public inbox for linux-efi@vger.kernel.org
 help / color / mirror / Atom feed
From: Jeffrey Hugo <jhugo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
To: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
	Matt Fleming
	<matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>,
	"linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Timur Tabi <timur-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
	Leif Lindholm
	<leif.lindholm-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Subject: Re: [RFC PATCH] efi/libstub: Retry ExitBootServices if map key is invalid
Date: Thu, 30 Jun 2016 15:05:12 -0600	[thread overview]
Message-ID: <1b487d6d-624c-6acb-d9c1-318cd63070d5@codeaurora.org> (raw)
In-Reply-To: <CAKv+Gu8N3ORp_tg80wxJAgyYbNNPtfw2h-Hxy3DMkDcM6MQbAg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

On 6/30/2016 12:31 PM, Ard Biesheuvel wrote:
>
> No, I think x86's implementation is incorrect. efi_get_memory_map()
> should allocate some slack (i.e., the 8 entries you mentioned), and if
> the first call to ExitBootServices() fails, we should reuse the memory
> map buffer, and call GetMemoryMap() directly to repopulate it. Then,
> we call ExitBootServices() once more, or give up if either call fails.
>
> This way, we are 100% compliant with the wording of the spec, and err
> on the side of caution.
>

Ok.  Let me take some time to think upon this approach and develop a 
working prototype.

Thanks for providing your guidance in a very expedient manner.

-- 
Jeffrey Hugo
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project

  parent reply	other threads:[~2016-06-30 21:05 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-30 15:35 [RFC PATCH] efi/libstub: Retry ExitBootServices if map key is invalid Jeff Hugo
     [not found] ` <1467300933-3991-1-git-send-email-jhugo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2016-06-30 16:27   ` Mark Rutland
2016-06-30 16:47     ` Ard Biesheuvel
     [not found]       ` <CAKv+Gu_PLqOVZQC4i3v75M0a-Z9tuE86DSU4v=Vg_pBj-5Y1WQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-06-30 17:56         ` Jeffrey Hugo
     [not found]           ` <36dc8c28-e659-7d93-d705-ccc7734fd3d2-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2016-06-30 18:31             ` Ard Biesheuvel
     [not found]               ` <CAKv+Gu8N3ORp_tg80wxJAgyYbNNPtfw2h-Hxy3DMkDcM6MQbAg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-06-30 21:05                 ` Jeffrey Hugo [this message]
     [not found]                   ` <1b487d6d-624c-6acb-d9c1-318cd63070d5-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2016-07-04 13:44                     ` Matt Fleming
2016-07-01 10:00         ` Mark Rutland

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=1b487d6d-624c-6acb-d9c1-318cd63070d5@codeaurora.org \
    --to=jhugo-sgv2jx0feol9jmxxk+q4oq@public.gmane.org \
    --cc=ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
    --cc=leif.lindholm-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
    --cc=linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=mark.rutland-5wv7dgnIgG8@public.gmane.org \
    --cc=matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org \
    --cc=timur-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.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