Re: SLUB: Return ZERO_SIZE_PTR for kmalloc(0)

Christoph Lameter wrote:

SLUB: Return ZERO_SIZE_PTR for kmalloc(0) V3

Instead of returning the smallest available object return ZERO_SIZE_PTR.

A ZERO_SIZE_PTR can be legitimately used as an object pointer as long
as it is not deferenced. The dereference of ZERO_SIZE_PTR causes a
distinctive fault.
kfree can handle a ZERO_SIZE_PTR in the same way as NULL.

FWIW, I am happy :-). We should add a comment to kmalloc() that we return non-unique pointers for zero-length allocations though.

Acked-by: Pekka Enberg <[email protected]>
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