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Subject: Re: [PATCH 2/2] arm64: Fix watchpoint recursion when single-step is
 wrongly triggered in irq
To: Pratyush Anand <panand@redhat.com>, He Kuang <hekuang@huawei.com>
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From: Li Bin <huawei.libin@huawei.com>
Message-ID: <56FD1BD1.7070101@huawei.com>
Date: Thu, 31 Mar 2016 20:45:05 +0800
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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

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