mon_text.c

来自「linux 内核源代码」· C语言 代码 · 共 753 行 · 第 1/2 页

{
	struct mon_reader_text *rp = file->private_data;
	struct mon_event_text *ep;
	struct mon_text_ptr ptr;

	if (IS_ERR(ep = mon_text_read_wait(rp, file)))
		return PTR_ERR(ep);
	mutex_lock(&rp->printf_lock);
	ptr.cnt = 0;
	ptr.pbuf = rp->printf_buf;
	ptr.limit = rp->printf_size;

	mon_text_read_head_t(rp, &ptr, ep);
	mon_text_read_statset(rp, &ptr, ep);
	ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
	    " %d", ep->length);
	mon_text_read_data(rp, &ptr, ep);

	if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
		ptr.cnt = -EFAULT;
	mutex_unlock(&rp->printf_lock);
	kmem_cache_free(rp->e_slab, ep);
	return ptr.cnt;
}

static ssize_t mon_text_read_u(struct file *file, char __user *buf,
				size_t nbytes, loff_t *ppos)
{
	struct mon_reader_text *rp = file->private_data;
	struct mon_event_text *ep;
	struct mon_text_ptr ptr;

	if (IS_ERR(ep = mon_text_read_wait(rp, file)))
		return PTR_ERR(ep);
	mutex_lock(&rp->printf_lock);
	ptr.cnt = 0;
	ptr.pbuf = rp->printf_buf;
	ptr.limit = rp->printf_size;

	mon_text_read_head_u(rp, &ptr, ep);
	if (ep->type == 'E') {
		mon_text_read_statset(rp, &ptr, ep);
	} else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) {
		mon_text_read_isostat(rp, &ptr, ep);
		mon_text_read_isodesc(rp, &ptr, ep);
	} else if (ep->xfertype == USB_ENDPOINT_XFER_INT) {
		mon_text_read_intstat(rp, &ptr, ep);
	} else {
		mon_text_read_statset(rp, &ptr, ep);
	}
	ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
	    " %d", ep->length);
	mon_text_read_data(rp, &ptr, ep);

	if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
		ptr.cnt = -EFAULT;
	mutex_unlock(&rp->printf_lock);
	kmem_cache_free(rp->e_slab, ep);
	return ptr.cnt;
}

static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp,
    struct file *file)
{
	struct mon_bus *mbus = rp->r.m_bus;
	DECLARE_WAITQUEUE(waita, current);
	struct mon_event_text *ep;

	add_wait_queue(&rp->wait, &waita);
	set_current_state(TASK_INTERRUPTIBLE);
	while ((ep = mon_text_fetch(rp, mbus)) == NULL) {
		if (file->f_flags & O_NONBLOCK) {
			set_current_state(TASK_RUNNING);
			remove_wait_queue(&rp->wait, &waita);
			return ERR_PTR(-EWOULDBLOCK);
		}
		/*
		 * We do not count nwaiters, because ->release is supposed
		 * to be called when all openers are gone only.
		 */
		schedule();
		if (signal_pending(current)) {
			remove_wait_queue(&rp->wait, &waita);
			return ERR_PTR(-EINTR);
		}
		set_current_state(TASK_INTERRUPTIBLE);
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&rp->wait, &waita);
	return ep;
}

static void mon_text_read_head_t(struct mon_reader_text *rp,
	struct mon_text_ptr *p, const struct mon_event_text *ep)
{
	char udir, utype;

	udir = (ep->is_in ? 'i' : 'o');
	switch (ep->xfertype) {
	case USB_ENDPOINT_XFER_ISOC:	utype = 'Z'; break;
	case USB_ENDPOINT_XFER_INT:	utype = 'I'; break;
	case USB_ENDPOINT_XFER_CONTROL:	utype = 'C'; break;
	default: /* PIPE_BULK */  utype = 'B';
	}
	p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
	    "%lx %u %c %c%c:%03u:%02u",
	    ep->id, ep->tstamp, ep->type,
	    utype, udir, ep->devnum, ep->epnum);
}

