CVS commit: src/sys/dev/usb

[Nick Hudson]

Module Name:    src
Committed By:   skrll
Date:           Sat Sep 23 14:27:44 UTC 2017

Modified Files:
        src/sys/dev/usb: if_athn_usb.c

Log Message:
PR/52553 Panic on "ifconfig athn0 up"

Don't race for a transfer in athn_usb_init on the free list for beacons.
Instead pre-assign a transfer to beacons in athn_usb_alloc_tx_list


To generate a diff of this commit:
cvs rdiff -u -r1.22 -r1.23 src/sys/dev/usb/if_athn_usb.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/dev/usb/if_athn_usb.c
diff -u src/sys/dev/usb/if_athn_usb.c:1.22 src/sys/dev/usb/if_athn_usb.c:1.23
--- src/sys/dev/usb/if_athn_usb.c:1.22	Thu Jun  1 02:45:11 2017
+++ src/sys/dev/usb/if_athn_usb.c	Sat Sep 23 14:27:44 2017
@@ -1,4 +1,4 @@
-/*	$NetBSD: if_athn_usb.c,v 1.22 2017/06/01 02:45:11 chs Exp $	*/
+/*	$NetBSD: if_athn_usb.c,v 1.23 2017/09/23 14:27:44 skrll Exp $	*/
 /*	$OpenBSD: if_athn_usb.c,v 1.12 2013/01/14 09:50:31 jsing Exp $	*/
 
 /*-
@@ -22,7 +22,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_athn_usb.c,v 1.22 2017/06/01 02:45:11 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_athn_usb.c,v 1.23 2017/09/23 14:27:44 skrll Exp $");
 
 #ifdef	_KERNEL_OPT
 #include "opt_inet.h"
@@ -728,9 +728,15 @@ athn_usb_alloc_tx_list(struct athn_usb_s
 		/* Append this Tx buffer to our free list. */
 		TAILQ_INSERT_TAIL(&usc->usc_tx_free_list, data, next);
 	}
-	if (error != 0)
+	if (error == 0) {
+		/* Steal one buffer for beacons. */
+		usc->usc_tx_bcn = TAILQ_FIRST(&usc->usc_tx_free_list);
+		TAILQ_REMOVE(&usc->usc_tx_free_list, usc->usc_tx_bcn, next);
+	} else {
 		athn_usb_free_tx_list(usc);
+	}
 	mutex_exit(&usc->usc_tx_mtx);
+
 	return error;
 }
 
@@ -749,6 +755,10 @@ athn_usb_free_tx_list(struct athn_usb_so
 		if (xfer != NULL)
 			usbd_destroy_xfer(xfer);
 	}
+	if (usc->usc_tx_bcn) {
+		usbd_destroy_xfer(usc->usc_tx_bcn->xfer);
+		usc->usc_tx_bcn = NULL;
+	}
 }
 
 Static int
@@ -2756,12 +2766,6 @@ athn_usb_init_locked(struct ifnet *ifp)
 	usc->usc_cmdq.cur = usc->usc_cmdq.next = usc->usc_cmdq.queued = 0;
 	mutex_spin_exit(&usc->usc_task_mtx);
 
-	/* Steal one buffer for beacons. */
-	mutex_enter(&usc->usc_tx_mtx);
-	usc->usc_tx_bcn = TAILQ_FIRST(&usc->usc_tx_free_list);
-	TAILQ_REMOVE(&usc->usc_tx_free_list, usc->usc_tx_bcn, next);
-	mutex_exit(&usc->usc_tx_mtx);
-
 	curchan = ic->ic_curchan;
 	extchan = NULL;