CVS commit: src/sys/dev/usb

[Nick Hudson]

Module Name:    src
Committed By:   skrll
Date:           Mon Feb 22 07:46:00 UTC 2016

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

Log Message:
Only clear the endpoint information in ugen_set_interface only if setting
the new altno suceeds.

Avoids the null de-ref in PR/50597 and PR/50810


To generate a diff of this commit:
cvs rdiff -u -r1.129 -r1.130 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:1.129 src/sys/dev/usb/ugen.c:1.130
--- src/sys/dev/usb/ugen.c:1.129	Sun Feb 21 09:50:10 2016
+++ src/sys/dev/usb/ugen.c	Mon Feb 22 07:46:00 2016
@@ -1,4 +1,4 @@
-/*	$NetBSD: ugen.c,v 1.129 2016/02/21 09:50:10 skrll Exp $	*/
+/*	$NetBSD: ugen.c,v 1.130 2016/02/22 07:46:00 skrll Exp $	*/
 
 /*
  * Copyright (c) 1998, 2004 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
 
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ugen.c,v 1.129 2016/02/21 09:50:10 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ugen.c,v 1.130 2016/02/22 07:46:00 skrll Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_compat_netbsd.h"
@@ -270,6 +270,19 @@ ugen_attach(device_t parent, device_t se
 	return;
 }
 
+Static void
+ugen_clear_endpoints(struct ugen_softc *sc)
+{
+
+	/* Clear out the old info, but leave the selinfo and cv initialised. */
+	for (int i = 0; i < USB_MAX_ENDPOINTS; i++) {
+		for (int dir = OUT; dir <= IN; dir++) {
+			struct ugen_endpoint *sce = &sc->sc_endpoints[i][dir];
+			memset(sce, 0, UGEN_ENDPOINT_NONZERO_CRUFT);
+		}
+	}
+}
+
 Static int
 ugen_set_config(struct ugen_softc *sc, int configno)
 {
@@ -281,7 +294,7 @@ ugen_set_config(struct ugen_softc *sc, i
 	u_int8_t niface, nendpt;
 	int ifaceno, endptno, endpt;
 	usbd_status err;
-	int dir, i;
+	int dir;
 
 	DPRINTFN(1,("ugen_set_config: %s to configno %d, sc=%p\n",
 		    device_xname(sc->sc_dev), configno, sc));
@@ -310,13 +323,7 @@ ugen_set_config(struct ugen_softc *sc, i
 	if (err)
 		return (err);
 
-	/* Clear out the old info, but leave the selinfo and cv initialised. */
-	for (i = 0; i < USB_MAX_ENDPOINTS; i++) {
-		for (dir = OUT; dir <= IN; dir++) {
-			sce = &sc->sc_endpoints[i][dir];
-			memset(sce, 0, UGEN_ENDPOINT_NONZERO_CRUFT);
-		}
-	}
+	ugen_clear_endpoints(sc);
 
 	for (ifaceno = 0; ifaceno < niface; ifaceno++) {
 		DPRINTFN(1,("ugen_set_config: ifaceno %d\n", ifaceno));
@@ -1336,16 +1343,6 @@ ugen_set_interface(struct ugen_softc *sc
 	err = usbd_endpoint_count(iface, &nendpt);
 	if (err)
 		return (err);
-	/* XXX should only do this after setting new altno has succeeded */
-	for (endptno = 0; endptno < nendpt; endptno++) {
-		ed = usbd_interface2endpoint_descriptor(iface,endptno);
-		endpt = ed->bEndpointAddress;
-		dir = UE_GET_DIR(endpt) == UE_DIR_IN ? IN : OUT;
-		sce = &sc->sc_endpoints[UE_GET_ADDR(endpt)][dir];
-		sce->sc = NULL;
-		sce->edesc = NULL;
-		sce->iface = NULL;
-	}
 
 	/* change setting */
 	err = usbd_set_interface(iface, altno);
@@ -1355,6 +1352,9 @@ ugen_set_interface(struct ugen_softc *sc
 	err = usbd_endpoint_count(iface, &nendpt);
 	if (err)
 		return (err);
+
+	ugen_clear_endpoints(sc);
+
 	for (endptno = 0; endptno < nendpt; endptno++) {
 		ed = usbd_interface2endpoint_descriptor(iface,endptno);
 		KASSERT(ed != NULL);