Module Name: src
Committed By: riastradh
Date: Thu Mar 3 05:50:40 UTC 2022
Modified Files:
src/sys/dev/usb: usbnet.c
Log Message:
usbnet: Use atomic_load/store_relaxed for unp_dying.
This way we don't need to hold the core lock to avoid upsetting
sanitizers (which probably find the current code upsetting), and we
can use it to exit early from timeout loops that run under the core
lock (which is probably not necessary for them to do anyway, but
let's worry about that later).
To generate a diff of this commit:
cvs rdiff -u -r1.72 -r1.73 src/sys/dev/usb/usbnet.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/usbnet.c
diff -u src/sys/dev/usb/usbnet.c:1.72 src/sys/dev/usb/usbnet.c:1.73
--- src/sys/dev/usb/usbnet.c:1.72 Thu Mar 3 05:50:31 2022
+++ src/sys/dev/usb/usbnet.c Thu Mar 3 05:50:39 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: usbnet.c,v 1.72 2022/03/03 05:50:31 riastradh Exp $ */
+/* $NetBSD: usbnet.c,v 1.73 2022/03/03 05:50:39 riastradh Exp $ */
/*
* Copyright (c) 2019 Matthew R. Green
@@ -31,7 +31,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.72 2022/03/03 05:50:31 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.73 2022/03/03 05:50:39 riastradh Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
@@ -77,7 +77,7 @@ struct usbnet_private {
struct callout unp_stat_ch;
struct usbd_pipe *unp_ep[USBNET_ENDPT_MAX];
- bool unp_dying;
+ volatile bool unp_dying;
bool unp_stopping;
bool unp_attached;
bool unp_ifp_attached;
@@ -356,7 +356,7 @@ usbnet_rxeof(struct usbd_xfer *xfer, voi
mutex_enter(&unp->unp_rxlock);
- if (unp->unp_dying || unp->unp_stopping ||
+ if (usbnet_isdying(un) || unp->unp_stopping ||
status == USBD_INVAL || status == USBD_NOT_STARTED ||
status == USBD_CANCELLED)
goto out;
@@ -383,7 +383,7 @@ usbnet_rxeof(struct usbd_xfer *xfer, voi
usbnet_isowned_rx(un);
done:
- if (unp->unp_dying || unp->unp_stopping)
+ if (usbnet_isdying(un) || unp->unp_stopping)
goto out;
mutex_exit(&unp->unp_rxlock);
@@ -412,7 +412,7 @@ usbnet_txeof(struct usbd_xfer *xfer, voi
unp->unp_number, status, (uintptr_t)xfer, 0);
mutex_enter(&unp->unp_txlock);
- if (unp->unp_stopping || unp->unp_dying) {
+ if (unp->unp_stopping || usbnet_isdying(un)) {
mutex_exit(&unp->unp_txlock);
return;
}
@@ -456,12 +456,12 @@ usbnet_pipe_intr(struct usbd_xfer *xfer,
struct usbnet_private * const unp = un->un_pri;
struct usbnet_intr * const uni = un->un_intr;
- if (uni == NULL || unp->unp_dying || unp->unp_stopping ||
+ if (uni == NULL || usbnet_isdying(un) || unp->unp_stopping ||
status == USBD_INVAL || status == USBD_NOT_STARTED ||
status == USBD_CANCELLED) {
USBNETHIST_CALLARGS("%jd: uni %#jx d/s %#jx status %#jx",
unp->unp_number, (uintptr_t)uni,
- (unp->unp_dying << 8) | unp->unp_stopping, status);
+ (usbnet_isdying(un) << 8) | unp->unp_stopping, status);
return;
}
@@ -837,7 +837,7 @@ usbnet_init_rx_tx(struct usbnet * const
usbnet_isowned_core(un);
- if (unp->unp_dying) {
+ if (usbnet_isdying(un)) {
return EIO;
}
@@ -918,13 +918,12 @@ usbnet_mii_readreg(device_t dev, int phy
{
USBNETHIST_FUNC();
struct usbnet * const un = device_private(dev);
- struct usbnet_private * const unp = un->un_pri;
int err;
/* MII layer ensures core_lock is held. */
