Re: [GIT PULL] hash addresses printed with %p

From: Tobin C. Harding
Date: Wed Nov 29 2017 - 16:28:26 EST


On Wed, Nov 29, 2017 at 01:14:38PM -0800, Linus Torvalds wrote:
> On Wed, Nov 29, 2017 at 1:08 PM, Tobin C. Harding <me@xxxxxxxx> wrote:
> >
> > If you haven't wasted enough time on this can you tell me what you mean
> > by 'completely breaks %pK'?
>
> The whole point of %pK is that it's a "safer" %p that doesn't leak
> information if you set kptr_restrict.
>
> With that patch-set, it now leaks _more_ information than %p when
> kptr_restrict isn't set, so %pK went from "be more careful than %p" to
> "be wildly less careful than %p".
>
> Not because %pK itself changed, but because the semantics of %p did.
> The baseline moved, and the "safe" version did not.

Oh sweet, I was shitting bricks when I read your email :)