rxe: Fix a sleep-in-atomic bug in post_one_send

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

There is no flow that makes "qp->is_user" true, and copy_from_user may
cause bug when a non-user pointer is used. So the lines of copy_from_user
and check of "qp->is_user" are removed.

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Jia-Ju Bai 2017-06-05 20:23:40 +08:00 committed by Doug Ledford
parent e57bb6be5e
commit 07d432bb97
1 changed files with 2 additions and 7 deletions

View File

@ -740,13 +740,8 @@ 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))
return -EFAULT;
else if (!qp->is_user)
memcpy(p, (void *)(uintptr_t)sge->addr,
sge->length);
memcpy(p, (void *)(uintptr_t)sge->addr,
sge->length);
p += sge->length;
}