Re: [PATCH] RDMA/cxgb4: don't declare wr_wait objects on the stack.

Steve Wise
2011-05-16T15:56:45Z

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. :)