Ensure that the stores to rb_left and rb_right are complete before
inserting the new node into the tree. Otherwise a concurrent reader
could see garbage in the new leaf.
Cc: qemu-sta...@nongnu.org
Reviewed-by: Peter Maydell <peter.mayd...@linaro.org>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
util/interval-tree.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/util/interval-tree.c b/util/interval-tree.c
index 5a0ad21b2d..759562db7d 100644
--- a/util/interval-tree.c
+++ b/util/interval-tree.c
@@ -128,7 +128,11 @@ static inline void rb_link_node(RBNode *node, RBNode
*parent, RBNode **rb_link)
node->rb_parent_color = (uintptr_t)parent;
node->rb_left = node->rb_right = NULL;
- qatomic_set(rb_link, node);
+ /*
+ * Ensure that node is initialized before insertion,
+ * as viewed by a concurrent search.
+ */
+ qatomic_set_mb(rb_link, node);
}
static RBNode *rb_next(RBNode *node)
--
2.34.1
