[PATCH bpf-next 07/10] bpftool: add `gen bpfo` command to perform BPF static linking
From: Andrii Nakryiko <andrii@kernel.org>
Date: 2021-03-10 04:05:59
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
Add `bpftool gen bpfo <output-file> <input_file>...` command to statically link multiple BPF object files into a single output BPF object file. Similarly to existing '*.o' convention, bpftool is establishing a '*.bpfo' convention for statically-linked BPF object files. Both .o and .bpfo suffixes will be stripped out during BPF skeleton generation to infer BPF object name. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> --- tools/bpf/bpftool/gen.c | 46 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 4033c46d83e7..8b1ed6c0a62f 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c@@ -54,7 +54,9 @@ static void get_obj_name(char *name, const char *file) strncpy(name, basename(file), MAX_OBJ_NAME_LEN - 1); name[MAX_OBJ_NAME_LEN - 1] = '\0'; if (str_has_suffix(name, ".o")) - name[strlen(name) - 2] = '\0'; + name[strlen(name) - sizeof(".o") + 1] = '\0'; + else if (str_has_suffix(name, ".bpfo")) + name[strlen(name) - sizeof(".bpfo") + 1] = '\0'; sanitize_identifier(name); }
@@ -591,6 +593,47 @@ static int do_skeleton(int argc, char **argv) return err; } +static int do_bpfo(int argc, char **argv) +{ + struct bpf_linker *linker; + const char *output_file, *file; + int err; + + if (!REQ_ARGS(2)) { + usage(); + return -1; + } + + output_file = GET_ARG(); + + linker = bpf_linker__new(output_file, NULL); + if (!linker) { + p_err("failed to create BPF linker instance"); + return -1; + } + + while (argc) { + file = GET_ARG(); + + err = bpf_linker__add_file(linker, file); + if (err) { + p_err("failed to link '%s': %d", file, err); + goto err_out; + } + } + + err = bpf_linker__finalize(linker); + if (err) { + p_err("failed to finalize ELF file: %d", err); + goto err_out; + } + + return 0; +err_out: + bpf_linker__free(linker); + return -1; +} + static int do_help(int argc, char **argv) { if (json_output) {
@@ -611,6 +654,7 @@ static int do_help(int argc, char **argv) static const struct cmd cmds[] = { { "skeleton", do_skeleton }, + { "bpfo", do_bpfo }, { "help", do_help }, { 0 } };
--
2.24.1