From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758026AbbJ2Wpo (ORCPT ); Thu, 29 Oct 2015 18:45:44 -0400 Received: from mail.kernel.org ([198.145.29.136]:36213 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757173AbbJ2Wpn (ORCPT ); Thu, 29 Oct 2015 18:45:43 -0400 Date: Thu, 29 Oct 2015 19:45:38 -0300 From: Arnaldo Carvalho de Melo To: Wang Nan Cc: ast@plumgrid.com, brendan.d.gregg@gmail.com, a.p.zijlstra@chello.nl, daniel@iogearbox.net, dsahern@gmail.com, hekuang@huawei.com, jolsa@kernel.org, lizefan@huawei.com, masami.hiramatsu.pt@hitachi.com, namhyung@kernel.org, paulus@samba.org, linux-kernel@vger.kernel.org, pi3orama@163.com, xiakaixu@huawei.com Subject: Re: [PATCH 14/31] perf tools: Add BPF_PROLOGUE config options for further patches Message-ID: <20151029224538.GN2923@kernel.org> References: <1444826502-49291-1-git-send-email-wangnan0@huawei.com> <1444826502-49291-15-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1444826502-49291-15-git-send-email-wangnan0@huawei.com> X-Url: http://acmel.wordpress.com 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 Em Wed, Oct 14, 2015 at 12:41:25PM +0000, Wang Nan escreveu: > If both LIBBPF and DWARF are detected, it is possible to create prologue > for eBPF programs to help them accessing kernel data. HAVE_BPF_PROLOGUE what kernel data? you mean to be able to map from variable/function argument name to where they are in memory/registers? > and CONFIG_BPF_PROLOGUE is added as flags for this feature. > > PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET indicates an architecture > supports converting name of a register to its offset in > 'struct pt_regs'. Without this support, BPF_PROLOGUE should be turned off. > > HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET is introduced as the corresponding > CFLAGS of PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET. > > Signed-off-by: Wang Nan > Cc: Alexei Starovoitov > Cc: Brendan Gregg > Cc: Daniel Borkmann > Cc: David Ahern > Cc: He Kuang > Cc: Jiri Olsa > Cc: Kaixu Xia > Cc: Masami Hiramatsu > Cc: Namhyung Kim > Cc: Paul Mackerras > Cc: Peter Zijlstra > Cc: Zefan Li > Cc: pi3orama@163.com > Cc: Arnaldo Carvalho de Melo > Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngkw86@git.kernel.org > --- > tools/perf/config/Makefile | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile > index de89ec5..6eb9a95 100644 > --- a/tools/perf/config/Makefile > +++ b/tools/perf/config/Makefile > @@ -318,6 +318,18 @@ ifndef NO_LIBELF > CFLAGS += -DHAVE_LIBBPF_SUPPORT > $(call detected,CONFIG_LIBBPF) > endif > + > + ifndef NO_DWARF > + ifdef PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET > + CFLAGS += -DHAVE_BPF_PROLOGUE > + $(call detected,CONFIG_BPF_PROLOGUE) > + else > + msg := $(warning BPF prologue is not supported by architecture $(ARCH), missing regs_query_register_offset()); > + endif > + else > + msg := $(warning DWARF support is off, BPF prologue is disabled); > + endif > + > endif # NO_LIBBPF > endif # NO_LIBELF > > -- > 1.8.3.4