1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (c) 2018 Facebook */
5 #include <stdio.h> /* for (FILE *) used by json_writer */
8 #include <asm/byteorder.h>
9 #include <linux/bitops.h>
10 #include <linux/btf.h>
11 #include <linux/err.h>
15 #include "json_writer.h"
18 #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
19 #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
20 #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
21 #define BITS_ROUNDUP_BYTES(bits) \
22 (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
24 static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
25 __u8 bit_offset, const void *data);
27 static int btf_dump_func(const struct btf *btf, char *func_sig,
28 const struct btf_type *func_proto,
29 const struct btf_type *func, int pos, int size);
31 static int dump_prog_id_as_func_ptr(const struct btf_dumper *d,
32 const struct btf_type *func_proto,
35 struct bpf_prog_info_linear *prog_info = NULL;
36 const struct btf_type *func_type;
37 const char *prog_name = NULL;
38 struct bpf_func_info *finfo;
39 struct btf *prog_btf = NULL;
40 struct bpf_prog_info *info;
41 int prog_fd, func_sig_len;
44 /* Get the ptr's func_proto */
45 func_sig_len = btf_dump_func(d->btf, prog_str, func_proto, NULL, 0,
47 if (func_sig_len == -1)
53 /* Get the bpf_prog's name. Obtain from func_info. */
54 prog_fd = bpf_prog_get_fd_by_id(prog_id);
58 prog_info = bpf_program__get_prog_info_linear(prog_fd,
59 1UL << BPF_PROG_INFO_FUNC_INFO);
61 if (IS_ERR(prog_info)) {
65 info = &prog_info->info;
67 if (!info->btf_id || !info->nr_func_info ||
68 btf__get_from_id(info->btf_id, &prog_btf))
70 finfo = (struct bpf_func_info *)info->func_info;
71 func_type = btf__type_by_id(prog_btf, finfo->type_id);
72 if (!func_type || !btf_is_func(func_type))
75 prog_name = btf__name_by_offset(prog_btf, func_type->name_off);
79 snprintf(&prog_str[func_sig_len],
80 sizeof(prog_str) - func_sig_len, " 0");
82 snprintf(&prog_str[func_sig_len],
83 sizeof(prog_str) - func_sig_len,
84 " %s/prog_id:%u", prog_name, prog_id);
86 snprintf(&prog_str[func_sig_len],
87 sizeof(prog_str) - func_sig_len,
88 " <unknown_prog_name>/prog_id:%u", prog_id);
90 prog_str[sizeof(prog_str) - 1] = '\0';
91 jsonw_string(d->jw, prog_str);
97 static void btf_dumper_ptr(const struct btf_dumper *d,
98 const struct btf_type *t,
101 unsigned long value = *(unsigned long *)data;
102 const struct btf_type *ptr_type;
105 if (!d->prog_id_as_func_ptr || value > UINT32_MAX)
106 goto print_ptr_value;
108 ptr_type_id = btf__resolve_type(d->btf, t->type);
110 goto print_ptr_value;
111 ptr_type = btf__type_by_id(d->btf, ptr_type_id);
112 if (!ptr_type || !btf_is_func_proto(ptr_type))
113 goto print_ptr_value;
115 if (!dump_prog_id_as_func_ptr(d, ptr_type, value))
119 if (d->is_plain_text)
120 jsonw_printf(d->jw, "%p", (void *)value);
122 jsonw_printf(d->jw, "%lu", value);
125 static int btf_dumper_modifier(const struct btf_dumper *d, __u32 type_id,
126 __u8 bit_offset, const void *data)
130 actual_type_id = btf__resolve_type(d->btf, type_id);
131 if (actual_type_id < 0)
132 return actual_type_id;
134 return btf_dumper_do_type(d, actual_type_id, bit_offset, data);
137 static int btf_dumper_enum(const struct btf_dumper *d,
138 const struct btf_type *t,
141 const struct btf_enum *enums = btf_enum(t);
147 value = *(__s64 *)data;
150 value = *(__s32 *)data;
153 value = *(__s16 *)data;
156 value = *(__s8 *)data;
162 for (i = 0; i < btf_vlen(t); i++) {
163 if (value == enums[i].val) {
165 btf__name_by_offset(d->btf,
171 jsonw_int(d->jw, value);
175 static bool is_str_array(const struct btf *btf, const struct btf_array *arr,
