[PATCH 01/10] hbitmap: introduce HBITMAP_MAX_ORIG_SIZE

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 include/qemu/hbitmap.h | 7 +++++++
 util/hbitmap.c         | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index 1bf944ca3d..82317c5364 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -33,6 +33,13 @@ typedef struct HBitmapIter HBitmapIter;
  */
 #define HBITMAP_LEVELS         ((HBITMAP_LOG_MAX_SIZE / BITS_PER_LEVEL) + 1)
 
+/*
+ * We have APIs which returns signed int64_t, to be able to return error.
+ * Therefore we can't handle bitmaps with absolute size larger than
+ * (INT64_MAX+1). Still, keep it INT64_MAX to be a bit safer.
+ */
+#define HBITMAP_MAX_ORIG_SIZE INT64_MAX
+
 struct HBitmapIter {
     const HBitmap *hb;
 
diff --git a/util/hbitmap.c b/util/hbitmap.c
index 757d39e360..df192234e3 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -708,6 +708,7 @@ HBitmap *hbitmap_alloc(uint64_t size, int granularity)
     HBitmap *hb = g_new0(struct HBitmap, 1);
     unsigned i;
 
+    assert(size <= HBITMAP_MAX_ORIG_SIZE);
     hb->orig_size = size;
 
     assert(granularity >= 0 && granularity < 64);
@@ -738,6 +739,7 @@ void hbitmap_truncate(HBitmap *hb, uint64_t size)
     uint64_t num_elements = size;
     uint64_t old;
 
+    assert(size <= HBITMAP_MAX_ORIG_SIZE);
     hb->orig_size = size;
 
     /* Size comes in as logical elements, adjust for granularity. */
-- 
2.21.0