* [PATCH net 1/2] net: systemport: check harder for out of memory conditions
2014-09-08 18:37 [PATCH net 0/2] net: systemport and bcmgenet OOM fixes Florian Fainelli
@ 2014-09-08 18:37 ` Florian Fainelli
2014-09-08 18:37 ` [PATCH net 2/2] net: bcmgenet: " Florian Fainelli
2014-09-08 23:03 ` [PATCH net 0/2] net: systemport and bcmgenet OOM fixes David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Florian Fainelli @ 2014-09-08 18:37 UTC (permalink / raw)
To: netdev; +Cc: davem, Florian Fainelli
There is a potential case where we might be failing to refill a
control block, leaving it with both a NULL skb pointer *and* a NULL
dma_unmap_addr.
The way we process incoming packets, by first calling
dma_unmap_single(), and then only checking for a potential NULL skb can
lead to situations where do pass a NULL dma_unmap_addr() to
dma_unmap_single(), resulting in an oops.
Fix this my moving the NULL skb check earlier, since no backing skb
also means no corresponding DMA mapping for this packet.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/net/ethernet/broadcom/bcmsysport.c | 31 ++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index 6f4e18644bd4..d9b9170ed2fc 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -534,6 +534,25 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
while ((processed < to_process) && (processed < budget)) {
cb = &priv->rx_cbs[priv->rx_read_ptr];
skb = cb->skb;
+
+ processed++;
+ priv->rx_read_ptr++;
+
+ if (priv->rx_read_ptr == priv->num_rx_bds)
+ priv->rx_read_ptr = 0;
+
+ /* We do not have a backing SKB, so we do not a corresponding
+ * DMA mapping for this incoming packet since
+ * bcm_sysport_rx_refill always either has both skb and mapping
+ * or none.
+ */
+ if (unlikely(!skb)) {
+ netif_err(priv, rx_err, ndev, "out of memory!\n");
+ ndev->stats.rx_dropped++;
+ ndev->stats.rx_errors++;
+ goto refill;
+ }
+
dma_unmap_single(kdev, dma_unmap_addr(cb, dma_addr),
RX_BUF_LENGTH, DMA_FROM_DEVICE);
@@ -543,23 +562,11 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
status = (rsb->rx_status_len >> DESC_STATUS_SHIFT) &
DESC_STATUS_MASK;
- processed++;
- priv->rx_read_ptr++;
- if (priv->rx_read_ptr == priv->num_rx_bds)
- priv->rx_read_ptr = 0;
-
netif_dbg(priv, rx_status, ndev,
"p=%d, c=%d, rd_ptr=%d, len=%d, flag=0x%04x\n",
p_index, priv->rx_c_index, priv->rx_read_ptr,
len, status);
- if (unlikely(!skb)) {
- netif_err(priv, rx_err, ndev, "out of memory!\n");
- ndev->stats.rx_dropped++;
- ndev->stats.rx_errors++;
- goto refill;
- }
-
if (unlikely(!(status & DESC_EOP) || !(status & DESC_SOP))) {
netif_err(priv, rx_status, ndev, "fragmented packet!\n");
ndev->stats.rx_dropped++;
--
1.9.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH net 2/2] net: bcmgenet: check harder for out of memory conditions
2014-09-08 18:37 [PATCH net 0/2] net: systemport and bcmgenet OOM fixes Florian Fainelli
2014-09-08 18:37 ` [PATCH net 1/2] net: systemport: check harder for out of memory conditions Florian Fainelli
@ 2014-09-08 18:37 ` Florian Fainelli
2014-09-08 23:03 ` [PATCH net 0/2] net: systemport and bcmgenet OOM fixes David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Florian Fainelli @ 2014-09-08 18:37 UTC (permalink / raw)
To: netdev; +Cc: davem, Florian Fainelli
There is a potential case where we might be failing to refill a
control block, leaving it with both a NULL skb pointer *and* a NULL
dma_unmap_addr.
The way we process incoming packets, by first calling
dma_unmap_single(), and then only checking for a potential NULL skb can
lead to situations where do pass a NULL dma_unmap_addr() to
dma_unmap_single(), resulting in an oops.
Fix this my moving the NULL skb check earlier, since no backing skb
also means no corresponding DMA mapping for this packet.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/net/ethernet/broadcom/genet/bcmgenet.c | 33 +++++++++++++++-----------
1 file changed, 19 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 3f9d4de8173c..cdef86a03862 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -1274,12 +1274,29 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
while ((rxpktprocessed < rxpkttoprocess) &&
(rxpktprocessed < budget)) {
+ cb = &priv->rx_cbs[priv->rx_read_ptr];
+ skb = cb->skb;
+
+ rxpktprocessed++;
+
+ priv->rx_read_ptr++;
+ priv->rx_read_ptr &= (priv->num_rx_bds - 1);
+
+ /* We do not have a backing SKB, so we do not have a
+ * corresponding DMA mapping for this incoming packet since
+ * bcmgenet_rx_refill always either has both skb and mapping or
+ * none.
+ */
+ if (unlikely(!skb)) {
+ dev->stats.rx_dropped++;
+ dev->stats.rx_errors++;
+ goto refill;
+ }
+
/* Unmap the packet contents such that we can use the
* RSV from the 64 bytes descriptor when enabled and save
* a 32-bits register read
*/
- cb = &priv->rx_cbs[priv->rx_read_ptr];
- skb = cb->skb;
dma_unmap_single(&dev->dev, dma_unmap_addr(cb, dma_addr),
priv->rx_buf_len, DMA_FROM_DEVICE);
@@ -1307,18 +1324,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
__func__, p_index, priv->rx_c_index,
priv->rx_read_ptr, dma_length_status);
- rxpktprocessed++;
-
- priv->rx_read_ptr++;
- priv->rx_read_ptr &= (priv->num_rx_bds - 1);
-
- /* out of memory, just drop packets at the hardware level */
- if (unlikely(!skb)) {
- dev->stats.rx_dropped++;
- dev->stats.rx_errors++;
- goto refill;
- }
-
if (unlikely(!(dma_flag & DMA_EOP) || !(dma_flag & DMA_SOP))) {
netif_err(priv, rx_status, dev,
"dropping fragmented packet!\n");
--
1.9.1
^ permalink raw reply related [flat|nested] 4+ messages in thread