From 254471e57a86b8dc1a2cc19848e99f5d7c0558f4 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:21 -0800 Subject: tools/bpf: bpftool: add support for func types This patch added support to print function signature if btf func_info is available. Note that ksym now uses function name instead of prog_name as prog_name has a limit of 16 bytes including ending '\0'. The following is a sample output for selftests test_btf with file test_btf_haskv.o for translated insns and jited insns respectively. $ bpftool prog dump xlated id 1 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): 0: (85) call pc+2#bpf_prog_2dcecc18072623fc_test_long_fname_1 1: (b7) r0 = 0 2: (95) exit int test_long_fname_1(struct dummy_tracepoint_args * arg): 3: (85) call pc+1#bpf_prog_89d64e4abf0f0126_test_long_fname_2 4: (95) exit int test_long_fname_2(struct dummy_tracepoint_args * arg): 5: (b7) r2 = 0 6: (63) *(u32 *)(r10 -4) = r2 7: (79) r1 = *(u64 *)(r1 +8) ... 22: (07) r1 += 1 23: (63) *(u32 *)(r0 +4) = r1 24: (95) exit $ bpftool prog dump jited id 1 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): bpf_prog_b07ccb89267cf242__dummy_tracepoint: 0: push %rbp 1: mov %rsp,%rbp ...... 3c: add $0x28,%rbp 40: leaveq 41: retq int test_long_fname_1(struct dummy_tracepoint_args * arg): bpf_prog_2dcecc18072623fc_test_long_fname_1: 0: push %rbp 1: mov %rsp,%rbp ...... 3a: add $0x28,%rbp 3e: leaveq 3f: retq int test_long_fname_2(struct dummy_tracepoint_args * arg): bpf_prog_89d64e4abf0f0126_test_long_fname_2: 0: push %rbp 1: mov %rsp,%rbp ...... 80: add $0x28,%rbp 84: leaveq 85: retq Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/btf_dumper.c | 136 ++++++++++++++++++++++++++++++++++++++ tools/bpf/bpftool/main.h | 2 + tools/bpf/bpftool/prog.c | 56 ++++++++++++++++ tools/bpf/bpftool/xlated_dumper.c | 33 +++++++++ tools/bpf/bpftool/xlated_dumper.h | 3 + 5 files changed, 230 insertions(+) diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 55bc512a1831..c3fd3a7cb787 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -249,3 +249,139 @@ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id, { return btf_dumper_do_type(d, type_id, 0, data); } + +#define BTF_PRINT_ARG(...) \ + do { \ + pos += snprintf(func_sig + pos, size - pos, \ + __VA_ARGS__); \ + if (pos >= size) \ + return -1; \ + } while (0) +#define BTF_PRINT_TYPE(type) \ + do { \ + pos = __btf_dumper_type_only(btf, type, func_sig, \ + pos, size); \ + if (pos == -1) \ + return -1; \ + } while (0) + +static int btf_dump_func(const struct btf *btf, char *func_sig, + const struct btf_type *func_proto, + const struct btf_type *func, int pos, int size); + +static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id, + char *func_sig, int pos, int size) +{ + const struct btf_type *proto_type; + const struct btf_array *array; + const struct btf_type *t; + + if (!type_id) { + BTF_PRINT_ARG("void "); + return pos; + } + + t = btf__type_by_id(btf, type_id); + + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_INT: + BTF_PRINT_ARG("%s ", btf__name_by_offset(btf, t->name_off)); + break; + case BTF_KIND_STRUCT: + BTF_PRINT_ARG("struct %s ", + btf__name_by_offset(btf, t->name_off)); + break; + case BTF_KIND_UNION: + BTF_PRINT_ARG("union %s ", + btf__name_by_offset(btf, t->name_off)); + break; + case BTF_KIND_ENUM: + BTF_PRINT_ARG("enum %s ", + btf__name_by_offset(btf, t->name_off)); + break; + case BTF_KIND_ARRAY: + array = (struct btf_array *)(t + 1); + BTF_PRINT_TYPE(array->type); + BTF_PRINT_ARG("[%d]", array->nelems); + break; + case BTF_KIND_PTR: + BTF_PRINT_TYPE(t->type); + BTF_PRINT_ARG("* "); + break; + case BTF_KIND_UNKN: + case BTF_KIND_FWD: + case BTF_KIND_TYPEDEF: + return -1; + case BTF_KIND_VOLATILE: + BTF_PRINT_ARG("volatile "); + BTF_PRINT_TYPE(t->type); + break; + case BTF_KIND_CONST: + BTF_PRINT_ARG("const "); + BTF_PRINT_TYPE(t->type); + break; + case