[Beowulf] RHEL7 kernel update for L1TF vulnerability breaks RDMA

[John Hearns]

Linux should have coded the kernel in Python then. Easily caught there.

(Yes. I am making a joke)
On Mon, 10 Sep 2018 at 09:23, Chris Samuel <chris at csamuel.org> wrote:
>
> On Friday, 17 August 2018 2:47:37 PM AEST Chris Samuel wrote:
>
> > Just a heads up that the 3.10.0-862.11.6.el7.x86_64 kernel from RHEL/CentOS
> > that was released to address the most recent Intel CPU problem "L1TF" seems
> > to break RDMA (found by a colleague here at Swinburne).
>
> So this CentOS bug has a one line bug fix for this problem!
>
> https://bugs.centos.org/view.php?id=15193
>
> It's a corker - basically it looks like someone typo'd a ; into an if
> statement, the fix is:
>
> -       if (!rdma_is_port_valid_nospec(device, &ah_attr->port_num));
> +       if (!rdma_is_port_valid_nospec(device, &ah_attr->port_num))
>                 return -EINVAL;
>
> So it always returns -EINVAL when checking the port as the if becomes a noop..
> :-(
>
> Patch attached...
>
> --
>  Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC
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