With 64 bytes heap and 1 byte allocation on a big heap, we get:
0 1 2 3 4 5 6 7
| h | h | b | b | c | 1 | s | f |
where
- h: chunk0 header
- b: buckets in chunk0
- c: chunk header for the first allocation
- 1: chunk mem
- s: solo free header
- f: end marker / footer
max_chunkid() was returning h->end_chunk - min_chunk_size(h), which is
5 because min_chunk_size() on a big heap is 2. This works if you
don't have the solo free header at 6 and the heap is like:
0 1 2 3 4 5 6
| h | h | b | b | c | 1 | f |
max_chunkid() in this case gives you 6 - 2 = 4, which is the right
chunkid for the last chunk header.
This commit replaces max_chunkid() with h->end_chunk and "<=" (less
than or equal to) with "<" (less than), so that it always compares
against the end maker chunkid, but the code won't touch the end maker
itself.
Signed-off-by: Yasushi SHOJI <yashi@spacecubics.com>
fedab40576