4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
commit a0fa72683e78979ef1123d679b1c40ae28bd9096 upstream.
A race condition fix added an rxe_qp structure to the stack in order
to be able to perform rollback in rxe_requester(), but the structure
is large enough to trigger the warning for possible stack overflow:
drivers/infiniband/sw/rxe/rxe_req.c: In function 'rxe_requester':
drivers/infiniband/sw/rxe/rxe_req.c:757:1: error: the frame size of 2064 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
This changes the rollback function to only save the psn inside
the qp, which is the only field we access in the rollback_qp
anyway.
Fixes: 3050b9985024 ("IB/rxe: Fix race condition between requester and completer")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/infiniband/sw/rxe/rxe_req.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -548,23 +548,23 @@ static void update_wqe_psn(struct rxe_qp
static void save_state(struct rxe_send_wqe *wqe,
struct rxe_qp *qp,
struct rxe_send_wqe *rollback_wqe,
- struct rxe_qp *rollback_qp)
+ u32 *rollback_psn)
{
rollback_wqe->state = wqe->state;
rollback_wqe->first_psn = wqe->first_psn;
rollback_wqe->last_psn = wqe->last_psn;
- rollback_qp->req.psn = qp->req.psn;
+ *rollback_psn = qp->req.psn;
}
static void rollback_state(struct rxe_send_wqe *wqe,
struct rxe_qp *qp,
struct rxe_send_wqe *rollback_wqe,
- struct rxe_qp *rollback_qp)
+ u32 rollback_psn)
{
wqe->state = rollback_wqe->state;
wqe->first_psn = rollback_wqe->first_psn;
wqe->last_psn = rollback_wqe->last_psn;
- qp->req.psn = rollback_qp->req.psn;
+ qp->req.psn = rollback_psn;
}
static void update_state(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
@@ -593,8 +593,8 @@ int rxe_requester(void *arg)
int mtu;
int opcode;
int ret;
- struct rxe_qp rollback_qp;
struct rxe_send_wqe rollback_wqe;
+ u32 rollback_psn;
next_wqe:
if (unlikely(!qp->valid || qp->req.state == QP_STATE_ERROR))
@@ -719,7 +719,7 @@ next_wqe:
* rxe_xmit_packet().
* Otherwise, completer might initiate an unjustified retry flow.
*/
- save_state(wqe, qp, &rollback_wqe, &rollback_qp);
+ save_state(wqe, qp, &rollback_wqe, &rollback_psn);
update_wqe_state(qp, wqe, &pkt);
update_wqe_psn(qp, wqe, &pkt, payload);
ret = rxe_xmit_packet(to_rdev(qp->ibqp.device), qp, &pkt, skb);
@@ -727,7 +727,7 @@ next_wqe:
qp->need_req_skb = 1;
kfree_skb(skb);
- rollback_state(wqe, qp, &rollback_wqe, &rollback_qp);
+ rollback_state(wqe, qp, &rollback_wqe, rollback_psn);
if (ret == -EAGAIN) {
rxe_run_task(&qp->req.task, 1);
--
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