On Fri, Jun 12, 2020 at 4:31 PM Yanjun Zhu <yanjunz@xxxxxxxxxxxx> wrote:
>
>
>
> -----Original Message-----
> From: Kamal Heib <kamalheib1@xxxxxxxxx>
> Sent: Wednesday, June 3, 2020 6:18 PM
> To: linux-rdma@xxxxxxxxxxxxxxx
> Cc: Doug Ledford <dledford@xxxxxxxxxx>; Jason Gunthorpe <jgg@xxxxxxxx>; Yanjun Zhu <yanjunz@xxxxxxxxxxxx>; Kamal Heib <kamalheib1@xxxxxxxxx>
> Subject: [PATCH for-rc] RDMA/rxe: Fix QP cleanup flow
>
> Avoid releasing the socket associated with each QP in rxe_qp_cleanup() which can sleep and move it to rxe_destroy_qp() instead, after doing this there is no need for the execute_work that used to avoid calling
> rxe_qp_cleanup() directly. also check that the socket is valid in
> rxe_skb_tx_dtor() to avoid use-after-free.
>
> Fixes: 8700e3e7c485 ("Soft RoCE driver")
> Fixes: bb3ffb7ad48a ("RDMA/rxe: Fix rxe_qp_cleanup()")
> Signed-off-by: Kamal Heib <kamalheib1@xxxxxxxxx>
> ---
> drivers/infiniband/sw/rxe/rxe_net.c | 14 ++++++++++++--
> drivers/infiniband/sw/rxe/rxe_qp.c | 22 ++++++----------------
> drivers/infiniband/sw/rxe/rxe_verbs.h | 3 ---
> 3 files changed, 18 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
> index 312c2fc961c0..298ccd3fd3e2 100644
> --- a/drivers/infiniband/sw/rxe/rxe_net.c
> +++ b/drivers/infiniband/sw/rxe/rxe_net.c
> @@ -411,8 +411,18 @@ int rxe_prepare(struct rxe_pkt_info *pkt, struct sk_buff *skb, u32 *crc) static void rxe_skb_tx_dtor(struct sk_buff *skb) {
> struct sock *sk = skb->sk;
> - struct rxe_qp *qp = sk->sk_user_data;
> - int skb_out = atomic_dec_return(&qp->skb_out);
> + struct rxe_qp *qp;
> + int skb_out;
> +
> + if (!sk)
When does sk become NULL?
> + return;
> +
> + qp = sk->sk_user_data;
> +
> + if (!qp)
When does qp become NULL?
> + return;
> +
> + skb_out = atomic_dec_return(&qp->skb_out);
>
> if (unlikely(qp->need_req_skb &&
> skb_out < RXE_INFLIGHT_SKBS_PER_QP_LOW)) diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c
> index 6c11c3aeeca6..89dac6c1111c 100644
> --- a/drivers/infiniband/sw/rxe/rxe_qp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_qp.c
> @@ -787,6 +787,7 @@ void rxe_qp_destroy(struct rxe_qp *qp)
> if (qp_type(qp) == IB_QPT_RC) {
> del_timer_sync(&qp->retrans_timer);
> del_timer_sync(&qp->rnr_nak_timer);
> + sk_dst_reset(qp->sk->sk);
> }
>
> rxe_cleanup_task(&qp->req.task);
> @@ -798,12 +799,15 @@ void rxe_qp_destroy(struct rxe_qp *qp)
> __rxe_do_task(&qp->comp.task);
> __rxe_do_task(&qp->req.task);
> }
> +
> + kernel_sock_shutdown(qp->sk, SHUT_RDWR);
> + sock_release(qp->sk);
> }
>
> /* called when the last reference to the qp is dropped */ -static void rxe_qp_do_cleanup(struct work_struct *work)
> +void rxe_qp_cleanup(struct rxe_pool_entry *arg)
> {
> - struct rxe_qp *qp = container_of(work, typeof(*qp), cleanup_work.work);
> + struct rxe_qp *qp = container_of(arg, typeof(*qp), pelem);
>
> rxe_drop_all_mcast_groups(qp);
>
> @@ -828,19 +832,5 @@ static void rxe_qp_do_cleanup(struct work_struct *work)
> qp->resp.mr = NULL;
> }
>
> - if (qp_type(qp) == IB_QPT_RC)
> - sk_dst_reset(qp->sk->sk);
> -
> free_rd_atomic_resources(qp);
> -
> - kernel_sock_shutdown(qp->sk, SHUT_RDWR);
> - sock_release(qp->sk);
> -}
> -
> -/* called when the last reference to the qp is dropped */ -void rxe_qp_cleanup(struct rxe_pool_entry *arg) -{
> - struct rxe_qp *qp = container_of(arg, typeof(*qp), pelem);
> -
> - execute_in_process_context(rxe_qp_do_cleanup, &qp->cleanup_work);
> }
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> index 92de39c4a7c1..339debaf095f 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> @@ -35,7 +35,6 @@
> #define RXE_VERBS_H
>
> #include <linux/interrupt.h>
> -#include <linux/workqueue.h>
> #include <rdma/rdma_user_rxe.h>
> #include "rxe_pool.h"
> #include "rxe_task.h"
> @@ -285,8 +284,6 @@ struct rxe_qp {
> struct timer_list rnr_nak_timer;
>
> spinlock_t state_lock; /* guard requester and completer */
> -
> - struct execute_work cleanup_work;
> };
>
> enum rxe_mem_state {
> --
> 2.25.4
>
