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usbdi(9): Avoid calling ubm_softint with lock held and polling on. 

PR kern/57783

XXX pullup-10
XXX pullup-9
XXX pullup-8
This commit is contained in:
riastradh 2024-01-13 12:27:54 +00:00
parent 312b884dfe
commit dd95526d08
1 changed files with 28 additions and 8 deletions
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36
sys/dev/usb/usbdi.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: usbdi.c,v 1.247 2022/09/13 10:32:58 riastradh Exp $ */
/* $NetBSD: usbdi.c,v 1.248 2024/01/13 12:27:54 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 1.247 2022/09/13 10:32:58 riastradh Exp $");
__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.248 2024/01/13 12:27:54 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_usb.h"
@ -1362,14 +1362,34 @@ usbd_dopoll(struct usbd_interface *iface)
void
usbd_set_polling(struct usbd_device *dev, int on)
{
if (on)
dev->ud_bus->ub_usepolling++;
else
dev->ud_bus->ub_usepolling--;
/* Kick the host controller when switching modes */
mutex_enter(dev->ud_bus->ub_lock);
dev->ud_bus->ub_methods->ubm_softint(dev->ud_bus);
if (on) {
/*
* Enabling polling. If we're enabling for the first
* time, call the softint routine on transition while
* we hold the lock and polling is still disabled, and
* then enable polling -- once polling is enabled, we
* must not hold the lock when we call the softint
* routine.
*/
KASSERT(dev->ud_bus->ub_usepolling < __type_max(char));
if (dev->ud_bus->ub_usepolling == 0)
dev->ud_bus->ub_methods->ubm_softint(dev->ud_bus);
dev->ud_bus->ub_usepolling++;
} else {
/*
* Disabling polling. If we're disabling polling for
* the last time, disable polling first and then call
* the softint routine while we hold the lock -- until
* polling is disabled, we must not hold the lock when
* we call the softint routine.
*/
KASSERT(dev->ud_bus->ub_usepolling > 0);
dev->ud_bus->ub_usepolling--;
if (dev->ud_bus->ub_usepolling == 0)
dev->ud_bus->ub_methods->ubm_softint(dev->ud_bus);
}
mutex_exit(dev->ud_bus->ub_lock);
}