178 const struct btf_type *elem_type;
184 elem_type = btf__type_by_id(btf, arr->type);
185 /* Not skipping typedef. typedef to char does not count as
188 while (elem_type && btf_is_mod(elem_type))
189 elem_type = btf__type_by_id(btf, elem_type->type);
191 if (!elem_type || !btf_is_int(elem_type) || elem_type->size != 1)
194 if (btf_int_encoding(elem_type) != BTF_INT_CHAR &&
195 strcmp("char", btf__name_by_offset(btf, elem_type->name_off)))
198 end_s = s + arr->nelems;
202 if (*s <= 0x1f || *s >= 0x7f)
207 /* '\0' is not found */
211 static int btf_dumper_array(const struct btf_dumper *d, __u32 type_id,
214 const struct btf_type *t = btf__type_by_id(d->btf, type_id);
215 struct btf_array *arr = (struct btf_array *)(t + 1);
220 if (is_str_array(d->btf, arr, data)) {
221 jsonw_string(d->jw, data);
225 elem_size = btf__resolve_size(d->btf, arr->type);
229 jsonw_start_array(d->jw);
230 for (i = 0; i < arr->nelems; i++) {
231 ret = btf_dumper_do_type(d, arr->type, 0,
232 data + i * elem_size);
237 jsonw_end_array(d->jw);
241 static void btf_int128_print(json_writer_t *jw, const void *data,
244 /* data points to a __int128 number.
246 * int128_num = *(__int128 *)data;
247 * The below formulas shows what upper_num and lower_num represents:
248 * upper_num = int128_num >> 64;
249 * lower_num = int128_num & 0xffffffffFFFFFFFFULL;
251 __u64 upper_num, lower_num;
253 #ifdef __BIG_ENDIAN_BITFIELD
254 upper_num = *(__u64 *)data;
255 lower_num = *(__u64 *)(data + 8);
257 upper_num = *(__u64 *)(data + 8);
258 lower_num = *(__u64 *)data;
263 jsonw_printf(jw, "0x%llx", lower_num);
265 jsonw_printf(jw, "0x%llx%016llx", upper_num, lower_num);
268 jsonw_printf(jw, "\"0x%llx\"", lower_num);
270 jsonw_printf(jw, "\"0x%llx%016llx\"", upper_num, lower_num);
274 static void btf_int128_shift(__u64 *print_num, __u16 left_shift_bits,
275 __u16 right_shift_bits)
277 __u64 upper_num, lower_num;
279 #ifdef __BIG_ENDIAN_BITFIELD
280 upper_num = print_num[0];
281 lower_num = print_num[1];
283 upper_num = print_num[1];
284 lower_num = print_num[0];
287 /* shake out un-needed bits by shift/or operations */
288 if (left_shift_bits >= 64) {
289 upper_num = lower_num << (left_shift_bits - 64);
292 upper_num = (upper_num << left_shift_bits) |
293 (lower_num >> (64 - left_shift_bits));
294 lower_num = lower_num << left_shift_bits;
297 if (right_shift_bits >= 64) {
298 lower_num = upper_num >> (right_shift_bits - 64);
301 lower_num = (lower_num >> right_shift_bits) |
302 (upper_num << (64 - right_shift_bits));
303 upper_num = upper_num >> right_shift_bits;
306 #ifdef __BIG_ENDIAN_BITFIELD
307 print_num[0] = upper_num;
308 print_num[1] = lower_num;
310 print_num[0] = lower_num;
311 print_num[1] = upper_num;
315 static void btf_dumper_bitfield(__u32 nr_bits, __u8 bit_offset,
316 const void *data, json_writer_t *jw,
319 int left_shift_bits, right_shift_bits;
320 __u64 print_num[2] = {};
324 bits_to_copy = bit_offset + nr_bits;
325 bytes_to_copy = BITS_ROUNDUP_BYTES(bits_to_copy);
327 memcpy(print_num, data, bytes_to_copy);
328 #if defined(__BIG_ENDIAN_BITFIELD)
329 left_shift_bits = bit_offset;
330 #elif defined(__LITTLE_ENDIAN_BITFIELD)
331 left_shift_bits = 128 - bits_to_copy;
333 #error neither big nor little endian
335 right_shift_bits = 128 - nr_bits;
337 btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
338 btf_int128_print(jw, print_num, is_plain_text);
342 static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset,
343 const void *data, json_writer_t *jw,
346 int nr_bits = BTF_INT_BITS(int_type);
347 int total_bits_offset;
349 /* bits_offset is at most 7.
