On Thu, Jun 01, 2017 at 09:48:34AM +0800, Jia-Ju Bai wrote: > The driver may sleep under a spin lock, and the function call path is: > post_one_send (acquire the lock by spin_lock_irqsave) > init_send_wqe > copy_from_user --> may sleep > > To fix it, the lock is released before copy_from_user, and the lock is > acquired again after this function. > > Signed-off-by: Jia-Ju Bai <[email protected]> > --- > drivers/infiniband/sw/rxe/rxe_verbs.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c > b/drivers/infiniband/sw/rxe/rxe_verbs.c > index 83d709e..6fb7e1a 100644 > --- a/drivers/infiniband/sw/rxe/rxe_verbs.c > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c > @@ -725,7 +725,7 @@ static int init_send_wqe(struct rxe_qp *qp, struct > ib_send_wr *ibwr, > { > int num_sge = ibwr->num_sge; > struct ib_sge *sge; > - int i; > + int i, err; > u8 *p; > > init_send_wr(qp, &wqe->wr, ibwr); > @@ -740,8 +740,11 @@ static int init_send_wqe(struct rxe_qp *qp, struct > ib_send_wr *ibwr, > > sge = ibwr->sg_list; > for (i = 0; i < num_sge; i++, sge++) { > - if (qp->is_user && copy_from_user(p, (__user void *) > - (uintptr_t)sge->addr, sge->length)) > + spin_unlock_irq(&qp->sq.sq_lock);
In original spin_lock, the flags of irq were saved, hence it should be restored here too, but it is unclear to me if spin_lock is needed here and it can't be converted to mutex_lock. > + err = copy_from_user(p, (__user void *) > + (uintptr_t)sge->addr, sge->length); > + spin_lock_irq(&qp->sq.sq_lock); > + if (qp->is_user && err) > return -EFAULT; > > else if (!qp->is_user) > -- > 1.7.9.5 > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html
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