From: Ivo van Doorn Date: Sun, 9 Mar 2008 21:44:30 +0000 (+0100) Subject: rt2x00: Upgrade queue->lock to use irqsave X-Git-Tag: v2.6.26-rc1~1138^2~435 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5f46c4d0537a870f9d9c1fd998aa9d6dac682595;p=linux-2.6 rt2x00: Upgrade queue->lock to use irqsave The queue->lock could be grabbed from interrupt context, which could lead to lockdep panic like this: kernel: ====================================================== kernel: [ INFO: soft-safe -> soft-unsafe lock order detected ] kernel: 2.6.25-0.95.rc4.fc9 #1 kernel: ------------------------------------------------------ kernel: rt2500pci/1251 [HC0[0]:SC0[1]:HE1:SE0] is trying to acquire: kernel: (&queue->lock){--..}, at: [] rt2x00queue_get_entry+0x5a/0x81 [rt2x00lib] kernel: kernel: and this task is already holding: kernel: (_xmit_IEEE80211){-...}, at: [] __qdisc_run+0x84/0x1a9 kernel: which would create a new lock dependency: kernel: (_xmit_IEEE80211){-...} -> (&queue->lock){--..} kernel: kernel: but this new dependency connects a soft-irq-safe lock: kernel: (_xmit_ETHER){-+..} kernel: ... which became soft-irq-safe at: kernel: [] 0xffffffffffffffff kernel: kernel: to a soft-irq-unsafe lock: kernel: (&queue->lock){--..} kernel: ... which became soft-irq-unsafe at: kernel: ... [] __lock_acquire+0x62d/0xd63 kernel: [] lock_acquire+0x5e/0x78 kernel: [] _spin_lock+0x26/0x53 kernel: [] rt2x00queue_reset+0x16/0x40 [rt2x00lib] kernel: [] rt2x00queue_alloc_entries+0x12/0xab [rt2x00lib] kernel: [] rt2x00queue_initialize+0x24/0xf2 [rt2x00lib] kernel: [] rt2x00lib_start+0x3b/0xd4 [rt2x00lib] kernel: [] rt2x00mac_start+0x18/0x1a [rt2x00lib] kernel: [] ieee80211_open+0x1f3/0x46d [mac80211] kernel: [] dev_open+0x4d/0x8b kernel: [] dev_change_flags+0xaf/0x172 kernel: [] do_setlink+0x276/0x338 kernel: [] rtnl_setlink+0x114/0x116 kernel: [] rtnetlink_rcv_msg+0x1d8/0x1f9 kernel: [] netlink_rcv_skb+0x3e/0xac kernel: [] rtnetlink_rcv+0x29/0x33 kernel: [] netlink_unicast+0x1fe/0x26b kernel: [] netlink_sendmsg+0x2ca/0x2dd kernel: [] sock_sendmsg+0xfd/0x120 kernel: [] sys_sendmsg+0x1d2/0x23c kernel: [] tracesys+0xdc/0xe1 kernel: [] 0xffffffffffffffff This can be fixed by using the irqsave/irqrestore versions during the queue->lock handling. Signed-off-by: Ivo van Doorn Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/rt2x00/rt2x00debug.c b/drivers/net/wireless/rt2x00/rt2x00debug.c index 21af11a973..bfab3b8780 100644 --- a/drivers/net/wireless/rt2x00/rt2x00debug.c +++ b/drivers/net/wireless/rt2x00/rt2x00debug.c @@ -278,6 +278,7 @@ static ssize_t rt2x00debug_read_queue_stats(struct file *file, { struct rt2x00debug_intf *intf = file->private_data; struct data_queue *queue; + unsigned long irqflags; unsigned int lines = 1 + intf->rt2x00dev->data_queues; size_t size; char *data; @@ -294,7 +295,7 @@ static ssize_t rt2x00debug_read_queue_stats(struct file *file, sprintf(data, "qid\tcount\tlimit\tlength\tindex\tdone\tcrypto\n"); queue_for_each(intf->rt2x00dev, queue) { - spin_lock(&queue->lock); + spin_lock_irqsave(&queue->lock, irqflags); temp += sprintf(temp, "%d\t%d\t%d\t%d\t%d\t%d\t%d\n", queue->qid, queue->count, queue->limit, queue->length, @@ -302,7 +303,7 @@ static ssize_t rt2x00debug_read_queue_stats(struct file *file, queue->index[Q_INDEX_DONE], queue->index[Q_INDEX_CRYPTO]); - spin_unlock(&queue->lock); + spin_unlock_irqrestore(&queue->lock, irqflags); } size = strlen(data); diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c index 9188323f06..659e9f44c4 100644 --- a/drivers/net/wireless/rt2x00/rt2x00queue.c +++ b/drivers/net/wireless/rt2x00/rt2x00queue.c @@ -53,6 +53,7 @@ struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue, enum queue_index index) { struct queue_entry *entry; + unsigned long irqflags; if (unlikely(index >= Q_INDEX_MAX)) { ERROR(queue->rt2x00dev, @@ -60,11 +61,11 @@ struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue, return NULL; } - spin_lock(&queue->lock); + spin_lock_irqsave(&queue->lock, irqflags); entry = &queue->entries[queue->index[index]]; - spin_unlock(&queue->lock); + spin_unlock_irqrestore(&queue->lock, irqflags); return entry; } @@ -72,13 +73,15 @@ EXPORT_SYMBOL_GPL(rt2x00queue_get_entry); void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index) { + unsigned long irqflags; + if (unlikely(index >= Q_INDEX_MAX)) { ERROR(queue->rt2x00dev, "Index change on invalid index type (%d)\n", index); return; } - spin_lock(&queue->lock); + spin_lock_irqsave(&queue->lock, irqflags); queue->index[index]++; if (queue->index[index] >= queue->limit) @@ -91,19 +94,21 @@ void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index) queue->count ++; } - spin_unlock(&queue->lock); + spin_unlock_irqrestore(&queue->lock, irqflags); } EXPORT_SYMBOL_GPL(rt2x00queue_index_inc); static void rt2x00queue_reset(struct data_queue *queue) { - spin_lock(&queue->lock); + unsigned long irqflags; + + spin_lock_irqsave(&queue->lock, irqflags); queue->count = 0; queue->length = 0; memset(queue->index, 0, sizeof(queue->index)); - spin_unlock(&queue->lock); + spin_unlock_irqrestore(&queue->lock, irqflags); } void rt2x00queue_init_rx(struct rt2x00_dev *rt2x00dev)