run userspace with IRQs disabled - that would be a
security hole.
> I've explained why this is in the past - please search the mailing list.
See
http://lists.arm.linux.org.uk/lurker/message/20100523.141301.a94bee0c.en.html
http://lists.arm.linux.org.uk/lurker/message/20100523.194746.203225eb.en.html
prev parent reply other threads:[~2010-11-13 9:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-13 3:40 [PATCH] ARM: Stop irqsoff tracing if return to user with interrupts enabled Todd Poynor
2010-11-13 8:48 ` Russell King - ARM Linux
2010-11-13 9:35 ` Todd Poynor
2010-11-13 9:38 ` Russell King - ARM Linux [this message]
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