---

yaml --- r: 171061 b: refs/heads/master c: 29b1b26 h: refs/heads/master i: 171059: 9a11052 v: v3
git-mirror · Oct 27, 2009 · 9aa6799 · 9aa6799
1 parent 66d9d75
commit 9aa6799
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Showing 5 changed files with 47 additions and 20 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 52aa081c40324ecb04a47864e4e56dafc5a72a34
+refs/heads/master: 29b1b2688fd71346f78f175d9669c006686b6dc3
diff --git a/trunk/drivers/net/wireless/iwlwifi/iwl-3945.c b/trunk/drivers/net/wireless/iwlwifi/iwl-3945.c
@@ -548,6 +548,7 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
 	u16 len = le16_to_cpu(rx_hdr->len);
 	struct sk_buff *skb;
 	int ret;
+	__le16 fc = hdr->frame_control;
 
 	/* We received data from the HW, so stop the watchdog */
 	if (unlikely(len + IWL39_RX_FRAME_SIZE >
@@ -580,9 +581,9 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
 	/* mac80211 currently doesn't support paged SKB. Convert it to
 	 * linear SKB for management frame and data frame requires
 	 * software decryption or software defragementation. */
-	if (ieee80211_is_mgmt(hdr->frame_control) ||
-	    ieee80211_has_protected(hdr->frame_control) ||
-	    ieee80211_has_morefrags(hdr->frame_control) ||
+	if (ieee80211_is_mgmt(fc) ||
+	    ieee80211_has_protected(fc) ||
+	    ieee80211_has_morefrags(fc) ||
 	    le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG)
 		ret = skb_linearize(skb);
 	else
@@ -594,11 +595,15 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
 		goto out;
 	}
 
-	iwl_update_stats(priv, false, hdr->frame_control, len);
+	/*
+	 * XXX: We cannot touch the page and its virtual memory (pkt) after
+	 * here. It might have already been freed by the above skb change.
+	 */
 
+	iwl_update_stats(priv, false, fc, len);
 	memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
-	ieee80211_rx(priv->hw, skb);
 
+	ieee80211_rx(priv->hw, skb);
  out:
 	priv->alloc_rxb_page--;
 	rxb->page = NULL;

diff --git a/trunk/drivers/net/wireless/iwlwifi/iwl-agn.c b/trunk/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -814,8 +814,8 @@ void iwl_rx_handle(struct iwl_priv *priv)
 		if (priv->rx_handlers[pkt->hdr.cmd]) {
 			IWL_DEBUG_RX(priv, "r = %d, i = %d, %s, 0x%02x\n", r,
 				i, get_cmd_string(pkt->hdr.cmd), pkt->hdr.cmd);
-			priv->rx_handlers[pkt->hdr.cmd] (priv, rxb);
 			priv->isr_stats.rx_handlers[pkt->hdr.cmd]++;
+			priv->rx_handlers[pkt->hdr.cmd] (priv, rxb);
 		} else {
 			/* No handling needed */
 			IWL_DEBUG_RX(priv,
@@ -824,11 +824,18 @@ void iwl_rx_handle(struct iwl_priv *priv)
 				pkt->hdr.cmd);
 		}
 
+		/*
+		 * XXX: After here, we should always check rxb->page
+		 * against NULL before touching it or its virtual
+		 * memory (pkt). Because some rx_handler might have
+		 * already taken or freed the pages.
+		 */
+
 		if (reclaim) {
 			/* Invoke any callbacks, transfer the buffer to caller,
 			 * and fire off the (possibly) blocking iwl_send_cmd()
 			 * as we reclaim the driver command queue */
-			if (rxb && rxb->page)
+			if (rxb->page)
 				iwl_tx_cmd_complete(priv, rxb);
 			else
 				IWL_WARN(priv, "Claim null rxb?\n");

diff --git a/trunk/drivers/net/wireless/iwlwifi/iwl-rx.c b/trunk/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -241,6 +241,7 @@ void iwl_rx_allocate(struct iwl_priv *priv, gfp_t priority)
 	struct iwl_rx_mem_buffer *rxb;
 	struct page *page;
 	unsigned long flags;
+	gfp_t gfp_mask = priority;
 
 	while (1) {
 		spin_lock_irqsave(&rxq->lock, flags);
@@ -251,13 +252,13 @@ void iwl_rx_allocate(struct iwl_priv *priv, gfp_t priority)
 		spin_unlock_irqrestore(&rxq->lock, flags);
 
 		if (rxq->free_count > RX_LOW_WATERMARK)
-			priority |= __GFP_NOWARN;
+			gfp_mask |= __GFP_NOWARN;
 
 		if (priv->hw_params.rx_page_order > 0)
-			priority |= __GFP_COMP;
+			gfp_mask |= __GFP_COMP;
 
