Catalin Marinas kirjoitti:On Tue, 2009-12-01 at 11:49 +0000, Pekka Enberg wrote:hooanon05@xxxxxxxxxxx kirjoitti:Pekka Enberg:No. The pointer returned by cpu_cache_get() is not changed byWe are setting an element in the per CPU array to NULL so the theThanks for reply.
kmemleak code in ____cache_alloc() is safe. Red-zoning is done at the
_object_ which is not touched by kmemleak. Looking at the oops, it
does seem likely that you have a bug in your module (or in some other
part of the kernel).
In ____cache_alloc(), the variable 'ac' is assigned before
cache_alloc_refill() call, and it is used for the parameter of
kmemleak_erase(). The value may be changed by cache_alloc_refill(),
isn't it?
cache_alloc_refill(). The contents of the array might change, yes. That
said, we should check if objp is NULL before calling kmemleak_erase().
Possibly but I don't understand why that's needed. The kmemleak_erase()
call just sets the ac->entry[ac->avail] to NULL. If ac->avail is 0, it
doesn't cause any harm.
No, you are absolutely correct. Can you please send an updated patch to Catalin that adds a comment on top of the cpu_cache_get() call that explains why we need it there?