usbnet_isowned_core(un);
- if (unp->unp_dying) {
+ if (usbnet_isdying(un)) {
return EIO;
}
@@ -934,7 +933,7 @@ usbnet_mii_readreg(device_t dev, int phy
if (err) {
USBNETHIST_CALLARGS("%jd: read PHY failed: %jd",
- unp->unp_number, err, 0, 0);
+ un->un_pri->unp_number, err, 0, 0);
return err;
}
@@ -946,13 +945,12 @@ usbnet_mii_writereg(device_t dev, int ph
{
USBNETHIST_FUNC();
struct usbnet * const un = device_private(dev);
- struct usbnet_private * const unp = un->un_pri;
int err;
/* MII layer ensures core_lock is held. */
usbnet_isowned_core(un);
- if (unp->unp_dying) {
+ if (usbnet_isdying(un)) {
return EIO;
}
@@ -962,7 +960,7 @@ usbnet_mii_writereg(device_t dev, int ph
if (err) {
USBNETHIST_CALLARGS("%jd: write PHY failed: %jd",
- unp->unp_number, err, 0, 0);
+ un->un_pri->unp_number, err, 0, 0);
return err;
}
@@ -997,7 +995,7 @@ usbnet_media_upd(struct ifnet *ifp)
/* ifmedia changes only with IFNET_LOCK held. */
KASSERTMSG(IFNET_LOCKED(ifp), "%s", ifp->if_xname);
- if (unp->unp_dying)
+ if (usbnet_isdying(un))
return EIO;
unp->unp_link = false;
@@ -1085,7 +1083,7 @@ usbnet_mcast_task(void *arg)
USBNETHIST_CALLARGSN(10, "%jd: enter", unp->unp_number, 0, 0, 0);
/*
- * If we're detaching, we must check unp_dying _before_
+ * If we're detaching, we must check usbnet_isdying _before_
* touching IFNET_LOCK -- the ifnet may have been detached by
* the time this task runs. This is racy -- unp_dying may be
* set immediately after we test it -- but nevertheless safe,
@@ -1094,7 +1092,7 @@ usbnet_mcast_task(void *arg)
* IFNET_LOCK after if_detach. See usbnet_detach for details.
*/
mutex_enter(&unp->unp_core_lock);
- dying = unp->unp_dying;
+ dying = usbnet_isdying(un);
mutex_exit(&unp->unp_core_lock);
if (dying)
return;
@@ -1171,7 +1169,7 @@ usbnet_stop(struct usbnet *un, struct if
* it's been unplugged then there's no point in trying to touch
* the registers.
*/
- if (!unp->unp_dying)
+ if (!usbnet_isdying(un))
uno_stop(un, ifp, disable);
/* Stop transfers. */
@@ -1280,7 +1278,7 @@ usbnet_tick_task(void *arg)
uno_tick(un);
mutex_enter(&unp->unp_core_lock);
- if (!unp->unp_stopping && !unp->unp_dying)
+ if (!unp->unp_stopping && !usbnet_isdying(un))
callout_schedule(&unp->unp_stat_ch, hz);
mutex_exit(&unp->unp_core_lock);
}
@@ -1300,7 +1298,7 @@ usbnet_if_init(struct ifnet *ifp)
* we're detaching.
*/
mutex_enter(&un->un_pri->unp_core_lock);
- dying = un->un_pri->unp_dying;
+ dying = usbnet_isdying(un);
mutex_exit(&un->un_pri->unp_core_lock);
if (dying)
return EIO;
@@ -1360,7 +1358,7 @@ usbnet_havelink(struct usbnet *un)
bool
usbnet_isdying(struct usbnet *un)
{
- return un->un_pri->unp_dying;
+ return atomic_load_relaxed(&un->un_pri->unp_dying);
}
@@ -1594,7 +1592,7 @@ usbnet_detach(device_t self, int flags)
* cannot be brought back up.
*/
mutex_enter(&unp->unp_core_lock);
- unp->unp_dying = true;
+ atomic_store_relaxed(&unp->unp_dying, true);
mutex_exit(&unp->unp_core_lock);
/*
@@ -1723,7 +1721,7 @@ usbnet_activate(device_t self, devact_t
if_deactivate(ifp);
mutex_enter(&unp->unp_core_lock);
- unp->unp_dying = true;
+ atomic_store_relaxed(&unp->unp_dying, true);
mutex_exit(&unp->unp_core_lock);
mutex_enter(&unp->unp_rxlock);
