Re: [PATCH v2] Fix INT1 Exception with unregistered breakpoints

From: Jeff Merkey
Date: Mon Dec 14 2015 - 23:52:32 EST


On 12/14/15, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> On December 14, 2015 4:49:51 PM PST, Jeff Merkey <linux.mdb@xxxxxxxxx>
> wrote:
>>On 12/14/15, Jeff Merkey <linux.mdb@xxxxxxxxx> wrote:
>>> Please consider the attached patch.
>>>
>>> SUMMARY
>>>
>>> This patch corrects a hard lockup failure of the system kernel if the
>>> operating system receives a breakpoint exception at a code execution
>>> address which was not registered with the operating system. The
>>patch
>>> allows kernel debuggers, application profiling and performance
>>modules,
>>> and external debugging tools to work better together at sharing the
>>> breakpoint registers on the platform in a way that they do not cause
>>> errors and system faults, and enables the full feature set in the
>>> breakpoint API. If a kernel application triggers a breakpoint
>>> or programs one in error, this patch will catch the condition and
>>report
>>> it to the system log without the operating system experiencing a
>>system
>>> fault. There are several consumers of the Linux Breakpoint API and
>>all
>>> of them can and sometimes do cause the condition this patch corrects.
>>>
>>
>>Peter,
>>
>>Is that the type of summary that meets the standards. I tried to be
>>concise.
>>
>>Jeff
>
> It would be good if you could be a bit more precise. In particular, explain
> how and why the condition can appear rather than just explain that it can.
> --
> Sent from my Android device with K-9 Mail. Please excuse brevity and
> formatting.
>

Yes sir. I'll be more concise and re-submit

Jeff
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