Re: [PATCH V5 1/8] mm/slab: use unsigned long for orig_size to ensure proper metadata align

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Instead of calculating the offset of the original size in several places, should we maybe introduce a function that returns a pointer to it?

Good point.

The calculation of various metadata offset (including the original size) is repeated in several places, and perhaps it's worth cleaning up, something like this:

enum { FREE_POINTER_OFFSET, ALLOC_TRACK_OFFSET, FREE_TRACK_OFFSET, ORIG_SIZE_OFFSET, KASAN_ALLOC_META_OFFSET, OBJ_EXT_OFFSET, FINAL_ALIGNMENT_PADDING_OFFSET, ... };

orig_size = *(unsigned long *)get_metadata_ptr(p, ORIG_SIZE_OFFSET);

An alternative would be to declare a struct containing all the metadata fields and use offsetof() (or simply do a cast and access the fields via the struct pointer)