From: Dave Hansen <dave@linux.vnet.ibm.com>
To: Christoph Lameter <cl@linux.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC][PATCH] fix move/migrate_pages() race on task struct
Date: Fri, 24 Feb 2012 13:37:42 -0800 [thread overview]
Message-ID: <4F480326.8070706@linux.vnet.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1202241131400.3726@router.home>
On 02/24/2012 09:32 AM, Christoph Lameter wrote:
> @@ -1318,10 +1318,10 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pi
> rcu_read_lock();
> task = pid ? find_task_by_vpid(pid) : current;
> if (!task) {
> - rcu_read_unlock();
> err = -ESRCH;
> goto out;
> }
...
> + put_task_struct(task);
> + task = NULL;
> err = do_migrate_pages(mm, old, new,
> capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
> out:
> + if (task)
> + put_task_struct(task);
> +
> if (mm)
> mmput(mm);
> NODEMASK_SCRATCH_FREE(scratch);
Man, patch did not like this for some reason. I kept throwing most of
the mempolicy.c hunks away. I've never seen anything like it.
Anyway... This looks fine except I think that rcu_read_unlock() need to
stay. There's currently no release of it after out:.
--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2012-02-24 21:37 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-23 18:07 [RFC][PATCH] fix move/migrate_pages() race on task struct Dave Hansen
2012-02-23 18:45 ` Andi Kleen
2012-02-23 18:45 ` Christoph Lameter
2012-02-23 19:10 ` Dave Hansen
2012-02-23 19:40 ` Christoph Lameter
2012-02-23 20:04 ` Dave Hansen
2012-02-23 21:41 ` Christoph Lameter
2012-02-24 3:14 ` Eric W. Biederman
2012-02-24 15:20 ` Christoph Lameter
2012-02-24 15:41 ` Eric W. Biederman
2012-02-24 16:48 ` Dave Hansen
2012-02-24 16:54 ` Christoph Lameter
2012-02-24 17:04 ` Dave Hansen
2012-02-24 17:08 ` Christoph Lameter
2012-02-24 17:25 ` Dave Hansen
2012-02-24 17:32 ` Christoph Lameter
2012-02-24 21:37 ` Dave Hansen [this message]
2012-02-24 23:12 ` Eric W. Biederman
2012-02-27 16:43 ` Christoph Lameter
2012-02-25 12:13 ` Eric W. Biederman
2012-02-27 19:01 ` Christoph Lameter
2012-02-27 20:15 ` Eric W. Biederman
2012-02-27 22:39 ` Christoph Lameter
2012-02-28 19:30 ` Christoph Lameter
2012-02-29 20:31 ` Andrew Morton
2012-02-29 20:33 ` Christoph Lameter
2012-02-29 20:36 ` Dave Hansen
2012-02-24 17:07 ` KOSAKI Motohiro
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=4F480326.8070706@linux.vnet.ibm.com \
--to=dave@linux.vnet.ibm.com \
--cc=cl@linux.com \
--cc=ebiederm@xmission.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/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).