On Wed, Dec 20, 2017 at 01:52:18PM -0800, Jakub Kicinski wrote: > On Wed, 20 Dec 2017 20:53:41 +0000, Roman Gushchin wrote: > > On Wed, Dec 20, 2017 at 12:29:21PM -0800, Jakub Kicinski wrote: > > > On Wed, 20 Dec 2017 20:19:43 +0000, Roman Gushchin wrote: > > > > Bpftool determines it's own version based on the kernel > > > > version, which is picked from the linux/version.h header. > > > > > > > > It's strange to use the version of the installed kernel > > > > headers, and makes much more sense to use the version > > > > of the actual source tree, where bpftool sources are. > > > > > > > > This patch adds $(srctree)/usr/include to the list > > > > of include files, which causes bpftool to use the version > > > > from the source tree. > > > > > > > > Example: > > > > before: > > > > > > > > $ bpftool version > > > > bpftool v4.14.6 > > > > > > > > after: > > > > $ bpftool version > > > > bpftool v4.15.0 > > > > > > Thanks for the patch, this would indeed use some improvement. > > > > > > How about we just run make to get the version like liblockdep does? > > > > > > LIBLOCKDEP_VERSION=$(shell make --no-print-directory -sC ../../.. > > > kernelversion) > > > > > > probably s@../../..@$(srctree)@ > > > > > > $(srctree)/usr/include is not going to be there for out-of-source builds. > > > > > > > Hm, why it's better? It's not only about the kernel version, > > IMO it's generally better to use includes from the source tree, > > rather then system-wide installed kernel headers. > > Right I agree the kernel headers are preferred. I'm not entirely sure > why we don't use them, if it was OK to assume usr/ is there we wouldn't > need the tools/include/uapi/ contraption. Maybe Arnaldo could explain? > > > I've got about out-of-source builds, but do we support it in general? > > How can I build bpftool outside of the kernel tree? > > I've tried a bit, but failed. > > This is what I do: > > make -C tools/bpf/bpftool/ W=1 O=/tmp/builds/bpftool
This works perfectly with my patch: $ make -C ~/linux/tools/bpf/ W=1 O=/home/guro/build/ --trace <...> echo ' CC '/home/guro/build/main.o;gcc -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow -D__EXPORTED_HEADERS__ -I/home/guro/linux/tools/include/uapi -I/home/guro/linux/tools/include -I/home/guro/linux/tools/lib/bpf -I/home/guro/linux/kernel/bpf/ -I/home/guro/linux/usr/include -DNEW_DISSASSEMBLER_SIGNATURE -c -MMD -o /home/guro/build/main.o main.c <...> echo ' LINK '/home/guro/build/bpftool;gcc -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow -D__EXPORTED_HEADERS__ -I/home/guro/linux/tools/include/uapi -I/home/guro/linux/tools/include -I/home/guro/linux/tools/lib/bpf -I/home/guro/linux/kernel/bpf/ -I/home/guro/linux/usr/include -DNEW_DISSASSEMBLER_SIGNATURE -o /home/guro/build/bpftool /home/guro/build/common.o /home/guro/build/cgroup.o /home/guro/build/main.o /home/guro/build/json_writer.o /home/guro/build/prog.o /home/guro/build/map.o /home/guro/build/jit_disasm.o /home/guro/build/disasm.o /home/guro/build/libbpf.a -lelf -lbfd -lopcodes /home/guro/build/libbpf.a LINK /home/guro/build/bpftool make[1]: Leaving directory '/home/guro/linux/tools/bpf/bpftool' make: Leaving directory '/home/guro/linux/tools/bpf' $ ./build/bpftool version ./build/bpftool v4.15.0 Thanks!
