diff mbox series

[4/4] RDMA/bnxt_re: synchronize the qp-handle table array

Message ID 1726079379-19272-5-git-send-email-selvin.xavier@broadcom.com (mailing list archive)
State Superseded
Headers show
Series RDMA/bnxt_re: Bug fixes for 6.12 kernel | expand

Commit Message

Selvin Xavier Sept. 11, 2024, 6:29 p.m. UTC
There is a race between the CREQ tasklet and destroy
qp when accessing the qp-handle table. There is
a chance of reading a valid qp-handle in the
CREQ tasklet handler while the QP is already moving
ahead with the destruction.

Fixing this race by implementing a table-lock to
synchronize the access.

Fixes: f218d67ef004 ("RDMA/bnxt_re: Allow posting when QPs are in error")
Fixes: 84cf229f4001 ("RDMA/bnxt_re: Fix the qp table indexing")
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
---
 drivers/infiniband/hw/bnxt_re/qplib_fp.c   |  5 +++++
 drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 12 ++++++++----
 drivers/infiniband/hw/bnxt_re/qplib_rcfw.h |  2 ++
 3 files changed, 15 insertions(+), 4 deletions(-)

Comments

Zhu Yanjun Sept. 13, 2024, 4:26 a.m. UTC | #1
在 2024/9/12 2:29, Selvin Xavier 写道:
> There is a race between the CREQ tasklet and destroy
> qp when accessing the qp-handle table. There is
> a chance of reading a valid qp-handle in the
> CREQ tasklet handler while the QP is already moving
> ahead with the destruction.
> 
> Fixing this race by implementing a table-lock to
> synchronize the access.
> 
> Fixes: f218d67ef004 ("RDMA/bnxt_re: Allow posting when QPs are in error")
> Fixes: 84cf229f4001 ("RDMA/bnxt_re: Fix the qp table indexing")
> Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
> ---
>   drivers/infiniband/hw/bnxt_re/qplib_fp.c   |  5 +++++
>   drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 12 ++++++++----
>   drivers/infiniband/hw/bnxt_re/qplib_rcfw.h |  2 ++
>   3 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.c b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> index 42e98e5..5d36216 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> @@ -1524,12 +1524,15 @@ int bnxt_qplib_destroy_qp(struct bnxt_qplib_res *res,
>   	struct creq_destroy_qp_resp resp = {};
>   	struct bnxt_qplib_cmdqmsg msg = {};
>   	struct cmdq_destroy_qp req = {};
> +	unsigned long flags;
>   	u32 tbl_indx;
>   	int rc;
>   
> +	spin_lock_irqsave(&rcfw->tbl_lock, flags);
>   	tbl_indx = map_qp_id_to_tbl_indx(qp->id, rcfw);
>   	rcfw->qp_tbl[tbl_indx].qp_id = BNXT_QPLIB_QP_ID_INVALID;
>   	rcfw->qp_tbl[tbl_indx].qp_handle = NULL;
> +	spin_unlock_irqrestore(&rcfw->tbl_lock, flags);
>   
>   	bnxt_qplib_rcfw_cmd_prep((struct cmdq_base *)&req,
>   				 CMDQ_BASE_OPCODE_DESTROY_QP,
> @@ -1540,8 +1543,10 @@ int bnxt_qplib_destroy_qp(struct bnxt_qplib_res *res,
>   				sizeof(resp), 0);
>   	rc = bnxt_qplib_rcfw_send_message(rcfw, &msg);
>   	if (rc) {
> +		spin_lock_irqsave(&rcfw->tbl_lock, flags);
>   		rcfw->qp_tbl[tbl_indx].qp_id = qp->id;
>   		rcfw->qp_tbl[tbl_indx].qp_handle = qp;
> +		spin_unlock_irqrestore(&rcfw->tbl_lock, flags);
>   		return rc;
>   	}
>   
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> index 3ffaef0c..993c356 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> @@ -637,17 +637,21 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
>   	case CREQ_QP_EVENT_EVENT_QP_ERROR_NOTIFICATION:
>   		err_event = (struct creq_qp_error_notification *)qp_event;
>   		qp_id = le32_to_cpu(err_event->xid);
> +		spin_lock(&rcfw->tbl_lock);
>   		tbl_indx = map_qp_id_to_tbl_indx(qp_id, rcfw);
>   		qp = rcfw->qp_tbl[tbl_indx].qp_handle;
> +		if (!qp) {
> +			spin_unlock(&rcfw->tbl_lock);
> +			break;
> +		}
> +		bnxt_qplib_mark_qp_error(qp);
> +		rc = rcfw->creq.aeq_handler(rcfw, qp_event, qp);
> +		spin_unlock(&rcfw->tbl_lock);
>   		dev_dbg(&pdev->dev, "Received QP error notification\n");
>   		dev_dbg(&pdev->dev,
>   			"qpid 0x%x, req_err=0x%x, resp_err=0x%x\n",
>   			qp_id, err_event->req_err_state_reason,
>   			err_event->res_err_state_reason);
> -		if (!qp)
> -			break;
> -		bnxt_qplib_mark_qp_error(qp);
> -		rc = rcfw->creq.aeq_handler(rcfw, qp_event, qp);
>   		break;
>   	default:
>   		/*
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> index 45996e6..07779ae 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> @@ -224,6 +224,8 @@ struct bnxt_qplib_rcfw {
>   	struct bnxt_qplib_crsqe		*crsqe_tbl;
>   	int qp_tbl_size;
>   	struct bnxt_qplib_qp_node *qp_tbl;
> +	/* To synchronize the qp-handle hash table */
> +	spinlock_t			tbl_lock;

