public inbox for linux-next@vger.kernel.org 
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation•org>
To: Konstantin Khlebnikov <khlebnikov@openvz•org>
Cc: Siddhesh Poyarekar <siddhesh.poyarekar@gmail•com>,
	linux-next@vger•kernel.org, linux-kernel@vger•kernel.org
Subject: Re: [PATCH linux-next] mm: fix rcu-lock/unlock balance in vm_is_stack()
Date: Tue, 20 Mar 2012 14:03:16 -0700	[thread overview]
Message-ID: <20120320140316.f52388bd.akpm@linux-foundation.org> (raw)
In-Reply-To: <20120320205455.31285.23096.stgit@zurg>

On Wed, 21 Mar 2012 00:54:55 +0400
Konstantin Khlebnikov <khlebnikov@openvz•org> wrote:

> Fix bug introduced in "procfs: mark thread stack correctly in proc/<pid>/maps"
> (patch in mm/linux-next)
> 
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz•org>
> ---
>  mm/memory.c |    5 ++---
>  1 files changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index ee85fc4..cc08b86 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3932,13 +3932,12 @@ pid_t vm_is_stack(struct task_struct *task,
>  		while_each_thread(task, t) {
>  			if (vm_is_stack_for_task(t, vma)) {
>  				ret = t->pid;
> -				goto done;
> +				break;
>  			}
>  		}
> +		rcu_read_unlock();
>  	}
>  
> -done:
> -	rcu_read_unlock();
>  	return ret;
>  }
>  

Appears to have been fixed in v3:

pid_t vm_is_stack(struct task_struct *task,
		  struct vm_area_struct *vma, int in_group)
{
	pid_t ret = 0;

	if (vm_is_stack_for_task(task, vma))
		return task->pid;

	if (in_group) {
		struct task_struct *t;
		rcu_read_lock();
		if (!pid_alive(task))
			goto done;

		t = task;
		do {
			if (vm_is_stack_for_task(t, vma)) {
				ret = t->pid;
				goto done;
			}
		} while_each_thread(task, t);
done:
		rcu_read_unlock();
	}

	return ret;
}

I'm working on getting a -next update sent to Stephen today.

      reply	other threads:[~2012-03-20 21:03 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-20 20:54 [PATCH linux-next] mm: fix rcu-lock/unlock balance in vm_is_stack() Konstantin Khlebnikov
2012-03-20 21:03 ` Andrew Morton [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=20120320140316.f52388bd.akpm@linux-foundation.org \
    --to=akpm@linux-foundation$(echo .)org \
    --cc=khlebnikov@openvz$(echo .)org \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linux-next@vger$(echo .)kernel.org \
    --cc=siddhesh.poyarekar@gmail$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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