diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 259a6360475f..ffccb5af32a5 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -330,24 +330,35 @@ struct bpf_map { enum extern_type { EXT_UNKNOWN, - EXT_CHAR, - EXT_BOOL, - EXT_INT, - EXT_TRISTATE, - EXT_CHAR_ARR, + EXT_KCFG, +}; + +enum kcfg_type { + KCFG_UNKNOWN, + KCFG_CHAR, + KCFG_BOOL, + KCFG_INT, + KCFG_TRISTATE, + KCFG_CHAR_ARR, }; struct extern_desc { - const char *name; + enum extern_type type; int sym_idx; int btf_id; - enum extern_type type; - int sz; - int align; - int data_off; - bool is_signed; - bool is_weak; + int sec_btf_id; + const char *name; bool is_set; + bool is_weak; + union { + struct { + enum kcfg_type type; + int sz; + int align; + int data_off; + bool is_signed; + } kcfg; + }; }; static LIST_HEAD(bpf_objects_list); @@ -1424,19 +1435,19 @@ static struct extern_desc *find_extern_by_name(const struct bpf_object *obj, return NULL; } -static int set_ext_value_tri(struct extern_desc *ext, void *ext_val, - char value) +static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val, + char value) { - switch (ext->type) { - case EXT_BOOL: + switch (ext->kcfg.type) { + case KCFG_BOOL: if (value == 'm') { - pr_warn("extern %s=%c should be tristate or char\n", + pr_warn("extern (kcfg) %s=%c should be tristate or char\n", ext->name, value); return -EINVAL; } *(bool *)ext_val = value == 'y' ? true : false; break; - case EXT_TRISTATE: + case KCFG_TRISTATE: if (value == 'y') *(enum libbpf_tristate *)ext_val = TRI_YES; else if (value == 'm') @@ -1444,14 +1455,14 @@ static int set_ext_value_tri(struct extern_desc *ext, void *ext_val, else /* value == 'n' */ *(enum libbpf_tristate *)ext_val = TRI_NO; break; - case EXT_CHAR: + case KCFG_CHAR: *(char *)ext_val = value; break; - case EXT_UNKNOWN: - case EXT_INT: - case EXT_CHAR_ARR: + case KCFG_UNKNOWN: + case KCFG_INT: + case KCFG_CHAR_ARR: default: - pr_warn("extern %s=%c should be bool, tristate, or char\n", + pr_warn("extern (kcfg) %s=%c should be bool, tristate, or char\n", ext->name, value); return -EINVAL; } @@ -1459,29 +1470,29 @@ static int set_ext_value_tri(struct extern_desc *ext, void *ext_val, return 0; } -static int set_ext_value_str(struct extern_desc *ext, char *ext_val, - const char *value) +static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val, + const char *value) { size_t len; - if (ext->type != EXT_CHAR_ARR) { - pr_warn("extern %s=%s should char array\n", ext->name, value); + if (ext->kcfg.type != KCFG_CHAR_ARR) { + pr_warn("extern (kcfg) %s=%s should be char array\n", ext->name, value); return -EINVAL; } len = strlen(value); if (value[len - 1] != '"') { - pr_warn("extern '%s': invalid string config '%s'\n", + pr_warn("extern (kcfg) '%s': invalid string config '%s'\n", ext->name, value); return -EINVAL; } /* strip quotes */ len -= 2; - if (len >= ext->sz) { - pr_warn("extern '%s': long string config %s of (%zu bytes) truncated to %d bytes\n", - ext->name, value, len, ext->sz - 1); - len = ext->sz - 1; + if (len >= ext->kcfg.sz) { + pr_warn("extern (kcfg) '%s': long string config %s of (%zu bytes) truncated to %d bytes\n", + ext->name, value, len, ext->kcfg.sz - 1); + len = ext->kcfg.sz - 1; } memcpy(ext_val, value + 1, len); ext_val[len] = '\0'; @@ -1508,11 +1519,11 @@ static int parse_u64(const char *value, __u64 *res) return 0; } -static bool is_ext_value_in_range(const