BNX2: fix a Null Pointer for stats_blk

we have two processes to do:
P1#: ifconfig eth0 down; which will call bnx2_close, then will
, and set Null to stats_blk
P2#: ifconfig eth0; which will call bnx2_get_stats64, it will
use stats_blk.
In one case:
    --P1#--                   --P2#--
                              stats_blk(no null)
    bnx2_free_mem
    ->bp->stats_blk = NULL
                              GET_64BIT_NET_STATS

then it will cause 'NULL Pointer' Problem.
it is as well with 'ethtool -S ethx'.

Allocate the statistics block at probe time so that this problem is
impossible

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c
index 2b66ef3..6259064 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnx2.c
+++ b/drivers/net/ethernet/broadcom/bnx2.c
@@ -813,6 +813,46 @@ bnx2_alloc_rx_mem(struct bnx2 *bp)
 }
 
 static void
+bnx2_free_stats_blk(struct net_device *dev)
+{
+       struct bnx2 *bp = netdev_priv(dev);
+
+       if (bp->status_blk) {
+               dma_free_coherent(&bp->pdev->dev, bp->status_stats_size,
+                                 bp->status_blk,
+                                 bp->status_blk_mapping);
+               bp->status_blk = NULL;
+               bp->stats_blk = NULL;
+       }
+}
+
+static int
+bnx2_alloc_stats_blk(struct net_device *dev)
+{
+       int status_blk_size;
+       void *status_blk;
+       struct bnx2 *bp = netdev_priv(dev);
+
+       /* Combine status and statistics blocks into one allocation. */
+       status_blk_size = L1_CACHE_ALIGN(sizeof(struct status_block));
+       if (bp->flags & BNX2_FLAG_MSIX_CAP)
+               status_blk_size = L1_CACHE_ALIGN(BNX2_MAX_MSIX_HW_VEC *
+                                                BNX2_SBLK_MSIX_ALIGN_SIZE);
+       bp->status_stats_size = status_blk_size +
+                               sizeof(struct statistics_block);
+       status_blk = dma_zalloc_coherent(&bp->pdev->dev, bp->status_stats_size,
+                                        &bp->status_blk_mapping, GFP_KERNEL);
+       if (status_blk == NULL)
+               return -ENOMEM;
+
+       bp->status_blk = status_blk;
+       bp->stats_blk = status_blk + status_blk_size;
+       bp->stats_blk_mapping = bp->status_blk_mapping + status_blk_size;
+
+       return 0;
+}
+
+static void
 bnx2_free_mem(struct bnx2 *bp)
 {
        int i;
@@ -829,37 +869,19 @@ bnx2_free_mem(struct bnx2 *bp)
                        bp->ctx_blk[i] = NULL;
                }
        }
-       if (bnapi->status_blk.msi) {
-               dma_free_coherent(&bp->pdev->dev, bp->status_stats_size,
-                                 bnapi->status_blk.msi,
-                                 bp->status_blk_mapping);
+
+       if (bnapi->status_blk.msi)
                bnapi->status_blk.msi = NULL;
-               bp->stats_blk = NULL;
-       }
 }
 
 static int
 bnx2_alloc_mem(struct bnx2 *bp)
 {
-       int i, status_blk_size, err;
+       int i, err;
        struct bnx2_napi *bnapi;
-       void *status_blk;
-
-       /* Combine status and statistics blocks into one allocation. */
-       status_blk_size = L1_CACHE_ALIGN(sizeof(struct status_block));
-       if (bp->flags & BNX2_FLAG_MSIX_CAP)
-               status_blk_size = L1_CACHE_ALIGN(BNX2_MAX_MSIX_HW_VEC *
-                                                BNX2_SBLK_MSIX_ALIGN_SIZE);
-       bp->status_stats_size = status_blk_size +
-                               sizeof(struct statistics_block);
-
-       status_blk = dma_zalloc_coherent(&bp->pdev->dev, bp->status_stats_size,
-                                        &bp->status_blk_mapping, GFP_KERNEL);
-       if (status_blk == NULL)
-               goto alloc_mem_err;
 
        bnapi = &bp->bnx2_napi[0];
-       bnapi->status_blk.msi = status_blk;
+       bnapi->status_blk.msi = bp->status_blk;
        bnapi->hw_tx_cons_ptr =
                &bnapi->status_blk.msi->status_tx_quick_consumer_index0;
        bnapi->hw_rx_cons_ptr =
@@ -870,7 +892,7 @@ bnx2_alloc_mem(struct bnx2 *bp)
 
                        bnapi = &bp->bnx2_napi[i];
 
-                       sblk = (status_blk + BNX2_SBLK_MSIX_ALIGN_SIZE * i);
+                       sblk = (bp->status_blk + BNX2_SBLK_MSIX_ALIGN_SIZE * i);
                        bnapi->status_blk.msix = sblk;
                        bnapi->hw_tx_cons_ptr =
                                &sblk->status_tx_quick_consumer_index;
@@ -880,10 +902,6 @@ bnx2_alloc_mem(struct bnx2 *bp)
                }
        }
 
-       bp->stats_blk = status_blk + status_blk_size;
-
-       bp->stats_blk_mapping = bp->status_blk_mapping + status_blk_size;
-
        if (BNX2_CHIP(bp) == BNX2_CHIP_5709) {
                bp->ctx_pages = 0x2000 / BNX2_PAGE_SIZE;
                if (bp->ctx_pages == 0)
@@ -8330,6 +8348,11 @@ bnx2_init_board(struct pci_dev *pdev, struct net_device *dev)
 
        bp->phy_addr = 1;
 
+       /* allocate stats_blk */
+       rc = bnx2_alloc_stats_blk(dev);
+       if (rc)
+               goto err_out_unmap;
+
        /* Disable WOL support if we are running on a SERDES chip. */
        if (BNX2_CHIP(bp) == BNX2_CHIP_5709)
                bnx2_get_5709_media(bp);
@@ -8586,6 +8609,7 @@ error:
        pci_release_regions(pdev);
        pci_disable_device(pdev);
 err_free:
+       bnx2_free_stats_blk(dev);
        free_netdev(dev);
        return rc;
 }
@@ -8603,6 +8627,7 @@ bnx2_remove_one(struct pci_dev *pdev)
 
        pci_iounmap(bp->pdev, bp->regview);
 
+       bnx2_free_stats_blk(dev);
        kfree(bp->temp_stats_blk);
 
        if (bp->flags & BNX2_FLAG_AER_ENABLED) {

diff --git a/drivers/net/ethernet/broadcom/bnx2.h b/drivers/net/ethernet/broadcom/bnx2.h
index f92f76c..380234d 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnx2.h
+++ b/drivers/net/ethernet/broadcom/bnx2.h
@@ -6928,6 +6928,7 @@ struct bnx2 {
 
        dma_addr_t              status_blk_mapping;
 
+       void *status_blk;
        struct statistics_block *stats_blk;
        struct statistics_block *temp_stats_blk;
        dma_addr_t              stats_blk_mapping;