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From: Ingo Molnar <mingo@kernel.org>
To: Wang Nan <wangnan0@huawei.com>
Cc: acme@kernel.org, jolsa@kernel.org, namhyung@kernel.org,
	mingo@redhat.com, lizefan@huawei.com, pi3orama@163.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf: unwind: fix segbase for libunwind.
Date: Wed, 1 Apr 2015 16:48:39 +0200	[thread overview]
Message-ID: <20150401144839.GA17340@gmail.com> (raw)
In-Reply-To: <1427897332-145581-1-git-send-email-wangnan0@huawei.com>


* Wang Nan <wangnan0@huawei.com> wrote:

> Perf passes incorrect segbase and table_data to libunwind when 
> map->pgoff != 0, causes unwind failure. This patch fixes this 
> problem.
> 
> segbase is an absolute offset from the head of object file, directly 
> read from ELF file. Original code computes corresponding virtual 
> address using map->start + segbase, doesn't consider map->pgoff. 
> Which causes libunwind read from incorrect offset.

What's the effect of this bug in practice?

Is there any before/after output you can show that demonstrates the 
fix?

Thanks,

	Ingo

  reply	other threads:[~2015-04-01 14:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-01 14:08 [PATCH] perf: unwind: fix segbase for libunwind Wang Nan
2015-04-01 14:48 ` Ingo Molnar [this message]
2015-04-02  5:07   ` Wang Nan
2015-04-02  5:19     ` Wang Nan
2015-04-02  8:11       ` Namhyung Kim

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