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> | |
5a0e3ad6 | 11 | #include <linux/slab.h> |
f940fcd8 | 12 | #include <linux/export.h> |
1da177e4 | 13 | #include <linux/usb.h> |
518386c7 | 14 | #include <linux/fs.h> |
1da177e4 LT |
15 | #include <asm/uaccess.h> |
16 | ||
17 | #include "usb_mon.h" | |
18 | ||
19 | #define STAT_BUF_SIZE 80 | |
20 | ||
21 | struct snap { | |
22 | int slen; | |
23 | char str[STAT_BUF_SIZE]; | |
24 | }; | |
25 | ||
26 | static int mon_stat_open(struct inode *inode, struct file *file) | |
27 | { | |
28 | struct mon_bus *mbus; | |
29 | struct snap *sp; | |
30 | ||
4c08ccf0 GKH |
31 | sp = kmalloc(sizeof(struct snap), GFP_KERNEL); |
32 | if (sp == NULL) | |
1da177e4 LT |
33 | return -ENOMEM; |
34 | ||
8e18e294 | 35 | mbus = inode->i_private; |
1da177e4 LT |
36 | |
37 | sp->slen = snprintf(sp->str, STAT_BUF_SIZE, | |
5b1c674d PZ |
38 | "nreaders %d events %u text_lost %u\n", |
39 | mbus->nreaders, mbus->cnt_events, mbus->cnt_text_lost); | |
1da177e4 LT |
40 | |
41 | file->private_data = sp; | |
42 | return 0; | |
43 | } | |
44 | ||
45 | static ssize_t mon_stat_read(struct file *file, char __user *buf, | |
46 | size_t nbytes, loff_t *ppos) | |
47 | { | |
48 | struct snap *sp = file->private_data; | |
1da177e4 | 49 | |
518386c7 | 50 | return simple_read_from_buffer(buf, nbytes, ppos, sp->str, sp->slen); |
1da177e4 LT |
51 | } |
52 | ||
53 | static int mon_stat_release(struct inode *inode, struct file *file) | |
54 | { | |
d4062fcb ML |
55 | struct snap *sp = file->private_data; |
56 | file->private_data = NULL; | |
57 | kfree(sp); | |
1da177e4 LT |
58 | return 0; |
59 | } | |
60 | ||
066202dd | 61 | const struct file_operations mon_fops_stat = { |
1da177e4 LT |
62 | .owner = THIS_MODULE, |
63 | .open = mon_stat_open, | |
64 | .llseek = no_llseek, | |
65 | .read = mon_stat_read, | |
66 | /* .write = mon_stat_write, */ | |
67 | /* .poll = mon_stat_poll, */ | |
55929332 | 68 | /* .unlocked_ioctl = mon_stat_ioctl, */ |
1da177e4 LT |
69 | .release = mon_stat_release, |
70 | }; |