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authorEric Dumazet <eric.dumazet@gmail.com>2012-03-24 05:29:46 +0100
committerJohn W. Linville <linville@tuxdriver.com>2012-05-03 16:52:30 +0200
commited90542b0ce5415050c6fbfca324bccaafa69f2f (patch)
treebc8426e780dd399259af2f8ba6e775b613714dc8 /drivers/net
parentRevert "ath9k_hw: Fix incorrect spur_freq_sd for AR9003" (diff)
downloadlinux-ed90542b0ce5415050c6fbfca324bccaafa69f2f.tar.xz
linux-ed90542b0ce5415050c6fbfca324bccaafa69f2f.zip
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>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/wireless/iwlwifi/iwl-agn-rx.c21
-rw-r--r--drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c3
-rw-r--r--drivers/net/wireless/iwlwifi/iwl-trans.h1
3 files changed, 17 insertions, 8 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rx.c b/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
index f4b84d1596e3..22474608a70b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
@@ -773,8 +773,7 @@ static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv,
struct sk_buff *skb;
__le16 fc = hdr->frame_control;
struct iwl_rxon_context *ctx;
- struct page *p;
- int offset;
+ unsigned int hdrlen, fraglen;
/* We only process data packets if the interface is open */
if (unlikely(!priv->is_open)) {
@@ -788,16 +787,24 @@ static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv,
iwlagn_set_decrypted_flag(priv, hdr, ampdu_status, stats))
return;
- skb = dev_alloc_skb(128);
+ /* Dont use dev_alloc_skb(), we'll have enough headroom once
+ * ieee80211_hdr pulled.
+ */
+ skb = alloc_skb(128, GFP_ATOMIC);
if (!skb) {
- IWL_ERR(priv, "dev_alloc_skb failed\n");
+ IWL_ERR(priv, "alloc_skb failed\n");
return;
}
+ hdrlen = min_t(unsigned int, len, skb_tailroom(skb));
+ memcpy(skb_put(skb, hdrlen), hdr, hdrlen);
+ fraglen = len - hdrlen;
- offset = (void *)hdr - rxb_addr(rxb);
- p = rxb_steal_page(rxb);
- skb_add_rx_frag(skb, 0, p, offset, len, len);
+ if (fraglen) {
+ int offset = (void *)hdr + hdrlen - rxb_addr(rxb);
+ skb_add_rx_frag(skb, 0, rxb_steal_page(rxb), offset,
+ fraglen, rxb->truesize);
+ }
iwl_update_stats(priv, false, fc, len);
/*
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
index 8b1a7988e176..aa7aea168138 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 @@ static void iwl_rx_handle_rxbuf(struct iwl_trans *trans,
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;
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h
index 0c81cbaa8088..fdf97886a5e4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans.h
@@ -260,6 +260,7 @@ static inline void iwl_free_resp(struct iwl_host_cmd *cmd)
struct iwl_rx_cmd_buffer {
struct page *_page;
+ unsigned int truesize;
};
static inline void *rxb_addr(struct iwl_rx_cmd_buffer *r)