struct extern_desc *ext, __u64 v) +static bool is_kcfg_value_in_range(const struct extern_desc *ext, __u64 v) { - int bit_sz = ext->sz * 8; + int bit_sz = ext->kcfg.sz * 8; - if (ext->sz == 8) + if (ext->kcfg.sz == 8) return true; /* Validate that value stored in u64 fits in integer of `ext->sz` @@ -1527,26 +1538,26 @@ static bool is_ext_value_in_range(const struct extern_desc *ext, __u64 v) * For unsigned target integer, check that all the (64 - Y) bits are * zero. */ - if (ext->is_signed) + if (ext->kcfg.is_signed) return v + (1ULL << (bit_sz - 1)) < (1ULL << bit_sz); else return (v >> bit_sz) == 0; } -static int set_ext_value_num(struct extern_desc *ext, void *ext_val, - __u64 value) +static int set_kcfg_value_num(struct extern_desc *ext, void *ext_val, + __u64 value) { - if (ext->type != EXT_INT && ext->type != EXT_CHAR) { - pr_warn("extern %s=%llu should be integer\n", + if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) { + pr_warn("extern (kcfg) %s=%llu should be integer\n", ext->name, (unsigned long long)value); return -EINVAL; } - if (!is_ext_value_in_range(ext, value)) { - pr_warn("extern %s=%llu value doesn't fit in %d bytes\n", - ext->name, (unsigned long long)value, ext->sz); + if (!is_kcfg_value_in_range(ext, value)) { + pr_warn("extern (kcfg) %s=%llu value doesn't fit in %d bytes\n", + ext->name, (unsigned long long)value, ext->kcfg.sz); return -ERANGE; } - switch (ext->sz) { + switch (ext->kcfg.sz) { case 1: *(__u8 *)ext_val = value; break; case 2: *(__u16 *)ext_val = value; break; case 4: *(__u32 *)ext_val = value; break; @@ -1592,30 +1603,30 @@ static int bpf_object__process_kconfig_line(struct bpf_object *obj, if (!ext || ext->is_set) return 0; - ext_val = data + ext->data_off; + ext_val = data + ext->kcfg.data_off; value = sep + 1; switch (*value) { case 'y': case 'n': case 'm': - err = set_ext_value_tri(ext, ext_val, *value); + err = set_kcfg_value_tri(ext, ext_val, *value); break; case '"': - err = set_ext_value_str(ext, ext_val, value); + err = set_kcfg_value_str(ext, ext_val, value); break; default: /* assume integer */ err = parse_u64(value, &num); if (err) { - pr_warn("extern %s=%s should be integer\n", + pr_warn("extern (kcfg) %s=%s should be integer\n", ext->name, value); return err; } - err = set_ext_value_num(ext, ext_val, num); + err = set_kcfg_value_num(ext, ext_val, num); break; } if (err) return err; - pr_debug("extern %s=%s\n", ext->name, value); + pr_debug("extern (kcfg) %s=%s\n", ext->name, value); return 0; } @@ -1686,16 +1697,20 @@ static int bpf_object__read_kconfig_mem(struct bpf_object *obj, static int bpf_object__init_kconfig_map(struct bpf_object *obj) { - struct extern_desc *last_ext; + struct extern_desc *last_ext = NULL, *ext; size_t map_sz; - int err; + int i, err; - if (obj->nr_extern == 0) + for (i = 0; i < obj->nr_extern; i++) { + ext = &obj->externs[i]; + if (ext->type == EXT_KCFG) + last_ext = ext; + } + + if (!last_ext) return 0; - last_ext = &obj->externs[obj->nr_extern - 1]; - map_sz = last_ext->data_off + last_ext->sz; - + map_sz = last_ext->kcfg.data_off + last_ext->kcfg.sz; err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG, obj->efile.symbols_shndx, NULL, map_sz); @@ -2714,8 +2729,33 @@ static int find_extern_btf_id(const struct btf *btf, const char *ext_name) return -ENOENT; } -static enum extern_type find_extern_type(const