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https://github.com/FEX-Emu/linux.git
synced 2024-12-15 21:30:43 +00:00
CAPI: Rework locking of capidev members
Rename 'ncci_list_mtx' to 'lock', expressing that it now protects a larger set of capidev members: the NCCI list, ap.applid (ie. the registration of the application), and modifications of userflags. We do not need to protect each and every check for ap.applid because, once an application is registered, it will stay for the whole lifetime of the device. Also, there is no need to apply the capidev mutex during release (if there could be concurrent users, we would crash them anyway by freeing the device at the end of capi_release). Signed-off-by: Jan Kiszka <jan.kiszka@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jan Kiszka
David S. Miller
parent
eca39dd830
commit
05b4149433
@ -141,7 +141,7 @@ struct capidev {
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struct capincci *nccis;
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struct mutex ncci_list_mtx;
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struct mutex lock;
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};
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/* -------- global variables ---------------------------------------- */
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@ -574,38 +574,31 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
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u16 datahandle;
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#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
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struct capincci *np;
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u32 ncci;
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unsigned long flags;
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mutex_lock(&cdev->lock);
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if (CAPIMSG_CMD(skb->data) == CAPI_CONNECT_B3_CONF) {
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u16 info = CAPIMSG_U16(skb->data, 12); // Info field
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if ((info & 0xff00) == 0) {
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mutex_lock(&cdev->ncci_list_mtx);
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if ((info & 0xff00) == 0)
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capincci_alloc(cdev, CAPIMSG_NCCI(skb->data));
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mutex_unlock(&cdev->ncci_list_mtx);
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}
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}
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if (CAPIMSG_CMD(skb->data) == CAPI_CONNECT_B3_IND) {
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mutex_lock(&cdev->ncci_list_mtx);
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if (CAPIMSG_CMD(skb->data) == CAPI_CONNECT_B3_IND)
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capincci_alloc(cdev, CAPIMSG_NCCI(skb->data));
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mutex_unlock(&cdev->ncci_list_mtx);
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}
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spin_lock_irqsave(&workaround_lock, flags);
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if (CAPIMSG_COMMAND(skb->data) != CAPI_DATA_B3) {
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skb_queue_tail(&cdev->recvqueue, skb);
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wake_up_interruptible(&cdev->recvwait);
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spin_unlock_irqrestore(&workaround_lock, flags);
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return;
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goto unlock_out;
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}
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ncci = CAPIMSG_CONTROL(skb->data);
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for (np = cdev->nccis; np && np->ncci != ncci; np = np->next)
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;
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np = capincci_find(cdev, CAPIMSG_CONTROL(skb->data));
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if (!np) {
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printk(KERN_ERR "BUG: capi_signal: ncci not found\n");
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skb_queue_tail(&cdev->recvqueue, skb);
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wake_up_interruptible(&cdev->recvwait);
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spin_unlock_irqrestore(&workaround_lock, flags);
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return;
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goto unlock_out;
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}
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#ifndef CONFIG_ISDN_CAPI_MIDDLEWARE
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@ -618,8 +611,7 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
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if (!mp) {
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skb_queue_tail(&cdev->recvqueue, skb);
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wake_up_interruptible(&cdev->recvwait);
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spin_unlock_irqrestore(&workaround_lock, flags);
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return;
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goto unlock_out;
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}
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if (CAPIMSG_SUBCOMMAND(skb->data) == CAPI_IND) {
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datahandle = CAPIMSG_U16(skb->data, CAPIMSG_BASELEN+4+4+2);
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@ -652,7 +644,9 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
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}
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#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
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unlock_out:
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spin_unlock_irqrestore(&workaround_lock, flags);
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mutex_unlock(&cdev->lock);
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}
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/* -------- file_operations for capidev ----------------------------- */
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@ -730,9 +724,9 @@ capi_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos
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CAPIMSG_SETAPPID(skb->data, cdev->ap.applid);
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if (CAPIMSG_CMD(skb->data) == CAPI_DISCONNECT_B3_RESP) {
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mutex_lock(&cdev->ncci_list_mtx);
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mutex_lock(&cdev->lock);
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capincci_free(cdev, CAPIMSG_NCCI(skb->data));
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mutex_unlock(&cdev->ncci_list_mtx);
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mutex_unlock(&cdev->lock);
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}
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cdev->errcode = capi20_put_message(&cdev->ap, skb);
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@ -765,30 +759,35 @@ capi_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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struct capidev *cdev = file->private_data;
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struct capi20_appl *ap = &cdev->ap;
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capi_ioctl_struct data;
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int retval = -EINVAL;
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void __user *argp = (void __user *)arg;
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switch (cmd) {
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case CAPI_REGISTER:
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{
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if (ap->applid)
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return -EEXIST;
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mutex_lock(&cdev->lock);
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if (copy_from_user(&cdev->ap.rparam, argp,
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sizeof(struct capi_register_params)))
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return -EFAULT;
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cdev->ap.private = cdev;
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cdev->ap.recv_message = capi_recv_message;
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cdev->errcode = capi20_register(ap);
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if (cdev->errcode) {
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ap->applid = 0;
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return -EIO;
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}
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if (cdev->ap.applid) {
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retval = -EEXIST;
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goto register_out;
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}
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return (int)ap->applid;
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if (copy_from_user(&cdev->ap.rparam, argp,
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sizeof(struct capi_register_params))) {
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retval = -EFAULT;
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goto register_out;
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}
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cdev->ap.private = cdev;
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cdev->ap.recv_message = capi_recv_message;
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cdev->errcode = capi20_register(&cdev->ap);
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retval = (int)cdev->ap.applid;
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if (cdev->errcode) {
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cdev->ap.applid = 0;
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retval = -EIO;
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}
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register_out:
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mutex_unlock(&cdev->lock);
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return retval;
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case CAPI_GET_VERSION:
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{
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@ -887,68 +886,67 @@ capi_ioctl(struct inode *inode, struct file *file,
