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.
WARNING: multiple messages have this Message-ID (diff)
From: "Wangnan (F)" <wangnan0@huawei.com>
To: Will Deacon <will.deacon@arm.com>
Cc: <takahiro.akashi@linaro.org>, <guohanjun@huawei.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <pi3orama@163.com>,
Fengguang Wu <fengguang.wu@intel.com>,
Jiri Olsa <jolsa@kernel.org>
Subject: Re: [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@huawei.com
Thank you.
next prev parent reply other threads:[~2016-01-05 5:06 UTC|newest]
Thread overview: 36+ 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 8:52 ` Wang Nan
2015-12-23 10:44 ` kbuild test robot
2015-12-23 10:44 ` kbuild test robot
2015-12-24 1:42 ` [PATCH v2] " Wang Nan
2015-12-24 1:42 ` Wang Nan
2016-01-04 16:55 ` Will Deacon
2016-01-04 16:55 ` Will Deacon
2016-01-05 1:41 ` Wangnan (F)
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 4:58 ` Wang Nan
2016-01-05 5:09 ` Wangnan (F)
2016-01-05 5:09 ` Wangnan (F)
2016-01-05 8:53 ` Jiri Olsa
2016-01-05 8:53 ` Jiri Olsa
2016-01-05 9:00 ` Jiri Olsa
2016-01-05 9:00 ` Jiri Olsa
2016-01-05 9:05 ` Jiri Olsa
2016-01-05 9:05 ` Jiri Olsa
2016-01-05 9:09 ` Jiri Olsa
2016-01-05 9:09 ` Jiri Olsa
2016-01-05 5:06 ` Wangnan (F) [this message]
2016-01-05 5:06 ` [PATCH v2] arm64: Store breakpoint single step state into pstate Wangnan (F)
2016-01-12 17:06 ` Will Deacon
2016-01-12 17:06 ` Will Deacon
2016-01-15 8:20 ` xiakaixu
2016-01-15 8:20 ` xiakaixu
2016-01-21 8:06 ` xiakaixu
2016-01-21 8:06 ` xiakaixu
2016-01-18 11:39 ` Wangnan (F)
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 9:57 ` Wang Nan
2016-01-05 10:07 ` Jiri Olsa
2016-01-05 10:07 ` Jiri Olsa
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