bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Brendan Jackman <jackmanb@chromium.org>,
	linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	Paul Renauld <renauld@google.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	James Morris <jmorris@namei.org>,
	pjt@google.com, jannh@google.com, rafael.j.wysocki@intel.com,
	keescook@chromium.org, thgarnie@chromium.org, kpsingh@google.com,
	paul.renauld.epfl@gmail.com,
	Brendan Jackman <jackmanb@google.com>,
	rostedt@goodmis.org
Subject: Re: [RFC] security: replace indirect calls with static calls
Date: Fri, 5 Feb 2021 16:40:10 +0100	[thread overview]
Message-ID: <YB1m2i6bUM0LO5wS@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210205150926.GA12608@localhost>

On Fri, Feb 05, 2021 at 10:09:26AM -0500, Mathieu Desnoyers wrote:
> Then we should be able to generate the following using static keys as a
> jump table and N static calls:
> 
>   jump <static key label target>
> label_N:
>   stack setup
>   call
> label_N-1:
>   stack setup
>   call
> label_N-2:
>   stack setup
>   call
>   ...
> label_0:
>   jump end
> label_fallback:
>   <iteration and indirect calls>
> end:
> 
> So the static keys would be used to jump to the appropriate label (using
> a static branch, which has pretty much 0 overhead). Static calls would
> be used to implement each of the calls.
> 
> Thoughts ?

At some point I tried to extend the static_branch infra to do multiple
targets and while the low level plumbing is trivial, I ran into trouble
trying to get a sane C level API for it.



  reply	other threads:[~2021-02-05 22:28 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-20 16:47 [RFC] security: replace indirect calls with static calls Brendan Jackman
2020-08-20 18:43 ` James Morris
2020-08-20 19:04   ` KP Singh
2020-08-20 21:45 ` Kees Cook
2020-08-24 14:09   ` Brendan Jackman
2020-08-24 14:33     ` Peter Zijlstra
2020-08-24 15:05       ` Brendan Jackman
2020-08-20 22:46 ` Casey Schaufler
2020-08-24 15:20   ` Brendan Jackman
2020-08-24 16:42     ` Casey Schaufler
2020-08-24 17:04       ` Brendan Jackman
2020-08-24 17:54         ` Casey Schaufler
2021-02-05 15:09 ` Mathieu Desnoyers
2021-02-05 15:40   ` Peter Zijlstra [this message]
2021-02-05 15:47     ` Mathieu Desnoyers

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=YB1m2i6bUM0LO5wS@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=jackmanb@chromium.org \
    --cc=jackmanb@google.com \
    --cc=jannh@google.com \
    --cc=jmorris@namei.org \
    --cc=keescook@chromium.org \
    --cc=kpsingh@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=paul.renauld.epfl@gmail.com \
    --cc=pjt@google.com \
    --cc=rafael.j.wysocki@intel.com \
    --cc=renauld@google.com \
    --cc=rostedt@goodmis.org \
    --cc=thgarnie@chromium.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).