From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751909AbeCVUMV (ORCPT ); Thu, 22 Mar 2018 16:12:21 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:43359 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751765AbeCVUMT (ORCPT ); Thu, 22 Mar 2018 16:12:19 -0400 X-ME-Sender: Date: Fri, 23 Mar 2018 07:12:14 +1100 From: "Tobin C . Harding" To: Joel Stanley Cc: Jonathan Corbet , Michael Ellerman , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Documentation: Mention why %p prints ptrval Message-ID: <20180322201214.GE3305@eros> References: <20180322052336.1001-1-joel@jms.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180322052336.1001-1-joel@jms.id.au> 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 Thu, Mar 22, 2018 at 03:53:36PM +1030, Joel Stanley wrote: > When debugging recent kernels, people will see '(ptrval)' but there > isn't much information as to what that means. Briefly describe why it's > there. > > Signed-off-by: Joel Stanley > --- > Documentation/core-api/printk-formats.rst | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst > index 934559b3c130..eb30efdd2e78 100644 > --- a/Documentation/core-api/printk-formats.rst > +++ b/Documentation/core-api/printk-formats.rst > @@ -60,8 +60,8 @@ Plain Pointers > Pointers printed without a specifier extension (i.e unadorned %p) are > hashed to prevent leaking information about the kernel memory layout. This > has the added benefit of providing a unique identifier. On 64-bit machines > -the first 32 bits are zeroed. If you *really* want the address see %px > -below. > +the first 32 bits are zeroed. The kernel will print ``(ptrval)`` until it > +gathers enough entropy. If you *really* want the address see %px below. Acked-by: Tobin C. Harding thanks, Tobin.