From f3420e006ec08a6466b9d5fd3f6797f04c4ad709 Mon Sep 17 00:00:00 2001 From: David Rowley Date: Thu, 30 Oct 2025 14:50:26 +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 81117104f9e..3130cd0db8c 100644 --- a/src/backend/utils/mmgr/aset.c +++ b/src/backend/utils/mmgr/aset.c @@ -1431,9 +1431,9 @@ 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; if (set->keeper == block) total_allocated += block->endptr - ((char *) set);