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.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
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]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100420171637.GN20640@cmpxchg.org \
--to=hannes@cmpxchg.org \
--cc=linux-mm@kvack.org \
--cc=shankar.vk@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).