From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751748AbdK2V2X (ORCPT ); Wed, 29 Nov 2017 16:28:23 -0500 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:50401 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877AbdK2V2W (ORCPT ); Wed, 29 Nov 2017 16:28:22 -0500 X-ME-Sender: Date: Thu, 30 Nov 2017 08:28:18 +1100 From: "Tobin C. Harding" To: Linus Torvalds Cc: LKML Subject: Re: [GIT PULL] hash addresses printed with %p Message-ID: <20171129212818.GK6217@eros> References: <20171129045927.GA6217@eros> <20171129210848.GF6217@eros> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailer: Mutt 1.5.24 (2015-08-30) User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 :)