[PATCH bpf-next v6 7/9] selftests/bpf: extract BPF skeleton generation into a helper script
Mykola Lysenko <[email protected]>
| Newsgroups | org.kernel.vger.bpf |
|---|---|
| Message-ID | <[email protected]> |
The four skeleton generation recipes (regular, light, signed light and linked) are near-identical five-step pipelines - link via "bpftool gen object" three times, compare the second and third results as a regression test for bpftool's determinism, generate the skeleton (and possibly subskeleton), remove intermediates - duplicated with small variations inside DEFINE_TEST_RUNNER_RULES, where every line pays the double-expansion escaping tax. Move the pipeline into gen_bpf_skel.sh; the differences between the four variants become the --lskel, --sign and --subskel flags. Signing takes the key and certificate from $PRIVATE_KEY and $VERIFICATION_CERT in the environment, like the bpftool binary comes from $BPFTOOL. The distinct linked/llinked intermediate infixes are kept but derived inside the script: tests listed in LSKELS_EXTRA generate both a .skel.h and a .lskel.h from the same .bpf.o, and distinct intermediate names are what keeps parallel builds from racing. The permissive-mode missing-input checks at the top of the recipes - when the object's compile already failed and was skipped, skip the skeleton quietly instead of running bpftool against a missing file - are kept, factored into a skip_if_missing helper next to skip_on_fail. The build-log messages stay folded behind the guard as in the original recipes, so a skipped skeleton prints SKIP-SKEL and nothing else; behavior is unchanged. Suggested-by: Eduard Zingerman <[email protected]> Assisted-by: Claude:claude-fable-5 shellcheck Signed-off-by: Mykola Lysenko <[email protected]> Acked-by: Eduard Zingerman <[email protected]> --- tools/testing/selftests/bpf/Makefile | 94 ++++++++------------- tools/testing/selftests/bpf/gen_bpf_skel.sh | 93 ++++++++++++++++++++ 2 files changed, 130 insertions(+), 57 deletions(-) create mode 100755 tools/testing/selftests/bpf/gen_bpf_skel.sh diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index fdedfab25d72..57907859c210 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -56,6 +56,17 @@ PERMISSIVE := $(filter 0,$(BPF_STRICT_BUILD)) skip_on_fail = $(if $(PERMISSIVE),|| { $(RM) $@ $(2); \ printf ' %-12s %s\n' 'SKIP-$(1)' '$(notdir $@)$(if $(3), $(3))' 1>&2; }) +# Permissive-mode recipe prefix: when a prerequisite object is missing +# (its compile failed and was skipped), remove the target and $(3), +# emit a SKIP marker and report success without running the rest of +# the recipe. +# $(1) - SKIP tag +# $(2) - input files to check +# $(3) - optional extra files to remove alongside the target +skip_if_missing = $(if $(PERMISSIVE),for f in $(2); do [ -f $$f ] || { \ + $(RM) $@ $(3); \ + printf ' %-12s %s\n' 'SKIP-$(1)' '$(notdir $@)' 1>&2; exit 0; }; done;) + ifeq ($(srctree),) srctree := $(patsubst %/,%,$(dir $(CURDIR))) srctree := $(patsubst %/,%,$(dir $(srctree))) @@ -565,8 +576,6 @@ HEADERS_FOR_BPF_OBJS := $(wildcard $(BPFDIR)/*.bpf.h) \ # $1 - test runner base binary name (e.g., test_progs) # $2 - test runner extra "flavor" (e.g., no_alu32, cpuv4, bpf_gcc, etc) define DEFINE_TEST_RUNNER - -LSKEL_SIGN := -S -k $(PRIVATE_KEY) -i $(VERIFICATION_CERT) TRUNNER_OUTPUT := $(OUTPUT)$(if $2,/)$2 TRUNNER_BINARY := $1$(if $2,-)$2 TRUNNER_TEST_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.test.o, \ @@ -626,70 +635,41 @@ $(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.bpf.o: \ $$($$<-CFLAGS) \ $$($$<-$2-CFLAGS),$(TRUNNER_BINARY)) -$(TRUNNER_BPF_SKELS): %.skel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT) - $(Q)$(if $(PERMISSIVE),if [ ! -f $$< ]; then \ - $$(RM) $$@ $$(@:.skel.h=.subskel.h); \ - printf ' %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; \ - exit 0; \ - fi;) \ +$(TRUNNER_BPF_SKELS): %.skel.h: %.bpf.o $(BPFTOOL) gen_bpf_skel.sh | $(TRUNNER_OUTPUT) + $(Q)$$(call skip_if_missing,SKEL,$$<,$$(@:.skel.h=.subskel.h)) \ printf ' %-12s %s\n' 'GEN-SKEL' '[$(TRUNNER_BINARY)] $$(notdir $$@)' 1>&2; \ - $$(BPFTOOL) gen object $$(<:.o=.linked1.o) $$< && \ - $$(BPFTOOL) gen object $$(<:.o=.linked2.o) $$(<:.o=.linked1.o) && \ - $$(BPFTOOL) gen object $$(<:.o=.linked3.o) $$(<:.o=.linked2.o) && \ - diff $$(<:.o=.linked2.o) $$(<:.o=.linked3.o) && \ - $$(BPFTOOL) gen skeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.bpf.o=)) > $$@ && \ - $$(BPFTOOL) gen subskeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.bpf.o=)) > $$(@:.skel.h=.subskel.h) $$(call skip_on_fail,SKEL,$$(@:.skel.h=.subskel.h)) && \ - rm -f $$(<:.o=.linked1.o) $$(<:.o=.linked2.o) $$(<:.o=.linked3.o) - -$(TRUNNER_BPF_LSKELS): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT) - $(Q)$(if $(PERMISSIVE),if [ ! -f $$< ]; then \ - $$(RM) $$@; \ - printf ' %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; \ - exit 0; \ - fi;) \ + BPFTOOL=$$(BPFTOOL) ./gen_bpf_skel.sh \ + --name $$(notdir $$(<:.bpf.o=)) \ + --skel $$@ --subskel $$(@:.skel.h=.subskel.h) $$< $$(call skip_on_fail,SKEL,$$(@:.skel.h=.subskel.h)) + +$(TRUNNER_BPF_LSKELS): %.lskel.h: %.bpf.o $(BPFTOOL) gen_bpf_skel.sh | $(TRUNNER_OUTPUT) + $(Q)$$(call skip_if_missing,SKEL,$$<) \ printf ' %-12s %s\n' 'GEN-SKEL' '[$(TRUNNER_BINARY)] $$(notdir $$@)' 1>&2; \ - $$(BPFTOOL) gen object $$(<:.o=.llinked1.o) $$< && \ - $$(BPFTOOL) gen object $$(<:.o=.llinked2.o) $$(<:.o=.llinked1.o) && \ - $$(BPFTOOL) gen object $$(<:.o=.llinked3.o) $$(<:.o=.llinked2.o) && \ - diff $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o) && \ - $$(BPFTOOL) gen skeleton -L $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@ $$(call skip_on_fail,SKEL) && \ - rm -f $$(<:.o=.llinked1.o) $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o) - -$(TRUNNER_BPF_LSKELS_SIGNED): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT) - $(Q)$(if $(PERMISSIVE),if [ ! -f $$< ]; then \ - $$(RM) $$@; \ - printf ' %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; \ - exit 0; \ - fi;) \ + BPFTOOL=$$(BPFTOOL) ./gen_bpf_skel.sh \ + --name $$(notdir $$(<:.bpf.o=_lskel)) --lskel \ + --skel $$@ $$< $$(call skip_on_fail,SKEL) + +$(TRUNNER_BPF_LSKELS_SIGNED): %.lskel.h: %.bpf.o $(BPFTOOL) gen_bpf_skel.sh | $(TRUNNER_OUTPUT) + $(Q)$$(call skip_if_missing,SKEL,$$<) \ printf ' %-12s %s\n' 'GEN-SKEL' '[$(TRUNNER_BINARY) (signed)] $$(notdir $$@)' 1>&2; \ - $$(BPFTOOL) gen object $$(<:.o=.llinked1.o) $$< && \ - $$(BPFTOOL) gen object $$(<:.o=.llinked2.o) $$(<:.o=.llinked1.o) && \ - $$(BPFTOOL) gen object $$(<:.o=.llinked3.o) $$(<:.o=.llinked2.o) && \ - diff $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o) && \ - $$(BPFTOOL) gen skeleton $(LSKEL_SIGN) $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@ $$(call skip_on_fail,SKEL) && \ - rm -f $$(<:.o=.llinked1.o) $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o) + BPFTOOL=$$(BPFTOOL) PRIVATE_KEY=$(PRIVATE_KEY) \ + VERIFICATION_CERT=$(VERIFICATION_CERT) \ + ./gen_bpf_skel.sh --sign \ + --name $$(notdir $$(<:.bpf.o=_lskel)) \ + --skel $$@ $$< $$(call skip_on_fail,SKEL) $(LINKED_BPF_OBJS): %: $(TRUNNER_OUTPUT)/% # .SECONDEXPANSION here allows to correctly expand %-deps variables as prerequisites .SECONDEXPANSION: -$(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_OUTPUT)/%: $$$$(%-deps) $(BPFTOOL) | $(TRUNNER_OUTPUT) - $(Q)$(if $(PERMISSIVE),for f in $$(addprefix $(TRUNNER_OUTPUT)/,$$($$(@F)-deps)); do \ - if [ ! -f $$$$f ]; then \ - $$(RM) $$@ $$(@:.skel.h=.subskel.h); \ - printf ' %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; \ - exit 0; \ - fi; \ - done;) \ +$(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_OUTPUT)/%: $$$$(%-deps) $(BPFTOOL) gen_bpf_skel.sh | $(TRUNNER_OUTPUT) + $(Q)$$(call skip_if_missing,SKEL,$$(addprefix $(TRUNNER_OUTPUT)/,$$($$(@F)-deps)),$$(@:.skel.h=.subskel.h)) \ printf ' %-12s %s\n' 'LINK-BPF' '[$(TRUNNER_BINARY)] $$(notdir $$(@:.skel.h=.bpf.o))' 1>&2; \ - $$(BPFTOOL) gen object $$(@:.skel.h=.linked1.o) $$(addprefix $(TRUNNER_OUTPUT)/,$$($$(@F)-deps)) && \ - $$(BPFTOOL) gen object $$(@:.skel.h=.linked2.o) $$(@:.skel.h=.linked1.o) && \ - $$(BPFTOOL) gen object $$(@:.skel.h=.linked3.o) $$(@:.skel.h=.linked2.o) && \ - diff $$(@:.skel.h=.linked2.o) $$(@:.skel.h=.linked3.o) && \ - printf ' %-12s %s\n' 'GEN-SKEL' '[$(TRUNNER_BINARY)] $$(notdir $$@)' 1>&2 && \ - $$(BPFTOOL) gen skeleton $$(@:.skel.h=.linked3.o) name $$(notdir $$(@:.skel.h=)) > $$@ && \ - $$(BPFTOOL) gen subskeleton $$(@:.skel.h=.linked3.o) name $$(notdir $$(@:.skel.h=)) > $$(@:.skel.h=.subskel.h) $$(call skip_on_fail,SKEL,$$(@:.skel.h=.subskel.h)) && \ - rm -f $$(@:.skel.h=.linked1.o) $$(@:.skel.h=.linked2.o) $$(@:.skel.h=.linked3.o) + printf ' %-12s %s\n' 'GEN-SKEL' '[$(TRUNNER_BINARY)] $$(notdir $$@)' 1>&2; \ + BPFTOOL=$$(BPFTOOL) ./gen_bpf_skel.sh \ + --name $$(notdir $$(@:.skel.h=)) \ + --skel $$@ --subskel $$(@:.skel.h=.subskel.h) \ + $$(addprefix $(TRUNNER_OUTPUT)/,$$($$(@F)-deps)) $$(call skip_on_fail,SKEL,$$(@:.skel.h=.subskel.h)) # When the compiler generates