static void mon_text_read_head_u(struct mon_reader_text *rp,
	struct mon_text_ptr *p, const struct mon_event_text *ep)
{
	char udir, utype;

	udir = (ep->is_in ? 'i' : 'o');
	switch (ep->xfertype) {
	case USB_ENDPOINT_XFER_ISOC:	utype = 'Z'; break;
	case USB_ENDPOINT_XFER_INT:	utype = 'I'; break;
	case USB_ENDPOINT_XFER_CONTROL:	utype = 'C'; break;
	default: /* PIPE_BULK */  utype = 'B';
	}
	p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
	    "%lx %u %c %c%c:%d:%03u:%u",
	    ep->id, ep->tstamp, ep->type,
	    utype, udir, ep->busnum, ep->devnum, ep->epnum);
}

static void mon_text_read_statset(struct mon_reader_text *rp,
	struct mon_text_ptr *p, const struct mon_event_text *ep)
{

	if (ep->setup_flag == 0) {   /* Setup packet is present and captured */
		p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
		    " s %02x %02x %04x %04x %04x",
		    ep->setup[0],
		    ep->setup[1],
		    (ep->setup[3] << 8) | ep->setup[2],
		    (ep->setup[5] << 8) | ep->setup[4],
		    (ep->setup[7] << 8) | ep->setup[6]);
	} else if (ep->setup_flag != '-') { /* Unable to capture setup packet */
		p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
		    " %c __ __ ____ ____ ____", ep->setup_flag);
	} else {                     /* No setup for this kind of URB */
		p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
		    " %d", ep->status);
	}
}

static void mon_text_read_intstat(struct mon_reader_text *rp,
	struct mon_text_ptr *p, const struct mon_event_text *ep)
{
	p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
	    " %d:%d", ep->status, ep->interval);
}

static void mon_text_read_isostat(struct mon_reader_text *rp,
	struct mon_text_ptr *p, const struct mon_event_text *ep)
{
	if (ep->type == 'S') {
		p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
		    " %d:%d:%d", ep->status, ep->interval, ep->start_frame);
	} else {
		p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
		    " %d:%d:%d:%d",
		    ep->status, ep->interval, ep->start_frame, ep->error_count);
	}
}

static void mon_text_read_isodesc(struct mon_reader_text *rp,
	struct mon_text_ptr *p, const struct mon_event_text *ep)
{
	int ndesc;	/* Display this many */
	int i;
	const struct mon_iso_desc *dp;

	p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
	    " %d", ep->numdesc);
	ndesc = ep->numdesc;
	if (ndesc > ISODESC_MAX)
		ndesc = ISODESC_MAX;
	if (ndesc < 0)
		ndesc = 0;
	dp = ep->isodesc;
	for (i = 0; i < ndesc; i++) {
		p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
		    " %d:%u:%u", dp->status, dp->offset, dp->length);
		dp++;
	}
}

static void mon_text_read_data(struct mon_reader_text *rp,
    struct mon_text_ptr *p, const struct mon_event_text *ep)
{
	int data_len, i;

	if ((data_len = ep->length) > 0) {
		if (ep->data_flag == 0) {
			p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
			    " =");
			if (data_len >= DATA_MAX)
				data_len = DATA_MAX;
			for (i = 0; i < data_len; i++) {
				if (i % 4 == 0) {
					p->cnt += snprintf(p->pbuf + p->cnt,
					    p->limit - p->cnt,
					    " ");
				}
				p->cnt += snprintf(p->pbuf + p->cnt,
				    p->limit - p->cnt,
				    "%02x", ep->data[i]);
			}
			p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
			    "\n");
		} else {
			p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
			    " %c\n", ep->data_flag);
		}
	} else {
		p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n");
	}
}

static int mon_text_release(struct inode *inode, struct file *file)
{
	struct mon_reader_text *rp = file->private_data;
	struct mon_bus *mbus;
	/* unsigned long flags; */
	struct list_head *p;
	struct mon_event_text *ep;

	mutex_lock(&mon_lock);
	mbus = inode->i_private;

	if (mbus->nreaders <= 0) {
		printk(KERN_ERR TAG ": consistency error on close\n");
		mutex_unlock(&mon_lock);
		return 0;
	}
	mon_reader_del(mbus, &rp->r);

