Re: virt_to_page/pci_map_page vs. pci_map_single

From: David S. Miller
Date: Mon Nov 03 2003 - 18:45:03 EST

On Mon, 3 Nov 2003 14:02:57 -0800
David Mosberger <davidm@xxxxxxxxxxxxxxxxx> wrote:

> >>>>> On 03 Nov 2003 09:17:59 -0500, Jes Sorensen <jes@xxxxxxxxxxxxxxxxxx> said:
> Jes> Hmmm, my brain has gotten ia64ified ;-) It's basically the normal
> Jes> mappings of the kernel, ie. the kernel text/data/bss segments as well
> Jes> as anything you do not get back as a dynamic mapping such as
> Jes> ioremap/vmalloc/kmap.
> I don't think it's safe to use virt_to_page() on static kernel
> addresses (text, data, and bss). For example, ia64 linux nowadays
> uses a virtual mapping for the static kernel memory, so it's not part
> of the identity-mapped segment.

That's correct and it'll break on sparc64 for similar reasons.

It's also not safe to do virt_to_page() on kernel stack addresses
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