struct btf *btf, int id, - bool *is_signed) +static int find_extern_sec_btf_id(struct btf *btf, int ext_btf_id) { + const struct btf_var_secinfo *vs; + const struct btf_type *t; + int i, j, n; + + if (!btf) + return -ESRCH; + + n = btf__get_nr_types(btf); + for (i = 1; i <= n; i++) { + t = btf__type_by_id(btf, i); + + if (!btf_is_datasec(t)) + continue; + + vs = btf_var_secinfos(t); + for (j = 0; j < btf_vlen(t); j++, vs++) { + if (vs->type == ext_btf_id) + return i; + } + } + + return -ENOENT; +} + +static enum kcfg_type find_kcfg_type(const struct btf *btf, int id, + bool *is_signed) { const struct btf_type *t; const char *name; @@ -2730,29 +2770,29 @@ static enum extern_type find_extern_type(const struct btf *btf, int id, int enc = btf_int_encoding(t); if (enc & BTF_INT_BOOL) - return t->size == 1 ? EXT_BOOL : EXT_UNKNOWN; + return t->size == 1 ? KCFG_BOOL : KCFG_UNKNOWN; if (is_signed) *is_signed = enc & BTF_INT_SIGNED; if (t->size == 1) - return EXT_CHAR; + return KCFG_CHAR; if (t->size < 1 || t->size > 8 || (t->size & (t->size - 1))) - return EXT_UNKNOWN; - return EXT_INT; + return KCFG_UNKNOWN; + return KCFG_INT; } case BTF_KIND_ENUM: if (t->size != 4) - return EXT_UNKNOWN; + return KCFG_UNKNOWN; if (strcmp(name, "libbpf_tristate")) - return EXT_UNKNOWN; - return EXT_TRISTATE; + return KCFG_UNKNOWN; + return KCFG_TRISTATE; case BTF_KIND_ARRAY: if (btf_array(t)->nelems == 0) - return EXT_UNKNOWN; - if (find_extern_type(btf, btf_array(t)->type, NULL) != EXT_CHAR) - return EXT_UNKNOWN; - return EXT_CHAR_ARR; + return KCFG_UNKNOWN; + if (find_kcfg_type(btf, btf_array(t)->type, NULL) != KCFG_CHAR) + return KCFG_UNKNOWN; + return KCFG_CHAR_ARR; default: - return EXT_UNKNOWN; + return KCFG_UNKNOWN; } } @@ -2761,23 +2801,29 @@ static int cmp_externs(const void *_a, const void *_b) const struct extern_desc *a = _a; const struct extern_desc *b = _b; - /* descending order by alignment requirements */ - if (a->align != b->align) - return a->align > b->align ? -1 : 1; - /* ascending order by size, within same alignment class */ - if (a->sz != b->sz) - return a->sz < b->sz ? -1 : 1; + if (a->type != b->type) + return a->type < b->type ? -1 : 1; + + if (a->type == EXT_KCFG) { + /* descending order by alignment requirements */ + if (a->kcfg.align != b->kcfg.align) + return a->kcfg.align > b->kcfg.align ? -1 : 1; + /* ascending order by size, within same alignment class */ + if (a->kcfg.sz != b->kcfg.sz) + return a->kcfg.sz < b->kcfg.sz ? -1 : 1; + } + /* resolve ties by name */ return strcmp(a->name, b->name); } static int bpf_object__collect_externs(struct bpf_object *obj) { + struct btf_type *sec, *kcfg_sec = NULL; const struct btf_type *t; struct extern_desc *ext; - int i, n, off, btf_id; - struct btf_type *sec; - const char *ext_name; + int i, n, off; + const char *ext_name, *sec_name; Elf_Scn *scn; GElf_Shdr sh; @@ -2823,22 +2869,39 @@ static int bpf_object__collect_externs(struct bpf_object *obj) ext->name = btf__name_by_offset(obj->btf, t->name_off); ext->sym_idx = i; ext->is_weak = GELF_ST_BIND(sym.st_info) == STB_WEAK; - ext->sz = btf__resolve_size(obj->btf, t->type); - if (ext->sz <= 0) { - pr_warn("failed to resolve size of extern '%s': %d\n", - ext_name, ext->sz); - return ext->sz; + + ext->sec_btf_id = find_extern_sec_btf_id(obj->btf, ext->btf_id); + if (ext->sec_btf_id <= 0) { + pr_warn("failed