From: Johannes Weiner <hannes@cmpxchg.org>
To: Uma shankar <shankar.vk@gmail.com>
Cc: linux-mm@kvack.org
Subject: Re: accessing stack of non-current task
Date: Tue, 20 Apr 2010 19:16:37 +0200 [thread overview]
Message-ID: <20100420171637.GN20640@cmpxchg.org> (raw)
In-Reply-To: <s2i448a67a1004200700n4242a936tbaf4df2b4c710ab2@mail.gmail.com>
On Tue, Apr 20, 2010 at 07:30:15PM +0530, Uma shankar wrote:
> On Tue, Apr 20, 2010 at 7:13 PM, Johannes Weiner <hannes@cmpxchg.org> wrote:
> > On Tue, Apr 20, 2010 at 06:08:14PM +0530, Uma shankar wrote:
> >> Hi,
> >>
> >> Is it possible for the kernel to access the user-stack data of a
> >> task different from "current" ? ( This is needed for stack-dump as
> >> well as backtrace. )
> >
> > Yes, have a look at __get_user_pages() in mm/memory.c.
> >
>
> Yes, I understand this.
>
> But have a look at "void show_stack(struct task_struct *tsk,
> unsigned long *sp) " in traps.c ( arch specific ).
>
> Is there a implicit assumption that "tsk" and "current" are threads
> sharing same "mm_strct" ?
No, this is dumping the _kernel stack_ of a process, not the user stack.
The mm_struct does not matter.
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prev parent reply other threads:[~2010-04-20 17:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-20 12:38 accessing stack of non-current task Uma shankar
2010-04-20 13:43 ` Johannes Weiner
2010-04-20 14:00 ` Uma shankar
2010-04-20 17:16 ` Johannes Weiner [this message]
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