Module Name: src
Committed By: riastradh
Date: Tue Sep 7 10:43:11 UTC 2021
Modified Files:
src/sys/dev/usb: ugen.c
Log Message:
ugen(4): Ensure we close pipes on detach.
Calling vdevgone has the effect of VOP_REVOKE -> spec_node_revoke ->
VOP_CLOSE -> spec_close -> cdev_close -> ugenclose, but:
(a) the flags passed to VOP_CLOSE don't have FREAD or FWRITE, and
(b) ugenclose has no effect when sc_dying is set anyway.
So create another path into the close logic, ugen_do_close. We have
to do this in detach _after_ the references have drained because we
may free buffers that other users are still using while the reference
count is nonzero.
To generate a diff of this commit:
cvs rdiff -u -r1.162 -r1.163 src/sys/dev/usb/ugen.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/ugen.c
diff -u src/sys/dev/usb/ugen.c:1.162 src/sys/dev/usb/ugen.c:1.163
--- src/sys/dev/usb/ugen.c:1.162 Tue Sep 7 10:42:59 2021
+++ src/sys/dev/usb/ugen.c Tue Sep 7 10:43:11 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: ugen.c,v 1.162 2021/09/07 10:42:59 riastradh Exp $ */
+/* $NetBSD: ugen.c,v 1.163 2021/09/07 10:43:11 riastradh Exp $ */
/*
* Copyright (c) 1998, 2004 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ugen.c,v 1.162 2021/09/07 10:42:59 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ugen.c,v 1.163 2021/09/07 10:43:11 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_compat_netbsd.h"
@@ -690,30 +690,25 @@ out: if (error && opened)
return error;
}
-static int
-ugenclose(dev_t dev, int flag, int mode, struct lwp *l)
+static void
+ugen_do_close(struct ugen_softc *sc, int flag, int endpt)
{
- int endpt = UGENENDPOINT(dev);
- struct ugen_softc *sc;
struct ugen_endpoint *sce;
int dir;
int i;
- int error;
KASSERT(KERNEL_LOCKED_P()); /* sc_is_open */
- if ((sc = ugenif_acquire(UGENUNIT(dev))) == NULL)
- return ENXIO;
-
- DPRINTFN(5, ("ugenclose: flag=%d, mode=%d, unit=%d, endpt=%d\n",
- flag, mode, UGENUNIT(dev), endpt));
-
- KASSERT(sc->sc_is_open[endpt]);
+ if (!sc->sc_is_open[endpt]) {
+ KASSERT(sc->sc_endpoints[endpt][IN].pipeh == NULL);
+ KASSERT(sc->sc_endpoints[endpt][OUT].pipeh == NULL);
+ KASSERT(sc->sc_endpoints[endpt][IN].ibuf == NULL);
+ KASSERT(sc->sc_endpoints[endpt][OUT].ibuf == NULL);
+ return;
+ }
if (endpt == USB_CONTROL_ENDPOINT) {
DPRINTFN(5, ("ugenclose: close control\n"));
- sc->sc_is_open[endpt] = 0;
- error = 0;
goto out;
}
@@ -758,11 +753,31 @@ ugenclose(dev_t dev, int flag, int mode,
sce->ibuf = NULL;
}
}
- sc->sc_is_open[endpt] = 0;
- error = 0;
-out: ugenif_release(sc);
- return error;
+out: sc->sc_is_open[endpt] = 0;
+}
+
+static int
+ugenclose(dev_t dev, int flag, int mode, struct lwp *l)
+{
+ int endpt = UGENENDPOINT(dev);
+ struct ugen_softc *sc;
+
+ DPRINTFN(5, ("ugenclose: flag=%d, mode=%d, unit=%d, endpt=%d\n",
+ flag, mode, UGENUNIT(dev), endpt));
+
+ KASSERT(KERNEL_LOCKED_P()); /* ugen_do_close */
+
+ if ((sc = ugenif_acquire(UGENUNIT(dev))) == NULL)
+ return ENXIO;
+
+ KASSERT(sc->sc_is_open[endpt]);
+ ugen_do_close(sc, flag, endpt);
+ KASSERT(!sc->sc_is_open[endpt]);
+
+ ugenif_release(sc);
+
+ return 0;
}
Static int
@@ -1214,10 +1229,17 @@ ugen_detach(device_t self, int flags)
/* locate the major number */
maj = cdevsw_lookup_major(&ugen_cdevsw);
- /* Nuke the vnodes for any open instances (calls close). */
+ /*
+ * Nuke the vnodes for any open instances (calls ugenclose, but
+ * with no effect because we already set sc_dying).
+ */
mn = sc->sc_unit * USB_MAX_ENDPOINTS;
vdevgone(maj, mn, mn + USB_MAX_ENDPOINTS - 1, VCHR);
+ /* Actually close any lingering pipes. */
+ for (i = 0; i < USB_MAX_ENDPOINTS; i++)
+ ugen_do_close(sc, FREAD|FWRITE, i);
+
usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_udev, sc->sc_dev);
ugenif_put_unit(sc);
