From: Peter Zijlstra <peterz@infradead.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: "Christopher M. Riedl" <cmr@codefail.de>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/8] powerpc: Mark functions called inside uaccess blocks w/ 'notrace'
Date: Fri, 16 Oct 2020 11:41:32 +0200 [thread overview]
Message-ID: <20201016094132.GI2611@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20201016065616.GB9343@infradead.org>
On Fri, Oct 16, 2020 at 07:56:16AM +0100, Christoph Hellwig wrote:
> On Thu, Oct 15, 2020 at 10:01:54AM -0500, Christopher M. Riedl wrote:
> > Functions called between user_*_access_begin() and user_*_access_end()
> > should be either inlined or marked 'notrace' to prevent leaving
> > userspace access exposed. Mark any such functions relevant to signal
> > handling so that subsequent patches can call them inside uaccess blocks.
>
> I don't think running this much code with uaccess enabled is a good
> idea. Please refactor the code to reduce the criticial sections with
> uaccess enabled.
>
> Btw, does powerpc already have the objtool validation that we don't
> accidentally jump out of unsafe uaccess critical sections?
It does not, there was some effort on that a while ago, but I suspect
they're waiting for the ARM64 effort to land and build on that.
next prev parent reply other threads:[~2020-10-16 9:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20201015150159.28933-1-cmr@codefail.de>
[not found] ` <20201015150159.28933-2-cmr@codefail.de>
2020-10-16 6:54 ` [PATCH 1/8] powerpc/uaccess: Add unsafe_copy_from_user Christoph Hellwig
2020-10-16 13:18 ` Christophe Leroy
[not found] ` <20201015150159.28933-4-cmr@codefail.de>
2020-10-16 6:56 ` [PATCH 3/8] powerpc: Mark functions called inside uaccess blocks w/ 'notrace' Christoph Hellwig
2020-10-16 9:41 ` Peter Zijlstra [this message]
2020-10-20 7:34 ` Michael Ellerman
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=20201016094132.GI2611@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=cmr@codefail.de \
--cc=hch@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.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
Powered by JetHome