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@xxxxxxx>
---
V5:
* Remove useless check of "qp->is_user".
Thank Leon for pointing it out.
V4:
* Remove the line of copy_from_user.
Thank Moni for good advice.
V3:
* It corrects the mistakes of remaining legacy code in V2.
Thank Ram for pointing it out.
V2:
* The parameter "flags" is added to restore and save the irq status.
Thank Leon for good advice.
---
drivers/infiniband/sw/rxe/rxe_verbs.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 83d709e..073e667 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -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;
}
--
1.7.9.5
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