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, 6 insertions, 0 deletions

diff --git a/usb_util/src/device_handle.rs b/usb_util/src/device_handle.rs
index 72ee178..32a963f 100644
--- a/usb_util/src/device_handle.rs
+++ b/usb_util/src/device_handle.rs
@@ -39,6 +39,12 @@ impl DeviceHandle {
         }
     }
 
+    /// Reset this usb device.
+    pub fn reset(&self) -> Result<()> {
+        // Safe because 'self.handle' is a valid pointer to device handle.
+        try_libusb!(unsafe { bindings::libusb_reset_device(self.handle) });
+        Ok(())
+    }
     /// Get bConfigurationValue of the currently active configuration.
     pub fn get_active_configuration(&self) -> Result<i32> {
         let mut config: c_int = 0;