From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>,
Andy Lutomirski <luto@kernel.org>,
Will Deacon <will.deacon@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Matt Fleming <matt@codeblueprint.co.uk>,
Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
joeyli <jlee@suse.com>, Borislav Petkov <bp@alien8.de>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Neri, Ricardo" <ricardo.neri@intel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>
Subject: Re: [PATCH 3/3] x86/efi: Use efi_switch_mm() rather than manually twiddling with cr3
Date: Mon, 21 Aug 2017 17:08:50 +0100 [thread overview]
Message-ID: <CAKv+Gu_whUkAdM4xHLs-Cm90hRmqBbVgyDTyBVrGoTO1G6WzLg@mail.gmail.com> (raw)
In-Reply-To: <20170821155913.7bmmy7zaihpd6s7h@hirez.programming.kicks-ass.net>
On 21 August 2017 at 16:59, Peter Zijlstra <peterz@infradead.org> wrote:
> On Mon, Aug 21, 2017 at 08:23:10AM -0700, Andy Lutomirski wrote:
>> > Ah, but only root can create per-cpu events or attach events to kernel
>> > threads (with sensible paranoia levels).
>>
>> But this may not need to be percpu. If a non root user can trigger, say, an EFI variable read in their own thread context, boom.
>
> I was going by the proposed: "everything EFI in a kthread" model. But
> yes, if that's not done, then you're quite right.
>
How does this work in cases where we need to call into UEFI from
non-process context? Or at least from a context where current != EFI's
kthread. We have EFI pstore code, for instance, that records panic
data. Should we make an exception for those?
I'm happy to have a stab at implementing the EFI kthread, but I'd like
to get some of these details clarified first.
next prev parent reply other threads:[~2017-08-21 16:08 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-15 19:18 [PATCH 0/3] Use mm_struct and switch_mm() instead of manually Sai Praneeth Prakhya
2017-08-15 19:18 ` [PATCH 1/3] efi: Use efi_mm in x86 as well as ARM Sai Praneeth Prakhya
2017-08-15 19:18 ` [PATCH 2/3] x86/efi: Replace efi_pgd with efi_mm.pgd Sai Praneeth Prakhya
2017-08-15 19:18 ` [PATCH 3/3] x86/efi: Use efi_switch_mm() rather than manually twiddling with cr3 Sai Praneeth Prakhya
2017-08-15 21:46 ` Andy Lutomirski
2017-08-16 0:23 ` Sai Praneeth Prakhya
2017-08-16 0:47 ` Andy Lutomirski
2017-08-16 9:31 ` Ard Biesheuvel
2017-08-16 9:53 ` Mark Rutland
2017-08-16 10:07 ` Will Deacon
2017-08-16 11:03 ` Mark Rutland
2017-08-16 12:57 ` Matt Fleming
2017-08-16 16:14 ` Andy Lutomirski
2017-08-15 22:35 ` Mark Rutland
2017-08-17 10:35 ` Will Deacon
2017-08-17 15:52 ` Andy Lutomirski
2017-08-21 10:33 ` Peter Zijlstra
2017-08-21 13:56 ` Andy Lutomirski
2017-08-21 14:08 ` Peter Zijlstra
2017-08-21 15:23 ` Andy Lutomirski
2017-08-21 15:59 ` Peter Zijlstra
2017-08-21 16:08 ` Ard Biesheuvel [this message]
2017-08-23 22:52 ` Sai Praneeth Prakhya
2017-08-25 15:13 ` Andy Lutomirski
2017-08-21 17:24 ` Peter Zijlstra
2017-08-25 2:36 ` Sai Praneeth Prakhya
2017-08-25 15:13 ` Andy Lutomirski
2017-12-17 0:06 [PATCH 3/3] x86/efi: Use efi_switch_mm() rather than manually twiddling with %cr3 Sai Praneeth Prakhya
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=CAKv+Gu_whUkAdM4xHLs-Cm90hRmqBbVgyDTyBVrGoTO1G6WzLg@mail.gmail.com \
--to=ard.biesheuvel@linaro.org \
--cc=bp@alien8.de \
--cc=jlee@suse.com \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=matt@codeblueprint.co.uk \
--cc=mst@redhat.com \
--cc=peterz@infradead.org \
--cc=ravi.v.shankar@intel.com \
--cc=ricardo.neri@intel.com \
--cc=sai.praneeth.prakhya@intel.com \
--cc=will.deacon@arm.com \
/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).