| Message ID | 20160919115826.553858-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, Sep 19, 2016 at 01:57:26PM +0200, Arnd Bergmann wrote: > 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@arndb.de> Thanks Arnd, It is much cleaner approach. Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
On 9/19/2016 9:28 AM, Leon Romanovsky wrote: > On Mon, Sep 19, 2016 at 01:57:26PM +0200, Arnd Bergmann wrote: >> 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@arndb.de> > > Thanks Arnd, > It is much cleaner approach. > Reviewed-by: Leon Romanovsky <leonro@mellanox.com> > Thanks, applied.
diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c index 13a848a518e8..cf1ffac25585 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)) @@ -717,7 +717,7 @@ int rxe_requester(void *arg) * 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); @@ -725,7 +725,7 @@ int rxe_requester(void *arg) 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);
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@arndb.de> --- drivers/infiniband/sw/rxe/rxe_req.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)