Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933473AbbFWNte (ORCPT ); Tue, 23 Jun 2015 09:49:34 -0400 Received: from mail-qg0-f52.google.com ([209.85.192.52]:36617 "EHLO mail-qg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933373AbbFWNsW (ORCPT ); Tue, 23 Jun 2015 09:48:22 -0400 Message-ID: <558963A3.4070503@linaro.org> Date: Tue, 23 Jun 2015 09:48:19 -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: Michael Ellerman CC: "H. Peter Anvin" , Andy Lutomirski , Anton Blanchard , Behan Webster , Benjamin Herrenschmidt , Eric Paris , Heiko Carstens , Ingo Molnar , Jan Willeke , Kees Cook , 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, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux390@de.ibm.com, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, mahesh@linux.vnet.ibm.com 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> <1435030328.28070.5.camel@ellerman.id.au> In-Reply-To: <1435030328.28070.5.camel@ellerman.id.au> 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: 3442 Lines: 72 On 06/22/15 23:32, Michael Ellerman wrote: > On Fri, 2015-06-19 at 10:12 -0400, 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. > > OK, so I went the whole hog and did: > > $ echo 'p do_fork %gpr0 %gpr1 %gpr2 %gpr3 %gpr4 %gpr5 %gpr6 %gpr7 %gpr8 %gpr9 %gpr10 %gpr11 %gpr12 %gpr13 %gpr14 %gpr15 %gpr16 %gpr17 %gpr18 %gpr19 %gpr20 %gpr21 %gpr22 %gpr23 %gpr24 %gpr25 %gpr26 %gpr27 %gpr28 %gpr29 %gpr30 %gpr31 %nip %msr %ctr %link %xer %ccr %softe %trap %dar %dsisr' > kprobe_events > > And I get: > > bash-2057 [001] d... 535.433941: p_do_fork_0: (do_fork+0x8/0x490) arg1=0xc0000000000094d0 arg2=0xc0000001fbe9be30 arg3=0xc000000001133bb8 arg4=0x1200011 arg5=0x0 arg6=0x0 arg7=0x0 arg8=0x3fff7c885940 arg9=0x1 arg10=0xc0000001fbe9bea0 arg11=0x0 arg12=0xc01 arg13=0xc0000000000094c8 arg14=0xc00000000fdc0480 arg15=0x0 arg16=0x22000000 arg17=0x1016d6e8 arg18=0x0 arg19=0x44000000 arg20=0x0 arg21=0x10037c82208 arg22=0x1017b008 arg23=0x10143d18 arg24=0x10178854 arg25=0x10144f90 arg26=0x10037c821e8 arg27=0x0 arg28=0x0 arg29=0x0 arg30=0x0 arg31=0x809 arg32=0x3ffff788c010 arg33=0xc0000000000a7fe8 arg34=0x8000000000029033 arg35=0xc0000000000094c8 arg36=0xc0000000000094d0 arg37=0x0 arg38=0x42222844 arg39=0x1 arg40=0x700 arg41=0xc0000001fbe9bd50 arg42=0xc0000001fbe9bd30 > > Which is ugly as hell, but appears unchanged since before your patch. > Excellent. Many thanks. > I take it it's expected that the names are not decoded in the output? > Yes. > Also I wonder why we choose "gpr" when "r" is the more usual prefix on powerpc. > I guess we can add new aliases to the table. > Yeah I can't answer that, this is just what the preexisting code is written to do. I believe you could add aliases to the table, perhaps as a step in migrating to supporting only the more common naming. The reverse translation would have to return one or the other though. -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/