commit 2d6c1ef40f3678ab47a4d14fb5dadaa486bfcda6
author Amit Shah <amit.shah@redhat.com> Thu Feb 10 12:55:20 2011 +0530
committer Amit Shah <amit.shah@redhat.com> Mon Mar 21 16:57:13 2011 +0530
tree c23a1a315307a23e0e97704a06226ed8288e5729
parent f9a90f189c780e066039f2de3906c73c48071bb7

char: Prevent multiple devices opening same chardev

Prevent:

-chardev socket,path=/tmp/foo,server,nowait,id=c0 \
-device virtserialport,chardev=c0,id=vs0 \
-device virtserialport,chardev=c0,id=vs1

Reported-by: Mike Cao <bcao@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>

hw/qdev-properties.c

diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
index a45b61e..1088a26 100644
--- a/hw/qdev-properties.c
+++ b/hw/qdev-properties.c
@@ -351,8 +351,13 @@
     CharDriverState **ptr = qdev_get_prop_ptr(dev, prop);
 
     *ptr = qemu_chr_find(str);
-    if (*ptr == NULL)
+    if (*ptr == NULL) {
         return -ENOENT;
+    }
+    if ((*ptr)->assigned) {
+        return -EEXIST;
+    }
+    (*ptr)->assigned = 1;
     return 0;
 }