diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/usb/mon/mon_stat.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/usb/mon/mon_stat.c')
-rw-r--r-- | drivers/usb/mon/mon_stat.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/usb/mon/mon_stat.c b/drivers/usb/mon/mon_stat.c new file mode 100644 index 000000000000..6e4b165d070a --- /dev/null +++ b/drivers/usb/mon/mon_stat.c @@ -0,0 +1,74 @@ +/* + * 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 <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->u.generic_ip; + + sp->slen = snprintf(sp->str, STAT_BUF_SIZE, + "nreaders %d text_lost %u\n", + mbus->nreaders, 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; + loff_t pos = *ppos; + int cnt; + + if (pos < 0 || pos >= sp->slen) + return 0; + if (nbytes == 0) + return 0; + if ((cnt = sp->slen - pos) > nbytes) + cnt = nbytes; + if (copy_to_user(buf, sp->str + pos, cnt)) + return -EFAULT; + *ppos = pos + cnt; + return cnt; +} + +static int mon_stat_release(struct inode *inode, struct file *file) +{ + return 0; +} + +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, +}; |