Re: [PATCH] IB/rdmavt: add lock to call to rvt_error_qp to prevent a race condition

[Jason Gunthorpe]

On Mon, Feb 28, 2022 at 05:53:30PM +0100, Niels Dossche wrote:
> The documentation of the function rvt_error_qp says both r_lock and
> s_lock need to be held when calling that function.
> It also asserts using lockdep that both of those locks are held.
> However, the commit I referenced in Fixes accidentally makes the call
> to rvt_error_qp in rvt_ruc_loopback no longer covered by r_lock.
> This results in the lockdep assertion failing and also possibly in a
> race condition.
> 
> Fixes: d757c60eca9b ("IB/rdmavt: Fix concurrency panics in QP post_send and modify to error")
> Signed-off-by: Niels Dossche <dossche.niels@xxxxxxxxx>
> ---
>  drivers/infiniband/sw/rdmavt/qp.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)

Dennis?

And this too:

https://patchwork.kernel.org/project/linux-rdma/patch/20220228195144.71946-1-dossche.niels@xxxxxxxxx/

Thanks,
Jason