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IB/rxe: avoid putting a large struct rxe_qp on stack

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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: 3050b99850 ("IB/rxe: Fix race condition between requester and completer")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Arnd Bergmann 2016-09-19 13:57:26 +02:00 committed by Doug Ledford
parent e37a79e5d4
commit a0fa72683e
1 changed files with 7 additions and 7 deletions
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14
drivers/infiniband/sw/rxe/rxe_req.c
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@ -548,23 +548,23 @@ static void update_wqe_psn(struct rxe_qp *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))
@ -718,7 +718,7 @@ 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);
@ -726,7 +726,7 @@ 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);