[deliverable/linux.git] / drivers / usb / mon / mon_stat.c

/*
 * The USB Monitor, inspired by Dave Harding's USBMon.
 *
 * This is the 's' or 'stat' reader which debugs usbmon itself.
 * Note that this code blows through locks, so make sure that
 * /dbg/usbmon/0s is well protected from non-root users.
 *
 */

#include <linux/kernel.h>
#include <linux/usb.h>
#include <linux/fs.h>
#include <asm/uaccess.h>

#include "usb_mon.h"

#define STAT_BUF_SIZE  80

struct snap {
	int slen;
	char str[STAT_BUF_SIZE];
};

static int mon_stat_open(struct inode *inode, struct file *file)
{
	struct mon_bus *mbus;
	struct snap *sp;

	if ((sp = kmalloc(sizeof(struct snap), GFP_KERNEL)) == NULL)
		return -ENOMEM;

	mbus = inode->i_private;

	sp->slen = snprintf(sp->str, STAT_BUF_SIZE,
	    "nreaders %d events %u text_lost %u\n",
	    mbus->nreaders, mbus->cnt_events, mbus->cnt_text_lost);

	file->private_data = sp;
	return 0;
}

static ssize_t mon_stat_read(struct file *file, char __user *buf,
				size_t nbytes, loff_t *ppos)
{
	struct snap *sp = file->private_data;

	return simple_read_from_buffer(buf, nbytes, ppos, sp->str, sp->slen);
}

static int mon_stat_release(struct inode *inode, struct file *file)
{
	struct snap *sp = file->private_data;
	file->private_data = NULL;
	kfree(sp);
	return 0;
}

const struct file_operations mon_fops_stat = {
	.owner =	THIS_MODULE,
	.open =		mon_stat_open,
	.llseek =	no_llseek,
	.read =		mon_stat_read,
	/* .write =	mon_stat_write, */
	/* .poll =		mon_stat_poll, */
	/* .ioctl =	mon_stat_ioctl, */
	.release =	mon_stat_release,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* The USB Monitor, inspired by Dave Harding's USBMon.
	3	*
	4	* This is the 's' or 'stat' reader which debugs usbmon itself.
	5	* Note that this code blows through locks, so make sure that
	6	* /dbg/usbmon/0s is well protected from non-root users.
	7	*
	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/usb.h>
518386c7	12	#include <linux/fs.h>
1da177e4 LT	13	#include <asm/uaccess.h>
	14
	15	#include "usb_mon.h"
	16
	17	#define STAT_BUF_SIZE 80
	18
	19	struct snap {
	20	int slen;
	21	char str[STAT_BUF_SIZE];
	22	};
	23
	24	static int mon_stat_open(struct inode inode, struct file file)
	25	{
	26	struct mon_bus *mbus;
	27	struct snap *sp;
	28
	29	if ((sp = kmalloc(sizeof(struct snap), GFP_KERNEL)) == NULL)
	30	return -ENOMEM;
	31
8e18e294	32	mbus = inode->i_private;
1da177e4 LT	33
1da177e4 LT	34	sp->slen = snprintf(sp->str, STAT_BUF_SIZE,
5b1c674d PZ	35	"nreaders %d events %u text_lost %u\n",
5b1c674d PZ	36	mbus->nreaders, mbus->cnt_events, mbus->cnt_text_lost);
1da177e4 LT	37
	38	file->private_data = sp;
	39	return 0;
	40	}
	41
	42	static ssize_t mon_stat_read(struct file file, char __user buf,
	43	size_t nbytes, loff_t *ppos)
	44	{
	45	struct snap *sp = file->private_data;
1da177e4	46
518386c7	47	return simple_read_from_buffer(buf, nbytes, ppos, sp->str, sp->slen);
1da177e4 LT	48	}
	49
	50	static int mon_stat_release(struct inode inode, struct file file)
	51	{
d4062fcb ML	52	struct snap *sp = file->private_data;
	53	file->private_data = NULL;
	54	kfree(sp);
1da177e4 LT	55	return 0;
	56	}
	57
066202dd	58	const struct file_operations mon_fops_stat = {
1da177e4 LT	59	.owner = THIS_MODULE,
	60	.open = mon_stat_open,
	61	.llseek = no_llseek,
	62	.read = mon_stat_read,
	63	/* .write = mon_stat_write, */
	64	/* .poll = mon_stat_poll, */
	65	/* .ioctl = mon_stat_ioctl, */
	66	.release = mon_stat_release,
	67	};