350 * BTF_INT_OFFSET() cannot exceed 128 bits.
352 total_bits_offset = bit_offset + BTF_INT_OFFSET(int_type);
353 data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
354 bit_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
355 btf_dumper_bitfield(nr_bits, bit_offset, data, jw,
359 static int btf_dumper_int(const struct btf_type *t, __u8 bit_offset,
360 const void *data, json_writer_t *jw,
366 int_type = (__u32 *)(t + 1);
367 nr_bits = BTF_INT_BITS(*int_type);
368 /* if this is bit field */
369 if (bit_offset || BTF_INT_OFFSET(*int_type) ||
370 BITS_PER_BYTE_MASKED(nr_bits)) {
371 btf_dumper_int_bits(*int_type, bit_offset, data, jw,
376 if (nr_bits == 128) {
377 btf_int128_print(jw, data, is_plain_text);
381 switch (BTF_INT_ENCODING(*int_type)) {
383 if (BTF_INT_BITS(*int_type) == 64)
384 jsonw_printf(jw, "%llu", *(__u64 *)data);
385 else if (BTF_INT_BITS(*int_type) == 32)
386 jsonw_printf(jw, "%u", *(__u32 *)data);
387 else if (BTF_INT_BITS(*int_type) == 16)
388 jsonw_printf(jw, "%hu", *(__u16 *)data);
389 else if (BTF_INT_BITS(*int_type) == 8)
390 jsonw_printf(jw, "%hhu", *(__u8 *)data);
392 btf_dumper_int_bits(*int_type, bit_offset, data, jw,
396 if (BTF_INT_BITS(*int_type) == 64)
397 jsonw_printf(jw, "%lld", *(long long *)data);
398 else if (BTF_INT_BITS(*int_type) == 32)
399 jsonw_printf(jw, "%d", *(int *)data);
400 else if (BTF_INT_BITS(*int_type) == 16)
401 jsonw_printf(jw, "%hd", *(short *)data);
402 else if (BTF_INT_BITS(*int_type) == 8)
403 jsonw_printf(jw, "%hhd", *(char *)data);
405 btf_dumper_int_bits(*int_type, bit_offset, data, jw,
409 if (isprint(*(char *)data))
410 jsonw_printf(jw, "\"%c\"", *(char *)data);
413 jsonw_printf(jw, "0x%hhx", *(char *)data);
415 jsonw_printf(jw, "\"\\u00%02hhx\"",
419 jsonw_bool(jw, *(int *)data);
422 /* shouldn't happen */
429 static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id,
432 const struct btf_type *t;
433 struct btf_member *m;
434 const void *data_off;
439 t = btf__type_by_id(d->btf, type_id);
443 kind_flag = BTF_INFO_KFLAG(t->info);
444 vlen = BTF_INFO_VLEN(t->info);
445 jsonw_start_object(d->jw);
446 m = (struct btf_member *)(t + 1);
448 for (i = 0; i < vlen; i++) {
449 __u32 bit_offset = m[i].offset;
450 __u32 bitfield_size = 0;
453 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(bit_offset);
454 bit_offset = BTF_MEMBER_BIT_OFFSET(bit_offset);
457 jsonw_name(d->jw, btf__name_by_offset(d->btf, m[i].name_off));
458 data_off = data + BITS_ROUNDDOWN_BYTES(bit_offset);
460 btf_dumper_bitfield(bitfield_size,
461 BITS_PER_BYTE_MASKED(bit_offset),
462 data_off, d->jw, d->is_plain_text);
464 ret = btf_dumper_do_type(d, m[i].type,
465 BITS_PER_BYTE_MASKED(bit_offset),
472 jsonw_end_object(d->jw);
477 static int btf_dumper_var(const struct btf_dumper *d, __u32 type_id,
478 __u8 bit_offset, const void *data)
480 const struct btf_type *t = btf__type_by_id(d->btf, type_id);
