Re: [PATCH V14] mm/debug: Add tests validating architecture page table helpers

[Christophe Leroy]

Le 26/02/2020 Ã 15:12, Qian Cai a ÃcritÂ:
> On Wed, 2020-02-26 at 09:09 -0500, Qian Cai wrote:
> > On Mon, 2020-02-17 at 08:47 +0530, Anshuman Khandual wrote:
> >
> > How useful is this that straightly crash the powerpc?
>
> And then generate warnings on arm64,
>
> [ÂÂ146.634626][ÂÂÂÂT1] debug_vm_pgtable: debug_vm_pgtable: Validating
> architecture page table helpers
> [ÂÂ146.643995][ÂÂÂÂT1] ------------[ cut here ]------------
> [ÂÂ146.649350][ÂÂÂÂT1] virt_to_phys used for non-linear address:
> (____ptrval____) (start_kernel+0x0/0x580)

Must be something wrong with the following in debug_vm_pgtable()

	paddr = __pa(&start_kernel);

Is there any explaination why start_kernel() is not in linear memory on 
ARM64 ?

Christophe