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From: wangnan0@huawei•com (Wangnan (F))
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2] arm64: Store breakpoint single step state into pstate
Date: Tue, 5 Jan 2016 13:06:15 +0800	[thread overview]
Message-ID: <568B4F47.5080307@huawei.com> (raw)
In-Reply-To: <20160104165535.GI1616@arm.com>

Hi Will,

On 2016/1/5 0:55, Will Deacon wrote:
> Hello,
>
> On Thu, Dec 24, 2015 at 01:42:42AM +0000, Wang Nan wrote:

[SNIP]

> The problem seems to be that we take the debug exception before the
> breakpointed instruction has been executed and call perf_bp_event at
> that moment, so when we single-step the faulting instruction we actually
> step into the SIGIO handler and end up getting stuck.
>
> Your fix doesn't really address this afaict, in that you don't (can't?)
> handle:
>
>    * A longjmp out of a signal handler
>    * A watchpoint and a breakpoint that fire on the same instruction
>    * User-controlled single-step from a signal handler that enables a
>      breakpoint explicitly
>    * Nested signals

Please have a look at [1], which I improve test__bp_signal() to
check bullet 2 and 4 you mentioned above. Seems my fix is correct.

[1] 
http://lkml.kernel.org/g/1451969880-14877-1-git-send-email-wangnan0 at huawei.com

Thank you.

  parent reply	other threads:[~2016-01-05  5:06 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-23  8:52 [RESEND PATCH] arm64: Store breakpoint single step state into pstate Wang Nan
2015-12-23 10:44 ` kbuild test robot
2015-12-24  1:42 ` [PATCH v2] " Wang Nan
2016-01-04 16:55   ` Will Deacon
2016-01-05  1:41     ` Wangnan (F)
2016-01-05  4:58     ` [RFC PATCH] arm64: perf test: Improbe bp_signal Wang Nan
2016-01-05  5:09       ` Wangnan (F)
2016-01-05  8:53       ` Jiri Olsa
2016-01-05  9:00       ` Jiri Olsa
2016-01-05  9:05       ` Jiri Olsa
2016-01-05  9:09       ` Jiri Olsa
2016-01-05  5:06     ` Wangnan (F) [this message]
2016-01-12 17:06       ` [PATCH v2] arm64: Store breakpoint single step state into pstate Will Deacon
2016-01-15  8:20         ` xiakaixu
2016-01-21  8:06           ` xiakaixu
2016-01-18 11:39         ` Wangnan (F)
2016-01-05  9:57     ` [RFC PATCH v2] perf test: Improve bp_signal Wang Nan
2016-01-05 10:07       ` Jiri Olsa

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