USB: snoop processes opening usbfs device files

This patch (as1148) adds a new "snoop" message to usbfs when a device
file is opened, identifying the process responsible.  This comes in
extremely handy when trying to determine which program is doing some
unwanted USB access.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 7a4fa791dc19..528befdcc781 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -624,6 +624,8 @@ static int usbdev_open(struct inode *inode, struct file *file)
         smp_wmb();
         list_add_tail(&ps->list, &dev->filelist);
         file->private_data = ps;
+        snoop(&dev->dev, "opened by process %d: %s\n", task_pid_nr(current),
+                        current->comm);
  out:
         if (ret) {
                 kfree(ps);