[src/trunk]: src/sys/dev/usb usbnet: Assert IFNET_LOCKED in usbnet_init_rx_tx...

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

details:   https://anonhg.NetBSD.org/src/rev/ceddbfe7ac95
branches:  trunk
changeset: 362489:ceddbfe7ac95
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Thu Mar 03 05:47:36 2022 +0000

description:
usbnet: Assert IFNET_LOCKED in usbnet_init_rx_tx, usbnet_stop.

Exception: urndis(4) abuses this API to start this logic before the
ifp is actually initialized.  So for the sake of urndis(4), until
sense can be beaten into it, allow the !unp_ifp_attached case to run
without IFNET_LOCK.

diffstat:

 sys/dev/usb/usbnet.c |  21 ++++++++++++---------
 1 files changed, 12 insertions(+), 9 deletions(-)

diffs (63 lines):

diff -r ff1bab205054 -r ceddbfe7ac95 sys/dev/usb/usbnet.c
--- a/sys/dev/usb/usbnet.c      Thu Mar 03 05:47:28 2022 +0000
+++ b/sys/dev/usb/usbnet.c      Thu Mar 03 05:47:36 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usbnet.c,v 1.50 2022/03/03 05:47:28 riastradh Exp $    */
+/*     $NetBSD: usbnet.c,v 1.51 2022/03/03 05:47:36 riastradh Exp $    */
 
 /*
  * Copyright (c) 2019 Matthew R. Green
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.50 2022/03/03 05:47:28 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.51 2022/03/03 05:47:36 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -151,6 +151,8 @@
 static void
 uno_stop(struct usbnet *un, struct ifnet *ifp, int disable)
 {
+       KASSERTMSG(!un->un_pri->unp_ifp_attached || IFNET_LOCKED(ifp),
+           "%s", ifp->if_xname);
        usbnet_isowned_core(un);
        if (un->un_ops->uno_stop)
                (*un->un_ops->uno_stop)(ifp, disable);
@@ -820,6 +822,9 @@
        usbd_status err;
        int error = 0;
 
+       KASSERTMSG(!unp->unp_ifp_attached || IFNET_LOCKED(ifp),
+           "%s", ifp->if_xname);
+
        usbnet_isowned_core(un);
 
        if (unp->unp_dying) {
@@ -1117,6 +1122,8 @@
 
        USBNETHIST_FUNC(); USBNETHIST_CALLED();
 
+       KASSERTMSG(!unp->unp_ifp_attached || IFNET_LOCKED(ifp),
+           "%s", ifp->if_xname);
        usbnet_isowned_core(un);
 
        usbnet_busy(un);
@@ -1147,13 +1154,9 @@
        /* Close pipes. */
        usbnet_ep_close_pipes(un);
 
-       /*
-        * XXXSMP Would like to
-        *      KASSERT(IFNET_LOCKED(ifp))
-        * here but the locking order is:
-        *      ifnet -> core_lock -> rxlock -> txlock
-        * and core_lock is already held.
-        */
+       /* Everything is quesced now. */
+       KASSERTMSG(!unp->unp_ifp_attached || IFNET_LOCKED(ifp),
+           "%s", ifp->if_xname);
        ifp->if_flags &= ~IFF_RUNNING;
 
        usbnet_unbusy(un);