From 45c5589d07158eb1d0b5b313314706024bf451c5 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 30 Aug 2019 12:00:38 +0100 Subject: [PATCH] tools: bpftool: improve and check builds for different make invocations There are a number of alternative "make" invocations that can be used to compile bpftool. The following invocations are expected to work: - through the kbuild system, from the top of the repository (make tools/bpf) - by telling make to change to the bpftool directory (make -C tools/bpf/bpftool) - by building the BPF tools from tools/ (cd tools && make bpf) - by running make from bpftool directory (cd tools/bpf/bpftool && make) Additionally, setting the O or OUTPUT variables should tell the build system to use a custom output path, for each of these alternatives. The following patch fixes the following invocations: $ make tools/bpf $ make tools/bpf O= $ make -C tools/bpf/bpftool OUTPUT= $ make -C tools/bpf/bpftool O= $ cd tools/ && make bpf O= $ cd tools/bpf/bpftool && make OUTPUT= $ cd tools/bpf/bpftool && make O= After this commit, the build still fails for two variants when passing the OUTPUT variable: $ make tools/bpf OUTPUT= $ cd tools/ && make bpf OUTPUT= In order to remember and check what make invocations are supposed to work, and to document the ones which do not, a new script is added to the BPF selftests. Note that some invocations require the kernel to be configured, so the script skips them if no .config file is found. v2: - In make_and_clean(), set $ERROR to 1 when "make" returns non-zero, even if the binary was produced. - Run "make clean" from the correct directory (bpf/ instead of bpftool/, when relevant). Reported-by: Lorenz Bauer Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/Makefile | 12 +- tools/testing/selftests/bpf/Makefile | 3 +- .../selftests/bpf/test_bpftool_build.sh | 143 ++++++++++++++++++ 3 files changed, 152 insertions(+), 6 deletions(-) create mode 100755 tools/testing/selftests/bpf/test_bpftool_build.sh diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index cd0fc05464e7..3fc82ff9b52c 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -17,21 +17,23 @@ endif BPF_DIR = $(srctree)/tools/lib/bpf/ ifneq ($(OUTPUT),) - BPF_PATH = $(OUTPUT) + LIBBPF_OUTPUT = $(OUTPUT)/libbpf/ + LIBBPF_PATH = $(LIBBPF_OUTPUT) else - BPF_PATH = $(BPF_DIR) + LIBBPF_PATH = $(BPF_DIR) endif -LIBBPF = $(BPF_PATH)libbpf.a +LIBBPF = $(LIBBPF_PATH)libbpf.a BPFTOOL_VERSION := $(shell make -rR --no-print-directory -sC ../../.. kernelversion) $(LIBBPF): FORCE - $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(OUTPUT) $(OUTPUT)libbpf.a + $(if $(LIBBPF_OUTPUT),@mkdir -p $(LIBBPF_OUTPUT)) + $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) $(LIBBPF_OUTPUT)libbpf.a $(LIBBPF)-clean: $(call QUIET_CLEAN, libbpf) - $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(OUTPUT) clean >/dev/null + $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) clean >/dev/null prefix ?= /usr/local bash_compdir ?= /usr/share/bash-completion/completions diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 1faad0c3c3c9..c7595b4ed55d 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -63,7 +63,8 @@ TEST_PROGS := test_kmod.sh \ test_tcp_check_syncookie.sh \ test_tc_tunnel.sh \ test_tc_edt.sh \ - test_xdping.sh + test_xdping.sh \ + test_bpftool_build.sh TEST_PROGS_EXTENDED := with_addr.sh \ with_tunnels.sh \ diff --git a/tools/testing/selftests/bpf/test_bpftool_build.sh b/tools/testing/selftests/bpf/test_bpftool_build.sh new file mode 100755 index 000000000000..4ba5a34bff56 --- /dev/null +++ b/tools/testing/selftests/bpf/test_bpftool_build.sh @@ -0,0 +1,143 @@ +#!