| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 50/53] ntb_transport: fix qp count bug | Date | Mon, 28 Aug 2017 10:05:55 +0200 |
| |
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Logan Gunthorpe <logang@deltatee.com>
commit cb827ee6ccc3e480f0d9c0e8e53eef55be5b0414 upstream.
In cases where there are more mw's than spads/2-2, the mw count gets reduced to match the limitation. ntb_transport also tries to ensure that there are fewer qps than mws but uses the full mw count instead of the reduced one. When this happens, the math in 'ntb_transport_setup_qp_mw' will get confused and result in a kernel paging request bug.
This patch fixes the bug by reducing qp_count to the reduced mw count instead of the full mw count.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers") Acked-by: Allen Hubbe <Allen.Hubbe@dell.com> Signed-off-by: Jon Mason <jdmason@kudzu.us> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/ntb/ntb_transport.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -1065,8 +1065,8 @@ static int ntb_transport_probe(struct nt qp_count = ilog2(qp_bitmap); if (max_num_clients && max_num_clients < qp_count) qp_count = max_num_clients; - else if (mw_count < qp_count) - qp_count = mw_count; + else if (nt->mw_count < qp_count) + qp_count = nt->mw_count; qp_bitmap &= BIT_ULL(qp_count) - 1;
|