mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Andi Kleen <andi@firstfloor.org>
To: David Laight <David.Laight@ACULAB.COM>
Cc: 'Andi Kleen' <andi@firstfloor.org>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"dwmw@amazon.co.uk" <dwmw@amazon.co.uk>,
	"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	"arjan.van.de.ven@intel.com" <arjan.van.de.ven@intel.com>,
	"peterz@infradead.org" <peterz@infradead.org>,
	Andi Kleen <ak@linux.intel.com>,
	"jeyu@kernel.org" <jeyu@kernel.org>
Subject: Re: [PATCH] retpoline/module: Taint kernel for missing retpoline in module
Date: Mon, 15 Jan 2018 08:48:12 -0800	[thread overview]
Message-ID: <20180115164811.oqf5yo56vx255hej@two.firstfloor.org> (raw)
In-Reply-To: <a8ff2d96e82248ee97068459a8bd903b@AcuMS.aculab.com>

> It is not unlikely that most of a module's code is released as a
> binary 'blob', with only the part that needs to match the kernel ABI
> compiled on the target system.

Yes that is true. However such blob build systems are usually
done with custom Makefiles, not Kbuild, and those Makefiles don't set
-DRETPOLINE, so it would still be caught.

Now if someone sets -DRETPOLINE on a blob build it wouldn't warn,
but that would be actively malicious and there's no way to protect
against that.

It's merely aimed at detecting mistakes.

-Andi

      parent reply	other threads:[~2018-01-15 16:48 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-12 17:55 Andi Kleen
2018-01-12 19:01 ` David Woodhouse
2018-01-12 19:17   ` Andi Kleen
2018-01-13 14:12 ` Greg KH
2018-01-13 14:38   ` Van De Ven, Arjan
2018-01-13 15:37     ` Greg KH
2018-01-13 14:53   ` Andi Kleen
2018-01-13 15:36     ` Greg KH
2018-01-13 18:20       ` Andi Kleen
2018-01-16 20:08       ` Andi Kleen
2018-01-15 12:47 ` David Laight
2018-01-15 12:53   ` Van De Ven, Arjan
2018-01-15 13:01     ` David Woodhouse
2018-01-15 14:08       ` David Laight
2018-01-15 16:48   ` Andi Kleen [this message]

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=20180115164811.oqf5yo56vx255hej@two.firstfloor.org \
    --to=andi@firstfloor.org \
    --cc=David.Laight@ACULAB.COM \
    --cc=ak@linux.intel.com \
    --cc=arjan.van.de.ven@intel.com \
    --cc=dwmw@amazon.co.uk \
    --cc=gregkh@linuxfoundation.org \
    --cc=jeyu@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.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

all inboxes | Powered by JetHome®