From a0fa72683e78979ef1123d679b1c40ae28bd9096 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 19 Sep 2016 13:57:26 +0200 Subject: [PATCH] IB/rxe: avoid putting a large struct rxe_qp on stack 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 Reviewed-by: Leon Romanovsky Signed-off-by: Doug Ledford --- drivers/infiniband/sw/rxe/rxe_req.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c index 832846b73ea0..205222909e53 100644 --- 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 *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); -- 2.30.2