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From: Bart Van Assche <Bart.VanAssche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
To: "noaos-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org"
	<noaos-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>,
	"hch-jcswGhMUV9g@public.gmane.org"
	<hch-jcswGhMUV9g@public.gmane.org>,
	"sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org"
	<sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Cc: "majd-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org"
	<majd-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>,
	"linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: Poll CQ syncing problem
Date: Thu, 2 Mar 2017 06:06:32 +0000	[thread overview]
Message-ID: <1488434773.3505.12.camel@sandisk.com> (raw)
In-Reply-To: <4d8ac8fd-8ef1-6f6b-177c-2c3ab131f99c-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

On Thu, 2017-03-02 at 07:59 +0200, Noa Osherovich wrote:
> On 3/1/2017 6:52 PM, Bart Van Assche wrote:
> 
> > On Wed, 2017-03-01 at 16:30 +0200, Noa Osherovich wrote:
> > > REGS: c0000001ce7077e0 TRAP: 0300   Not tainted  (2.6.32-642.el6.ppc64)
> > 
> > Hello Noa,
> > 
> > I agree with Christoph and Sagi that your analysis doesn't match the upstream
> > code. I think the above information means that you are using RHEL 6.8?
> 
> Yes, as well as other older kernel, as I wrote to Christoph. We'll adapt the code.

It might be good to know that I ran into a similar issue earlier today with kernel
v4.10 by using the IB/CM and by destroying the QP before the CM ID. In other words,
the behavior you observed is not necessarily a bug in the polling code but may also
be a use-after-free of the memory that was allocated for the QP WR and/or WC buffers.
With the new polling API such errors are much more serious than before because the
new polling API jumps to an address retrieved from a WC entry.

Bart.

      parent reply	other threads:[~2017-03-02  6:06 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <b4355d22-fc79-c860-de8a-5a4d468c884d@mellanox.com>
     [not found] ` <b4355d22-fc79-c860-de8a-5a4d468c884d-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2017-03-01 14:30   ` Poll CQ syncing problem Noa Osherovich
     [not found]     ` <3ba1baab-e2ac-358d-3b3b-ff4a27405c93-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2017-03-01 14:51       ` Christoph Hellwig
2017-03-01 15:28         ` Noa Osherovich
2017-03-01 16:44       ` Sagi Grimberg
     [not found]         ` <0786659a-da12-e8f7-329e-3caa8cc8791f-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-03-01 16:46           ` Sagi Grimberg
2017-03-02  6:04           ` Noa Osherovich
2017-03-01 16:52       ` Bart Van Assche
     [not found]         ` <1488387143.2699.6.camel-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
2017-03-02  5:59           ` Noa Osherovich
     [not found]             ` <4d8ac8fd-8ef1-6f6b-177c-2c3ab131f99c-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2017-03-02  6:06               ` Bart Van Assche [this message]

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