Messages in this thread | | | Date | Thu, 21 May 2015 15:10:23 +0800 | From | "Wangnan (F)" <> | Subject | Re: [RFC PATCH v3 06/37] bpf tools: Introduce 'bpf' library to tools |
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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 <wangnan0@huawei.com> >> --- > ... >> + >> +# 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 <wangnan0@huawei.com> >> + * 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.
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