a %.d file, only skel basenames (not # full paths) are specified as prerequisites for corresponding %.o diff --git a/tools/testing/selftests/bpf/gen_bpf_skel.sh b/tools/testing/selftests/bpf/gen_bpf_skel.sh new file mode 100755 index 000000000000..a752cb78c139 --- /dev/null +++ b/tools/testing/selftests/bpf/gen_bpf_skel.sh @@ -0,0 +1,93 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Link BPF object file(s) with "bpftool gen object" and generate a +# skeleton (or light skeleton) header from the result. +# +# Usage: +# BPFTOOL=<bpftool> gen_bpf_skel.sh --name NAME --skel OUT [options] OBJ... +# +# --name NAME skeleton object name ("name NAME" for bpftool) +# --skel OUT output header ("foo.skel.h" or "foo.lskel.h") +# --subskel OUT also generate a subskeleton header into OUT +# --lskel generate a light skeleton (bpftool gen skeleton -L) +# --sign sign the (light) skeleton, with the key and +# certificate taken from $PRIVATE_KEY and +# $VERIFICATION_CERT +# +# The inputs are linked three times and the 2nd and 3rd results +# compared, as a regression test for the determinism of "bpftool gen +# object". +# +# Intermediate files carry a "linked" infix - "llinked" for light or +# signed skeletons, so generating a .skel.h and a .lskel.h from the +# same .bpf.o in parallel never races on the intermediates. +# +# The bpftool binary is taken from $BPFTOOL (default: bpftool from PATH). +# On failure all outputs and intermediates are removed and the script +# exits non-zero; permissive-mode skipping is the caller's business +# (see skip_on_fail in the Makefile). + +set -u + +bpftool=${BPFTOOL:-bpftool} +name='' skel='' subskel='' +lskel=0 sign=0 + +while [ $# -gt 0 ]; do + case "$1" in + --name) name=$2; shift 2 ;; + --skel) skel=$2; shift 2 ;; + --subskel) subskel=$2; shift 2 ;; + --lskel) lskel=1; shift ;; + --sign) sign=1; shift ;; + --) shift; break ;; + -*) echo "$0: unknown option: $1" >&2; exit 1 ;; + *) break ;; + esac +done + +if [ -z "$name" ] || [ -z "$skel" ] || [ $# -eq 0 ]; then + echo "usage: $0 --name NAME --skel OUT [options] OBJ..." >&2 + exit 1 +fi + +infix=linked +if [ "$lskel" -eq 1 ] || [ "$sign" -eq 1 ]; then + infix=llinked +fi + +base=${skel%.skel.h} +base=${base%.lskel.h} +t1=$base.${infix}1.o +t2=$base.${infix}2.o +t3=$base.${infix}3.o + +fail() { + rm -f "$skel" ${subskel:+"$subskel"} "$t1" "$t2" "$t3" + exit 1 +} + +"$bpftool" gen object "$t1" "$@" || fail +"$bpftool" gen object "$t2" "$t1" || fail +"$bpftool" gen object "$t3" "$t2" || fail +if ! cmp -s "$t2" "$t3"; then + echo "$0: bpftool gen object is not deterministic for $skel" >&2 + fail +fi + +args=() +if [ "$sign" -eq 1 ]; then + args+=(-S -k "${PRIVATE_KEY:?}" -i "${VERIFICATION_CERT:?}") +fi +if [ "$lskel" -eq 1 ]; then + args+=(-L) +fi +"$bpftool" gen skeleton ${args[@]+"${args[@]}"} "$t3" name "$name" > "$skel" || fail + +if [ -n "$subskel" ]; then + "$bpftool" gen subskeleton "$t3" name "$name" > "$subskel" || fail +fi + +rm -f "$t1" "$t2" "$t3" +exit 0 -- 2.43.0