From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Andrew Morton <akpm@osdl.org>
Cc: bstroesser@fujitsu-siemens.com, roland@redhat.com,
jdike@addtoit.com, blaisorblade_spam@yahoo.it,
user-mode-linux-devel@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: Re: Race condition in ptrace
Date: Sat, 05 Feb 2005 10:15:27 +1100 [thread overview]
Message-ID: <4204020F.2000501@yahoo.com.au> (raw)
In-Reply-To: <20050204143917.1f9507cb.akpm@osdl.org>
Andrew Morton wrote:
> Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
>>Bodo Stroesser wrote:
>>
>>>Nick Piggin wrote:
>>>
>>>
>>>>Bodo Stroesser wrote:
>>
>>>>I don't see how this could help because AFAIKS, child->saving is only
>>>>set and cleared while the runqueue is locked. And the same runqueue lock
>>>>is taken by wait_task_inactive.
>>>>
>>>
>>>Sorry, that not right. There are some routines called by sched(), that
>>>release
>>>and reacquire the runqueue lock.
>>>
>>
>>Oh yeah, it is the wake_sleeping_dependent / dependent_sleeper crap.
>>Sorry, you are right. And that's definitely a bug in sched.c, because
>>it breaks wait_task_inactive, as you've rightly observed.
>>
>>Andrew, IMO this is another bug to hold 2.6.11 for.
>
>
> Sure. I wouldn't consider Bodo's patch to be the one to use though..
No. Something similar could be done that works on all architectures
and all wait_task_inactive callers (and is confined to sched.c). That
would still be more or less a hack to work around smtnice's unfortunate
locking though.
next prev parent reply other threads:[~2005-02-04 23:16 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-02-03 12:51 Race condition in ptrace Bodo Stroesser
2005-02-04 0:27 ` Nick Piggin
2005-02-04 12:35 ` Bodo Stroesser
2005-02-04 22:15 ` Nick Piggin
2005-02-04 22:39 ` Andrew Morton
2005-02-04 23:15 ` Nick Piggin [this message]
2005-02-05 4:35 ` Nick Piggin
2005-02-06 3:26 ` [PATCH] fix wait_task_inactive race (was Re: Race condition in ptrace) Nick Piggin
2005-02-06 7:19 ` Ingo Molnar
2005-02-06 7:36 ` Nick Piggin
2005-02-06 7:47 ` Nick Piggin
2005-02-14 16:07 ` Bodo Stroesser
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=4204020F.2000501@yahoo.com.au \
--to=nickpiggin@yahoo.com.au \
--cc=akpm@osdl.org \
--cc=blaisorblade_spam@yahoo.it \
--cc=bstroesser@fujitsu-siemens.com \
--cc=jdike@addtoit.com \
--cc=linux-kernel@vger.kernel.org \
--cc=roland@redhat.com \
--cc=user-mode-linux-devel@lists.sourceforge.net \
/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).