From: Steve Wise <larrystevenwise@gmail.com>
Date: Mon, 2 Dec 2019 20:03:20 -0600
Subject: rxe: correctly calculate iCRC for unaligned payloads
Patch-mainline: v5.5-rc2
Git-commit: 2030abddec6884aaf5892f5724c48fc340e6826f
References: jsc#SLE-8449

If RoCE PDUs being sent or received contain pad bytes, then the iCRC
is miscalculated, resulting in PDUs being emitted by RXE with an incorrect
iCRC, as well as ingress PDUs being dropped due to erroneously detecting
a bad iCRC in the PDU.  The fix is to include the pad bytes, if any,
in iCRC computations.

Note: This bug has caused broken on-the-wire compatibility with actual
hardware RoCE devices since the soft-RoCE driver was first put into the
mainstream kernel.  Fixing it will create an incompatibility with the
original soft-RoCE devices, but is necessary to be compatible with real
hardware devices.

Fixes: 8700e3e7c485 ("Soft RoCE driver")
Signed-off-by: Steve Wise <larrystevenwise@gmail.com>
Link: https://lore.kernel.org/r/20191203020319.15036-2-larrystevenwise@gmail.com
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/sw/rxe/rxe_recv.c |    2 +-
 drivers/infiniband/sw/rxe/rxe_req.c  |    6 ++++++
 drivers/infiniband/sw/rxe/rxe_resp.c |    7 +++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

--- a/drivers/infiniband/sw/rxe/rxe_recv.c
+++ b/drivers/infiniband/sw/rxe/rxe_recv.c
@@ -389,7 +389,7 @@ void rxe_rcv(struct sk_buff *skb)
 
 	calc_icrc = rxe_icrc_hdr(pkt, skb);
 	calc_icrc = rxe_crc32(rxe, calc_icrc, (u8 *)payload_addr(pkt),
-			      payload_size(pkt));
+			      payload_size(pkt) + bth_pad(pkt));
 	calc_icrc = (__force u32)cpu_to_be32(~calc_icrc);
 	if (unlikely(calc_icrc != pack_icrc)) {
 		if (skb->protocol == htons(ETH_P_IPV6))
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -500,6 +500,12 @@ static int fill_packet(struct rxe_qp *qp
 			if (err)
 				return err;
 		}
+		if (bth_pad(pkt)) {
+			u8 *pad = payload_addr(pkt) + paylen;
+
+			memset(pad, 0, bth_pad(pkt));
+			crc = rxe_crc32(rxe, crc, pad, bth_pad(pkt));
+		}
 	}
 	p = payload_addr(pkt) + paylen + bth_pad(pkt);
 
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -732,6 +732,13 @@ static enum resp_states read_reply(struc
 	if (err)
 		pr_err("Failed copying memory\n");
 
+	if (bth_pad(&ack_pkt)) {
+		struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+		u8 *pad = payload_addr(&ack_pkt) + payload;
+
+		memset(pad, 0, bth_pad(&ack_pkt));
+		icrc = rxe_crc32(rxe, icrc, pad, bth_pad(&ack_pkt));
+	}
 	p = payload_addr(&ack_pkt) + payload + bth_pad(&ack_pkt);
 	*p = ~icrc;