	/*
	 * In theory, e_list is protected by mbus->lock. However,
	 * after mon_reader_del has finished, the following is the case:
	 *  - we are not on reader list anymore, so new events won't be added;
	 *  - whole mbus may be dropped if it was orphaned.
	 * So, we better not touch mbus.
	 */
	/* spin_lock_irqsave(&mbus->lock, flags); */
	while (!list_empty(&rp->e_list)) {
		p = rp->e_list.next;
		ep = list_entry(p, struct mon_event_text, e_link);
		list_del(p);
		--rp->nevents;
		kmem_cache_free(rp->e_slab, ep);
	}
	/* spin_unlock_irqrestore(&mbus->lock, flags); */

	kmem_cache_destroy(rp->e_slab);
	kfree(rp->printf_buf);
	kfree(rp);

	mutex_unlock(&mon_lock);
	return 0;
}

static const struct file_operations mon_fops_text_t = {
	.owner =	THIS_MODULE,
	.open =		mon_text_open,
	.llseek =	no_llseek,
	.read =		mon_text_read_t,
	.release =	mon_text_release,
};

static const struct file_operations mon_fops_text_u = {
	.owner =	THIS_MODULE,
	.open =		mon_text_open,
	.llseek =	no_llseek,
	.read =		mon_text_read_u,
	.release =	mon_text_release,
};

int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
{
	struct dentry *d;
	enum { NAMESZ = 10 };
	char name[NAMESZ];
	int busnum = ubus? ubus->busnum: 0;
	int rc;

	if (ubus != NULL) {
		rc = snprintf(name, NAMESZ, "%dt", busnum);
		if (rc <= 0 || rc >= NAMESZ)
			goto err_print_t;
		d = debugfs_create_file(name, 0600, mon_dir, mbus,
							     &mon_fops_text_t);
		if (d == NULL)
			goto err_create_t;
		mbus->dent_t = d;
	}

	rc = snprintf(name, NAMESZ, "%du", busnum);
	if (rc <= 0 || rc >= NAMESZ)
		goto err_print_u;
	d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u);
	if (d == NULL)
		goto err_create_u;
	mbus->dent_u = d;

	rc = snprintf(name, NAMESZ, "%ds", busnum);
	if (rc <= 0 || rc >= NAMESZ)
		goto err_print_s;
	d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat);
	if (d == NULL)
		goto err_create_s;
	mbus->dent_s = d;

	return 1;

err_create_s:
err_print_s:
	debugfs_remove(mbus->dent_u);
	mbus->dent_u = NULL;
err_create_u:
err_print_u:
	if (ubus != NULL) {
		debugfs_remove(mbus->dent_t);
		mbus->dent_t = NULL;
	}
err_create_t:
err_print_t:
	return 0;
}

void mon_text_del(struct mon_bus *mbus)
{
	debugfs_remove(mbus->dent_u);
	if (mbus->dent_t != NULL)
		debugfs_remove(mbus->dent_t);
	debugfs_remove(mbus->dent_s);
}

/*
 * Slab interface: constructor.
 */
static void mon_text_ctor(struct kmem_cache *slab, void *mem)
{
	/*
	 * Nothing to initialize. No, really!
	 * So, we fill it with garbage to emulate a reused object.
	 */
	memset(mem, 0xe5, sizeof(struct mon_event_text));
}

int __init mon_text_init(void)
{
	struct dentry *mondir;

	mondir = debugfs_create_dir("usbmon", NULL);
	if (IS_ERR(mondir)) {
		printk(KERN_NOTICE TAG ": debugfs is not available\n");
		return -ENODEV;
	}
	if (mondir == NULL) {
		printk(KERN_NOTICE TAG ": unable to create usbmon directory\n");
		return -ENODEV;
	}
	mon_dir = mondir;
	return 0;
}

void mon_text_exit(void)
{
	debugfs_remove(mon_dir);
}