On 2018/8/20 15:09, Yuval Shaia wrote:
On Sun, Aug 19, 2018 at 03:04:01PM +0800, Yanjun Zhu wrote:
In the commit 536ca245c512 ("IB/rxe: Drop QP0 silently"), if qpn is
zero, the function directly returns. So in the following function,
it is not necessary to check qpn. The qpn check in the function
check_keys is removed.
But check_keys can be called from other places besides hdr_check, e.x
rxe_rcv_mcast_pkt.
check_keys is called by rxe_rcv_mcast_pkt and hdr_check now.
rxe_rcv_mcast_pkt is a static function in rxe_recv.c.
Its call trace is as below.
void rxe_rcv(struct sk_buff *skb)
{
...
err = hdr_check(pkt);
if (unlikely(err))
goto drop;
...
if (unlikely(bth_qpn(pkt) == IB_MULTICAST_QPN))
rxe_rcv_mcast_pkt(rxe, skb);
else
rxe_rcv_pkt(rxe, pkt, skb);
...
drop:
if (pkt->qp)
rxe_drop_ref(pkt->qp);
If qpn is zero, hdr_check will return error. Then the function rxe_rcv
will goto label drop.
The function rxe_rcv_mcast_pkt will not be called.
So even though check_keys is called by rxe_rcv_mcast_pkt and hdr_check,
when qpn is zero,
hdr_check will not call check_keys and rxe_rcv_mcast_pkt will not be
called.
So this patch is safe.
Zhu Yanjun
Fixes: 536ca245c512 ("IB/rxe: Drop QP0 silently")
CC: Srinivas Eeda <srinivas.eeda@xxxxxxxxxx>
CC: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Signed-off-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxxx>
---
drivers/infiniband/sw/rxe/rxe_recv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c
index d30dbac24583..8dfbe2c2ca74 100644
--- a/drivers/infiniband/sw/rxe/rxe_recv.c
+++ b/drivers/infiniband/sw/rxe/rxe_recv.c
@@ -122,7 +122,7 @@ static int check_keys(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
set_bad_pkey_cntr(port);
goto err1;
}
- } else if (qpn != 0) {
+ } else {
if (unlikely(!pkey_match(pkey,
port->pkey_tbl[qp->attr.pkey_index]
))) {
@@ -134,7 +134,7 @@ static int check_keys(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
}
if ((qp_type(qp) == IB_QPT_UD || qp_type(qp) == IB_QPT_GSI) &&
- qpn != 0 && pkt->mask) {
+ pkt->mask) {
u32 qkey = (qpn == 1) ? GSI_QKEY : qp->attr.qkey;
if (unlikely(deth_qkey(pkt) != qkey)) {
--
2.17.1
