Re: [PATCH] doc: convert printk-formats.txt to rst

From: Tobin C. Harding
Date: Sat Dec 09 2017 - 01:33:46 EST


[Adding Laura]

On Fri, Dec 08, 2017 at 06:18:45PM -0800, Joe Perches wrote:
> On Sat, 2017-12-09 at 12:27 +1100, Tobin C. Harding wrote:
> > On Fri, Dec 08, 2017 at 01:22:37PM -0800, Joe Perches wrote:
>
> > > Outside of the documentation, what could be useful is for
> > > someone to add a tool to verify %p<foo> extension to
> > > the typeof address actually passed as an argument.
> >
> > This sounds interesting to work no. At first glance I have no idea how
> > one would go about this. Some form of static analysis would be a good
> > place to start, right? I'd like to allocate some cycles to this, any
> > pointers most appreciated.
>
> A gcc-plugin would likely work best.

What's the learning curve like in your opinion to do a gcc-plugin. I
recall reading someplace 'deep understanding of how the compiler works'
or some such thing. I suppose reading the Dragon book would be a good
place to start?

We could also catch pointers being cast to longs and printed with %x
(and %u) or so I would guess.

> There was some discussion about such a thing here:
> http://www.openwall.com/lists/kernel-hardening/2017/02/14/38

Did you make much progress with this Laura?

> I vaguely recall someone else doing a broader use tool
> which I believe was not smatch, but my google-fu isn't
> finding it.
>
> It might have been coccinelle based.

thanks,
Tobin.