From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754112AbbIBOL6 (ORCPT ); Wed, 2 Sep 2015 10:11:58 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:34599 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752761AbbIBOL5 (ORCPT ); Wed, 2 Sep 2015 10:11:57 -0400 Date: Wed, 2 Sep 2015 23:08:46 +0900 From: Namhyung Kim To: Wang Nan Cc: acme@kernel.org, linux-kernel@vger.kernel.org, Alexei Starovoitov , Brendan Gregg , Daniel Borkmann , David Ahern , He Kuang , Jiri Olsa , Kaixu Xia , Masami Hiramatsu , Paul Mackerras , Peter Zijlstra , Zefan Li , pi3orama@163.com, Arnaldo Carvalho de Melo Subject: Re: [PATCH 22/31] perf tools: Add BPF_PROLOGUE config options for further patches Message-ID: <20150902140846.GB27663@danjae.kornet> References: <1440822125-52691-23-git-send-email-wangnan0@huawei.com> <1441090789-108382-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1441090789-108382-1-git-send-email-wangnan0@huawei.com> User-Agent: Mutt/1.5.23+102 (2ca89bed6448) (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 01, 2015 at 06:59:48AM +0000, Wang Nan wrote: > 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 > 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/1436445342-1402-33-git-send-email-wangnan0@huawei.com > [wawngnan: > - Introduce new CFLAGS to control BPF prologue and arch_get_reg_info() > separately. > - Rename ARCH_GET_REG_INFO to ARCH_REGS_QUERY_REGISTER_OFFSET, > arch_get_reg_info() to regs_query_register_offset(), change its API accordingly > to make it similar to kernel's regs_query_register_offset(). > ] > --- > tools/perf/config/Makefile | 17 +++++++++++++++++ > tools/perf/util/include/dwarf-regs.h | 8 ++++++++ > 2 files changed, 25 insertions(+) > > diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile > index 38a4144..33785a1 100644 > --- a/tools/perf/config/Makefile > +++ b/tools/perf/config/Makefile > @@ -110,6 +110,11 @@ FEATURE_CHECK_CFLAGS-bpf = -I. -I$(srctree)/tools/include -I$(srctree)/arch/$(AR > # include ARCH specific config > -include $(src-perf)/arch/$(ARCH)/Makefile > > +ifneq ($(origin PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET), undefined) Why not just using ifdef PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET ? > + CFLAGS += -DHAVE_ARCH_REGS_QUERY_REGISTER_OFFSET > +endif > + > + > include $(src-perf)/config/utilities.mak > > ifeq ($(call get-executable,$(FLEX)),) > @@ -314,6 +319,18 @@ ifndef NO_LIBELF > CFLAGS += -DHAVE_LIBBPF_SUPPORT > $(call detected,CONFIG_LIBBPF) > endif > + > + ifndef NO_DWARF > + ifneq ($(origin PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET), undefined) Ditto. Thanks, Namhyung > + 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 > > diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h > index 8f14965..07c644e 100644 > --- a/tools/perf/util/include/dwarf-regs.h > +++ b/tools/perf/util/include/dwarf-regs.h > @@ -5,4 +5,12 @@ > const char *get_arch_regstr(unsigned int n); > #endif > > +#ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET > +/* > + * Arch should support fetching the offset of a register in pt_regs > + * by its name. See kernel's regs_query_register_offset in > + * arch/xxx/kernel/ptrace.c. > + */ > +int regs_query_register_offset(const char *name); > +#endif > #endif > -- > 1.8.3.4 >