diff options
Diffstat (limited to 'kernel/bpf/btf.c')
| -rw-r--r-- | kernel/bpf/btf.c | 393 |
1 files changed, 348 insertions, 45 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index bf34933cc413..715f9fcf4712 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -164,7 +164,7 @@ #define BITS_ROUNDUP_BYTES(bits) \ (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) -#define BTF_INFO_MASK 0x0f00ffff +#define BTF_INFO_MASK 0x8f00ffff #define BTF_INT_MASK 0x0fffffff #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) @@ -274,6 +274,10 @@ struct btf_kind_operations { const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type); + int (*check_kflag_member)(struct btf_verifier_env *env, + const struct btf_type *struct_type, + const struct btf_member *member, + const struct btf_type *member_type); void (*log_details)(struct btf_verifier_env *env, const struct btf_type *t); void (*seq_show)(const struct btf *btf, const struct btf_type *t, @@ -419,6 +423,25 @@ static u16 btf_type_vlen(const struct btf_type *t) return BTF_INFO_VLEN(t->info); } +static bool btf_type_kflag(const struct btf_type *t) +{ + return BTF_INFO_KFLAG(t->info); +} + +static u32 btf_member_bit_offset(const struct btf_type *struct_type, + const struct btf_member *member) +{ + return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset) + : member->offset; +} + +static u32 btf_member_bitfield_size(const struct btf_type *struct_type, + const struct btf_member *member) +{ + return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset) + : 0; +} + static u32 btf_type_int(const struct btf_type *t) { return *(u32 *)(t + 1); @@ -474,7 +497,7 @@ static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) return !*src; } -const char *btf_name_by_offset(const struct btf *btf, u32 offset) +static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) { if (!offset) return "(anon)"; @@ -484,6 +507,14 @@ const char *btf_name_by_offset(const struct btf *btf, u32 offset) return "(invalid-name-offset)"; } +const char *btf_name_by_offset(const struct btf *btf, u32 offset) +{ + if (offset < btf->hdr.str_len) + return &btf->strings[offset]; + + return NULL; +} + const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) { if (type_id > btf->nr_types) @@ -514,6 +545,47 @@ static bool btf_type_int_is_regular(const struct btf_type *t) return true; } +/* + * Check that given struct member is a regular int with expected + * offset and size. + */ +bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, + const struct btf_member *m, + u32 expected_offset, u32 expected_size) +{ + const struct btf_type *t; + u32 id, int_data; + u8 nr_bits; + + id = m->type; + t = btf_type_id_size(btf, &id, NULL); + if (!t || !btf_type_is_int(t)) + return false; + + int_data = btf_type_int(t); + nr_bits = BTF_INT_BITS(int_data); + if (btf_type_kflag(s)) { + u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); + u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); + + /* if kflag set, int should be a regular int and + * bit offset should be at byte boundary. + */ + return !bitfield_size && + BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && + BITS_ROUNDUP_BYTES(nr_bits) == expected_size; + } + + if (BTF_INT_OFFSET(int_data) || + BITS_PER_BYTE_MASKED(m->offset) || + BITS_ROUNDUP_BYTES(m->offset) != expected_offset || + BITS_PER_BYTE_MASKED(nr_bits) || + BITS_ROUNDUP_BYTES(nr_bits) != expected_size) + return false; + + return true; +} + __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, const char *fmt, ...) { @@ -554,7 +626,7 @@ __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, __btf_verifier_log(log, "[%u] %s %s%s", env->log_type_id, btf_kind_str[kind], - btf_name_by_offset(btf, t->name_off), + __btf_name_by_offset(btf, t->name_off), log_details ? " " : ""); if (log_details) @@ -597,9 +669,17 @@ static void btf_verifier_log_member(struct btf_verifier_env *env, if (env->phase != CHECK_META) btf_verifier_log_type(env, struct_type, NULL); - __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", - btf_name_by_offset(btf, member->name_off), - member->type, member->offset); + if (btf_type_kflag(struct_type)) + __btf_verifier_log(log, + "\t%s type_id=%u bitfield_size=%u bits_offset=%u", + __btf_name_by_offset(btf, member->name_off), + member->type, + BTF_MEMBER_BITFIELD_SIZE(member->offset), + BTF_MEMBER_BIT_OFFSET(member->offset)); + else + __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", + __btf_name_by_offset(btf, member->name_off), + member->type, member->offset); if (fmt && *fmt) { __btf_verifier_log(log, " "); @@ -915,6 +995,38 @@ static int btf_df_check_member(struct btf_verifier_env *env, return -EINVAL; } +static int btf_df_check_kflag_member(struct btf_verifier_env *env, + const struct btf_type *struct_type, + const struct btf_member *member, + const struct btf_type *member_type) +{ + btf_verifier_log_basic(env, struct_type, + "Unsupported check_kflag_member"); + return -EINVAL; +} + +/* Used for ptr, array and struct/union type members. + * int, enum and modifier types have their specific callback functions. + */ +static int btf_generic_check_kflag_member(struct btf_verifier_env *env, + const struct btf_type *struct_type, + const struct btf_member *member, + const struct btf_type *member_type) +{ + if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { + btf_verifier_log_member(env, struct_type, member, + "Invalid member bitfield_size"); + return -EINVAL; + } + + /* bitfield size is 0, so member->offset represents bit offset only. + * It is safe to call non kflag check_member variants. + */ + return btf_type_ops(member_type)->check_member(env, struct_type, + member, + member_type); +} + static int btf_df_resolve(struct btf_verifier_env *env, const struct resolve_vertex *v) { @@ -967,6 +1079,62 @@ static int btf_int_check_member(struct btf_verifier_env *env, return 0; } +static int btf_int_check_kflag_member(struct btf_verifier_env *env, + const struct btf_type *struct_type, + const struct btf_member *member, + const struct btf_type *member_type) +{ + u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; + u32 int_data = btf_type_int(member_type); + u32 struct_size = struct_type->size; + u32 nr_copy_bits; + + /* a regular int type is required for the kflag int member */ + if (!btf_type_int_is_regular(member_type)) { + btf_verifier_log_member(env, struct_type, member, + "Invalid member base type"); + return -EINVAL; + } + + /* check sanity of bitfield size */ + nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); + struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); + nr_int_data_bits = BTF_INT_BITS(int_data); + if (!nr_bits) { + /* Not a bitfield member, member offset must be at byte + * boundary. + */ + if (BITS_PER_BYTE_MASKED(struct_bits_off)) { + btf_verifier_log_member(env, struct_type, member, + "Invalid member offset"); + return -EINVAL; + } + + nr_bits = nr_int_data_bits; + } else if (nr_bits > nr_int_data_bits) { + btf_verifier_log_member(env, struct_type, member, + "Invalid member bitfield_size"); + return -EINVAL; + } + + bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); + nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); + if (nr_copy_bits > BITS_PER_U64) { + btf_verifier_log_member(env, struct_type, member, + "nr_copy_bits exceeds 64"); + return -EINVAL; + } + + if (struct_size < bytes_offset || + struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { + btf_verifier_log_member(env, struct_type, member, + "Member exceeds struct_size"); + return -EINVAL; + } + + return 0; +} + static s32 btf_int_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) @@ -986,6 +1154,11 @@ static s32 btf_int_check_meta(struct btf_verifier_env *env, return -EINVAL; } + if (btf_type_kflag(t)) { + btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); + return -EINVAL; + } + int_data = btf_type_int(t); if (int_data & ~BTF_INT_MASK) { btf_verifier_log_basic(env, t, "Invalid int_data:%x", @@ -1038,26 +1211,16 @@ static void btf_int_log(struct btf_verifier_env *env, btf_int_encoding_str(BTF_INT_ENCODING(int_data))); } -static void btf_int_bits_seq_show(const struct btf *btf, - const struct btf_type *t, - void *data, u8 bits_offset, - struct