diff options
Diffstat (limited to 'tools/bpf/bpftool/btf_dumper.c')
-rw-r--r-- | tools/bpf/bpftool/btf_dumper.c | 360 |
1 files changed, 333 insertions, 27 deletions
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 55bc512a1831..e63bce0755eb 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -1,4 +1,4 @@ -// SPDX-License-Identifier: GPL-2.0 +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) /* Copyright (c) 2018 Facebook */ #include <ctype.h> @@ -32,7 +32,7 @@ static void btf_dumper_ptr(const void *data, json_writer_t *jw, } static int btf_dumper_modifier(const struct btf_dumper *d, __u32 type_id, - const void *data) + __u8 bit_offset, const void *data) { int actual_type_id; @@ -40,7 +40,7 @@ static int btf_dumper_modifier(const struct btf_dumper *d, __u32 type_id, if (actual_type_id < 0) return actual_type_id; - return btf_dumper_do_type(d, actual_type_id, 0, data); + return btf_dumper_do_type(d, actual_type_id, bit_offset, data); } static void btf_dumper_enum(const void *data, json_writer_t *jw) @@ -73,40 +73,122 @@ static int btf_dumper_array(const struct btf_dumper *d, __u32 type_id, return ret; } -static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset, +static void btf_int128_print(json_writer_t *jw, const void *data, + bool is_plain_text) +{ + /* data points to a __int128 number. + * Suppose + * int128_num = *(__int128 *)data; + * The below formulas shows what upper_num and lower_num represents: + * upper_num = int128_num >> 64; + * lower_num = int128_num & 0xffffffffFFFFFFFFULL; + */ + __u64 upper_num, lower_num; + +#ifdef __BIG_ENDIAN_BITFIELD + upper_num = *(__u64 *)data; + lower_num = *(__u64 *)(data + 8); +#else + upper_num = *(__u64 *)(data + 8); + lower_num = *(__u64 *)data; +#endif + + if (is_plain_text) { + if (upper_num == 0) + jsonw_printf(jw, "0x%llx", lower_num); + else + jsonw_printf(jw, "0x%llx%016llx", upper_num, lower_num); + } else { + if (upper_num == 0) + jsonw_printf(jw, "\"0x%llx\"", lower_num); + else + jsonw_printf(jw, "\"0x%llx%016llx\"", upper_num, lower_num); + } +} + +static void btf_int128_shift(__u64 *print_num, u16 left_shift_bits, + u16 right_shift_bits) +{ + __u64 upper_num, lower_num; + +#ifdef __BIG_ENDIAN_BITFIELD + upper_num = print_num[0]; + lower_num = print_num[1]; +#else + upper_num = print_num[1]; + lower_num = print_num[0]; +#endif + + /* shake out un-needed bits by shift/or operations */ + if (left_shift_bits >= 64) { + upper_num = lower_num << (left_shift_bits - 64); + lower_num = 0; + } else { + upper_num = (upper_num << left_shift_bits) | + (lower_num >> (64 - left_shift_bits)); + lower_num = lower_num << left_shift_bits; + } + + if (right_shift_bits >= 64) { + lower_num = upper_num >> (right_shift_bits - 64); + upper_num = 0; + } else { + lower_num = (lower_num >> right_shift_bits) | + (upper_num << (64 - right_shift_bits)); + upper_num = upper_num >> right_shift_bits; + } + +#ifdef __BIG_ENDIAN_BITFIELD + print_num[0] = upper_num; + print_num[1] = lower_num; +#else + print_num[0] = lower_num; + print_num[1] = upper_num; +#endif +} + +static void btf_dumper_bitfield(__u32 nr_bits, __u8 bit_offset, const void *data, json_writer_t *jw, bool is_plain_text) { int left_shift_bits, right_shift_bits; - int nr_bits = BTF_INT_BITS(int_type); - int total_bits_offset; + __u64 print_num[2] = {}; int bytes_to_copy; int bits_to_copy; - __u64 print_num; - total_bits_offset = bit_offset + BTF_INT_OFFSET(int_type); - data += BITS_ROUNDDOWN_BYTES(total_bits_offset); - bit_offset = BITS_PER_BYTE_MASKED(total_bits_offset); bits_to_copy = bit_offset + nr_bits; bytes_to_copy = BITS_ROUNDUP_BYTES(bits_to_copy); - print_num = 0; - memcpy(&print_num, data, bytes_to_copy); + memcpy(print_num, data, bytes_to_copy); #if defined(__BIG_ENDIAN_BITFIELD) left_shift_bits = bit_offset; #elif defined(__LITTLE_ENDIAN_BITFIELD) - left_shift_bits = 64 - bits_to_copy; + left_shift_bits = 128 - bits_to_copy; #else #error neither big nor little endian #endif - right_shift_bits = 64 - nr_bits; + right_shift_bits = 128 - nr_bits; - print_num <<= left_shift_bits; - print_num >>= right_shift_bits; - if (is_plain_text) - jsonw_printf(jw, "0x%llx", print_num); - else - jsonw_printf(jw, "%llu", print_num); + btf_int128_shift(print_num, left_shift_bits, right_shift_bits); + btf_int128_print(jw, print_num, is_plain_text); +} + + +static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset, + const