Re: [PATCH 3/4] EFI: Add support for variables longer than 1024bytes

From: Matthew Garrett
Date: Thu Dec 15 2011 - 10:44:25 EST


On Wed, Dec 14, 2011 at 02:57:51PM -0800, Mike Waychison wrote:
> On Wed, Dec 14, 2011 at 2:39 PM, Matthew Garrett <mjg59@xxxxxxxxxxxxx> wrote:
> > Hm. I think that'd only work if we expose a new interface. Writes would
> > be easy enough to handle, but reads still need to work for old apps.
>
> Well,l we could *not* support returning all the data field for
> datasize > 1024, and simply truncate the field. We are limited by
> PAGE_SIZE by sysfs here anyway (so we don't really want to have a
> variable size memcpy in efivar_show_raw).

We'll pretty much definitely want to be able to read values > 1024 once
people start shoving keys in there. The PAGE_SIZE limit is one that I'd
forgotten about, though.

--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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