Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752238AbbFZSfl (ORCPT ); Fri, 26 Jun 2015 14:35:41 -0400 Received: from mail-qg0-f49.google.com ([209.85.192.49]:36096 "EHLO mail-qg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752196AbbFZSfc (ORCPT ); Fri, 26 Jun 2015 14:35:32 -0400 Message-ID: <558D9B71.2080605@linaro.org> Date: Fri, 26 Jun 2015 14:35:29 -0400 From: David Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Kees Cook CC: Michael Ellerman , "H. Peter Anvin" , Andy Lutomirski , Anton Blanchard , Behan Webster , Benjamin Herrenschmidt , Eric Paris , Heiko Carstens , Ingo Molnar , Jan Willeke , Martin Schwidefsky , Nikolay Borisov , Oleg Nesterov , Paul Mackerras , Richard Kuo , Robert Richter , Roland McGrath , Russell King , Tejun Heo , Thomas Gleixner , Will Deacon , "linux-arm-kernel@lists.infradead.org" , linux-hexagon@vger.kernel.org, LKML , "linux-s390@vger.kernel.org" , linux-sh , "linux390@de.ibm.com" , "linuxppc-dev@lists.ozlabs.org" , "x86@kernel.org" Subject: Re: [PATCH 1/2] Move the pt_regs_offset struct definition from arch to common include file References: <1434386579-6045-1-git-send-email-dave.long@linaro.org> <1434386579-6045-2-git-send-email-dave.long@linaro.org> <1434687583.23771.5.camel@ellerman.id.au> <5584234E.2040701@linaro.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2685 Lines: 78 On 06/19/15 12:58, Kees Cook wrote: > On Fri, Jun 19, 2015 at 7:12 AM, David Long wrote: >> On 06/19/15 00:19, Michael Ellerman wrote: >>> >>> On Mon, 2015-06-15 at 12:42 -0400, David Long wrote: >>>> >>>> From: "David A. Long" >>>> >>>> The pt_regs_offset structure is used for HAVE_REGS_AND_STACK_ACCESS_API >>>> feature and has identical definitions in four different arch ptrace.h >>>> include files. It seems unlikely that definition would ever need to be >>>> changed regardless of architecture so lets move it into >>>> include/linux/ptrace.h. >>>> >>>> Signed-off-by: David A. Long >>>> --- >>>> arch/powerpc/kernel/ptrace.c | 5 ----- >>> >>> >>> Built and booted on powerpc, but is there an easy way to actually test the >>> code >>> paths in question? >>> >> >> There is an easy way to "smoke test" it on all archiectures that also >> implement kprobes (which powerpc does). If I'm understanding the powerpc >> code correctly (WRT register naming conventions) just do the following: >> >> cd /sys/kernel/debug/tracing >> echo 'p do_fork %gpr0' > kprobe_events >> echo 1 > events/kprobes/enable >> ls >> cat trace >> echo 0 > events/kprobes/enable >> >> Every fork() call done on the system between those two echo commands (hence >> the "ls") should append a line to the trace file. For a more exhaustive >> test one could repeat this sequence for every register in the architecture. >> >> This should work the same on all architectures supporting kprobes. You just >> have to use the appropriate register names for your architecture after the >> "%". > > Is this something we could codify into the selftests directory? It > seems like a great thing to capture in a single place somewhere (the > register lists, that is). > e > -Kees > Due to the architecture-specific naming of registers this would have to be added to the architecture subdirectories. I only see powerpc and x86 subdirs at this time so extending that infrastructure would have to be part of this. Verifying the register contents would also require some change to the kernel, possibly a simple test module, which would have to be unique to each architecture. Without that we could only check for recognition of the register name, although maybe that's good enough. >> >>> Acked-by: Michael Ellerman >>> >>> cheers >>> >>> >> >> Thanks, >> -dl >> -dl -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/