483 jsonw_start_object(d->jw);
484 jsonw_name(d->jw, btf__name_by_offset(d->btf, t->name_off));
485 ret = btf_dumper_do_type(d, t->type, bit_offset, data);
486 jsonw_end_object(d->jw);
491 static int btf_dumper_datasec(const struct btf_dumper *d, __u32 type_id,
494 struct btf_var_secinfo *vsi;
495 const struct btf_type *t;
496 int ret = 0, i, vlen;
498 t = btf__type_by_id(d->btf, type_id);
502 vlen = BTF_INFO_VLEN(t->info);
503 vsi = (struct btf_var_secinfo *)(t + 1);
505 jsonw_start_object(d->jw);
506 jsonw_name(d->jw, btf__name_by_offset(d->btf, t->name_off));
507 jsonw_start_array(d->jw);
508 for (i = 0; i < vlen; i++) {
509 ret = btf_dumper_do_type(d, vsi[i].type, 0, data + vsi[i].offset);
513 jsonw_end_array(d->jw);
514 jsonw_end_object(d->jw);
519 static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
520 __u8 bit_offset, const void *data)
522 const struct btf_type *t = btf__type_by_id(d->btf, type_id);
524 switch (BTF_INFO_KIND(t->info)) {
526 return btf_dumper_int(t, bit_offset, data, d->jw,
528 case BTF_KIND_STRUCT:
530 return btf_dumper_struct(d, type_id, data);
532 return btf_dumper_array(d, type_id, data);
534 return btf_dumper_enum(d, t, data);
536 btf_dumper_ptr(d, t, data);
539 jsonw_printf(d->jw, "(unknown)");
542 /* map key or value can't be forward */
543 jsonw_printf(d->jw, "(fwd-kind-invalid)");
545 case BTF_KIND_TYPEDEF:
546 case BTF_KIND_VOLATILE:
548 case BTF_KIND_RESTRICT:
549 return btf_dumper_modifier(d, type_id, bit_offset, data);
551 return btf_dumper_var(d, type_id, bit_offset, data);
552 case BTF_KIND_DATASEC:
553 return btf_dumper_datasec(d, type_id, data);
555 jsonw_printf(d->jw, "(unsupported-kind");
560 int btf_dumper_type(const struct btf_dumper *d, __u32 type_id,
563 return btf_dumper_do_type(d, type_id, 0, data);
566 #define BTF_PRINT_ARG(...) \
568 pos += snprintf(func_sig + pos, size - pos, \
573 #define BTF_PRINT_TYPE(type) \
575 pos = __btf_dumper_type_only(btf, type, func_sig, \
581 static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
582 char *func_sig, int pos, int size)
584 const struct btf_type *proto_type;
585 const struct btf_array *array;
586 const struct btf_var *var;
587 const struct btf_type *t;
590 BTF_PRINT_ARG("void ");
594 t = btf__type_by_id(btf, type_id);
596 switch (BTF_INFO_KIND(t->info)) {
598 case BTF_KIND_TYPEDEF:
599 BTF_PRINT_ARG("%s ", btf__name_by_offset(btf, t->name_off));
601 case BTF_KIND_STRUCT:
602 BTF_PRINT_ARG("struct %s ",
603 btf__name_by_offset(btf, t->name_off));
606 BTF_PRINT_ARG("union %s ",
607 btf__name_by_offset(btf, t->name_off));
610 BTF_PRINT_ARG("enum %s ",
611 btf__name_by_offset(btf, t->name_off));
614 array = (struct btf_array *)(t + 1);
615 BTF_PRINT_TYPE(array->type);
616 BTF_PRINT_ARG("[%d]", array->nelems);
619 BTF_PRINT_TYPE(t->type);
623 BTF_PRINT_ARG("%s %s ",