seq_file *m) +static void btf_bitfield_seq_show(void *data, u8 bits_offset, + u8 nr_bits, struct seq_file *m) { u16 left_shift_bits, right_shift_bits; - u32 int_data = btf_type_int(t); - u8 nr_bits = BTF_INT_BITS(int_data); - u8 total_bits_offset; u8 nr_copy_bytes; u8 nr_copy_bits; u64 print_num; - /* - * bits_offset is at most 7. - * BTF_INT_OFFSET() cannot exceed 64 bits. - */ - total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); - data += BITS_ROUNDDOWN_BYTES(total_bits_offset); - bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); + data += BITS_ROUNDDOWN_BYTES(bits_offset); + bits_offset = BITS_PER_BYTE_MASKED(bits_offset); nr_copy_bits = nr_bits + bits_offset; nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); @@ -1077,6 +1240,24 @@ static void btf_int_bits_seq_show(const struct btf *btf, seq_printf(m, "0x%llx", print_num); } + +static void btf_int_bits_seq_show(const struct btf *btf, + const struct btf_type *t, + void *data, u8 bits_offset, + struct seq_file *m) +{ + u32 int_data = btf_type_int(t); + u8 nr_bits = BTF_INT_BITS(int_data); + u8 total_bits_offset; + + /* + * bits_offset is at most 7. + * BTF_INT_OFFSET() cannot exceed 64 bits. + */ + total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); + btf_bitfield_seq_show(data, total_bits_offset, nr_bits, m); +} + static void btf_int_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) @@ -1126,6 +1307,7 @@ static const struct btf_kind_operations int_ops = { .check_meta = btf_int_check_meta, .resolve = btf_df_resolve, .check_member = btf_int_check_member, + .check_kflag_member = btf_int_check_kflag_member, .log_details = btf_int_log, .seq_show = btf_int_seq_show, }; @@ -1155,6 +1337,31 @@ static int btf_modifier_check_member(struct btf_verifier_env *env, resolved_type); } +static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, + const struct btf_type *struct_type, + const struct btf_member *member, + const struct btf_type *member_type) +{ + const struct btf_type *resolved_type; + u32 resolved_type_id = member->type; + struct btf_member resolved_member; + struct btf *btf = env->btf; + + resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); + if (!resolved_type) { + btf_verifier_log_member(env, struct_type, member, + "Invalid member"); + return -EINVAL; + } + + resolved_member = *member; + resolved_member.type = resolved_type_id; + + return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, + &resolved_member, + resolved_type); +} + static int btf_ptr_check_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, @@ -1190,6 +1397,11 @@ static int btf_ref_type_check_meta(struct btf_verifier_env *env, return -EINVAL; } + if (btf_type_kflag(t)) { + btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); + return -EINVAL; + } + if (!BTF_TYPE_ID_VALID(t->type)) { btf_verifier_log_type(env, t, "Invalid type_id"); return -EINVAL; @@ -1343,6 +1555,7 @@ static struct btf_kind_operations modifier_ops = { .check_meta = btf_ref_type_check_meta, .resolve = btf_modifier_resolve, .check_member = btf_modifier_check_member, + .check_kflag_member = btf_modifier_check_kflag_member, .log_details = btf_ref_type_log, .seq_show = btf_modifier_seq_show, }; @@ -1351,6 +1564,7 @@ static struct btf_kind_operations ptr_ops = { .check_meta = btf_ref_type_check_meta, .resolve = btf_ptr_resolve, .check_member = btf_ptr_check_member, + .check_kflag_member = btf_generic_check_kflag_member, .log_details = btf_ref_type_log, .seq_show = btf_ptr_seq_show, }; @@ -1381,11 +1595,18 @@ static s32 btf_fwd_check_meta(struct btf_verifier_env *env, return 0; } +static void btf_fwd_type_log(struct btf_verifier_env *env, + const struct btf_type *t) +{ + btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); +} + static struct btf_kind_operations fwd_ops = { .check_meta = btf_fwd_check_meta, .resolve = btf_df_resolve, .check_member = btf_df_check_member, - .log_details = btf_ref_type_log, + .check_kflag_member = btf_df_check_kflag_member, + .log_details = btf_fwd_type_log, .seq_show = btf_df_seq_show, }; @@ -1443,6 +1664,11 @@ static s32 btf_array_check_meta(struct