From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Subject: Re: [PATCH -tip v2 4/7] kprobes: Replace %p with other pointer types Date: Fri, 27 Apr 2018 11:39:51 +0900 Message-ID: <20180427113951.8e3192af570c0bae925b2a71@kernel.org> References: <152473007907.8819.10449983839199591406.stgit@devbox> <152473020349.8819.11597612324633031612.stgit@devbox> <20180426211351.419d3502@vmware.local.home> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180426211351.419d3502@vmware.local.home> Sender: stable-owner@vger.kernel.org To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Ingo Molnar , "H . Peter Anvin" , x86@kernel.org, Ananth N Mavinakayanahalli , Anil S Keshavamurthy , "David S . Miller" , Jon Medhurst , Will Deacon , Arnd Bergmann , David Howells , Heiko Carstens , "Tobin C . Harding" , Linus Torvalds , Thomas Richter , akpm@linux-foundation.org, acme@kernel.org, brueckner@linux.vnet.ibm.com, schwidefsky@de.ibm.com, stable@vger.kernel.org List-Id: linux-arch.vger.kernel.org On Thu, 26 Apr 2018 21:13:51 -0400 Steven Rostedt wrote: > On Thu, 26 Apr 2018 17:10:03 +0900 > Masami Hiramatsu wrote: > > > Replace %p with appropriate pointer types (or just remove it) > > - Use %pS if possible > > - Use %px only for the function right before BUG(). > > - Remove unneeded error message. > > I'm not sure "right before BUG()" is legitimate for using %px. Why not > still use %pS? Since BUG() will dump all registers and stacks which includes raw address information and reboot the system (means reset the kaslr base offset), I thought it may not add additional damage. Anyway, for this patch we can use %pS. For the next [5/7] patch, I'm not sure %pS is good for dumping a stack address... Thank you, > > -- Steve > -- Masami Hiramatsu From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:38982 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757029AbeD0Cj6 (ORCPT ); Thu, 26 Apr 2018 22:39:58 -0400 Date: Fri, 27 Apr 2018 11:39:51 +0900 From: Masami Hiramatsu Subject: Re: [PATCH -tip v2 4/7] kprobes: Replace %p with other pointer types Message-ID: <20180427113951.8e3192af570c0bae925b2a71@kernel.org> In-Reply-To: <20180426211351.419d3502@vmware.local.home> References: <152473007907.8819.10449983839199591406.stgit@devbox> <152473020349.8819.11597612324633031612.stgit@devbox> <20180426211351.419d3502@vmware.local.home> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Ingo Molnar , "H . Peter Anvin" , x86@kernel.org, Ananth N Mavinakayanahalli , Anil S Keshavamurthy , "David S . Miller" , Jon Medhurst , Will Deacon , Arnd Bergmann , David Howells , Heiko Carstens , "Tobin C . Harding" , Linus Torvalds , Thomas Richter , akpm@linux-foundation.org, acme@kernel.org, brueckner@linux.vnet.ibm.com, schwidefsky@de.ibm.com, stable@vger.kernel.org Message-ID: <20180427023951.alO6widDNdty8VWTzlt-Yr2ikYi7hW-h-Jw-bZz3lN4@z> On Thu, 26 Apr 2018 21:13:51 -0400 Steven Rostedt wrote: > On Thu, 26 Apr 2018 17:10:03 +0900 > Masami Hiramatsu wrote: > > > Replace %p with appropriate pointer types (or just remove it) > > - Use %pS if possible > > - Use %px only for the function right before BUG(). > > - Remove unneeded error message. > > I'm not sure "right before BUG()" is legitimate for using %px. Why not > still use %pS? Since BUG() will dump all registers and stacks which includes raw address information and reboot the system (means reset the kaslr base offset), I thought it may not add additional damage. Anyway, for this patch we can use %pS. For the next [5/7] patch, I'm not sure %pS is good for dumping a stack address... Thank you, > > -- Steve > -- Masami Hiramatsu