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. The parameter "flags" is used to
restore and save the irq status.
Thank Leon for good advice.
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxx>
---
drivers/infiniband/sw/rxe/rxe_verbs.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 83d709e..7dcdf67 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -721,11 +721,11 @@ static void init_send_wr(struct rxe_qp *qp, struct rxe_send_wr *wr,
static int init_send_wqe(struct rxe_qp *qp, struct ib_send_wr *ibwr,
unsigned int mask, unsigned int length,
- struct rxe_send_wqe *wqe)
+ struct rxe_send_wqe *wqe, unsigned long *flags)
{
int num_sge = ibwr->num_sge;
struct ib_sge *sge;
- int i;
+ int i, err;
u8 *p;
init_send_wr(qp, &wqe->wr, ibwr);
@@ -742,7 +742,12 @@ static int init_send_wqe(struct rxe_qp *qp, struct ib_send_wr *ibwr,
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;
+ spin_unlock_irqrestore(&qp->sq.sq_lock, *flags);
+ err = copy_from_user(p, (__user void *)
+ (uintptr_t)sge->addr, sge->length);
+ spin_lock_irqsave(&qp->sq.sq_lock, *flags);
+ if (qp->is_user && err)
+ return -EFAULT;
else if (!qp->is_user)
memcpy(p, (void *)(uintptr_t)sge->addr,
@@ -794,7 +799,7 @@ static int post_one_send(struct rxe_qp *qp, struct ib_send_wr *ibwr,
send_wqe = producer_addr(sq->queue);
- err = init_send_wqe(qp, ibwr, mask, length, send_wqe);
+ err = init_send_wqe(qp, ibwr, mask, length, send_wqe, &flags);
if (unlikely(err))
goto err1;
--
1.7.9.5
--
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