missing spin_lock_init?

In this commit, spin_lock_init is not found, maybe this function is 
called in other commit?

Or now spin_lock_init is not used again?

Zhu Yanjun
>   	u64 oos_prev;
>   	u32 init_oos_stats;
>   	u32 cmdq_depth;
Zhu Yanjun Sept. 13, 2024, 4:30 a.m. UTC | #2
在 2024/9/12 2:29, Selvin Xavier 写道:
> There is a race between the CREQ tasklet and destroy
> qp when accessing the qp-handle table. There is
> a chance of reading a valid qp-handle in the
> CREQ tasklet handler while the QP is already moving
> ahead with the destruction.
> 
> Fixing this race by implementing a table-lock to
> synchronize the access.
> 
> Fixes: f218d67ef004 ("RDMA/bnxt_re: Allow posting when QPs are in error")
> Fixes: 84cf229f4001 ("RDMA/bnxt_re: Fix the qp table indexing")
> Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
> ---
>   drivers/infiniband/hw/bnxt_re/qplib_fp.c   |  5 +++++
>   drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 12 ++++++++----
>   drivers/infiniband/hw/bnxt_re/qplib_rcfw.h |  2 ++
>   3 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.c b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> index 42e98e5..5d36216 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> @@ -1524,12 +1524,15 @@ int bnxt_qplib_destroy_qp(struct bnxt_qplib_res *res,
>   	struct creq_destroy_qp_resp resp = {};
>   	struct bnxt_qplib_cmdqmsg msg = {};
>   	struct cmdq_destroy_qp req = {};
> +	unsigned long flags;
>   	u32 tbl_indx;
>   	int rc;
>   
> +	spin_lock_irqsave(&rcfw->tbl_lock, flags);

Because the race occurs between tasklets, spin_lock_bh is enough to this?

