[src/trunk]: src/sys/dev/usb usbdi(9): Make sure aborting a pipe waits for al...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b9e9b89bff6b
branches:  trunk
changeset: 364381:b9e9b89bff6b
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Mar 20 00:40:52 2022 +0000

description:
usbdi(9): Make sure aborting a pipe waits for all callbacks.

There may be a callback in flight from an xfer that has already been
taken off the queue by the time usbd_ar_pipe gets to it.  We must
guarantee that even that callback has completed before returning
control to the caller.

diffstat:

 sys/dev/usb/usbdi.c |  17 +++++++++++++++--
 1 files changed, 15 insertions(+), 2 deletions(-)

diffs (38 lines):

diff -r 0f0ec0fd0c4c -r b9e9b89bff6b sys/dev/usb/usbdi.c
--- a/sys/dev/usb/usbdi.c       Sun Mar 20 00:19:11 2022 +0000
+++ b/sys/dev/usb/usbdi.c       Sun Mar 20 00:40:52 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usbdi.c,v 1.239 2022/03/19 10:05:52 riastradh Exp $    */
+/*     $NetBSD: usbdi.c,v 1.240 2022/03/20 00:40:52 riastradh Exp $    */
 
 /*
  * Copyright (c) 1998, 2012, 2015 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.239 2022/03/19 10:05:52 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.240 2022/03/20 00:40:52 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -1071,6 +1071,19 @@
                }
        }
 
+       /*
+        * There may be an xfer callback already in progress which was
+        * taken off the queue before we got to it.  We must wait for
+        * the callback to finish before returning control to the
+        * caller.
+        */
+       while (pipe->up_callingxfer) {
+               USBHIST_LOG(usbdebug, "wait for callback"
+                   "pipe = %#jx xfer = %#jx",
+                   (uintptr_t)pipe, (uintptr_t)pipe->up_callingxfer, 0, 0);
+               cv_wait(&pipe->up_callingcv, pipe->up_dev->ud_bus->ub_lock);
+       }
+
        KASSERT(mutex_owned(pipe->up_dev->ud_bus->ub_lock));
        KASSERTMSG(pipe->up_abortlwp == curlwp, "pipe->up_abortlwp=%p",
            pipe->up_abortlwp);