Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:53292 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752964AbZGFTuF (ORCPT ); Mon, 6 Jul 2009 15:50:05 -0400 Date: Mon, 06 Jul 2009 12:50:11 -0700 (PDT) Message-Id: <20090706.125011.56653570.davem@davemloft.net> To: Larry.Finger@lwfinger.net Cc: chunkeey@web.de, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] p54: Fix regression in 2.6.31-rcX since commit a1091aa - sleeping function called from invalid context From: David Miller In-Reply-To: <4A5253F1.50504@lwfinger.net> References: <200907062119.25642.chunkeey@web.de> <20090706.123441.246532764.davem@davemloft.net> <4A5253F1.50504@lwfinger.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Larry Finger Date: Mon, 06 Jul 2009 14:43:45 -0500 > I'm available for testing. I just committed the following to my net-2.6 tree, give it a spin: >From 0ca1b08eba627b4245efd0f71b55a062bf163777 Mon Sep 17 00:00:00 2001 From: David S. Miller Date: Mon, 6 Jul 2009 12:49:18 -0700 Subject: [PATCH] Revert "p54: Use SKB list handling helpers instead of by-hand code." This reverts commit a1091aae19b1d9c85d91c86915a611387f67a26b. --- drivers/net/wireless/p54/p54common.c | 46 ++++++++++++++++++++-------------- 1 files changed, 27 insertions(+), 19 deletions(-) diff --git a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c index b618bd1..48d81d9 100644 --- a/drivers/net/wireless/p54/p54common.c +++ b/drivers/net/wireless/p54/p54common.c @@ -823,30 +823,30 @@ void p54_free_skb(struct ieee80211_hw *dev, struct sk_buff *skb) struct p54_tx_info *range; unsigned long flags; - if (unlikely(!skb || !dev || skb_queue_empty(&priv->tx_queue))) + if (unlikely(!skb || !dev || !skb_queue_len(&priv->tx_queue))) return; - /* There used to be a check here to see if the SKB was on the - * TX queue or not. This can never happen because all SKBs we - * see here successfully went through p54_assign_address() - * which means the SKB is on the ->tx_queue. + /* + * don't try to free an already unlinked skb */ + if (unlikely((!skb->next) || (!skb->prev))) + return; spin_lock_irqsave(&priv->tx_queue.lock, flags); info = IEEE80211_SKB_CB(skb); range = (void *)info->rate_driver_data; - if (!skb_queue_is_first(&priv->tx_queue, skb)) { + if (skb->prev != (struct sk_buff *)&priv->tx_queue) { struct ieee80211_tx_info *ni; struct p54_tx_info *mr; - ni = IEEE80211_SKB_CB(skb_queue_prev(&priv->tx_queue, skb)); + ni = IEEE80211_SKB_CB(skb->prev); mr = (struct p54_tx_info *)ni->rate_driver_data; } - if (!skb_queue_is_last(&priv->tx_queue, skb)) { + if (skb->next != (struct sk_buff *)&priv->tx_queue) { struct ieee80211_tx_info *ni; struct p54_tx_info *mr; - ni = IEEE80211_SKB_CB(skb_queue_next(&priv->tx_queue, skb)); + ni = IEEE80211_SKB_CB(skb->next); mr = (struct p54_tx_info *)ni->rate_driver_data; } __skb_unlink(skb, &priv->tx_queue); @@ -864,13 +864,15 @@ static struct sk_buff *p54_find_tx_entry(struct ieee80211_hw *dev, unsigned long flags; spin_lock_irqsave(&priv->tx_queue.lock, flags); - skb_queue_walk(&priv->tx_queue, entry) { + entry = priv->tx_queue.next; + while (entry != (struct sk_buff *)&priv->tx_queue) { struct p54_hdr *hdr = (struct p54_hdr *) entry->data; if (hdr->req_id == req_id) { spin_unlock_irqrestore(&priv->tx_queue.lock, flags); return entry; } + entry = entry->next; } spin_unlock_irqrestore(&priv->tx_queue.lock, flags); return NULL; @@ -888,22 +890,24 @@ static void p54_rx_frame_sent(struct ieee80211_hw *dev, struct sk_buff *skb) int count, idx; spin_lock_irqsave(&priv->tx_queue.lock, flags); - skb_queue_walk(&priv->tx_queue, entry) { + entry = (struct sk_buff *) priv->tx_queue.next; + while (entry != (struct sk_buff *)&priv->tx_queue) { struct ieee80211_tx_info *info = IEEE80211_SKB_CB(entry); struct p54_hdr *entry_hdr; struct p54_tx_data *entry_data; unsigned int pad = 0, frame_len; range = (void *)info->rate_driver_data; - if (range->start_addr != addr) + if (range->start_addr != addr) { + entry = entry->next; continue; + } - if (!skb_queue_is_last(&priv->tx_queue, entry)) { + if (entry->next != (struct sk_buff *)&priv->tx_queue) { struct ieee80211_tx_info *ni; struct p54_tx_info *mr; - ni = IEEE80211_SKB_CB(skb_queue_next(&priv->tx_queue, - entry)); + ni = IEEE80211_SKB_CB(entry->next); mr = (struct p54_tx_info *)ni->rate_driver_data; } @@ -1164,21 +1168,23 @@ static int p54_assign_address(struct ieee80211_hw *dev, struct sk_buff *skb, } } - skb_queue_walk(&priv->tx_queue, entry) { + entry = priv->tx_queue.next; + while (left--) { u32 hole_size; info = IEEE80211_SKB_CB(entry); range = (void *)info->rate_driver_data; hole_size = range->start_addr - last_addr; if (!target_skb && hole_size >= len) { - target_skb = skb_queue_prev(&priv->tx_queue, entry); + target_skb = entry->prev; hole_size -= len; target_addr = last_addr; } largest_hole = max(largest_hole, hole_size); last_addr = range->end_addr; + entry = entry->next; } if (!target_skb && priv->rx_end - last_addr >= len) { - target_skb = skb_peek_tail(&priv->tx_queue); + target_skb = priv->tx_queue.prev; largest_hole = max(largest_hole, priv->rx_end - last_addr - len); if (!skb_queue_empty(&priv->tx_queue)) { info = IEEE80211_SKB_CB(target_skb); @@ -2084,6 +2090,7 @@ out: static void p54_stop(struct ieee80211_hw *dev) { struct p54_common *priv = dev->priv; + struct sk_buff *skb; mutex_lock(&priv->conf_mutex); priv->mode = NL80211_IFTYPE_UNSPECIFIED; @@ -2098,7 +2105,8 @@ static void p54_stop(struct ieee80211_hw *dev) p54_tx_cancel(dev, priv->cached_beacon); priv->stop(dev); - skb_queue_purge(&priv->tx_queue); + while ((skb = skb_dequeue(&priv->tx_queue))) + kfree_skb(skb); priv->cached_beacon = NULL; priv->tsf_high32 = priv->tsf_low32 = 0; mutex_unlock(&priv->conf_mutex); -- 1.6.3.3