btf_verifier_env *env, return -EINVAL; } + if (btf_type_kflag(t)) { + btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); + return -EINVAL; + } + if (t->size) { btf_verifier_log_type(env, t, "size != 0"); return -EINVAL; @@ -1566,6 +1792,7 @@ static struct btf_kind_operations array_ops = { .check_meta = btf_array_check_meta, .resolve = btf_array_resolve, .check_member = btf_array_check_member, + .check_kflag_member = btf_generic_check_kflag_member, .log_details = btf_array_log, .seq_show = btf_array_seq_show, }; @@ -1604,6 +1831,7 @@ static s32 btf_struct_check_meta(struct btf_verifier_env *env, u32 meta_needed, last_offset; struct btf *btf = env->btf; u32 struct_size = t->size; + u32 offset; u16 i; meta_needed = btf_type_vlen(t) * sizeof(*member); @@ -1645,7 +1873,8 @@ static s32 btf_struct_check_meta(struct btf_verifier_env *env, return -EINVAL; } - if (is_union && member->offset) { + offset = btf_member_bit_offset(t, member); + if (is_union && offset) { btf_verifier_log_member(env, t, member, "Invalid member bits_offset"); return -EINVAL; @@ -1655,20 +1884,20 @@ static s32 btf_struct_check_meta(struct btf_verifier_env *env, * ">" instead of ">=" because the last member could be * "char a[0];" */ - if (last_offset > member->offset) { + if (last_offset > offset) { btf_verifier_log_member(env, t, member, "Invalid member bits_offset"); return -EINVAL; } - if (BITS_ROUNDUP_BYTES(member->offset) > struct_size) { + if (BITS_ROUNDUP_BYTES(offset) > struct_size) { btf_verifier_log_member(env, t, member, "Member bits_offset exceeds its struct size"); return -EINVAL; } btf_verifier_log_member(env, t, member, NULL); - last_offset = member->offset; + last_offset = offset; } return meta_needed; @@ -1698,9 +1927,14 @@ static int btf_struct_resolve(struct btf_verifier_env *env, last_member_type = btf_type_by_id(env->btf, last_member_type_id); - err = btf_type_ops(last_member_type)->check_member(env, v->t, - last_member, - last_member_type); + if (btf_type_kflag(v->t)) + err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, + last_member, + last_member_type); + else + err = btf_type_ops(last_member_type)->check_member(env, v->t, + last_member, + last_member_type); if (err) return err; } @@ -1722,9 +1956,14 @@ static int btf_struct_resolve(struct btf_verifier_env *env, return env_stack_push(env, member_type, member_type_id); } - err = btf_type_ops(member_type)->check_member(env, v->t, - member, - member_type); + if (btf_type_kflag(v->t)) + err = btf_type_ops(member_type)->check_kflag_member(env, v->t, + member, + member_type); + else + err = btf_type_ops(member_type)->check_member(env, v->t, + member, + member_type); if (err) return err; } @@ -1752,17 +1991,26 @@ static void btf_struct_seq_show(const struct btf *btf, const struct btf_type *t, for_each_member(i, t, member) { const struct btf_type *member_type = btf_type_by_id(btf, member->type); - u32 member_offset = member->offset; - u32 bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); - u8 bits8_offset = BITS_PER_BYTE_MASKED(member_offset); const struct btf_kind_operations *ops; + u32 member_offset, bitfield_size; + u32 bytes_offset; + u8 bits8_offset; if (i) seq_puts(m, seq); - ops = btf_type_ops(member_type); - ops->seq_show(btf, member_type, member->type, - data + bytes_offset, bits8_offset, m); + member_offset = btf_member_bit_offset(t, member); + bitfield_size = btf_member_bitfield_size(t, member); + if (bitfield_size) { + btf_bitfield_seq_show(data, member_offset, + bitfield_size, m); + } else { + bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); + bits8_offset = BITS_PER_BYTE_MASKED(member_offset); + ops = btf_type_ops(member_type); + ops->seq_show(btf, member_type, member->type, + data + bytes_offset, bits8_offset, m); + } } seq_puts(m, "}"); } @@ -1771,6 +2019,7 @@ static struct btf_kind_operations struct_ops = { .check_meta = btf_struct_check_meta, .resolve = btf_struct_resolve, .check_member = btf_struct_check_member, + .check_kflag_member = btf_generic_check_kflag_member, .log_details = btf_struct_log, .seq_show = btf_struct_seq_show, }; @@ -1800,6 +2049,41 @@ static int btf_enum_check_member(struct btf_verifier_env *env, return 0; } +static int btf_enum_check_kflag_member(struct btf_verifier_env *env, + const struct btf_type *struct_type, + const struct btf_member *member, + const struct btf_type *member_type) +{ + u32 struct_bits_off, nr_bits, bytes_end, struct_size; + u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; + + struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); + nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); + if (!nr_bits) { + if (BITS_PER_BYTE_MASKED(struct_bits_off)) { + btf_verifier_log_member(env, struct_type, member, + "Member is not byte aligned"); + return -EINVAL; + } + + nr_bits = int_bitsize; + } else if (nr_bits > int_bitsize) { + btf_verifier_log_member(env, struct_type, member, + "Invalid member bitfield_size"); + return -EINVAL; + } + + struct_size = struct_type->size; + bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); + if (struct_size < bytes_end) { + btf_verifier_log_member(env, struct_type, member, + "Member exceeds struct_size"); + return -EINVAL; + } + + return 0; +} + static s32 btf_enum_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) @@ -1819,6 +2103,11 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env, return -EINVAL; } + if (btf_type_kflag(t)) { + btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); + return -EINVAL; + } + if (t->size != sizeof(int)) { btf_verifier_log_type(env, t, "Expected size:%zu", sizeof(int)); @@ -1850,7 +2139,7 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env, btf_verifier_log(env, "\t%s val=%d\n", - btf_name_by_offset(btf, enums[i].name_off), + __btf_name_by_offset(btf, enums[i].name_off), enums[i].val); } @@ -1874,7 +2163,8 @@ static void btf_enum_seq_show(const struct btf *btf, const struct btf_type *t, for (i = 0; i < nr_enums; i++) { if (v == enums[i].val) { seq_printf(m, "%s", - btf_name_by_offset(btf, enums[i].name_off)); + __btf_name_by_offset(btf, + enums[i].name_off)); return; } } @@ -1886,6 +2176,7 @@ static struct btf_kind_operations enum_ops = { .check_meta = btf_enum_check_meta, .resolve = btf_df_resolve, .check_member = btf_enum_check_member, + .check_kflag_member = btf_enum_check_kflag_member, .log_details = btf_enum_log, .seq_show = btf_enum_seq_show, }; @@ -1908,6 +2199,11 @@ static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, return -EINVAL; } + if (btf_type_kflag(t)) { + btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); + return -EINVAL; + } + btf_verifier_log_type(env, t, NULL); return meta_needed; @@ -1932,20 +2228,20 @@ static void btf_func_proto_log(struct btf_verifier_env *env, } btf_verifier_log(env, "%u %s", args[0].type, - btf_name_by_offset(env->btf, - args[0].name_off)); + __btf_name_by_offset(env->btf, + args[0].name_off)); for (i = 1; i < nr_args - 1; i++) btf_verifier_log(env, ", %u %s", args[i].type, - btf_name_by_offset(env->btf, - args[i].name_off)); + __btf_name_by_offset(env->btf, + args[i].name_off)); if (nr_args > 1) { const struct btf_param *last_arg = &args[nr_args - 1]; if (last_arg->type) btf_verifier_log(env, ", %u %s", last_arg->type, - btf_name_by_offset(env->btf, - last_arg->name_off)); + __btf_name_by_offset(env->btf, + last_arg->name_off)); else btf_verifier_log(env, ", vararg"); } @@ -1967,6 +2263,7 @@ static struct btf_kind_operations func_proto_ops = { * Hence, there is no btf_func_check_member(). */ .check_member = btf_df_check_member, + .check_kflag_member = btf_df_check_kflag_member, .log_details = btf_func_proto_log, .seq_show = btf_df_seq_show, }; @@ -1986,6 +2283,11 @@ static s32 btf_func_check_meta(struct btf_verifier_env *env, return -EINVAL; } + if (btf_type_kflag(t)) { + btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); + return -EINVAL; + } + btf_verifier_log_type(env, t, NULL); return 0; @@ -1995,6 +2297,7 @@ static struct btf_kind_operations func_ops = { .check_meta = btf_func_check_meta, .resolve = btf_df_resolve, .check_member = btf_df_check_member, + .check_kflag_member = btf_df_check_kflag_member, .log_details = btf_ref_type_log, .seq_show = btf_df_seq_show, }; |