};
#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
+/* FIXME: The following lock is a sledgehammer-workaround to a
+ * locking issue with the capiminor (and maybe other) data structure(s).
+ * Access to this data is done in a racy way and crashes the machine with
+ * a FritzCard DSL driver; sooner or later. This is a workaround
+ * which trades scalability vs stability, so it doesn't crash the kernel anymore.
+ * The correct (and scalable) fix for the issue seems to require
+ * an API change to the drivers... . */
+static DEFINE_SPINLOCK(workaround_lock);
+
struct capincci {
struct capincci *next;
u32 ncci;
#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
struct capincci *np;
u32 ncci;
+ unsigned long flags;
if (CAPIMSG_CMD(skb->data) == CAPI_CONNECT_B3_CONF) {
u16 info = CAPIMSG_U16(skb->data, 12); // Info field
capincci_alloc(cdev, CAPIMSG_NCCI(skb->data));
up(&cdev->ncci_list_sem);
}
+ spin_lock_irqsave(&workaround_lock, flags);
if (CAPIMSG_COMMAND(skb->data) != CAPI_DATA_B3) {
skb_queue_tail(&cdev->recvqueue, skb);
wake_up_interruptible(&cdev->recvwait);
+ spin_unlock_irqrestore(&workaround_lock, flags);
return;
}
ncci = CAPIMSG_CONTROL(skb->data);
printk(KERN_ERR "BUG: capi_signal: ncci not found\n");
skb_queue_tail(&cdev->recvqueue, skb);
wake_up_interruptible(&cdev->recvwait);
+ spin_unlock_irqrestore(&workaround_lock, flags);
return;
}
#ifndef CONFIG_ISDN_CAPI_MIDDLEWARE
if (!mp) {
skb_queue_tail(&cdev->recvqueue, skb);
wake_up_interruptible(&cdev->recvwait);
+ spin_unlock_irqrestore(&workaround_lock, flags);
return;
}
wake_up_interruptible(&cdev->recvwait);
}
#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
+ spin_unlock_irqrestore(&workaround_lock, flags);
}
/* -------- file_operations for capidev ----------------------------- */
static int capinc_tty_open(struct tty_struct * tty, struct file * file)
{
struct capiminor *mp;
+ unsigned long flags;
if ((mp = capiminor_find(iminor(file->f_path.dentry->d_inode))) == 0)
return -ENXIO;
tty->driver_data = (void *)mp;
+ spin_lock_irqsave(&workaround_lock, flags);
if (atomic_read(&mp->ttyopencount) == 0)
mp->tty = tty;
atomic_inc(&mp->ttyopencount);
printk(KERN_DEBUG "capinc_tty_open ocount=%d\n", atomic_read(&mp->ttyopencount));
#endif
handle_minor_recv(mp);
+ spin_unlock_irqrestore(&workaround_lock, flags);
return 0;
}
{
struct capiminor *mp = (struct capiminor *)tty->driver_data;
struct sk_buff *skb;
+ unsigned long flags;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_write(count=%d)\n", count);
return 0;
}
+ spin_lock_irqsave(&workaround_lock, flags);
skb = mp->ttyskb;
if (skb) {
mp->ttyskb = NULL;
skb = alloc_skb(CAPI_DATA_B3_REQ_LEN+count, GFP_ATOMIC);
if (!skb) {
printk(KERN_ERR "capinc_tty_write: alloc_skb failed\n");
+ spin_unlock_irqrestore(&workaround_lock, flags);
return -ENOMEM;
}
mp->outbytes += skb->len;
(void)handle_minor_send(mp);
(void)handle_minor_recv(mp);
+ spin_unlock_irqrestore(&workaround_lock, flags);
return count;
}
{
struct capiminor *mp = (struct capiminor *)tty->driver_data;
struct sk_buff *skb;
+ unsigned long flags;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_put_char(%u)\n", ch);
return;
}
+ spin_lock_irqsave(&workaround_lock, flags);
skb = mp->ttyskb;
if (skb) {
if (skb_tailroom(skb) > 0) {
*(skb_put(skb, 1)) = ch;
+ spin_unlock_irqrestore(&workaround_lock, flags);
return;
}
mp->ttyskb = NULL;
} else {
printk(KERN_ERR "capinc_put_char: char %u lost\n", ch);
}
+ spin_unlock_irqrestore(&workaround_lock, flags);
}
static void capinc_tty_flush_chars(struct tty_struct *tty)
{
struct capiminor *mp = (struct capiminor *)tty->driver_data;
struct sk_buff *skb;
+ unsigned long flags;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_flush_chars\n");
return;
}
+ spin_lock_irqsave(&workaround_lock, flags);
skb = mp->ttyskb;
if (skb) {
mp->ttyskb = NULL;
(void)handle_minor_send(mp);
}
(void)handle_minor_recv(mp);
+ spin_unlock_irqrestore(&workaround_lock, flags);
}
static int capinc_tty_write_room(struct tty_struct *tty)
static void capinc_tty_unthrottle(struct tty_struct * tty)
{
struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ unsigned long flags;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_unthrottle\n");
#endif
if (mp) {
+ spin_lock_irqsave(&workaround_lock, flags);
mp->ttyinstop = 0;
handle_minor_recv(mp);
+ spin_unlock_irqrestore(&workaround_lock, flags);
}
}
static void capinc_tty_start(struct tty_struct *tty)
{
struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ unsigned long flags;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_start\n");
#endif
if (mp) {
+ spin_lock_irqsave(&workaround_lock, flags);
mp->ttyoutstop = 0;
(void)handle_minor_send(mp);
+ spin_unlock_irqrestore(&workaround_lock, flags);
}
}