From 16e9b187aba60f9014f11a7e95b878850b6c95e5 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 19 Jun 2020 16:16:59 -0700 Subject: tools/bpftool: Minimize bootstrap bpftool Build minimal "bootstrap mode" bpftool to enable skeleton (and, later, vmlinux.h generation), instead of building almost complete, but slightly different (w/o skeletons, etc) bpftool to bootstrap complete bpftool build. Current approach doesn't scale well (engineering-wise) when adding more BPF programs to bpftool and other complicated functionality, as it requires constant adjusting of the code to work in both bootstrapped mode and normal mode. So it's better to build only minimal bpftool version that supports only BPF skeleton code generation and BTF-to-C conversion. Thankfully, this is quite easy to accomplish due to internal modularity of bpftool commands. This will also allow to keep adding new functionality to bpftool in general, without the need to care about bootstrap mode for those new parts of bpftool. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20200619231703.738941-6-andriin@fb.com --- tools/bpf/bpftool/.gitignore | 2 +- tools/bpf/bpftool/Makefile | 30 +++++++++++++----------------- tools/bpf/bpftool/main.c | 11 +++++++++-- tools/bpf/bpftool/main.h | 27 +++++++++++++++------------ 4 files changed, 38 insertions(+), 32 deletions(-) (limited to 'tools/bpf/bpftool') diff --git a/tools/bpf/bpftool/.gitignore b/tools/bpf/bpftool/.gitignore index 26cde83e1ca3..ce721adf3161 100644 --- a/tools/bpf/bpftool/.gitignore +++ b/tools/bpf/bpftool/.gitignore @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only *.d -/_bpftool +/bpftool-bootstrap /bpftool bpftool*.8 bpf-helpers.* diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 9e85f101be85..eec2da4d45d2 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -116,40 +116,36 @@ CFLAGS += -DHAVE_LIBBFD_SUPPORT SRCS += $(BFD_SRCS) endif +BPFTOOL_BOOTSTRAP := $(if $(OUTPUT),$(OUTPUT)bpftool-bootstrap,./bpftool-bootstrap) + +BOOTSTRAP_OBJS = $(addprefix $(OUTPUT),main.o common.o json_writer.o gen.o btf.o) OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o -_OBJS = $(filter-out $(OUTPUT)prog.o,$(OBJS)) $(OUTPUT)_prog.o -ifeq ($(feature-clang-bpf-global-var),1) - __OBJS = $(OBJS) -else - __OBJS = $(_OBJS) +ifneq ($(feature-clang-bpf-global-var),1) + CFLAGS += -DBPFTOOL_WITHOUT_SKELETONS endif -$(OUTPUT)_prog.o: prog.c - $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -DBPFTOOL_WITHOUT_SKELETONS -o $@ $< - -$(OUTPUT)_bpftool: $(_OBJS) $(LIBBPF) - $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(_OBJS) $(LIBS) - skeleton/profiler.bpf.o: skeleton/profiler.bpf.c $(LIBBPF) $(QUIET_CLANG)$(CLANG) \ -I$(srctree)/tools/include/uapi/ \ -I$(LIBBPF_PATH) -I$(srctree)/tools/lib \ -g -O2 -target bpf -c $< -o $@ -profiler.skel.h: $(OUTPUT)_bpftool skeleton/profiler.bpf.o - $(QUIET_GEN)$(OUTPUT)./_bpftool gen skeleton skeleton/profiler.bpf.o > $@ +profiler.skel.h: $(BPFTOOL_BOOTSTRAP) skeleton/profiler.bpf.o + $(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) gen skeleton skeleton/profiler.bpf.o > $@ $(OUTPUT)prog.o: prog.c profiler.skel.h - $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $< $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $< $(OUTPUT)feature.o: | zdep -$(OUTPUT)bpftool: $(__OBJS) $(LIBBPF) - $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(__OBJS) $(LIBS) +$(BPFTOOL_BOOTSTRAP): $(BOOTSTRAP_OBJS) $(LIBBPF) + $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(BOOTSTRAP_OBJS) $(LIBS) + +$(OUTPUT)bpftool: $(OBJS) $(LIBBPF) + $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJS) $(LIBS) $(OUTPUT)%.o: %.c $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $< @@ -157,7 +153,7 @@ $(OUTPUT)%.o: %.c clean: $(LIBBPF)-clean $(call QUIET_CLEAN, bpftool) $(Q)$(RM) -- $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d - $(Q)$(RM) -- $(OUTPUT)_bpftool profiler.skel.h skeleton/profiler.bpf.o + $(Q)$(RM) -- $(BPFTOOL_BOOTSTRAP) profiler.skel.h skeleton/profiler.bpf.o $(Q)$(RM) -r -- $(OUTPUT)libbpf/ $(call QUIET_CLEAN, core-gen) $(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.bpftool diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index 46bd716a9d86..bf4d7487552a 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -92,9 +92,16 @@ int cmd_select(const struct cmd *cmds, int argc, char **argv, if (argc < 1 && cmds[0].func) return cmds[0].func(argc, argv); - for (i = 0; cmds[i].func; i++) - if (is_prefix(*argv, cmds[i].cmd)) + for (i = 0; cmds[i].cmd; i++) { + if (is_prefix(*argv, cmds[i].cmd)) { + if (!cmds[i].func) { + p_err("command '%s' is not supported in bootstrap mode", + cmds[i].cmd); + return -1; + } return cmds[i].func(argc - 1, argv + 1); + } + } help(argc - 1, argv + 1); diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 4338ab9d86d4..aad7be74e8a7 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -194,19 +194,22 @@ int mount_bpffs_for_pin(const char *name); int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(int *, char ***)); int do_pin_fd(int fd, const char *name); -int do_prog(int argc, char **arg); -int do_map(int argc, char **arg); -int do_link(int argc, char **arg); -int do_event_pipe(int argc, char **argv); -int do_cgroup(int argc, char **arg); -int do_perf(int argc, char **arg); -int do_net(int argc, char **arg); -int do_tracelog(int argc, char **arg); -int do_feature(int argc, char **argv); -int do_btf(int argc, char **argv); +/* commands available in bootstrap mode */ int do_gen(int argc, char **argv); -int do_struct_ops(int argc, char **argv); -int do_iter(int argc, char **argv); +int do_btf(int argc, char **argv); + +/* non-bootstrap only commands */ +int do_prog(int argc, char **arg) __weak; +int do_map(int argc, char **arg) __weak; +int do_link(int argc, char **arg) __weak; +int do_event_pipe(int argc, char **argv) __weak; +int do_cgroup(int argc, char **arg) __weak; +int do_perf(int argc, char **arg) __weak; +int do_net(int argc, char **arg) __weak; +int do_tracelog(int argc, char **arg) __weak; +int do_feature(int argc, char **argv) __weak; +int do_struct_ops(int argc, char **argv) __weak; +int do_iter(int argc, char **argv) __weak; int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what); int prog_parse_fd(int *argc, char ***argv); -- cgit v1.2.3