[PATCH net] net: mana: Fix error handling in mana_create_txq/rxq's NAPI cleanup

[Souradeep Chakrabarti]

Currently napi_disable() gets called during rxq and txq cleanup,
even before napi is enabled and hrtimer is initialized. It causes
kernel panic.

? page_fault_oops+0x136/0x2b0
  ? page_counter_cancel+0x2e/0x80
  ? do_user_addr_fault+0x2f2/0x640
  ? refill_obj_stock+0xc4/0x110
  ? exc_page_fault+0x71/0x160
  ? asm_exc_page_fault+0x27/0x30
  ? __mmdrop+0x10/0x180
  ? __mmdrop+0xec/0x180
  ? hrtimer_active+0xd/0x50
  hrtimer_try_to_cancel+0x2c/0xf0
  hrtimer_cancel+0x15/0x30
  napi_disable+0x65/0x90
  mana_destroy_rxq+0x4c/0x2f0
  mana_create_rxq.isra.0+0x56c/0x6d0
  ? mana_uncfg_vport+0x50/0x50
  mana_alloc_queues+0x21b/0x320
  ? skb_dequeue+0x5f/0x80

Fixes: e1b5683ff62e ("net: mana: Move NAPI from EQ to CQ")

Signed-off-by: Souradeep Chakrabarti <schakraba...@linux.microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 41 +++++++++++++------
 1 file changed, 28 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c 
b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 39f56973746d..882b05e087b9 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1862,7 +1862,7 @@ static void mana_deinit_txq(struct mana_port_context 
*apc, struct mana_txq *txq)
        mana_gd_destroy_queue(gd->gdma_context, txq->gdma_sq);
 }
 
-static void mana_destroy_txq(struct mana_port_context *apc)
+static void mana_cleanup_napi_txq(struct mana_port_context *apc)
 {
        struct napi_struct *napi;
        int i;
@@ -1875,7 +1875,17 @@ static void mana_destroy_txq(struct mana_port_context 
*apc)
                napi_synchronize(napi);
                napi_disable(napi);
                netif_napi_del(napi);
+       }
+}
+
+static void mana_destroy_txq(struct mana_port_context *apc)
+{
+       int i;
+
+       if (!apc->tx_qp)
+               return;
 
+       for (i = 0; i < apc->num_queues; i++) {
                mana_destroy_wq_obj(apc, GDMA_SQ, apc->tx_qp[i].tx_object);
 
                mana_deinit_cq(apc, &apc->tx_qp[i].tx_cq);
@@ -2007,6 +2017,21 @@ static int mana_create_txq(struct mana_port_context *apc,
        return err;
 }
 
+static void mana_cleanup_napi_rxq(struct mana_port_context *apc,
+                                 struct mana_rxq *rxq, bool validate_state)
+{
+       struct napi_struct *napi;
+
+       if (!rxq)
+               return;
+
+       napi = &rxq->rx_cq.napi;
+       if (validate_state)
+               napi_synchronize(napi);
+       napi_disable(napi);
+       netif_napi_del(napi);
+}
+
 static void mana_destroy_rxq(struct mana_port_context *apc,
                             struct mana_rxq *rxq, bool validate_state)
 
@@ -2014,24 +2039,14 @@ static void mana_destroy_rxq(struct mana_port_context 
*apc,
        struct gdma_context *gc = apc->ac->gdma_dev->gdma_context;
        struct mana_recv_buf_oob *rx_oob;
        struct device *dev = gc->dev;
-       struct napi_struct *napi;
        struct page *page;
        int i;
 
        if (!rxq)
                return;
 
-       napi = &rxq->rx_cq.napi;
-
-       if (validate_state)
-               napi_synchronize(napi);
-
-       napi_disable(napi);
-
        xdp_rxq_info_unreg(&rxq->xdp_rxq);
 
-       netif_napi_del(napi);
-
        mana_destroy_wq_obj(apc, GDMA_RQ, rxq->rxobj);
 
        mana_deinit_cq(apc, &rxq->rx_cq);
@@ -2336,11 +2351,11 @@ static void mana_destroy_vport(struct mana_port_context 
*apc)
                rxq = apc->rxqs[rxq_idx];
                if (!rxq)
                        continue;
-
+               mana_cleanup_napi_rxq(apc, rxq, true);
                mana_destroy_rxq(apc, rxq, true);
                apc->rxqs[rxq_idx] = NULL;
        }
-
+       mana_cleanup_napi_txq(apc);
        mana_destroy_txq(apc);
        mana_uncfg_vport(apc);
 
-- 
2.34.1