Re: [PATCH] powerpc/kvm: silence kmemleak false positives

[Catalin Marinas <catalin.marinas@arm.com>]

On Mon, May 11, 2020 at 07:43:30AM -0400, Qian Cai wrote:
> On May 11, 2020, at 7:15 AM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> > There is kmemleak_alloc_phys(), which according to the docs can be used
> > for tracking a phys address.
> > 
> > Did you try that?
> 
> Catalin, feel free to give your thoughts here.
> 
> My understanding is that it seems the doc is a bit misleading.
> kmemleak_alloc_phys() is to allocate kmemleak objects for a physical
> address range, so  kmemleak could scan those memory pointers within
> for possible referencing other memory. It was only used in memblock so
> far, but those new memory allocations here contain no reference to
> other memory.
> 
> In this case, we have already had kmemleak objects for those memory
> allocation. It is just that other pointers reference those memory by
> their physical address which is a known kmemleak limitation won’t be
> able to track the the connection. Thus, we always use
> kmemleak_ignore() to not reporting those as leaks and don’t scan those
> because they do not contain other memory reference.

Indeed. I replied directly to Michael along the same lines.

-- 
Catalin