diff options
Diffstat (limited to 'tools/bpf/bpftool/btf_dumper.c')
| -rw-r--r-- | tools/bpf/bpftool/btf_dumper.c | 199 |
1 files changed, 183 insertions, 16 deletions
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 01cc52b834fa..497807bec675 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -4,11 +4,13 @@ #include <ctype.h> #include <stdio.h> /* for (FILE *) used by json_writer */ #include <string.h> +#include <unistd.h> #include <asm/byteorder.h> #include <linux/bitops.h> #include <linux/btf.h> #include <linux/err.h> #include <bpf/btf.h> +#include <bpf/bpf.h> #include "json_writer.h" #include "main.h" @@ -22,13 +24,102 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id, __u8 bit_offset, const void *data); -static void btf_dumper_ptr(const void *data, json_writer_t *jw, - bool is_plain_text) +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 dump_prog_id_as_func_ptr(const struct btf_dumper *d, + const struct btf_type *func_proto, + __u32 prog_id) { - if (is_plain_text) - jsonw_printf(jw, "%p", *(void **)data); + struct bpf_prog_info_linear *prog_info = NULL; + const struct btf_type *func_type; + 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; + char prog_str[1024]; + + /* Get the ptr's func_proto */ + func_sig_len = btf_dump_func(d->btf, prog_str, func_proto, NULL, 0, + sizeof(prog_str)); + if (func_sig_len == -1) + return -1; + + if (!prog_id) + goto print; + + /* Get the bpf_prog's name. Obtain from func_info. */ + prog_fd = bpf_prog_get_fd_by_id(prog_id); + if (prog_fd == -1) + 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; + goto print; + } + info = &prog_info->info; + + if (!info->btf_id || !info->nr_func_info || + btf__get_from_id(info->btf_id, &prog_btf)) + goto print; + finfo = (struct bpf_func_info *)info->func_info; + func_type = btf__type_by_id(prog_btf, finfo->type_id); + if (!func_type || !btf_is_func(func_type)) + goto print; + + prog_name = btf__name_by_offset(prog_btf, func_type->name_off); + +print: + if (!prog_id) + snprintf(&prog_str[func_sig_len], + sizeof(prog_str) - func_sig_len, " 0"); + else if (prog_name) + snprintf(&prog_str[func_sig_len], + sizeof(prog_str) - func_sig_len, + " %s/prog_id:%u", prog_name, prog_id); else - jsonw_printf(jw, "%lu", *(unsigned long *)data); + snprintf(&prog_str[func_sig_len], + sizeof(prog_str) - func_sig_len, + " <unknown_prog_name>/prog_id:%u", prog_id); + + prog_str[sizeof(prog_str) - 1] = '\0'; + jsonw_string(d->jw, prog_str); + btf__free(prog_btf); + free(prog_info); + return 0; +} + +static void btf_dumper_ptr(const struct btf_dumper *d, + const struct btf_type *t, + const void *data) +{ + unsigned long value = *(unsigned long *)data; + const struct btf_type *ptr_type; + __s32 ptr_type_id; + + if (!d->prog_id_as_func_ptr || value > UINT32_MAX) + goto print_ptr_value; + + ptr_type_id = btf__resolve_type(d->btf, t->type); + if (ptr_type_id < 0) + goto print_ptr_value; + ptr_type = btf__type_by_id(d->btf, ptr_type_id); + if (!ptr_type || !btf_is_func_proto(ptr_type)) + goto print_ptr_value; + + if (!dump_prog_id_as_func_ptr(d, ptr_type, value)) + return; + +print_ptr_value: + if (d->is_plain_text) + jsonw_printf(d->jw, "%p", (void *)value); + else + jsonw_printf(d->jw, "%lu", value); } static int btf_dumper_modifier(const struct btf_dumper *d, __u32 type_id, @@ -43,9 +134,78 @@ static int btf_dumper_modifier(const struct btf_dumper *d, __u32 type_id, return btf_dumper_do_type(d, actual_type_id, bit_offset, data); } -static void btf_dumper_enum(const void *data, json_writer_t *jw) +static int btf_dumper_enum(const struct btf_dumper *d, + const struct btf_type *t, + const void *data) +{ + const struct btf_enum *enums = btf_enum(t); + __s64 value; + __u16 i; + + switch (t->size) { + case 8: + value = *(__s64 *)data; + break; + case 4: + value = *(__s32 *)data; + break; + case 2: + value = *(__s16 *)data; + break; + case 1: + value = *(__s8 *)data; + break; + default: + return -EINVAL; + } + + for (i = 0; i < btf_vlen(t); i++) { + if (value == enums[i].val) { + jsonw_string(d->jw, + btf__name_by_offset(d->btf, + enums[i].name_off)); + return 0; + } + } + + jsonw_int(d->jw, value); + return 0; +} + +static bool is_str_array(const struct btf *btf, const struct btf_array *arr, + const char *s) { - jsonw_printf(jw, "%d", *(int *)data); + const struct btf_type *elem_type; + const char *end_s; + + if (!arr->nelems) + return false; + + elem_type = btf__type_by_id(btf, arr->type); + /* Not skipping typedef. typedef to char does not count as + * a string now. + */ + while (elem_type && btf_is_mod(elem_type)) + elem_type = btf__type_by_id(btf, elem_type->type); + + if (!elem_type || !btf_is_int(elem_type) || elem_type->size != 1) + return false; + + if (btf_int_encoding(elem_type) != BTF_INT_CHAR && + strcmp("char", btf__name_by_offset(btf, elem_type->name_off))) + return false; + + end_s = s + arr->nelems; + while (s < end_s) { + if (!*s) + return true; + if (*s <= 0x1f || *s >= 0x7f) + return false; + s++; + } + + /* '\0' is not found */ + return false; } static int btf_dumper_array(const struct btf_dumper *d, __u32 type_id, @@ -57,6 +217,11 @@ static int btf_dumper_array(const struct btf_dumper *d, __u32 type_id, int ret = 0; __u32 i; + if (is_str_array(d->btf, arr, data)) { + jsonw_string(d->jw, data); + return 0; + } + elem_size = btf__resolve_size(d->btf, arr->type); if (elem_size < 0) return elem_size; @@ -366,10 +531,9 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id, case BTF_KIND_ARRAY: return btf_dumper_array(d, type_id, data); case BTF_KIND_ENUM: - btf_dumper_enum(data, d->jw); - return 0; + return btf_dumper_enum(d, t, data); case BTF_KIND_PTR: - btf_dumper_ptr(data, d->jw, d->is_plain_text); + btf_dumper_ptr(d, t, data); return 0; case BTF_KIND_UNKN: jsonw_printf(d->jw, "(unknown)"); @@ -414,10 +578,6 @@ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id, 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) { @@ -526,8 +686,15 @@ static int btf_dump_func(const struct btf *btf, char *func_sig, BTF_PRINT_ARG(", "); if (arg->type) { BTF_PRINT_TYPE(arg->type); - BTF_PRINT_ARG("%s", - btf__name_by_offset(btf, arg->name_off)); + if (arg->name_off) + BTF_PRINT_ARG("%s", + btf__name_by_offset(btf, arg->name_off)); + else if (pos && func_sig[pos - 1] == ' ') + /* Remove unnecessary space for + * FUNC_PROTO that does not have + * arg->name_off + */ + func_sig[--pos] = '\0'; } else { BTF_PRINT_ARG("..."); } |