Re: [PATCH] keys/encrypted: Fix two crypto-on-the-stack bugs

From: Andy Lutomirski
Date: Tue Dec 13 2016 - 12:04:43 EST

On Tue, Dec 13, 2016 at 8:45 AM, David Howells <dhowells@xxxxxxxxxx> wrote:
> Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>> After all, rodata is ordinary memory, is backed by struct page, etc.
> Is that actually true? I thought some arches excluded the kernel image from
> the page struct array to make the array consume less memory.

I don't know whether you're right, but that sounds a bit silly to me.
This is a *tiny* amount of memory.

But there's yet another snag. Alpha doesn't have empty_zero_page --
it only has ZERO_PAGE. I could do page_address(ZERO_PAGE(0))...