Fix alignment of stack variable

Declare with union similar to PGAlignedBlock.

Report and fix by Andres Freund

Discussion: https://postgr.es/m/20240407190731.izm3mdazednrsiqk%40awork3.anarazel.de

1 files changed, 6 insertions, 2 deletions

diff --git a/src/backend/access/common/tidstore.c b/src/backend/access/common/tidstore.c
index e1a7e824690..629390a1f88 100644
--- a/src/backend/access/common/tidstore.c
+++ b/src/backend/access/common/tidstore.c
@@ -303,8 +303,12 @@ void
 TidStoreSetBlockOffsets(TidStore *ts, BlockNumber blkno, OffsetNumber *offsets,
 						int num_offsets)
 {
-	char		data[MaxBlocktableEntrySize];
-	BlocktableEntry *page = (BlocktableEntry *) data;
+	union
+	{
+		char		data[MaxBlocktableEntrySize];
+		BlocktableEntry force_align_entry;
+	}			data;
+	BlocktableEntry *page = (BlocktableEntry *) data.data;
 	bitmapword	word;
 	int			wordnum;
 	int			next_word_threshold;