 		/* Alloc a new receive buffer */
-		page = alloc_pages(priority, priv->hw_params.rx_page_order);
+		page = alloc_pages(gfp_mask, priv->hw_params.rx_page_order);
 		if (!page) {
 			if (net_ratelimit())
 				IWL_DEBUG_INFO(priv, "alloc_pages failed, "
@@ -922,6 +923,7 @@ static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
 {
 	struct sk_buff *skb;
 	int ret = 0;
+	__le16 fc = hdr->frame_control;
 
 	/* We only process data packets if the interface is open */
 	if (unlikely(!priv->is_open)) {
@@ -946,9 +948,9 @@ static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
 	/* mac80211 currently doesn't support paged SKB. Convert it to
 	 * linear SKB for management frame and data frame requires
 	 * software decryption or software defragementation. */
-	if (ieee80211_is_mgmt(hdr->frame_control) ||
-	    ieee80211_has_protected(hdr->frame_control) ||
-	    ieee80211_has_morefrags(hdr->frame_control) ||
+	if (ieee80211_is_mgmt(fc) ||
+	    ieee80211_has_protected(fc) ||
+	    ieee80211_has_morefrags(fc) ||
 	    le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG)
 		ret = skb_linearize(skb);
 	else
@@ -960,7 +962,12 @@ static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
 		goto out;
 	}
 
-	iwl_update_stats(priv, false, hdr->frame_control, len);
+	/*
+	 * XXX: We cannot touch the page and its virtual memory (hdr) after
+	 * here. It might have already been freed by the above skb change.
+	 */
+
+	iwl_update_stats(priv, false, fc, len);
 	memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
 
 	ieee80211_rx(priv->hw, skb);

diff --git a/trunk/drivers/net/wireless/iwlwifi/iwl3945-base.c b/trunk/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -1124,6 +1124,7 @@ static void iwl3945_rx_allocate(struct iwl_priv *priv, gfp_t priority)
 	struct iwl_rx_mem_buffer *rxb;
 	struct page *page;
 	unsigned long flags;
+	gfp_t gfp_mask = priority;
 
 	while (1) {
 		spin_lock_irqsave(&rxq->lock, flags);
@@ -1135,13 +1136,13 @@ static void iwl3945_rx_allocate(struct iwl_priv *priv, gfp_t priority)
 		spin_unlock_irqrestore(&rxq->lock, flags);
 
 		if (rxq->free_count > RX_LOW_WATERMARK)
-			priority |= __GFP_NOWARN;
+			gfp_mask |= __GFP_NOWARN;
 
 		if (priv->hw_params.rx_page_order > 0)
-			priority |= __GFP_COMP;
+			gfp_mask |= __GFP_COMP;
 
 		/* Alloc a new receive buffer */
-		page = alloc_pages(priority, priv->hw_params.rx_page_order);
+		page = alloc_pages(gfp_mask, priv->hw_params.rx_page_order);
 		if (!page) {
 			if (net_ratelimit())
 				IWL_DEBUG_INFO(priv, "Failed to allocate SKB buffer.\n");
@@ -1410,8 +1411,8 @@ static void iwl3945_rx_handle(struct iwl_priv *priv)
 		if (priv->rx_handlers[pkt->hdr.cmd]) {
 			IWL_DEBUG_RX(priv, "r = %d, i = %d, %s, 0x%02x\n", r, i,
 				get_cmd_string(pkt->hdr.cmd), pkt->hdr.cmd);
-			priv->rx_handlers[pkt->hdr.cmd] (priv, rxb);
 			priv->isr_stats.rx_handlers[pkt->hdr.cmd]++;
+			priv->rx_handlers[pkt->hdr.cmd] (priv, rxb);
 		} else {
 			/* No handling needed */
 			IWL_DEBUG_RX(priv,
@@ -1420,11 +1421,18 @@ static void iwl3945_rx_handle(struct iwl_priv *priv)
 				pkt->hdr.cmd);
 		}
 
+		/*
+		 * XXX: After here, we should always check rxb->page
+		 * against NULL before touching it or its virtual
+		 * memory (pkt). Because some rx_handler might have
+		 * already taken or freed the pages.
+		 */
+
 		if (reclaim) {
 			/* Invoke any callbacks, transfer the buffer to caller,
 			 * and fire off the (possibly) blocking iwl_send_cmd()
 			 * as we reclaim the driver command queue */
-			if (rxb && rxb->page)
+			if (rxb->page)
 				iwl_tx_cmd_complete(priv, rxb);
 			else
 				IWL_WARN(priv, "Claim null rxb?\n");