On 07/09/14 18:48, Christoph Lameter wrote:

On Wed, 9 Jul 2014, Andrey Ryabinin wrote:

quoted

With this patch kasan will be able to catch bugs in memory allocated
by slub.
Allocated slab page, this whole page marked as unaccessible
in corresponding shadow memory.
On allocation of slub object requested allocation size marked as
accessible, and the rest of the object (including slub's metadata)
marked as redzone (unaccessible).

We also mark object as accessible if ksize was called for this object.
There is some places in kernel where ksize function is called to inquire
size of really allocated area. Such callers could validly access whole
allocated memory, so it should be marked as accessible by kasan_krealloc call.

Do you really need to go through all of this? Add the hooks to
kmem_cache_alloc_trace() instead and use the existing instrumentation
that is there for other purposes?

I could move kasan_kmalloc hooks kmem_cache_alloc_trace(), and I think it will look better.
Hovewer I will require two hooks instead of one (for CONFIG_TRACING=y and CONFIG_TRACING=n).

Btw, seems I broke CONFIG_SL[AO]B configurations in this patch by  introducing __ksize function
which used in krealloc now.