iwlwifi: fix skb truesize underestimation
By default, iwlwifi uses order-1 pages (8 KB) to store incoming frames,
but doesnt say so in skb->truesize.
This makes very possible to exhaust kernel memory since these skb evade
normal socket memory accounting.
As struct ieee80211_hdr is going to be pulled before calling IP stack,
there is no need to use dev_alloc_skb() to reserve NET_SKB_PAD bytes.
alloc_skb() is ok in this driver, allowing more tailroom.
Pull beginning of frame in skb header, in the hope we can reuse order-1
pages in the driver immediately for small frames and reduce their
truesize to the minimum (linear skbs)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
index 8b1a798..aa7aea1 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
@@ -374,8 +374,9 @@
if (WARN_ON(!rxb))
return;
+ rxcb.truesize = PAGE_SIZE << hw_params(trans).rx_page_order;
dma_unmap_page(trans->dev, rxb->page_dma,
- PAGE_SIZE << hw_params(trans).rx_page_order,
+ rxcb.truesize,
DMA_FROM_DEVICE);
rxcb._page = rxb->page;