From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: TAO HU <tghk48@motorola.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-omap <linux-omap@vger.kernel.org>,
Zhou Ming-a17711 <a17711@motorola.com>
Subject: Re: Bug in _und_usr on dual-core ARM?
Date: Tue, 21 Jun 2011 10:58:18 +0100 [thread overview]
Message-ID: <20110621095818.GA23802@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <BANLkTinUYZm+Q3WBGLTQRXz1V2ca1AwE=g@mail.gmail.com>
On Tue, Jun 21, 2011 at 05:37:31PM +0800, TAO HU wrote:
> Hi, Russell
>
> Wouldn't it lead to oops with your patch?
The might_sleep() occurs because its trying to process the page fault.
We shouldn't be trying to do that with IRQs disabled - instead, we
should try to fix up the fault from kernel space by invoking the fixup
for the ldrt instructions in __und_usr.
This may throw the system into a loop against your process (which you
should still be able to kill) which will suggest that there's dirty
I-cache lines - we seem to be executing code in a non-present page
(at 0xafd0ce5c).
WARNING: multiple messages have this Message-ID (diff)
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: Bug in _und_usr on dual-core ARM?
Date: Tue, 21 Jun 2011 10:58:18 +0100 [thread overview]
Message-ID: <20110621095818.GA23802@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <BANLkTinUYZm+Q3WBGLTQRXz1V2ca1AwE=g@mail.gmail.com>
On Tue, Jun 21, 2011 at 05:37:31PM +0800, TAO HU wrote:
> Hi, Russell
>
> Wouldn't it lead to oops with your patch?
The might_sleep() occurs because its trying to process the page fault.
We shouldn't be trying to do that with IRQs disabled - instead, we
should try to fix up the fault from kernel space by invoking the fixup
for the ldrt instructions in __und_usr.
This may throw the system into a loop against your process (which you
should still be able to kill) which will suggest that there's dirty
I-cache lines - we seem to be executing code in a non-present page
(at 0xafd0ce5c).
next prev parent reply other threads:[~2011-06-21 9:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-21 8:31 Bug in _und_usr on dual-core ARM? TAO HU
2011-06-21 8:31 ` TAO HU
2011-06-21 9:15 ` Russell King - ARM Linux
2011-06-21 9:15 ` Russell King - ARM Linux
2011-06-21 9:37 ` TAO HU
2011-06-21 9:37 ` TAO HU
2011-06-21 9:58 ` Russell King - ARM Linux [this message]
2011-06-21 9:58 ` Russell King - ARM Linux
2012-04-20 12:37 ` Rabin Vincent
2012-04-20 12:37 ` Rabin Vincent
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