Re: BUG() at boot in __phys_addr with DEBUG_VIRTUAL

From: Matt Fleming
Date: Thu Nov 13 2014 - 08:10:10 EST


On Wed, 2014-11-12 at 07:20 -0800, Dave Hansen wrote:
>
> The path that we're actually hitting this from is:
>
> > __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long
> ...
> > if (pfn_range_is_mapped(PFN_DOWN(__pa(address)),
> > PFN_DOWN(__pa(address)) + 1))
> > split_page_count(level);

I'm sure I'm just being dumb, but I can't for the life of me work out
why we need to calculate the physical address from the virtual address
at this point - we should already have that information.

> So perhaps efi_map_region() is handing an address from the EFI identity
> map down in here. __pa() gets called on it, but that fails since __pa()
> only works on the *KERNEL* identity map.

Yep, sounds right.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/