mini-os: Fix memory leaks in blkfront, netfront, pcifront, etc.

The return value of Xenbus routines xenbus_transaction_start(),
xenbus_printf(), xenbus_transaction_end(), etc.  is a pointer of error
message.  This pointer should be passed to free() to release the
allocated memory when it is no longer needed.

Signed-off-by: Yu Zhiguo <yuzg@cn.fujitsu.com>

1 files changed, 13 insertions, 4 deletions

diff --git a/extras/mini-os/blkfront.c b/extras/mini-os/blkfront.c
index 2d4f03b1a5..e06cf9f94a 100644
--- a/extras/mini-os/blkfront.c
+++ b/extras/mini-os/blkfront.c
@@ -93,7 +93,7 @@ struct blkfront_dev *init_blkfront(char *_nodename, struct blkfront_info *info)
     char* message=NULL;
     struct blkif_sring *s;
     int retry=0;
-    char* msg;
+    char* msg = NULL;
     char* c;
     char* nodename = _nodename ? _nodename : "device/vbd/768";
 
@@ -129,6 +129,7 @@ again:
     err = xenbus_transaction_start(&xbt);
     if (err) {
         printk("starting transaction\n");
+        free(err);
     }
 
     err = xenbus_printf(xbt, nodename, "ring-ref","%u",
@@ -159,6 +160,7 @@ again:
 
 
     err = xenbus_transaction_end(xbt, 0, &retry);
+    if (err) free(err);
     if (retry) {
             goto again;
         printk("completing transaction\n");
@@ -167,7 +169,8 @@ again:
     goto done;
 
 abort_transaction:
-    xenbus_transaction_end(xbt, 1, &retry);
+    free(err);
+    err = xenbus_transaction_end(xbt, 1, &retry);
     goto error;
 
 done:
@@ -238,6 +241,8 @@ done:
     return dev;
 
 error:
+    free(msg);
+    free(err);
     free_blkfront(dev);
     return NULL;
 }
@@ -265,6 +270,7 @@ void shutdown_blkfront(struct blkfront_dev *dev)
     state = xenbus_read_integer(path);
     while (err == NULL && state < XenbusStateClosing)
         err = xenbus_wait_for_state_change(path, &state, &dev->events);
+    if (err) free(err);
 
     if ((err = xenbus_switch_state(XBT_NIL, nodename, XenbusStateClosed)) != NULL) {
         printk("shutdown_blkfront: error changing state to %d: %s\n",
@@ -272,8 +278,10 @@ void shutdown_blkfront(struct blkfront_dev *dev)
         goto close;
     }
     state = xenbus_read_integer(path);
-    if (state < XenbusStateClosed)
-        xenbus_wait_for_state_change(path, &state, &dev->events);
+    if (state < XenbusStateClosed) {
+        err = xenbus_wait_for_state_change(path, &state, &dev->events);
+        if (err) free(err);
+    }
 
     if ((err = xenbus_switch_state(XBT_NIL, nodename, XenbusStateInitialising)) != NULL) {
         printk("shutdown_blkfront: error changing state to %d: %s\n",
@@ -286,6 +294,7 @@ void shutdown_blkfront(struct blkfront_dev *dev)
         err = xenbus_wait_for_state_change(path, &state, &dev->events);
 
 close:
+    if (err) free(err);
     xenbus_unwatch_path_token(XBT_NIL, path, path);
 
     snprintf(path, sizeof(path), "%s/ring-ref", nodename);