From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave.long@linaro.org (David Long) Date: Wed, 24 Jun 2015 09:49:53 -0400 Subject: [PATCH 1/2] Move the pt_regs_offset struct definition from arch to common include file In-Reply-To: <1435118879.3620.5.camel@ellerman.id.au> 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> <558963A3.4070503@linaro.org> <1435118879.3620.5.camel@ellerman.id.au> Message-ID: <558AB581.6050802@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/24/15 00:07, Michael Ellerman wrote: > On Tue, 2015-06-23 at 09:48 -0400, David Long wrote: >> 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. > > No worries. > > Did I already send you an ack? Have another one in case: > > Acked-by: Michael Ellerman > > Thanks. >>> I take it it's expected that the names are not decoded in the output? >> >> Yes. > > In fact I don't see anywhere that uses the reverse decoding, ie. > regs_query_register_name(). > Neither did I. I assumed it was intended to support either future kernel code or custom debug modules. > cheers > > -dl