[src/trunk]: src/sys/dev/usb usbnet: Ensure access to unp_timer is protected ...

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

details:   https://anonhg.NetBSD.org/src/rev/e2776d2f8b4b
branches:  trunk
changeset: 362487:e2776d2f8b4b
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Thu Mar 03 05:47:21 2022 +0000

description:
usbnet: Ensure access to unp_timer is protected by unp_txlock.

diffstat:

 sys/dev/usb/usbnet.c |  11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diffs (40 lines):

diff -r b1fe1ed322d6 -r e2776d2f8b4b sys/dev/usb/usbnet.c
--- a/sys/dev/usb/usbnet.c      Thu Mar 03 05:47:14 2022 +0000
+++ b/sys/dev/usb/usbnet.c      Thu Mar 03 05:47:21 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usbnet.c,v 1.48 2022/03/03 05:47:14 riastradh Exp $    */
+/*     $NetBSD: usbnet.c,v 1.49 2022/03/03 05:47:21 riastradh Exp $    */
 
 /*
  * Copyright (c) 2019 Matthew R. Green
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.48 2022/03/03 05:47:14 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.49 2022/03/03 05:47:21 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -1127,7 +1127,9 @@
 
        uno_stop(un, ifp, disable);
 
+       mutex_enter(&unp->unp_txlock);
        unp->unp_timer = 0;
+       mutex_exit(&unp->unp_txlock);
 
        callout_halt(&unp->unp_stat_ch, &unp->unp_core_lock);
        usb_rem_task_wait(un->un_udev, &unp->unp_ticktask, USB_TASKQ_DRIVER,
@@ -1239,7 +1241,10 @@
        usbnet_busy(un);
        mutex_exit(&unp->unp_core_lock);
 
-       if (unp->unp_timer != 0 && --unp->unp_timer == 0)
+       mutex_enter(&unp->unp_txlock);
+       const bool timeout = unp->unp_timer != 0 && --unp->unp_timer == 0;
+       mutex_exit(&unp->unp_txlock);
+       if (timeout)
                usbnet_watchdog(ifp);
 
        DPRINTFN(8, "mii %#jx ifp %#jx", (uintptr_t)mii, (uintptr_t)ifp, 0, 0);