From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753119AbbIBKfA (ORCPT ); Wed, 2 Sep 2015 06:35:00 -0400 Received: from foss.arm.com ([217.140.101.70]:35909 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752736AbbIBKe7 (ORCPT ); Wed, 2 Sep 2015 06:34:59 -0400 Date: Wed, 2 Sep 2015 11:34:55 +0100 From: Will Deacon To: Arnaldo Carvalho de Melo Cc: Jean Pihet , He Kuang , "wangnan0@huawei.com" , "a.p.zijlstra@chello.nl" , "mingo@redhat.com" , "jolsa@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] perf tools: Support bpf prologue for arm64 Message-ID: <20150902103455.GH25720@arm.com> References: <1440818212-121220-1-git-send-email-hekuang@huawei.com> <20150831201628.GH4423@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150831201628.GH4423@kernel.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 31, 2015 at 09:16:28PM +0100, Arnaldo Carvalho de Melo wrote: > Em Sat, Aug 29, 2015 at 03:16:52AM +0000, He Kuang escreveu: > > This patch implements arch_get_reg_info() for arm64 to enable > > HAVE_BPF_PROLOGUE feature. For arm64, structure pt_regs is not composed > > by fields of register names but an array of regs, so here we simply > > multiply fixed register size by index number to get the byte offset. > > Hi Jean, Will, are you ok with this? Can I have Acked-by or Reviewed-by > tags from you? Any idea what this applies against? It's difficult to review it without knowing what PERF_HAVE_ARCH_GET_REG_INFO or HAVE_BPF_PROLOGUE are. Anyway, a couple of small comments below. > He, please try to add the authors of the files you change in the CC > list. > > - Arnaldo > > > Signed-off-by: He Kuang > > --- > > tools/perf/arch/arm64/Makefile | 1 + > > tools/perf/arch/arm64/util/dwarf-regs.c | 26 ++++++++++++++++++++++++++ > > 2 files changed, 27 insertions(+) Any plan to do arch/arm/ too? > > diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile > > index 7fbca17..1256e6e 100644 > > --- a/tools/perf/arch/arm64/Makefile > > +++ b/tools/perf/arch/arm64/Makefile > > @@ -1,3 +1,4 @@ > > ifndef NO_DWARF > > PERF_HAVE_DWARF_REGS := 1 > > endif > > +PERF_HAVE_ARCH_GET_REG_INFO := 1 > > diff --git a/tools/perf/arch/arm64/util/dwarf-regs.c b/tools/perf/arch/arm64/util/dwarf-regs.c > > index d49efeb..cb2c50a 100644 > > --- a/tools/perf/arch/arm64/util/dwarf-regs.c > > +++ b/tools/perf/arch/arm64/util/dwarf-regs.c > > @@ -10,6 +10,10 @@ > > > > #include > > #include > > +#include > > +#include > > + > > +#define PT_REG_SIZE (sizeof(((struct user_pt_regs *)0)->regs[0])) Why not add an "offset" field to pt_regs_dwarfnum and just calculate that using offsetof in the GPR_DWARFNUM_NAME macro? > > > > struct pt_regs_dwarfnum { > > const char *name; > > @@ -78,3 +82,25 @@ const char *get_arch_regstr(unsigned int n) > > return roff->name; > > return NULL; > > } > > + > > +#ifdef HAVE_BPF_PROLOGUE > > +int arch_get_reg_info(const char *name, int *offset) > > +{ > > + const struct pt_regs_dwarfnum *roff; > > + > > + if (!name || !offset) > > + return -1; > > + > > + for (roff = regdwarfnum_table; roff->name != NULL; roff++) { > > + if (!strcmp(roff->name, name)) { > > + if (roff->dwarfnum < 0) When is this ever true? Do we need up update REG_DWARFNUM_END to use a negative index? Will