1 files changed, 35 insertions, 5 deletions

diff --git a/drivers/usb/usbip/stub_main.c b/drivers/usb/usbip/stub_main.c
index 587b9bc10042..41c7b9de2a92 100644
--- a/drivers/usb/usbip/stub_main.c
+++ b/drivers/usb/usbip/stub_main.c
@@ -26,6 +26,8 @@ static spinlock_t busid_table_lock;
 
 static void init_busid_table(void)
 {
+	int i;
+
 	/*
 	 * This also sets the bus_table[i].status to
 	 * STUB_BUSID_OTHER, which is 0.
@@ -33,6 +35,9 @@ static void init_busid_table(void)
 	memset(busid_table, 0, sizeof(busid_table));
 
 	spin_lock_init(&busid_table_lock);
+
+	for (i = 0; i < MAX_BUSID; i++)
+		spin_lock_init(&busid_table[i].busid_lock);
 }
 
 /*
@@ -44,15 +49,20 @@ static int get_busid_idx(const char *busid)
 	int i;
 	int idx = -1;
 
-	for (i = 0; i < MAX_BUSID; i++)
+	for (i = 0; i < MAX_BUSID; i++) {
+		spin_lock(&busid_table[i].busid_lock);
 		if (busid_table[i].name[0])
 			if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
 				idx = i;
+				spin_unlock(&busid_table[i].busid_lock);
 				break;
 			}
+		spin_unlock(&busid_table[i].busid_lock);
+	}
 	return idx;
 }
 
+/* Returns holding busid_lock. Should call put_busid_priv() to unlock */
 struct bus_id_priv *get_busid_priv(const char *busid)
 {
 	int idx;
@@ -60,13 +70,21 @@ struct bus_id_priv *get_busid_priv(const char *busid)
 
 	spin_lock(&busid_table_lock);
 	idx = get_busid_idx(busid);
-	if (idx >= 0)
+	if (idx >= 0) {
 		bid = &(busid_table[idx]);
+		/* get busid_lock before returning */
+		spin_lock(&bid->busid_lock);
+	}
 	spin_unlock(&busid_table_lock);
 
 	return bid;
 }
 
+void put_busid_priv(struct bus_id_priv *bid)
+{
+	spin_unlock(&bid->busid_lock);
+}
+
 static int add_match_busid(char *busid)
 {
 	int i;
@@ -79,15 +97,19 @@ static int add_match_busid(char *busid)
 		goto out;
 	}
 
-	for (i = 0; i < MAX_BUSID; i++)
+	for (i = 0; i < MAX_BUSID; i++) {
+		spin_lock(&busid_table[i].busid_lock);
 		if (!busid_table[i].name[0]) {
 			strlcpy(busid_table[i].name, busid, BUSID_SIZE);
 			if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
 			    (busid_table[i].status != STUB_BUSID_REMOV))
 				busid_table[i].status = STUB_BUSID_ADDED;
 			ret = 0;
+			spin_unlock(&busid_table[i].busid_lock);
 			break;
 		}
+		spin_unlock(&busid_table[i].busid_lock);
+	}
 
 out:
 	spin_unlock(&busid_table_lock);
@@ -108,6 +130,8 @@ int del_match_busid(char *busid)
 	/* found */
 	ret = 0;
 
+	spin_lock(&busid_table[idx].busid_lock);
+
 	if (busid_table[idx].status == STUB_BUSID_OTHER)
 		memset(busid_table[idx].name, 0, BUSID_SIZE);
 
@@ -115,6 +139,7 @@ int del_match_busid(char *busid)
 	    (busid_table[idx].status != STUB_BUSID_ADDED))
 		busid_table[idx].status = STUB_BUSID_REMOV;
 
+	spin_unlock(&busid_table[idx].busid_lock);
 out:
 	spin_unlock(&busid_table_lock);
 
@@ -127,9 +152,12 @@ static ssize_t match_busid_show(struct device_driver *drv, char *buf)
 	char *out = buf;
 
 	spin_lock(&busid_table_lock);
-	for (i = 0; i < MAX_BUSID; i++)
+	for (i = 0; i < MAX_BUSID; i++) {
+		spin_lock(&busid_table[i].busid_lock);
 		if (busid_table[i].name[0])
 			out += sprintf(out, "%s ", busid_table[i].name);
+		spin_unlock(&busid_table[i].busid_lock);
+	}
 	spin_unlock(&busid_table_lock);
 	out += sprintf(out, "\n");
 
@@ -204,7 +232,7 @@ static void stub_device_rebind(void)
 	}
 	spin_unlock(&busid_table_lock);
 
-	/* now run rebind */
+	/* now run rebind - no need to hold locks. driver files are removed */
 	for (i = 0; i < MAX_BUSID; i++) {
 		if (busid_table[i].name[0] &&
 		    busid_table[i].shutdown_busid) {
@@ -234,6 +262,8 @@ static ssize_t rebind_store(struct device_driver *dev, const char *buf,
 
 	/* mark the device for deletion so probe ignores it during rescan */
 	bid->status = STUB_BUSID_OTHER;
+	/* release the busid lock */
+	put_busid_priv(bid);
 
 	ret = do_rebind((char *) buf, bid);
 	if (ret < 0)