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return 0;
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case CAPI_SET_FLAGS:
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case CAPI_CLR_FLAGS:
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{
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unsigned userflags;
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if (copy_from_user(&userflags, argp,
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sizeof(userflags)))
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return -EFAULT;
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if (cmd == CAPI_SET_FLAGS)
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cdev->userflags |= userflags;
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else
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cdev->userflags &= ~userflags;
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}
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return 0;
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case CAPI_CLR_FLAGS: {
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unsigned userflags;
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if (copy_from_user(&userflags, argp, sizeof(userflags)))
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return -EFAULT;
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mutex_lock(&cdev->lock);
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if (cmd == CAPI_SET_FLAGS)
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cdev->userflags |= userflags;
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else
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cdev->userflags &= ~userflags;
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mutex_unlock(&cdev->lock);
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return 0;
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}
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case CAPI_GET_FLAGS:
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if (copy_to_user(argp, &cdev->userflags,
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sizeof(cdev->userflags)))
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return -EFAULT;
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return 0;
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case CAPI_NCCI_OPENCOUNT:
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{
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struct capincci *nccip;
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unsigned ncci;
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int count = 0;
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if (copy_from_user(&ncci, argp, sizeof(ncci)))
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return -EFAULT;
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case CAPI_NCCI_OPENCOUNT: {
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struct capincci *nccip;
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unsigned ncci;
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int count = 0;
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mutex_lock(&cdev->ncci_list_mtx);
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if ((nccip = capincci_find(cdev, (u32) ncci)) == NULL) {
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mutex_unlock(&cdev->ncci_list_mtx);
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return 0;
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}
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count += capincci_minor_opencount(nccip);
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mutex_unlock(&cdev->ncci_list_mtx);
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return count;
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}
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return 0;
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if (copy_from_user(&ncci, argp, sizeof(ncci)))
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return -EFAULT;
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mutex_lock(&cdev->lock);
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nccip = capincci_find(cdev, (u32)ncci);
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if (nccip)
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count = capincci_minor_opencount(nccip);
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mutex_unlock(&cdev->lock);
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return count;
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}
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#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
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case CAPI_NCCI_GETUNIT:
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{
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struct capincci *nccip;
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struct capiminor *mp;
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unsigned ncci;
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int unit = 0;
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if (copy_from_user(&ncci, argp,
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sizeof(ncci)))
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return -EFAULT;
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mutex_lock(&cdev->ncci_list_mtx);
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nccip = capincci_find(cdev, (u32) ncci);
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if (!nccip || (mp = nccip->minorp) == NULL) {
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mutex_unlock(&cdev->ncci_list_mtx);
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return -ESRCH;
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}
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unit = mp->minor;
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mutex_unlock(&cdev->ncci_list_mtx);
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return unit;
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case CAPI_NCCI_GETUNIT: {
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struct capincci *nccip;
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struct capiminor *mp;
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unsigned ncci;
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int unit = -ESRCH;
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if (copy_from_user(&ncci, argp, sizeof(ncci)))
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return -EFAULT;
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mutex_lock(&cdev->lock);
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nccip = capincci_find(cdev, (u32)ncci);
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if (nccip) {
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mp = nccip->minorp;
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if (mp)
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unit = mp->minor;
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}
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return 0;
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#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
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mutex_unlock(&cdev->lock);
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return unit;
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}
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#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
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default:
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return -EINVAL;
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}
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return -EINVAL;
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}
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static int capi_open(struct inode *inode, struct file *file)
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@ -959,7 +957,7 @@ static int capi_open(struct inode *inode, struct file *file)
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if (!cdev)
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return -ENOMEM;
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mutex_init(&cdev->ncci_list_mtx);
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mutex_init(&cdev->lock);
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skb_queue_head_init(&cdev->recvqueue);
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init_waitqueue_head(&cdev->recvwait);
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file->private_data = cdev;
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@ -979,15 +977,10 @@ static int capi_release(struct inode *inode, struct file *file)
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list_del(&cdev->list);
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mutex_unlock(&capidev_list_lock);
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if (cdev->ap.applid) {
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if (cdev->ap.applid)
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capi20_release(&cdev->ap);
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cdev->ap.applid = 0;
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}
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skb_queue_purge(&cdev->recvqueue);
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mutex_lock(&cdev->ncci_list_mtx);
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capincci_free(cdev, 0xffffffff);
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mutex_unlock(&cdev->ncci_list_mtx);
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kfree(cdev);
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return 0;
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@ -1446,11 +1439,13 @@ static int capi20ncci_proc_show(struct seq_file *m, void *v)
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mutex_lock(&capidev_list_lock);
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list_for_each(l, &capidev_list) {
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cdev = list_entry(l, struct capidev, list);
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mutex_lock(&cdev->lock);
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for (np=cdev->nccis; np; np = np->next) {
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seq_printf(m, "%d 0x%x\n",
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cdev->ap.applid,
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np->ncci);
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}
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mutex_unlock(&cdev->lock);
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}
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mutex_unlock(&capidev_list_lock);
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return 0;
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