Cc: Pekka Enberg <penberg@...>, Christoph Lameter <clameter@...>, Andrew Morton <akpm@...>, Arjan van de Ven <arjan@...>, Tim Bird <tim.bird@...>, linux kernel <linux-kernel@...>
No, not valid. Dereferencing it will oops. See ZERO_SIZE_PTR.
What we're doing presently is at least better than what SLAB did
previously (did return a valid pointer!), all this time :-)
I do agree with you in principle, of course. But it's not for the kind of
cases that you describe -- "kmalloc(0) just because I'd eventually want
to krealloc() it to something meaningful later". This was done because
there's a lot of lazy callsites that "don't want to write code for corner
cases explicitly". Sad, very sad, I say :-)
[ The krealloc() discussion on this thread came about when I noticed that
it's the only callsite of ksize() that would reasonably / meaningfully
want to deal with NULL ptrs, for whom I noticed (from Andrew's initial
mail) that ksize(NULL) returned 0. As you know from the canonical
semantics of realloc(), it _is_ supposed to deal with NULL ptrs, hence
the discussion. ]
Satyam
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