From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Russ Anderson <rja@sgi.com>, Ingo Molnar <mingo@kernel.org>,
Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
joeyli <jlee@suse.com>, Matt Fleming <matt@console-pimps.org>,
matt.fleming@intel.com, linux-efi@vger.kernel.org,
x86@kernel.org, linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [regression, bisected] x86: efi: Pass boot services variable info to runtime code
Date: Fri, 31 May 2013 10:35:32 -0700 [thread overview]
Message-ID: <1370021732.6250.4.camel@dabdike> (raw)
In-Reply-To: <20130531162815.GA8082@srcf.ucam.org>
On Fri, 2013-05-31 at 17:28 +0100, Matthew Garrett wrote:
> On Fri, May 31, 2013 at 10:43:49AM -0500, Russ Anderson wrote:
>
> > When did writing EFI variables to nvram become necessary to boot on
> > UEFI? And if it is necessary, why is it that only linux boot loaders
> > that use EFI stubs (generally grub2) need it? The current kernel
> > boots using EFI/grub and EFI/elilo. It is just when EFI stubs are
> > used that the boot fails.
>
> I think you've misunderstood the problem. If nvram becaomes full, some
> systems crash during firmware initialisation. So we can't let nvram
> become full. The obvious thing to do here is to look at the values from
> QueryVariableInfo, but many systems won't perform any garbage collection
> until they're almost out of space and so variables that have been
> deleted still show up as used space. We can work around that by adding
> up the size of the variables ourselves, but that only gives us the value
> for runtime-visible variables. We also need to know how much space is
> used by variables that are only visible during boot, hence calling
> QueryVariableInfo before ExitBootServices.
>
> > Which means the previous patch(es) that caused the bricking should
> > get pulled, too.
>
> There are no patches that cause the bricking.
This is the description of the original problem:
http://www.h-online.com/open/news/item/Booting-Linux-using-UEFI-can-brick-Samsung-laptops-1793958.html
And the further investigation:
http://mjg59.dreamwidth.org/22855.html
If you read the latter, it shows you why we have to use
QueryVariableInfo to try to work out how much space we have available.
James
next prev parent reply other threads:[~2013-05-31 17:36 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-22 16:27 [regression, bisected] x86: efi: Pass boot services variable info to runtime code Russ Anderson
2013-05-23 11:58 ` Matt Fleming
2013-05-23 20:32 ` Russ Anderson
2013-05-24 7:43 ` Matt Fleming
2013-05-24 11:09 ` Borislav Petkov
2013-05-24 11:40 ` Matt Fleming
2013-05-24 16:11 ` Robin Holt
2013-05-24 17:02 ` Russ Anderson
2013-05-24 21:05 ` Dave Jones
2013-05-27 4:27 ` joeyli
2013-05-27 4:32 ` joeyli
2013-05-28 2:43 ` Russ Anderson
2013-05-24 20:05 ` Russ Anderson
2013-05-24 20:11 ` Matthew Garrett
2013-05-24 20:49 ` Russ Anderson
2013-05-28 10:50 ` Matt Fleming
2013-05-28 10:53 ` Matt Fleming
2013-05-28 8:35 ` Ingo Molnar
2013-05-29 21:01 ` Russ Anderson
2013-05-29 22:22 ` Jiri Kosina
2013-05-29 22:46 ` Russ Anderson
2013-05-29 22:53 ` Jiri Kosina
2013-05-30 2:16 ` joeyli
2013-05-30 22:17 ` Russ Anderson
2013-05-30 22:21 ` Matthew Garrett
2013-05-30 22:28 ` Russ Anderson
2013-05-30 22:30 ` Jiri Kosina
2013-05-31 2:17 ` Russ Anderson
2013-05-31 3:28 ` joeyli
2013-05-30 22:32 ` Matthew Garrett
2013-05-31 2:54 ` Russ Anderson
2013-05-31 10:06 ` Ingo Molnar
2013-05-30 22:25 ` Jiri Kosina
2013-05-31 10:12 ` Ingo Molnar
2013-05-31 11:06 ` Jiri Kosina
2013-05-31 11:40 ` Ingo Molnar
2013-05-31 11:54 ` Josh Boyer
2013-05-31 12:30 ` Borislav Petkov
2013-05-31 12:43 ` Ingo Molnar
2013-05-31 14:34 ` Matthew Garrett
2013-05-31 14:42 ` James Bottomley
2013-05-31 14:45 ` H. Peter Anvin
2013-05-31 14:48 ` Matthew Garrett
2013-05-31 15:43 ` Russ Anderson
2013-05-31 16:28 ` Matthew Garrett
2013-05-31 17:35 ` James Bottomley [this message]
2013-05-31 22:57 ` Russ Anderson
2013-05-31 22:59 ` H. Peter Anvin
2013-05-31 23:30 ` Jiri Kosina
2013-06-01 0:03 ` Matthew Garrett
2013-06-01 4:20 ` Russ Anderson
2013-06-01 4:41 ` Matthew Garrett
2013-06-01 11:01 ` Linus Torvalds
2013-06-01 14:40 ` Matthew Garrett
2013-05-30 2:38 ` joeyli
2013-05-23 22:23 ` Russ Anderson
2013-05-24 7:45 ` Matt Fleming
2013-05-29 20:16 ` Russ Anderson
2013-05-31 14:41 ` H. Peter Anvin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1370021732.6250.4.camel@dabdike \
--to=james.bottomley@hansenpartnership.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=hpa@linux.intel.com \
--cc=jkosina@suse.cz \
--cc=jlee@suse.com \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=matt.fleming@intel.com \
--cc=matt@console-pimps.org \
--cc=mingo@kernel.org \
--cc=mjg59@srcf.ucam.org \
--cc=rja@sgi.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).