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From: Steve Wise <swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
To: Roland Dreier <roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] RDMA/cxgb4: don't declare wr_wait objects on the stack.
Date: Mon, 16 May 2011 10:56:45 -0500	[thread overview]
Message-ID: <4DD1493D.3060401@opengridcomputing.com> (raw)
In-Reply-To: <BANLkTimGzzo1xDTvApAVxvv4C8WcYuCdUA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

On 05/16/2011 10:53 AM, Roland Dreier wrote:
> On Mon, May 16, 2011 at 8:18 AM, Steve Wise<swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>  wrote:
>> Roland, I need to recall this patch.  It appears to have some problem.
> Good thing I didn't apply it yet.
>
> I did think it should be possible to declare wait objects on the stack... the
> origin of completions was to handle exactly that issue; the older semaphore
> structure was vulnerable to the wakeup after free, but completions handle
> that.  But I didn't look at the cxgb4 code at all...

I'm pretty sure the race exists as described in my commit comment.  And I don't see how the wait object code could avoid 
this issue.  Unless I'm just all wrong. :)


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  parent reply	other threads:[~2011-05-16 15:56 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-13 18:37 [PATCH] RDMA/cxgb4: don't declare wr_wait objects on the stack Steve Wise
     [not found] ` <20110513183727.32157.8873.stgit-T4OLL4TyM9aNDNWfRnPdfg@public.gmane.org>
2011-05-16 15:18   ` Steve Wise
     [not found]     ` <4DD14036.9050704-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2011-05-16 15:53       ` Roland Dreier
     [not found]         ` <BANLkTimGzzo1xDTvApAVxvv4C8WcYuCdUA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-05-16 15:56           ` Steve Wise [this message]
     [not found]             ` <4DD1493D.3060401-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2011-05-16 16:05               ` Steve Wise
     [not found]                 ` <4DD14B2D.9090104-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2011-05-16 16:47                   ` Steve Wise

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