On Mon, Jul 1, 2013 at 9:48 AM, Sebastian Andrzej Siewior
<bigeasy@xxxxxxxxxxxxx> wrote:
> On 06/29/2013 01:43 AM, Santosh Shilimkar wrote:
>> Apart from waste of 32bit, what is the other concern you
>> have ?
>
> You pass a u64 as a physical address which is represented in other
> parts of the kernel (for a good reason) by phys_addr_t.
>
>> I really want to converge on this patch because it
>> has been a open ended discussion for quite some time. Does
>> that really break any thing on x86 or your concern is more
>> from semantics of the physical address.
> You want to have your code in so you can continue with your work, that
> is okay. The other two arguments why u64 here is a good thing was "due
> to what I said earlier" and "+1" and I don't have the time to look
> that up.
>
> There should be no problems on x86 if this goes in as it is now.
>
> But think about this: What happens if you boot your ARM device without
> PAE and your initrd is in the upper region? If you are lucky the kernel
> looks at a different place where it also has a read permission, notices
> nothing sane is there, writes a message and continues. And if it is not
> allowed to read? It is clearly the user's fault for booting a non-PAE
> kernel.
That's actual the original reason: DT has it as 64 bit, and passes it to a
32 bit kernel when running in 32 bit mode without PAE.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
