Issue #15144: Fix possible integer overflow when handling pointers as integer values, by using Py_uintptr_t instead of size_t.
Patch by Serhiy Storchaka.
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
index 9254821..6225ebb 100644
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -138,7 +138,6 @@
*/
#define ALIGNMENT 8 /* must be 2^N */
#define ALIGNMENT_SHIFT 3
-#define ALIGNMENT_MASK (ALIGNMENT - 1)
/* Return the number of bytes in size class I, as a uint. */
#define INDEX2SIZE(I) (((uint)(I) + 1) << ALIGNMENT_SHIFT)
@@ -314,14 +313,12 @@
struct arena_object* prevarena;
};
-#undef ROUNDUP
-#define ROUNDUP(x) (((x) + ALIGNMENT_MASK) & ~ALIGNMENT_MASK)
-#define POOL_OVERHEAD ROUNDUP(sizeof(struct pool_header))
+#define POOL_OVERHEAD _Py_SIZE_ROUND_UP(sizeof(struct pool_header), ALIGNMENT)
#define DUMMY_SIZE_IDX 0xffff /* size class of newly cached pools */
/* Round pointer P down to the closest pool-aligned address <= P, as a poolp */
-#define POOL_ADDR(P) ((poolp)((uptr)(P) & ~(uptr)POOL_SIZE_MASK))
+#define POOL_ADDR(P) ((poolp)_Py_ALIGN_DOWN((P), POOL_SIZE))
/* Return total number of blocks in pool of size index I, as a uint. */
#define NUMBLOCKS(I) ((uint)(POOL_SIZE - POOL_OVERHEAD) / INDEX2SIZE(I))