vis: interpret count as addr if its big enough (#2342)

docs/commands/heap/vis_heap_chunks.md

@@ -21,7 +21,7 @@ usage: vis_heap_chunks [-h] [--beyond_top] [--no_truncate] [--all_chunks] [count
 
 |Positional Argument|Help|
 | :--- | :--- |
-|`count`|Number of chunks to visualize. (default: %(default)s)|
+|`count`|Number of chunks to visualize. If the value is big enough and addr isn't provided, this is interpreted as addr instead. (default: %(default)s)|
 |`addr`|Address of the first chunk.|
 
 ## Optional Arguments

pwndbg/commands/heap.py

@@ -944,7 +944,7 @@ group.add_argument(
     nargs="?",
     type=lambda n: max(int(n, 0), 1),
     default=pwndbg.config.default_visualize_chunk_number,
-    help="Number of chunks to visualize.",
+    help="Number of chunks to visualize. If the value is big enough and addr isn't provided, this is interpreted as addr instead.",
 )
 parser.add_argument("addr", nargs="?", default=None, help="Address of the first chunk.")
 parser.add_argument(
@@ -985,6 +985,11 @@ def vis_heap_chunks(
     allocator = pwndbg.gdblib.heap.current
     assert isinstance(allocator, GlibcMemoryAllocator)
 
+    # If the first argument (count) is big enough (and address isn't provided) interpret it as an address
+    if addr is None and count is not None and count > 0x1000:
+        addr = count
+        count = pwndbg.config.default_visualize_chunk_number
+
     if addr is not None:
         cursor = int(addr)
         heap_region = Heap(cursor)