usb: fix serial devices by removing device context verification

1. Removed for device slot reset and evaluate context. The verification was
   unnecessary and may cause some guest kernel operations to fail.
2. The context was updated after dequeue pointer set
3. Reset device when it's attached.
4. Add seccomp rules to allow the above reset.

The verification was copied from another implementation which works for
adb, but does not work with serial devices. The verification is also not
part of the spec, so we removed it here.

BUG=b:131336977
TEST=local build and test

Change-Id: Ifd7994ff5512346d1bab27654e60c97a602da8a6
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Signed-off-by: Zach Reizner <zachr@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1558934
Tested-by: kokoro <noreply+kokoro@google.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/devices/src/usb/xhci/ring_buffer.rs b/devices/src/usb/xhci/ring_buffer.rs
index 5e2c570..72c9ec0 100644
--- a/devices/src/usb/xhci/ring_buffer.rs
+++ b/devices/src/usb/xhci/ring_buffer.rs
@@ -85,6 +85,11 @@ impl RingBuffer {
                 }
             };
 
+            usb_debug!(
+                "{}: adding trb to td {}",
+                self.name.as_str(),
+                addressed_trb.trb
+            );
             td.push(addressed_trb);
             if !addressed_trb.trb.get_chain_bit().map_err(Error::TrbChain)? {
                 usb_debug!("trb chain is false returning");