From af3a79e0837d23fa536f859fc927b1379855ae24 Mon Sep 17 00:00:00 2001 From: David Rowley Date: Thu, 30 Oct 2025 14:49:07 +1300 Subject: [PATCH] Fix bogus use of "long" in AllocSetCheck() Because long is 32-bit on 64-bit Windows, it isn't a good datatype to store the difference between 2 pointers. The under-sized type could overflow and lead to scary warnings in MEMORY_CONTEXT_CHECKING builds, such as: WARNING: problem in alloc set ExecutorState: bad single-chunk %p in block %p However, the problem lies only in the code running the check, not from an actual memory accounting bug. Fix by using "Size" instead of "long". This means using an unsigned type rather than the previous signed type. If the block's freeptr was corrupted, we'd still catch that if the unsigned type wrapped. Unsigned allows us to avoid further needless complexities around comparing signed and unsigned types. Author: David Rowley Reviewed-by: Michael Paquier Reviewed-by: Tom Lane Backpatch-through: 13 Discussion: https://postgr.es/m/CAApHDvo-RmiT4s33J=aC9C_-wPZjOXQ232V-EZFgKftSsNRi4w@mail.gmail.com --- src/backend/utils/mmgr/aset.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c index 666ecd8f78d..bcb55296c43 100644 --- a/src/backend/utils/mmgr/aset.c +++ b/src/backend/utils/mmgr/aset.c @@ -1609,9 +1609,9 @@ AllocSetCheck(MemoryContext context) prevblock = block, block = block->next) { char *bpoz = ((char *) block) + ALLOC_BLOCKHDRSZ; - long blk_used = block->freeptr - bpoz; - long blk_data = 0; - long nchunks = 0; + Size blk_used = block->freeptr - bpoz; + Size blk_data = 0; + Size nchunks = 0; bool has_external_chunk = false; if (IsKeeperBlock(set, block))