void *data, json_writer_t *jw, + bool is_plain_text) +{ + int nr_bits = BTF_INT_BITS(int_type); + int total_bits_offset; + + /* bits_offset is at most 7. + * BTF_INT_OFFSET() cannot exceed 128 bits. + */ + total_bits_offset = bit_offset + BTF_INT_OFFSET(int_type); + data += BITS_ROUNDDOWN_BYTES(total_bits_offset); + bit_offset = BITS_PER_BYTE_MASKED(total_bits_offset); + btf_dumper_bitfield(nr_bits, bit_offset, data, jw, + is_plain_text); } static int btf_dumper_int(const struct btf_type *t, __u8 bit_offset, @@ -126,6 +208,11 @@ static int btf_dumper_int(const struct btf_type *t, __u8 bit_offset, return 0; } + if (nr_bits == 128) { + btf_int128_print(jw, data, is_plain_text); + return 0; + } + switch (BTF_INT_ENCODING(*int_type)) { case 0: if (BTF_INT_BITS(*int_type) == 64) @@ -180,6 +267,7 @@ static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id, const struct btf_type *t; struct btf_member *m; const void *data_off; + int kind_flag; int ret = 0; int i, vlen; @@ -187,18 +275,33 @@ static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id, if (!t) return -EINVAL; + kind_flag = BTF_INFO_KFLAG(t->info); vlen = BTF_INFO_VLEN(t->info); jsonw_start_object(d->jw); m = (struct btf_member *)(t + 1); for (i = 0; i < vlen; i++) { - data_off = data + BITS_ROUNDDOWN_BYTES(m[i].offset); + __u32 bit_offset = m[i].offset; + __u32 bitfield_size = 0; + + if (kind_flag) { + bitfield_size = BTF_MEMBER_BITFIELD_SIZE(bit_offset); + bit_offset = BTF_MEMBER_BIT_OFFSET(bit_offset); + } + jsonw_name(d->jw, btf__name_by_offset(d->btf, m[i].name_off)); - ret = btf_dumper_do_type(d, m[i].type, - BITS_PER_BYTE_MASKED(m[i].offset), - data_off); - if (ret) - break; + data_off = data + BITS_ROUNDDOWN_BYTES(bit_offset); + if (bitfield_size) { + btf_dumper_bitfield(bitfield_size, + BITS_PER_BYTE_MASKED(bit_offset), + data_off, d->jw, d->is_plain_text); + } else { + ret = btf_dumper_do_type(d, m[i].type, + BITS_PER_BYTE_MASKED(bit_offset), + data_off); + if (ret) + break; + } } jsonw_end_object(d->jw); @@ -237,7 +340,7 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id, case BTF_KIND_VOLATILE: case BTF_KIND_CONST: case BTF_KIND_RESTRICT: - return btf_dumper_modifier(d, type_id, data); + return btf_dumper_modifier(d, type_id, bit_offset, data); default: jsonw_printf(d->jw, "(unsupported-kind"); return -EINVAL; @@ -249,3 +352,206 @@ 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: + case BTF_KIND_TYPEDEF: + 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_FWD: + BTF_PRINT_ARG("%s %s ", + BTF_INFO_KFLAG(t->info) ? "union" : "struct", + btf__name_by_offset(btf, t->name_off)); + break; + 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; + case BTF_KIND_UNKN: + 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'; +} + +static const char *ltrim(const char *s) +{ + while (isspace(*s)) + s++; + + return s; +} + +void btf_dump_linfo_plain(const struct btf *btf, + const struct bpf_line_info *linfo, + const char *prefix, bool linum) +{ + const char *line = btf__name_by_offset(btf, linfo->line_off); + + if (!line) + return; + line = ltrim(line); + + if (!prefix) + prefix = ""; + + if (linum) { + const char *file = btf__name_by_offset(btf, linfo->file_name_off); + + /* More forgiving on file because linum option is + * expected to provide more info than the already + * available src line. + */ + if (!file) + file = ""; + + printf("%s%s [file:%s line_num:%u line_col:%u]\n", + prefix, line, file, + BPF_LINE_INFO_LINE_NUM(linfo->line_col), + BPF_LINE_INFO_LINE_COL(linfo->line_col)); + } else { + printf("%s%s\n", prefix, line); + } +} + +void btf_dump_linfo_json(const struct btf *btf, + const struct bpf_line_info *linfo, bool linum) +{ + const char *line = btf__name_by_offset(btf, linfo->line_off); + + if (line) + jsonw_string_field(json_wtr, "src", ltrim(line)); + + if (linum) { + const char *file = btf__name_by_offset(btf, linfo->file_name_off); + + if (file) + jsonw_string_field(json_wtr, "file", file); + + if (BPF_LINE_INFO_LINE_NUM(linfo->line_col)) + jsonw_int_field(json_wtr, "line_num", + BPF_LINE_INFO_LINE_NUM(linfo->line_col)); + + if (BPF_LINE_INFO_LINE_COL(linfo->line_col)) + jsonw_int_field(json_wtr, "line_col", + BPF_LINE_INFO_LINE_COL(linfo->line_col)); + } +} |