usbmon: bus zero

Add the "bus zero" feature to the usbmon. If a user process specifies bus
with number zero, it receives events from all buses. This is useful when
we wish to see initial enumeration when a bus is created, typically after
a modprobe. Until now, an application had to loop until a new bus could
be open, then start capturing on it. This procedure was cumbersome and
could lose initial events. Also, often it's too bothersome to find exactly
to which bus a specific device is attached.

Paolo Albeni provided the original concept implementation. I added the
handling of "bus->monitored" flag and generally fixed it up.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index b2bedd974ac3..0af11a66207c 100644
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -356,8 +356,10 @@ static inline char mon_bin_get_setup(unsigned char *setupb,
         if (!usb_pipecontrol(urb->pipe) || ev_type != 'S')
                 return '-';
 
-        if (urb->transfer_flags & URB_NO_SETUP_DMA_MAP)
+        if (urb->dev->bus->uses_dma &&
+            (urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
                 return mon_dmapeek(setupb, urb->setup_dma, SETUP_LEN);
+        }
         if (urb->setup_packet == NULL)
                 return 'Z';
 
@@ -369,7 +371,8 @@ static char mon_bin_get_data(const struct mon_reader_bin *rp,
     unsigned int offset, struct urb *urb, unsigned int length)
 {
 
-        if (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) {
+        if (urb->dev->bus->uses_dma &&
+            (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
                 mon_dmapeek_vec(rp, offset, urb->transfer_dma, length);
                 return 0;
         }
@@ -440,7 +443,7 @@ static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb,
         /* We use the fact that usb_pipein() returns 0x80 */
         ep->epnum = usb_pipeendpoint(urb->pipe) | usb_pipein(urb->pipe);
         ep->devnum = usb_pipedevice(urb->pipe);
-        ep->busnum = rp->r.m_bus->u_bus->busnum;
+        ep->busnum = urb->dev->bus->busnum;
         ep->id = (unsigned long) urb;
         ep->ts_sec = ts.tv_sec;
         ep->ts_usec = ts.tv_usec;
@@ -500,7 +503,7 @@ static void mon_bin_error(void *data, struct urb *urb, int error)
         /* We use the fact that usb_pipein() returns 0x80 */
         ep->epnum = usb_pipeendpoint(urb->pipe) | usb_pipein(urb->pipe);
         ep->devnum = usb_pipedevice(urb->pipe);
-        ep->busnum = rp->r.m_bus->u_bus->busnum;
+        ep->busnum = urb->dev->bus->busnum;
         ep->id = (unsigned long) urb;
         ep->status = error;
 
@@ -515,7 +518,6 @@ static void mon_bin_error(void *data, struct urb *urb, int error)
 static int mon_bin_open(struct inode *inode, struct file *file)
 {
         struct mon_bus *mbus;
-        struct usb_bus *ubus;
         struct mon_reader_bin *rp;
         size_t size;
         int rc;
@@ -525,7 +527,7 @@ static int mon_bin_open(struct inode *inode, struct file *file)
                 mutex_unlock(&mon_lock);
                 return -ENODEV;
         }
-        if ((ubus = mbus->u_bus) == NULL) {
+        if (mbus != &mon_bus0 && mbus->u_bus == NULL) {
                 printk(KERN_ERR TAG ": consistency error on open\n");
                 mutex_unlock(&mon_lock);
                 return -ENODEV;