Zhu Yanjun

>   	tbl_indx = map_qp_id_to_tbl_indx(qp->id, rcfw);
>   	rcfw->qp_tbl[tbl_indx].qp_id = BNXT_QPLIB_QP_ID_INVALID;
>   	rcfw->qp_tbl[tbl_indx].qp_handle = NULL;
> +	spin_unlock_irqrestore(&rcfw->tbl_lock, flags);
>   
>   	bnxt_qplib_rcfw_cmd_prep((struct cmdq_base *)&req,
>   				 CMDQ_BASE_OPCODE_DESTROY_QP,
> @@ -1540,8 +1543,10 @@ int bnxt_qplib_destroy_qp(struct bnxt_qplib_res *res,
>   				sizeof(resp), 0);
>   	rc = bnxt_qplib_rcfw_send_message(rcfw, &msg);
>   	if (rc) {
> +		spin_lock_irqsave(&rcfw->tbl_lock, flags);
>   		rcfw->qp_tbl[tbl_indx].qp_id = qp->id;
>   		rcfw->qp_tbl[tbl_indx].qp_handle = qp;
> +		spin_unlock_irqrestore(&rcfw->tbl_lock, flags);
>   		return rc;
>   	}
>   
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> index 3ffaef0c..993c356 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> @@ -637,17 +637,21 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
>   	case CREQ_QP_EVENT_EVENT_QP_ERROR_NOTIFICATION:
>   		err_event = (struct creq_qp_error_notification *)qp_event;
>   		qp_id = le32_to_cpu(err_event->xid);
> +		spin_lock(&rcfw->tbl_lock);
>   		tbl_indx = map_qp_id_to_tbl_indx(qp_id, rcfw);
>   		qp = rcfw->qp_tbl[tbl_indx].qp_handle;
> +		if (!qp) {
> +			spin_unlock(&rcfw->tbl_lock);
> +			break;
> +		}
> +		bnxt_qplib_mark_qp_error(qp);
> +		rc = rcfw->creq.aeq_handler(rcfw, qp_event, qp);
> +		spin_unlock(&rcfw->tbl_lock);
>   		dev_dbg(&pdev->dev, "Received QP error notification\n");
>   		dev_dbg(&pdev->dev,
>   			"qpid 0x%x, req_err=0x%x, resp_err=0x%x\n",
>   			qp_id, err_event->req_err_state_reason,
>   			err_event->res_err_state_reason);
> -		if (!qp)
> -			break;
> -		bnxt_qplib_mark_qp_error(qp);
> -		rc = rcfw->creq.aeq_handler(rcfw, qp_event, qp);
>   		break;
>   	default:
>   		/*
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> index 45996e6..07779ae 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> @@ -224,6 +224,8 @@ struct bnxt_qplib_rcfw {
>   	struct bnxt_qplib_crsqe		*crsqe_tbl;
>   	int qp_tbl_size;
>   	struct bnxt_qplib_qp_node *qp_tbl;
> +	/* To synchronize the qp-handle hash table */
> +	spinlock_t			tbl_lock;
>   	u64 oos_prev;
>   	u32 init_oos_stats;
>   	u32 cmdq_depth;
Selvin Xavier Sept. 13, 2024, 7:59 a.m. UTC | #3
On Fri, Sep 13, 2024 at 10:00 AM Zhu Yanjun <yanjun.zhu@linux.dev> wrote:
>
> 在 2024/9/12 2:29, Selvin Xavier 写道:
> > There is a race between the CREQ tasklet and destroy
> > qp when accessing the qp-handle table. There is
> > a chance of reading a valid qp-handle in the
> > CREQ tasklet handler while the QP is already moving
> > ahead with the destruction.
> >
> > Fixing this race by implementing a table-lock to
> > synchronize the access.
> >
> > Fixes: f218d67ef004 ("RDMA/bnxt_re: Allow posting when QPs are in error")
> > Fixes: 84cf229f4001 ("RDMA/bnxt_re: Fix the qp table indexing")
> > Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> > Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
> > ---
> >   drivers/infiniband/hw/bnxt_re/qplib_fp.c   |  5 +++++
> >   drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 12 ++++++++----
> >   drivers/infiniband/hw/bnxt_re/qplib_rcfw.h |  2 ++
> >   3 files changed, 15 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.c b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> > index 42e98e5..5d36216 100644
> > --- a/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> > +++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
> > @@ -1524,12 +1524,15 @@ int bnxt_qplib_destroy_qp(struct bnxt_qplib_res *res,
> >       struct creq_destroy_qp_resp resp = {};
> >       struct bnxt_qplib_cmdqmsg msg = {};
> >       struct cmdq_destroy_qp req = {};
> > +     unsigned long flags;
> >       u32 tbl_indx;
> >       int rc;
> >
> > +     spin_lock_irqsave(&rcfw->tbl_lock, flags);
>
> Because the race occurs between tasklets, spin_lock_bh is enough to this?
You are right. The race occurs in the BH handler.
bnxt_qplib_service_creq , which is scheduled in the tasklet context,
is already using the spin_lock_irqsave for synchronizing this function
with other contexts.  The current code change is with-in this context.
I added this change on top of the current code and used irqsave.

