From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932215AbbEUHMB (ORCPT ); Thu, 21 May 2015 03:12:01 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:5807 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932170AbbEUHL5 (ORCPT ); Thu, 21 May 2015 03:11:57 -0400 Message-ID: <555D84DF.5080200@huawei.com> Date: Thu, 21 May 2015 15:10:23 +0800 From: "Wangnan (F)" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Alexei Starovoitov , , , , , , , , , , CC: , , Subject: Re: [RFC PATCH v3 06/37] bpf tools: Introduce 'bpf' library to tools References: <1431860222-61636-1-git-send-email-wangnan0@huawei.com> <1431860222-61636-7-git-send-email-wangnan0@huawei.com> <555A22DB.5040200@plumgrid.com> In-Reply-To: <555A22DB.5040200@plumgrid.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.111.66.109] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2015/5/19 1:35, Alexei Starovoitov 写道: > On 5/17/15 3:56 AM, Wang Nan wrote: >> This is the first patch of libbpf. The goal of libbpf is to create a >> standard way for accessing eBPF object files. This patch creates >> Makefile and Build for it, allows 'make' to build libbpf.a and >> libbpf.so, 'make install' to put them into proper directories. >> Most part of Makefile is borrowed from traceevent. Before building, >> it checks the existance of libelf in Makefile, and deny to build if >> not found. Instead of throw an error if libelf not found, the error >> raises in a phony target "elfdep". This design is to ensure >> 'make clean' still workable even if libelf is not found. >> >> Signed-off-by: Wang Nan >> --- > ... >> + >> +# Version of eBPF elf file >> +FILE_VERSION = 1 > > what that comment suppose to mean? > >> +# Makefiles suck: This macro sets a default value of $(2) for the >> +# variable named by $(1), unless the variable has been set by >> +# environment or command line. This is necessary for CC and AR >> +# because make sets default values, so the simpler ?= approach >> +# won't work as expected. > > what this for? copy-paste? > >> +# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix. >> +$(call allow-override,CC,$(CROSS_COMPILE)gcc) >> +$(call allow-override,AR,$(CROSS_COMPILE)ar) > > was cross-compile tested or just copy-pasted? > Cross compiling is tested on aarch64. >> +EXT = -std=gnu99 > > I guess it was copy-pasted from libtraceevent, but please double > check that it's actually needed. > Will remove. >> +# Append required CFLAGS >> +override CFLAGS += -fPIC >> +override CFLAGS += $(INCLUDES) >> +override CFLAGS += -D_GNU_SOURCE > > _GNU_SOURCE actually needed? > Please sanitize the file. > >> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c >> new file mode 100644 >> index 0000000..bebe99a >> --- /dev/null >> +++ b/tools/lib/bpf/libbpf.c >> @@ -0,0 +1,15 @@ >> +/* >> + * common eBPF ELF loading operations. >> + * >> + * Copyright (C) 2015, Wang Nan >> + * Copyright (C) 2015, Huawei Inc. > > since it borrows heavily from samples/bpf/bpf_load.c, libbpf.h > would be nice if you mention the source and/or copyright in the header. > Will change. Could you please provide copyright information so I can add it here? >> + * >> + * Released under the GPL v2. (and only v2, not any later version) >> + */ > > are you sure about this restriction? libtracevent is LGPL, for example. > Will change. Thank you.