From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
I've noticed message on kvm exit:
Warning: serial8250__exit failed.
kvm tool is not able to remove ioport range which was added previously.
The issue is caused by bug in rbtree-interval. Search algorithm in
rb_int_search_single() expects correct value of max_high. But the tree
can contain leaf nodes, which never were updated by propagate_callback().
For this kind of nodes high_max will be 0 and we will not be able to
find and remove them.
Let's initialize max_high on RB_INT_INIT() time.
Fixing this bug makes other bug visible: propagate_callback() can be
called for empty tree: node == NULL. The callback is not ready for empty
tree. Let's fix that as well.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
tools/kvm/include/kvm/rbtree-interval.h | 3 ++-
tools/kvm/util/rbtree-interval.c | 6 +++++-
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/tools/kvm/include/kvm/rbtree-interval.h b/tools/kvm/include/kvm/rbtree-interval.h
index e97d05b..fb2102a 100644
--- a/tools/kvm/include/kvm/rbtree-interval.h
+++ b/tools/kvm/include/kvm/rbtree-interval.h
@@ -4,7 +4,8 @@
#include <linux/rbtree_augmented.h>
#include <linux/types.h>
-#define RB_INT_INIT(l, h) (struct rb_int_node){.low = l, .high = h}
+#define RB_INT_INIT(l, h) \
+ (struct rb_int_node){.low = l, .high = h, .max_high = h}
#define rb_int(n) rb_entry(n, struct rb_int_node, node)
struct rb_int_node {
diff --git a/tools/kvm/util/rbtree-interval.c b/tools/kvm/util/rbtree-interval.c
index c82ce98..d7fa96a 100644
--- a/tools/kvm/util/rbtree-interval.c
+++ b/tools/kvm/util/rbtree-interval.c
@@ -48,8 +48,12 @@ struct rb_int_node *rb_int_search_range(struct rb_root *root, u64 low, u64 high)
*/
static void propagate_callback(struct rb_node *node, struct rb_node *stop)
{
- struct rb_int_node *i_node = rb_int(node);
+ struct rb_int_node *i_node;
+ if (node == stop)
+ return;
+
+ i_node = rb_int(node);
i_node->max_high = i_node->high;
if (node->rb_left)
--
1.7.10.4
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