But  I will fix both the spin lock usage and post a v2.

Thanks for the review.

>
> Zhu Yanjun
>
> >       tbl_indx = map_qp_id_to_tbl_indx(qp->id, rcfw);
> >       rcfw->qp_tbl[tbl_indx].qp_id = BNXT_QPLIB_QP_ID_INVALID;
> >       rcfw->qp_tbl[tbl_indx].qp_handle = NULL;
> > +     spin_unlock_irqrestore(&rcfw->tbl_lock, flags);
> >
> >       bnxt_qplib_rcfw_cmd_prep((struct cmdq_base *)&req,
> >                                CMDQ_BASE_OPCODE_DESTROY_QP,
> > @@ -1540,8 +1543,10 @@ int bnxt_qplib_destroy_qp(struct bnxt_qplib_res *res,
> >                               sizeof(resp), 0);
> >       rc = bnxt_qplib_rcfw_send_message(rcfw, &msg);
> >       if (rc) {
> > +             spin_lock_irqsave(&rcfw->tbl_lock, flags);
> >               rcfw->qp_tbl[tbl_indx].qp_id = qp->id;
> >               rcfw->qp_tbl[tbl_indx].qp_handle = qp;
> > +             spin_unlock_irqrestore(&rcfw->tbl_lock, flags);
> >               return rc;
> >       }
> >
> > diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> > index 3ffaef0c..993c356 100644
> > --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> > +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> > @@ -637,17 +637,21 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
> >       case CREQ_QP_EVENT_EVENT_QP_ERROR_NOTIFICATION:
> >               err_event = (struct creq_qp_error_notification *)qp_event;
> >               qp_id = le32_to_cpu(err_event->xid);
> > +             spin_lock(&rcfw->tbl_lock);
> >               tbl_indx = map_qp_id_to_tbl_indx(qp_id, rcfw);
> >               qp = rcfw->qp_tbl[tbl_indx].qp_handle;
> > +             if (!qp) {
> > +                     spin_unlock(&rcfw->tbl_lock);
> > +                     break;
> > +             }
> > +             bnxt_qplib_mark_qp_error(qp);
> > +             rc = rcfw->creq.aeq_handler(rcfw, qp_event, qp);
> > +             spin_unlock(&rcfw->tbl_lock);
> >               dev_dbg(&pdev->dev, "Received QP error notification\n");
> >               dev_dbg(&pdev->dev,
> >                       "qpid 0x%x, req_err=0x%x, resp_err=0x%x\n",
> >                       qp_id, err_event->req_err_state_reason,
> >                       err_event->res_err_state_reason);
> > -             if (!qp)
> > -                     break;
> > -             bnxt_qplib_mark_qp_error(qp);
> > -             rc = rcfw->creq.aeq_handler(rcfw, qp_event, qp);
> >               break;
> >       default:
> >               /*
> > diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> > index 45996e6..07779ae 100644
> > --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> > +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> > @@ -224,6 +224,8 @@ struct bnxt_qplib_rcfw {
> >       struct bnxt_qplib_crsqe         *crsqe_tbl;
> >       int qp_tbl_size;
> >       struct bnxt_qplib_qp_node *qp_tbl;
> > +     /* To synchronize the qp-handle hash table */
> > +     spinlock_t                      tbl_lock;
> >       u64 oos_prev;
> >       u32 init_oos_stats;
> >       u32 cmdq_depth;
>
diff mbox series