/bin/bash +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) + +ERROR=0 +TMPDIR= + +# If one build fails, continue but return non-0 on exit. +return_value() { + if [ -d "$TMPDIR" ] ; then + rm -rf -- $TMPDIR + fi + exit $ERROR +} +trap return_value EXIT + +case $1 in + -h|--help) + echo -e "$0 [-j ]" + echo -e "\tTest the different ways of building bpftool." + echo -e "" + echo -e "\tOptions:" + echo -e "\t\t-j :\tPass -j flag to 'make'." + exit + ;; +esac + +J=$* + +# Assume script is located under tools/testing/selftests/bpf/. We want to start +# build attempts from the top of kernel repository. +SCRIPT_REL_PATH=$(realpath --relative-to=$PWD $0) +SCRIPT_REL_DIR=$(dirname $SCRIPT_REL_PATH) +KDIR_ROOT_DIR=$(realpath $PWD/$SCRIPT_REL_DIR/../../../../) +cd $KDIR_ROOT_DIR + +check() { + local dir=$(realpath $1) + + echo -n "binary: " + # Returns non-null if file is found (and "false" is run) + find $dir -type f -executable -name bpftool -print -exec false {} + && \ + ERROR=1 && printf "FAILURE: Did not find bpftool\n" +} + +make_and_clean() { + echo -e "\$PWD: $PWD" + echo -e "command: make -s $* >/dev/null" + make $J -s $* >/dev/null + if [ $? -ne 0 ] ; then + ERROR=1 + fi + if [ $# -ge 1 ] ; then + check ${@: -1} + else + check . + fi + ( + if [ $# -ge 1 ] ; then + cd ${@: -1} + fi + make -s clean + ) + echo +} + +make_with_tmpdir() { + local ARGS + + TMPDIR=$(mktemp -d) + if [ $# -ge 2 ] ; then + ARGS=${@:1:(($# - 1))} + fi + echo -e "\$PWD: $PWD" + echo -e "command: make -s $ARGS ${@: -1}=$TMPDIR/ >/dev/null" + make $J -s $ARGS ${@: -1}=$TMPDIR/ >/dev/null + if [ $? -ne 0 ] ; then + ERROR=1 + fi + check $TMPDIR + rm -rf -- $TMPDIR + echo +} + +echo "Trying to build bpftool" +echo -e "... through kbuild\n" + +if [ -f ".config" ] ; then + make_and_clean tools/bpf + + ## $OUTPUT is overwritten in kbuild Makefile, and thus cannot be passed + ## down from toplevel Makefile to bpftool's Makefile. + + # make_with_tmpdir tools/bpf OUTPUT + echo -e "skip: make tools/bpf OUTPUT= (not supported)\n" + + make_with_tmpdir tools/bpf O +else + echo -e "skip: make tools/bpf (no .config found)\n" + echo -e "skip: make tools/bpf OUTPUT= (not supported)\n" + echo -e "skip: make tools/bpf O= (no .config found)\n" +fi + +echo -e "... from kernel source tree\n" + +make_and_clean -C tools/bpf/bpftool + +make_with_tmpdir -C tools/bpf/bpftool OUTPUT + +make_with_tmpdir -C tools/bpf/bpftool O + +echo -e "... from tools/\n" +cd tools/ + +make_and_clean bpf + +## In tools/bpf/Makefile, function "descend" is called and passes $(O) and +## $(OUTPUT). We would like $(OUTPUT) to have "bpf/bpftool/" appended before +## calling bpftool's Makefile, but this is not the case as the "descend" +## function focuses on $(O)/$(subdir). However, in the present case, updating +## $(O) to have $(OUTPUT) recomputed from it in bpftool's Makefile does not +## work, because $(O) is not defined from command line and $(OUTPUT) is not +## updated in tools/scripts/Makefile.include. +## +## Workarounds would require to a) edit "descend" or use an alternative way to +## call bpftool's Makefile, b) modify the conditions to update $(OUTPUT) and +## other variables in tools/scripts/Makefile.include (at the risk of breaking +## the build of other tools), or c) append manually the "bpf/bpftool" suffix to +## $(OUTPUT) in bpf's Makefile, which may break if targets for other directories +## use "descend" in the future. + +# make_with_tmpdir bpf OUTPUT +echo -e "skip: make bpf OUTPUT= (not supported)\n" + +make_with_tmpdir bpf O + +echo -e "... from bpftool's dir\n" +cd bpf/bpftool + +make_and_clean + +make_with_tmpdir OUTPUT + +make_with_tmpdir O -- 2.30.2