linux-kernel - Re: [PATCH 2/2] arm64: Fix watchpoint recursion when single-step is wrongly triggered in irq

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Message-ID: <56FD1BD1.7070101@huawei.com>
Date:	Thu, 31 Mar 2016 20:45:05 +0800
From:	Li Bin <huawei.libin@...wei.com>
To:	Pratyush Anand <panand@...hat.com>, He Kuang <hekuang@...wei.com>
CC:	<mark.rutland@....com>, <yang.shi@...aro.org>,
	<wangnan0@...wei.com>, <marc.zyngier@....com>,
	<catalin.marinas@....com>, <will.deacon@....com>,
	<linux-kernel@...r.kernel.org>, <richard@....at>,
	<james.morse@....com>, <hanjun.guo@...aro.org>,
	<gregkh@...uxfoundation.org>, <Dave.Martin@....com>,
	<linux-arm-kernel@...ts.infradead.org>,
	Hanjun Guo <guohanjun@...wei.com>,
	Ding Tianhong <dingtianhong@...wei.com>
Subject: Re: [PATCH 2/2] arm64: Fix watchpoint recursion when single-step is
 wrongly triggered in irq

Hi Pratyush,

on 2016/3/21 18:24, Pratyush Anand wrote:
> On 21/03/2016:08:37:50 AM, He Kuang wrote:
>> On arm64, watchpoint handler enables single-step to bypass the next
>> instruction for not recursive enter. If an irq is triggered right
>> after the watchpoint, a single-step will be wrongly triggered in irq
>> handler, which causes the watchpoint address not stepped over and
>> system hang.
> 
> Does patch [1] resolves this issue as well? I hope it should. Patch[1] has still
> not been sent for review. Your test result will be helpful.
> 
> ~Pratyush
> 
> [1] https://github.com/pratyushanand/linux/commit/7623c8099ac22eaa00e7e0f52430f7a4bd154652

This patch did not consider that, when excetpion return, the singlestep flag
should be restored, otherwise the right singlestep will not triggered.
Right?

Thanks,
Li Bin

> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
> .
> 

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