BTF_KIND_RESTRICT: + BTF_PRINT_ARG("restrict "); + BTF_PRINT_TYPE(t->type); + break; + case BTF_KIND_FUNC_PROTO: + pos = btf_dump_func(btf, func_sig, t, NULL, pos, size); + if (pos == -1) + return -1; + break; + case BTF_KIND_FUNC: + proto_type = btf__type_by_id(btf, t->type); + pos = btf_dump_func(btf, func_sig, proto_type, t, pos, size); + if (pos == -1) + return -1; + break; + default: + return -1; + } + + return pos; +} + +static int btf_dump_func(const struct btf *btf, char *func_sig, + const struct btf_type *func_proto, + const struct btf_type *func, int pos, int size) +{ + int i, vlen; + + BTF_PRINT_TYPE(func_proto->type); + if (func) + BTF_PRINT_ARG("%s(", btf__name_by_offset(btf, func->name_off)); + else + BTF_PRINT_ARG("("); + vlen = BTF_INFO_VLEN(func_proto->info); + for (i = 0; i < vlen; i++) { + struct btf_param *arg = &((struct btf_param *)(func_proto + 1))[i]; + + if (i) + BTF_PRINT_ARG(", "); + if (arg->type) { + BTF_PRINT_TYPE(arg->type); + BTF_PRINT_ARG("%s", + btf__name_by_offset(btf, arg->name_off)); + } else { + BTF_PRINT_ARG("..."); + } + } + BTF_PRINT_ARG(")"); + + return pos; +} + +void btf_dumper_type_only(const struct btf *btf, __u32 type_id, char *func_sig, + int size) +{ + int err; + + func_sig[0] = '\0'; + if (!btf) + return; + + err = __btf_dumper_type_only(btf, type_id, func_sig, 0, size); + if (err < 0) + func_sig[0] = '\0'; +} diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 10c6c16fae29..3e8979567cf1 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -187,6 +187,8 @@ struct btf_dumper { */ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id, const void *data); +void btf_dumper_type_only(const struct btf *btf, __u32 func_type_id, + char *func_only, int size); struct nlattr; struct ifinfomsg; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index c176e1aa66fe..37b1daf19da6 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -47,6 +47,7 @@ #include #include +#include #include #include "cfg.h" @@ -451,14 +452,19 @@ static int do_dump(int argc, char **argv) struct bpf_prog_info info = {}; unsigned int *func_lens = NULL; const char *disasm_opt = NULL; + unsigned int finfo_rec_size; unsigned int nr_func_ksyms; unsigned int nr_func_lens; struct dump_data dd = {}; __u32 len = sizeof(info); + struct btf *btf = NULL; + void *func_info = NULL; + unsigned int finfo_cnt; unsigned int buf_size; char *filepath = NULL; bool opcodes = false; bool visual = false; + char func_sig[1024]; unsigned char *buf; __u32 *member_len; __u64 *member_ptr; @@ -551,6 +557,17 @@ static int do_dump(int argc, char **argv) } } + finfo_cnt = info.func_info_cnt; + finfo_rec_size = info.func_info_rec_size; + if (finfo_cnt && finfo_rec_size) { + func_info = malloc(finfo_cnt * finfo_rec_size); + if (!func_info) { + p_err("mem alloc failed"); + close(fd); + goto err_free; + } + } + memset(&info, 0, sizeof(info)); *member_ptr = ptr_to_u64(buf); @@ -559,6 +576,9 @@ static int do_dump(int argc, char **argv) info.nr_jited_ksyms = nr_func_ksyms; info.jited_func_lens = ptr_to_u64(func_lens); info.nr_jited_func_lens = nr_func_lens; + info.func_info_cnt = finfo_cnt; + info.func_info_rec_size = finfo_rec_size; + info.func_info = ptr_to_u64(func_info); err = bpf_obj_get_info_by_fd(fd, &info, &len); close(fd); @@ -582,6 +602,18 @@ static int do_dump(int argc, char **argv) goto err_free; } + if (info.func_info_cnt != finfo_cnt) { + p_err("incorrect func_info_cnt %d vs. expected %d", + info.func_info_cnt, finfo_cnt); + goto err_free; + } + + if (info.func_info_rec_size != finfo_rec_size) { + p_err("incorrect func_info_rec_size %d vs. expected %d", + info.func_info_rec_size, finfo_rec_size); + goto err_free; + } + if ((member_len == &info.jited_prog_len && info.jited_prog_insns == 0) || (member_len == &info.xlated_prog_len && @@ -590,6 +622,11 @@ static int do_dump(int argc, char **argv) goto err_free; } + if (info.btf_id && btf_get_from_id(info.btf_id, &btf)) { + p_err("failed to get btf"); + goto err_free; + } + if (filepath) { fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd < 0) { @@ -622,6 +659,7 @@ static int do_dump(int argc, char **argv) if (info.nr_jited_func_lens && info.jited_func_lens) { struct kernel_sym *sym = NULL; + struct bpf_func_info *record; char sym_name[SYM_MAX_NAME]; unsigned char *img = buf; __u64 *ksyms = NULL; @@ -648,12 +686,25 @@ static int do_dump(int argc, char **argv) strcpy(sym_name, "unknown"); } + if (func_info) { + record = func_info + i * finfo_rec_size; + btf_dumper_type_only(btf, record->type_id, + func_sig, + sizeof(func_sig)); + } + if (json_output) { jsonw_start_object(json_wtr); + if (func_info && func_sig[0] != '\0') { + jsonw_name(json_wtr, "proto"); + jsonw_string(json_wtr, func_sig); + } jsonw_name(json_wtr, "name"); jsonw_string(json_wtr, sym_name); jsonw_name(json_wtr, "insns"); } else { + if (func_info && func_sig[0] != '\0') + printf("%s:\n", func_sig); printf("%s:\n", sym_name); } @@ -682,6 +733,9 @@ static int do_dump(int argc, char **argv) kernel_syms_load(&dd); dd.nr_jited_ksyms = info.nr_jited_ksyms; dd.jited_ksyms = (__u64 *) info.jited_ksyms; + dd.btf = btf; + dd.func_info = func_info; + dd.finfo_rec_size = finfo_rec_size; if (json_output) dump_xlated_json(&dd, buf, *member_len, opcodes); @@ -693,12 +747,14 @@ static int do_dump(int argc, char **argv) free(buf); free(func_ksyms); free(func_lens); + free(func_info); return 0; err_free: free(buf); free(func_ksyms); free(func_lens); + free(func_info); return -1; } diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c index 3284759df98a..e06ac0286a75 100644 --- a/tools/bpf/bpftool/xlated_dumper.c +++ b/tools/bpf/bpftool/xlated_dumper.c @@ -242,11 +242,15 @@ void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, .cb_imm = print_imm, .private_data = dd, }; + struct bpf_func_info *record; struct bpf_insn *insn = buf; + struct btf *btf = dd->btf; bool double_insn = false; + char func_sig[1024]; unsigned int i; jsonw_start_array(json_wtr); + record = dd->func_info; for (i = 0; i < len / sizeof(*insn); i++) { if (double_insn) { double_insn = false; @@ -255,6 +259,20 @@ void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); jsonw_start_object(json_wtr); + + if (btf && record) { + if (record->insn_offset == i) { + btf_dumper_type_only(btf, record->type_id, + func_sig, + sizeof(func_sig)); + if (func_sig[0] != '\0') { + jsonw_name(json_wtr, "proto"); + jsonw_string(json_wtr, func_sig); + } + record = (void *)record + dd->finfo_rec_size; + } + } + jsonw_name(json_wtr, "disasm"); print_bpf_insn(&cbs, insn + i, true); @@ -297,16 +315,31 @@ void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, .cb_imm = print_imm, .private_data = dd, }; + struct bpf_func_info *record; struct bpf_insn *insn = buf; + struct btf *btf = dd->btf; bool double_insn = false; + char func_sig[1024]; unsigned int i; + record = dd->func_info; for (i = 0; i < len / sizeof(*insn); i++) { if (double_insn) { double_insn = false; continue; } + if (btf && record) { + if (record->insn_offset == i) { + btf_dumper_type_only(btf, record->type_id, + func_sig, + sizeof(func_sig)); + if (func_sig[0] != '\0') + printf("%s:\n", func_sig); + record = (void *)record + dd->finfo_rec_size; + } + } + double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); printf("% 4d: ", i); diff --git a/tools/bpf/bpftool/xlated_dumper.h b/tools/bpf/bpftool/xlated_dumper.h index 33d86e2b369b..aec31723e1e5 100644 --- a/tools/bpf/bpftool/xlated_dumper.h +++ b/tools/bpf/bpftool/xlated_dumper.h @@ -51,6 +51,9 @@ struct dump_data { __u32 sym_count; __u64 *jited_ksyms; __u32 nr_jited_ksyms; + struct btf *btf; + void *func_info; + __u32 finfo_rec_size; char scratch_buff[SYM_MAX_NAME + 8]; }; -- cgit v1.2.3-59-g8ed1b