Patch

diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.c b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
index 42e98e5..5d36216 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_fp.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
@@ -1524,12 +1524,15 @@  int bnxt_qplib_destroy_qp(struct bnxt_qplib_res *res,
 	struct creq_destroy_qp_resp resp = {};
 	struct bnxt_qplib_cmdqmsg msg = {};
 	struct cmdq_destroy_qp req = {};
+	unsigned long flags;
 	u32 tbl_indx;
 	int rc;
 
+	spin_lock_irqsave(&rcfw->tbl_lock, flags);
 	tbl_indx = map_qp_id_to_tbl_indx(qp->id, rcfw);
 	rcfw->qp_tbl[tbl_indx].qp_id = BNXT_QPLIB_QP_ID_INVALID;
 	rcfw->qp_tbl[tbl_indx].qp_handle = NULL;
+	spin_unlock_irqrestore(&rcfw->tbl_lock, flags);
 
 	bnxt_qplib_rcfw_cmd_prep((struct cmdq_base *)&req,
 				 CMDQ_BASE_OPCODE_DESTROY_QP,
@@ -1540,8 +1543,10 @@  int bnxt_qplib_destroy_qp(struct bnxt_qplib_res *res,
 				sizeof(resp), 0);
 	rc = bnxt_qplib_rcfw_send_message(rcfw, &msg);
 	if (rc) {
+		spin_lock_irqsave(&rcfw->tbl_lock, flags);
 		rcfw->qp_tbl[tbl_indx].qp_id = qp->id;
 		rcfw->qp_tbl[tbl_indx].qp_handle = qp;
+		spin_unlock_irqrestore(&rcfw->tbl_lock, flags);
 		return rc;
 	}
 
diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
index 3ffaef0c..993c356 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
@@ -637,17 +637,21 @@  static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
 	case CREQ_QP_EVENT_EVENT_QP_ERROR_NOTIFICATION:
 		err_event = (struct creq_qp_error_notification *)qp_event;
 		qp_id = le32_to_cpu(err_event->xid);
+		spin_lock(&rcfw->tbl_lock);
 		tbl_indx = map_qp_id_to_tbl_indx(qp_id, rcfw);
 		qp = rcfw->qp_tbl[tbl_indx].qp_handle;
+		if (!qp) {
+			spin_unlock(&rcfw->tbl_lock);
+			break;
+		}
+		bnxt_qplib_mark_qp_error(qp);
+		rc = rcfw->creq.aeq_handler(rcfw, qp_event, qp);
+		spin_unlock(&rcfw->tbl_lock);
 		dev_dbg(&pdev->dev, "Received QP error notification\n");
 		dev_dbg(&pdev->dev,
 			"qpid 0x%x, req_err=0x%x, resp_err=0x%x\n",
 			qp_id, err_event->req_err_state_reason,
 			err_event->res_err_state_reason);
-		if (!qp)
-			break;
-		bnxt_qplib_mark_qp_error(qp);
-		rc = rcfw->creq.aeq_handler(rcfw, qp_event, qp);
 		break;
 	default:
 		/*
diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
index 45996e6..07779ae 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
+++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
@@ -224,6 +224,8 @@  struct bnxt_qplib_rcfw {
 	struct bnxt_qplib_crsqe		*crsqe_tbl;
 	int qp_tbl_size;
 	struct bnxt_qplib_qp_node *qp_tbl;
+	/* To synchronize the qp-handle hash table */
+	spinlock_t			tbl_lock;
 	u64 oos_prev;
 	u32 init_oos_stats;
 	u32 cmdq_depth;