to find BTF for extern '%s' [%d] section: %d\n", + ext_name, ext->btf_id, ext->sec_btf_id); + return ext->sec_btf_id; } - ext->align = btf__align_of(obj->btf, t->type); - if (ext->align <= 0) { - pr_warn("failed to determine alignment of extern '%s': %d\n", - ext_name, ext->align); - return -EINVAL; - } - ext->type = find_extern_type(obj->btf, t->type, - &ext->is_signed); - if (ext->type == EXT_UNKNOWN) { - pr_warn("extern '%s' type is unsupported\n", ext_name); + sec = (void *)btf__type_by_id(obj->btf, ext->sec_btf_id); + sec_name = btf__name_by_offset(obj->btf, sec->name_off); + + if (strcmp(sec_name, KCONFIG_SEC) == 0) { + kcfg_sec = sec; + ext->type = EXT_KCFG; + ext->kcfg.sz = btf__resolve_size(obj->btf, t->type); + if (ext->kcfg.sz <= 0) { + pr_warn("failed to resolve size of extern (kcfg) '%s': %d\n", + ext_name, ext->kcfg.sz); + return ext->kcfg.sz; + } + ext->kcfg.align = btf__align_of(obj->btf, t->type); + if (ext->kcfg.align <= 0) { + pr_warn("failed to determine alignment of extern (kcfg) '%s': %d\n", + ext_name, ext->kcfg.align); + return -EINVAL; + } + ext->kcfg.type = find_kcfg_type(obj->btf, t->type, + &ext->kcfg.is_signed); + if (ext->kcfg.type == KCFG_UNKNOWN) { + pr_warn("extern (kcfg) '%s' type is unsupported\n", ext_name); + return -ENOTSUP; + } + } else { + pr_warn("unrecognized extern section '%s'\n", sec_name); return -ENOTSUP; } } @@ -2847,42 +2910,40 @@ static int bpf_object__collect_externs(struct bpf_object *obj) if (!obj->nr_extern) return 0; - /* sort externs by (alignment, size, name) and calculate their offsets - * within a map */ + /* sort externs by type, for kcfg ones also by (align, size, name) */ qsort(obj->externs, obj->nr_extern, sizeof(*ext), cmp_externs); - off = 0; - for (i = 0; i < obj->nr_extern; i++) { - ext = &obj->externs[i]; - ext->data_off = roundup(off, ext->align); - off = ext->data_off + ext->sz; - pr_debug("extern #%d: symbol %d, off %u, name %s\n", - i, ext->sym_idx, ext->data_off, ext->name); - } - btf_id = btf__find_by_name(obj->btf, KCONFIG_SEC); - if (btf_id <= 0) { - pr_warn("no BTF info found for '%s' datasec\n", KCONFIG_SEC); - return -ESRCH; - } + if (kcfg_sec) { + sec = kcfg_sec; + /* for kcfg externs calculate their offsets within a .kconfig map */ + off = 0; + for (i = 0; i < obj->nr_extern; i++) { + ext = &obj->externs[i]; + if (ext->type != EXT_KCFG) + continue; - sec = (struct btf_type *)btf__type_by_id(obj->btf, btf_id); - sec->size = off; - n = btf_vlen(sec); - for (i = 0; i < n; i++) { - struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i; - - t = btf__type_by_id(obj->btf, vs->type); - ext_name = btf__name_by_offset(obj->btf, t->name_off); - ext = find_extern_by_name(obj, ext_name); - if (!ext) { - pr_warn("failed to find extern definition for BTF var '%s'\n", - ext_name); - return -ESRCH; + ext->kcfg.data_off = roundup(off, ext->kcfg.align); + off = ext->kcfg.data_off + ext->kcfg.sz; + pr_debug("extern #%d (kcfg): symbol %d, off %u, name %s\n", + i, ext->sym_idx, ext->kcfg.data_off, ext->name); } - vs->offset = ext->data_off; - btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED; - } + sec->size = off; + n = btf_vlen(sec); + for (i = 0; i < n; i++) { + struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i; + t = btf__type_by_id(obj->btf, vs->type); + ext_name = btf__name_by_offset(obj->btf, t->name_off); + ext = find_extern_by_name(obj, ext_name); + if (!ext) { + pr_warn("failed to find extern definition for BTF var '%s'\n", + ext_name); + return -ESRCH; + } + btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED; + vs->offset = ext->kcfg.data_off; + } + } return 0; } @@ -3012,11 +3073,11 @@ static int bpf_program__record_reloc(struct bpf_program *prog, sym_idx); return -LIBBPF_ERRNO__RELOC; } - pr_debug("found extern #%d '%s' (sym %d, off %u) for insn %u\n", - i, ext->name, ext->sym_idx, ext->data_off, insn_idx); + pr_debug("found extern #%d '%s' (sym %d) for insn %u\n", + i, ext->name, ext->sym_idx, insn_idx); reloc_desc->type = RELO_EXTERN; reloc_desc->insn_idx = insn_idx; - reloc_desc->sym_off = ext->data_off; + reloc_desc->sym_off = i; /* sym_off stores extern index */ return 0; } @@ -4941,6 +5002,7 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) for (i = 0; i < prog->nr_reloc; i++) { struct reloc_desc *relo = &prog->reloc_desc[i]; struct bpf_insn *insn = &prog->insns[relo->insn_idx]; + struct extern_desc *ext; if (relo->insn_idx + 1 >= (int)prog->insns_cnt) { pr_warn("relocation out of range: '%s'\n", @@ -4959,9 +5021,10 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) insn[0].imm = obj->maps[relo->map_idx].fd; break; case RELO_EXTERN: + ext = &obj->externs[relo->sym_off]; insn[0].src_reg = BPF_PSEUDO_MAP_VALUE; insn[0].imm = obj->maps[obj->kconfig_map_idx].fd; - insn[1].imm = relo->sym_off; + insn[1].imm = ext->kcfg.data_off; break; case RELO_CALL: err = bpf_program__reloc_text(prog, obj, relo); @@ -5585,30 +5648,33 @@ static int bpf_object__resolve_externs(struct bpf_object *obj, { bool need_config = false; struct extern_desc *ext; + void *kcfg_data = NULL; int err, i; - void *data; if (obj->nr_extern == 0) return 0; - data = obj->maps[obj->kconfig_map_idx].mmaped; + if (obj->kconfig_map_idx >= 0) + kcfg_data = obj->maps[obj->kconfig_map_idx].mmaped; for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; - if (strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { - void *ext_val = data + ext->data_off; + if (ext->type == EXT_KCFG && + strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { + void *ext_val = kcfg_data + ext->kcfg.data_off; __u32 kver = get_kernel_version(); if (!kver) { pr_warn("failed to get kernel version\n"); return -EINVAL; } - err = set_ext_value_num(ext, ext_val, kver); + err = set_kcfg_value_num(ext, ext_val, kver); if (err) return err; - pr_debug("extern %s=0x%x\n", ext->name, kver); - } else if (strncmp(ext->name, "CONFIG_", 7) == 0) { + pr_debug("extern (kcfg) %s=0x%x\n", ext->name, kver); + } else if (ext->type == EXT_KCFG && + strncmp(ext->name, "CONFIG_", 7) == 0) { need_config = true; } else { pr_warn("unrecognized extern '%s'\n", ext->name); @@ -5616,20 +5682,20 @@ static int bpf_object__resolve_externs(struct bpf_object *obj, } } if (need_config && extra_kconfig) { - err = bpf_object__read_kconfig_mem(obj, extra_kconfig, data); + err = bpf_object__read_kconfig_mem(obj, extra_kconfig, kcfg_data); if (err) return -EINVAL; need_config = false; for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; - if (!ext->is_set) { + if (ext->type == EXT_KCFG && !ext->is_set) { need_config = true; break; } } } if (need_config) { - err = bpf_object__read_kconfig_file(obj, data); + err = bpf_object__read_kconfig_file(obj, kcfg_data); if (err) return -EINVAL; }