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

Christophe Leroy
2020-02-26T14:44:36Z

Le 26/02/2020 à 15:12, Qian Cai a écrit :
> 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,
>
> [  146.634626][    T1] debug_vm_pgtable: debug_vm_pgtable: Validating
> architecture page table helpers
> [  146.643995][    T1] ------------[ cut here ]------------
> [  146.649350][    T1] 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