624 BTF_INFO_KFLAG(t->info) ? "union" : "struct",
625 btf__name_by_offset(btf, t->name_off));
627 case BTF_KIND_VOLATILE:
628 BTF_PRINT_ARG("volatile ");
629 BTF_PRINT_TYPE(t->type);
632 BTF_PRINT_ARG("const ");
633 BTF_PRINT_TYPE(t->type);
635 case BTF_KIND_RESTRICT:
636 BTF_PRINT_ARG("restrict ");
637 BTF_PRINT_TYPE(t->type);
639 case BTF_KIND_FUNC_PROTO:
640 pos = btf_dump_func(btf, func_sig, t, NULL, pos, size);
645 proto_type = btf__type_by_id(btf, t->type);
646 pos = btf_dump_func(btf, func_sig, proto_type, t, pos, size);
651 var = (struct btf_var *)(t + 1);
652 if (var->linkage == BTF_VAR_STATIC)
653 BTF_PRINT_ARG("static ");
654 BTF_PRINT_TYPE(t->type);
656 btf__name_by_offset(btf, t->name_off));
658 case BTF_KIND_DATASEC:
659 BTF_PRINT_ARG("section (\"%s\") ",
660 btf__name_by_offset(btf, t->name_off));
670 static int btf_dump_func(const struct btf *btf, char *func_sig,
671 const struct btf_type *func_proto,
672 const struct btf_type *func, int pos, int size)
676 BTF_PRINT_TYPE(func_proto->type);
678 BTF_PRINT_ARG("%s(", btf__name_by_offset(btf, func->name_off));
681 vlen = BTF_INFO_VLEN(func_proto->info);
682 for (i = 0; i < vlen; i++) {
683 struct btf_param *arg = &((struct btf_param *)(func_proto + 1))[i];
688 BTF_PRINT_TYPE(arg->type);
691 btf__name_by_offset(btf, arg->name_off));
692 else if (pos && func_sig[pos - 1] == ' ')
693 /* Remove unnecessary space for
694 * FUNC_PROTO that does not have
697 func_sig[--pos] = '\0';
699 BTF_PRINT_ARG("...");
707 void btf_dumper_type_only(const struct btf *btf, __u32 type_id, char *func_sig,
716 err = __btf_dumper_type_only(btf, type_id, func_sig, 0, size);
721 static const char *ltrim(const char *s)
729 void btf_dump_linfo_plain(const struct btf *btf,
730 const struct bpf_line_info *linfo,
731 const char *prefix, bool linum)
733 const char *line = btf__name_by_offset(btf, linfo->line_off);
743 const char *file = btf__name_by_offset(btf, linfo->file_name_off);
745 /* More forgiving on file because linum option is
746 * expected to provide more info than the already
747 * available src line.
752 printf("%s%s [file:%s line_num:%u line_col:%u]\n",
754 BPF_LINE_INFO_LINE_NUM(linfo->line_col),
755 BPF_LINE_INFO_LINE_COL(linfo->line_col));
757 printf("%s%s\n", prefix, line);
761 void btf_dump_linfo_json(const struct btf *btf,
762 const struct bpf_line_info *linfo, bool linum)
764 const char *line = btf__name_by_offset(btf, linfo->line_off);
767 jsonw_string_field(json_wtr, "src", ltrim(line));
770 const char *file = btf__name_by_offset(btf, linfo->file_name_off);
773 jsonw_string_field(json_wtr, "file", file);
775 if (BPF_LINE_INFO_LINE_NUM(linfo->line_col))
776 jsonw_int_field(json_wtr, "line_num",
777 BPF_LINE_INFO_LINE_NUM(linfo->line_col));
779 if (BPF_LINE_INFO_LINE_COL(linfo->line_col))
780 jsonw_int_field(json_wtr, "line_col",
781 BPF_LINE_INFO_LINE_COL(linfo->line_col));