From c59765cfd193382b00454b1a4424cb78d4c065e2 Mon Sep 17 00:00:00 2001 From: Dave Marchevsky Date: Mon, 1 Nov 2021 15:43:55 -0700 Subject: bpftool: Use bpf_obj_get_info_by_fd directly To prepare for impending deprecation of libbpf's bpf_program__get_prog_info_linear, migrate uses of this function to use bpf_obj_get_info_by_fd. Since the profile_target_name and dump_prog_id_as_func_ptr helpers were only looking at the first func_info, avoid grabbing the rest to save a malloc. For do_dump, add a more full-featured helper, but avoid free/realloc of buffer when possible for multi-prog dumps. Signed-off-by: Dave Marchevsky Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20211101224357.2651181-3-davemarchevsky@fb.com --- tools/bpf/bpftool/btf_dumper.c | 40 ++++++----- tools/bpf/bpftool/prog.c | 159 ++++++++++++++++++++++++++++++++--------- 2 files changed, 149 insertions(+), 50 deletions(-) (limited to 'tools/bpf') diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 6934e8634b94..f5dddf8ef404 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -32,14 +32,16 @@ static int dump_prog_id_as_func_ptr(const struct btf_dumper *d, const struct btf_type *func_proto, __u32 prog_id) { - struct bpf_prog_info_linear *prog_info = NULL; const struct btf_type *func_type; + int prog_fd = -1, func_sig_len; + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); const char *prog_name = NULL; - struct bpf_func_info *finfo; struct btf *prog_btf = NULL; - struct bpf_prog_info *info; - int prog_fd, func_sig_len; + struct bpf_func_info finfo; + __u32 finfo_rec_size; char prog_str[1024]; + int err; /* Get the ptr's func_proto */ func_sig_len = btf_dump_func(d->btf, prog_str, func_proto, NULL, 0, @@ -55,22 +57,27 @@ static int dump_prog_id_as_func_ptr(const struct btf_dumper *d, if (prog_fd < 0) goto print; - prog_info = bpf_program__get_prog_info_linear(prog_fd, - 1UL << BPF_PROG_INFO_FUNC_INFO); - close(prog_fd); - if (IS_ERR(prog_info)) { - prog_info = NULL; + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + if (err) goto print; - } - info = &prog_info->info; - if (!info->btf_id || !info->nr_func_info) + if (!info.btf_id || !info.nr_func_info) + goto print; + + finfo_rec_size = info.func_info_rec_size; + memset(&info, 0, sizeof(info)); + info.nr_func_info = 1; + info.func_info_rec_size = finfo_rec_size; + info.func_info = ptr_to_u64(&finfo); + + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + if (err) goto print; - prog_btf = btf__load_from_kernel_by_id(info->btf_id); + + prog_btf = btf__load_from_kernel_by_id(info.btf_id); if (libbpf_get_error(prog_btf)) goto print; - finfo = u64_to_ptr(info->func_info); - func_type = btf__type_by_id(prog_btf, finfo->type_id); + func_type = btf__type_by_id(prog_btf, finfo.type_id); if (!func_type || !btf_is_func(func_type)) goto print; @@ -92,7 +99,8 @@ print: prog_str[sizeof(prog_str) - 1] = '\0'; jsonw_string(d->jw, prog_str); btf__free(prog_btf); - free(prog_info); + if (prog_fd >= 0) + close(prog_fd); return 0; } diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 515d22952602..dea7a49ec26e 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -100,6 +100,76 @@ static enum bpf_attach_type parse_attach_type(const char *str) return __MAX_BPF_ATTACH_TYPE; } +static int prep_prog_info(struct bpf_prog_info *const info, enum dump_mode mode, + void **info_data, size_t *const info_data_sz) +{ + struct bpf_prog_info holder = {}; + size_t needed = 0; + void *ptr; + + if (mode == DUMP_JITED) { + holder.jited_prog_len = info->jited_prog_len; + needed += info->jited_prog_len; + } else { + holder.xlated_prog_len = info->xlated_prog_len; + needed += info->xlated_prog_len; + } + + holder.nr_jited_ksyms = info->nr_jited_ksyms; + needed += info->nr_jited_ksyms * sizeof(__u64); + + holder.nr_jited_func_lens = info->nr_jited_func_lens; + needed += info->nr_jited_func_lens * sizeof(__u32); + + holder.nr_func_info = info->nr_func_info; + holder.func_info_rec_size = info->func_info_rec_size; + needed += info->nr_func_info * info->func_info_rec_size; + + holder.nr_line_info = info->nr_line_info; + holder.line_info_rec_size = info->line_info_rec_size; + needed += info->nr_line_info * info->line_info_rec_size; + + holder.nr_jited_line_info = info->nr_jited_line_info; + holder.jited_line_info_rec_size = info->jited_line_info_rec_size; + needed += info->nr_jited_line_info * info->jited_line_info_rec_size; + + if (needed > *info_data_sz) { + ptr = realloc(*info_data, needed); + if (!ptr) + return -1; + + *info_data = ptr; + *info_data_sz = needed; + } + ptr = *info_data; + + if (mode == DUMP_JITED) { + holder.jited_prog_insns = ptr_to_u64(ptr); + ptr += holder.jited_prog_len; + } else { + holder.xlated_prog_insns = ptr_to_u64(ptr); + ptr += holder.xlated_prog_len; + } + + holder.jited_ksyms = ptr_to_u64(ptr); + ptr += holder.nr_jited_ksyms * sizeof(__u64); + + holder.jited_func_lens = ptr_to_u64(ptr); + ptr += holder.nr_jited_func_lens * sizeof(__u32); + + holder.func_info = ptr_to_u64(ptr); + ptr += holder.nr_func_info * holder.func_info_rec_size; + + holder.line_info = ptr_to_u64(ptr); + ptr += holder.nr_line_info * holder.line_info_rec_size; + + holder.jited_line_info = ptr_to_u64(ptr); + ptr += holder.nr_jited_line_info * holder.jited_line_info_rec_size; + + *info = holder; + return 0; +} + static void print_boot_time(__u64 nsecs, char *buf, unsigned int size) { struct timespec real_time_ts, boot_time_ts; @@ -803,16 +873,18 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode, static int do_dump(int argc, char **argv) { - struct bpf_prog_info_linear *info_linear; + struct bpf_prog_info info; + __u32 info_len = sizeof(info); + size_t info_data_sz = 0; + void *info_data = NULL; char *filepath = NULL; bool opcodes = false; bool visual = false; enum dump_mode mode; bool linum = false; - int *fds = NULL; int nb_fds, i = 0; + int *fds = NULL; int err = -1; - __u64 arrays; if (is_prefix(*argv, "jited")) { if (disasm_init()) @@ -872,43 +944,44 @@ static int do_dump(int argc, char **argv) goto exit_close; } - if (mode == DUMP_JITED) - arrays = 1UL << BPF_PROG_INFO_JITED_INSNS; - else - arrays = 1UL << BPF_PROG_INFO_XLATED_INSNS; - - arrays |= 1UL << BPF_PROG_INFO_JITED_KSYMS; - arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS; - arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO; - arrays |= 1UL << BPF_PROG_INFO_LINE_INFO; - arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO; - if (json_output && nb_fds > 1) jsonw_start_array(json_wtr); /* root array */ for (i = 0; i < nb_fds; i++) { - info_linear = bpf_program__get_prog_info_linear(fds[i], arrays); - if (IS_ERR_OR_NULL(info_linear)) { + memset(&info, 0, sizeof(info)); + + err = bpf_obj_get_info_by_fd(fds[i], &info, &info_len); + if (err) { + p_err("can't get prog info: %s", strerror(errno)); + break; + } + + err = prep_prog_info(&info, mode, &info_data, &info_data_sz); + if (err) { + p_err("can't grow prog info_data"); + break; + } + + err = bpf_obj_get_info_by_fd(fds[i], &info, &info_len); + if (err) { p_err("can't get prog info: %s", strerror(errno)); break; } if (json_output && nb_fds > 1) { jsonw_start_object(json_wtr); /* prog object */ - print_prog_header_json(&info_linear->info); + print_prog_header_json(&info); jsonw_name(json_wtr, "insns"); } else if (nb_fds > 1) { - print_prog_header_plain(&info_linear->info); + print_prog_header_plain(&info); } - err = prog_dump(&info_linear->info, mode, filepath, opcodes, - visual, linum); + err = prog_dump(&info, mode, filepath, opcodes, visual, linum); if (json_output && nb_fds > 1) jsonw_end_object(json_wtr); /* prog object */ else if (i != nb_fds - 1 && nb_fds > 1) printf("\n"); - free(info_linear); if (err) break; close(fds[i]); @@ -920,6 +993,7 @@ exit_close: for (; i < nb_fds; i++) close(fds[i]); exit_free: + free(info_data); free(fds); return err; } @@ -2016,41 +2090,58 @@ static void profile_print_readings(void) static char *profile_target_name(int tgt_fd) { - struct bpf_prog_info_linear *info_linear; - struct bpf_func_info *func_info; + struct bpf_func_info func_info; + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); const struct btf_type *t; + __u32 func_info_rec_size; struct btf *btf = NULL; char *name = NULL; + int err; - info_linear = bpf_program__get_prog_info_linear( - tgt_fd, 1UL << BPF_PROG_INFO_FUNC_INFO); - if (IS_ERR_OR_NULL(info_linear)) { - p_err("failed to get info_linear for prog FD %d", tgt_fd); - return NULL; + err = bpf_obj_get_info_by_fd(tgt_fd, &info, &info_len); + if (err) { + p_err("failed to bpf_obj_get_info_by_fd for prog FD %d", tgt_fd); + goto out; } - if (info_linear->info.btf_id == 0) { + if (info.btf_id == 0) { p_err("prog FD %d doesn't have valid btf", tgt_fd); goto out; } - btf = btf__load_from_kernel_by_id(info_linear->info.btf_id); + func_info_rec_size = info.func_info_rec_size; + if (info.nr_func_info == 0) { + p_err("bpf_obj_get_info_by_fd for prog FD %d found 0 func_info", tgt_fd); + goto out; + } + + memset(&info, 0, sizeof(info)); + info.nr_func_info = 1; + info.func_info_rec_size = func_info_rec_size; + info.func_info = ptr_to_u64(&func_info); + + err = bpf_obj_get_info_by_fd(tgt_fd, &info, &info_len); + if (err) { + p_err("failed to get func_info for prog FD %d", tgt_fd); + goto out; + } + + btf = btf__load_from_kernel_by_id(info.btf_id); if (libbpf_get_error(btf)) { p_err("failed to load btf for prog FD %d", tgt_fd); goto out; } - func_info = u64_to_ptr(info_linear->info.func_info); - t = btf__type_by_id(btf, func_info[0].type_id); + t = btf__type_by_id(btf, func_info.type_id); if (!t) { p_err("btf %d doesn't have type %d", - info_linear->info.btf_id, func_info[0].type_id); + info.btf_id, func_info.type_id); goto out; } name = strdup(btf__name_by_offset(btf, t->name_off)); out: btf__free(btf); - free(info_linear); return name; } -- cgit