2011-06-06 14:12:17

by Mike McCormack

Subject: [PATCH 1/5] rtlwifi: Allocate new skb before modifying old

Make sure not to modify the skb we resubmit.

Signed-off-by: Mike McCormack <[email protected]>
---
drivers/net/wireless/rtlwifi/pci.c | 28 +++++++++++++---------------
1 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
index fc44005..e502db0 100644
--- a/drivers/net/wireless/rtlwifi/pci.c
+++ b/drivers/net/wireless/rtlwifi/pci.c
@@ -670,6 +670,19 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
&rx_status,
(u8 *) pdesc, skb);

+ new_skb = dev_alloc_skb(rtlpci->rxbuffersize);
+ if (unlikely(!new_skb)) {
+ RT_TRACE(rtlpriv, (COMP_INTR | COMP_RECV),
+ DBG_DMESG,
+ ("can't alloc skb for rx\n"));
+ goto done;
+ }
+
+ pci_unmap_single(rtlpci->pdev,
+ *((dma_addr_t *) skb->cb),
+ rtlpci->rxbuffersize,
+ PCI_DMA_FROMDEVICE);
+
skb_put(skb, rtlpriv->cfg->ops->get_desc((u8 *) pdesc,
false,
HW_DESC_RXPKT_LEN));
@@ -686,21 +699,6 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
hdr = rtl_get_hdr(skb);
fc = rtl_get_fc(skb);

- /* try for new buffer - if allocation fails, drop
- * frame and reuse old buffer
- */
- new_skb = dev_alloc_skb(rtlpci->rxbuffersize);
- if (unlikely(!new_skb)) {
- RT_TRACE(rtlpriv, (COMP_INTR | COMP_RECV),
- DBG_DMESG,
- ("can't alloc skb for rx\n"));
- goto done;
- }
- pci_unmap_single(rtlpci->pdev,
- *((dma_addr_t *) skb->cb),
- rtlpci->rxbuffersize,
- PCI_DMA_FROMDEVICE);
-
if (!stats.crc && !stats.hwerror) {
memcpy(IEEE80211_SKB_RXCB(skb), &rx_status,
sizeof(rx_status));
--
1.7.4.1

2011-06-06 16:55:49

by Larry Finger

Subject: Re: [PATCH 1/5] rtlwifi: Allocate new skb before modifying old

On 06/06/2011 09:11 AM, Mike McCormack wrote:
> Make sure not to modify the skb we resubmit.
>
> Signed-off-by: Mike McCormack<[email protected]>

I think this is a bug introduced by commit a9e1286975843042480. If it is, please
resubmit as a single patch with subject "rtlwifi: Fix case where modified skb
could be resubmitted", or something like this. Any bug fixes will go into 3.0,
while the enhancements will go to 3.1.

Larry

> ---
> drivers/net/wireless/rtlwifi/pci.c | 28 +++++++++++++---------------
> 1 files changed, 13 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
> index fc44005..e502db0 100644
> --- a/drivers/net/wireless/rtlwifi/pci.c
> +++ b/drivers/net/wireless/rtlwifi/pci.c
> @@ -670,6 +670,19 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
> &rx_status,
> (u8 *) pdesc, skb);
>
> + new_skb = dev_alloc_skb(rtlpci->rxbuffersize);
> + if (unlikely(!new_skb)) {
> + RT_TRACE(rtlpriv, (COMP_INTR | COMP_RECV),
> + DBG_DMESG,
> + ("can't alloc skb for rx\n"));
> + goto done;
> + }
> +
> + pci_unmap_single(rtlpci->pdev,
> + *((dma_addr_t *) skb->cb),
> + rtlpci->rxbuffersize,
> + PCI_DMA_FROMDEVICE);
> +
> skb_put(skb, rtlpriv->cfg->ops->get_desc((u8 *) pdesc,
> false,
> HW_DESC_RXPKT_LEN));
> @@ -686,21 +699,6 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
> hdr = rtl_get_hdr(skb);
> fc = rtl_get_fc(skb);
>
> - /* try for new buffer - if allocation fails, drop
> - * frame and reuse old buffer
> - */
> - new_skb = dev_alloc_skb(rtlpci->rxbuffersize);
> - if (unlikely(!new_skb)) {
> - RT_TRACE(rtlpriv, (COMP_INTR | COMP_RECV),
> - DBG_DMESG,
> - ("can't alloc skb for rx\n"));
> - goto done;
> - }
> - pci_unmap_single(rtlpci->pdev,
> - *((dma_addr_t *) skb->cb),
> - rtlpci->rxbuffersize,
> - PCI_DMA_FROMDEVICE);
> -
> if (!stats.crc&& !stats.hwerror) {
> memcpy(IEEE80211_SKB_RXCB(skb),&rx_status,
> sizeof(rx_status));