From: Christopher Yeoh <cyeoh@au1.ibm.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Subject: Re: [RESEND] Cross Memory Attach v3
Date: Tue, 19 Jul 2011 00:35:09 +0930 [thread overview]
Message-ID: <20110719003509.77b5ed66@lilo> (raw)
In-Reply-To: <20110715153743.a0b3efc7.akpm@linux-foundation.org>
On Fri, 15 Jul 2011 15:37:43 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:
> On Fri, 8 Jul 2011 18:06:07 +0930
> Christopher Yeoh <cyeoh@au1.ibm.com> wrote:
>
> > +static ssize_t process_vm_rw(pid_t pid, const struct iovec *lvec,
> > + unsigned long liovcnt,
> > + const struct iovec *rvec,
> > + unsigned long riovcnt,
> > + unsigned long flags, int vm_write)
> > +{
> >
> > ...
> >
> > + if (!mm || (task->flags & PF_KTHREAD)) {
>
> Can a PF_KTHREAD thread have a non-zero ->mm?
> > + task_unlock(task);
> > + rc = -EINVAL;
> > + goto put_task_struct;
> > + }
According to get_task_mm it can:
/**
* get_task_mm - acquire a reference to the task's mm
*
* Returns %NULL if the task has no mm. Checks PF_KTHREAD (meaning
* this kernel workthread has transiently adopted a user mm with use_mm,
* to do its AIO) is not set and if so returns a reference to it, after
* bumping up the use count. User must release the mm via mmput()
* after use. Typically used by /proc and ptrace.
*/
> anyway, grumble.
>
> Please resend, cc'ing linux-kernel.
Am doing the CC resends in a separate email...
Chris
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prev parent reply other threads:[~2011-07-18 15:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-08 8:36 [RESEND] Cross Memory Attach v3 Christopher Yeoh
2011-07-15 22:37 ` Andrew Morton
2011-07-18 15:05 ` Christopher Yeoh [this message]
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