diff options
Diffstat (limited to 'tools/lib/bpf/relo_core.c')
| -rw-r--r-- | tools/lib/bpf/relo_core.c | 479 |
1 files changed, 431 insertions, 48 deletions
diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c index ba4453dfd1ed..c4b0e81ae293 100644 --- a/tools/lib/bpf/relo_core.c +++ b/tools/lib/bpf/relo_core.c @@ -95,6 +95,7 @@ static const char *core_relo_kind_str(enum bpf_core_relo_kind kind) case BPF_CORE_TYPE_ID_LOCAL: return "local_type_id"; case BPF_CORE_TYPE_ID_TARGET: return "target_type_id"; case BPF_CORE_TYPE_EXISTS: return "type_exists"; + case BPF_CORE_TYPE_MATCHES: return "type_matches"; case BPF_CORE_TYPE_SIZE: return "type_size"; case BPF_CORE_ENUMVAL_EXISTS: return "enumval_exists"; case BPF_CORE_ENUMVAL_VALUE: return "enumval_value"; @@ -123,6 +124,7 @@ static bool core_relo_is_type_based(enum bpf_core_relo_kind kind) case BPF_CORE_TYPE_ID_LOCAL: case BPF_CORE_TYPE_ID_TARGET: case BPF_CORE_TYPE_EXISTS: + case BPF_CORE_TYPE_MATCHES: case BPF_CORE_TYPE_SIZE: return true; default: @@ -141,6 +143,86 @@ static bool core_relo_is_enumval_based(enum bpf_core_relo_kind kind) } } +int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, + const struct btf *targ_btf, __u32 targ_id, int level) +{ + const struct btf_type *local_type, *targ_type; + int depth = 32; /* max recursion depth */ + + /* caller made sure that names match (ignoring flavor suffix) */ + local_type = btf_type_by_id(local_btf, local_id); + targ_type = btf_type_by_id(targ_btf, targ_id); + if (!btf_kind_core_compat(local_type, targ_type)) + return 0; + +recur: + depth--; + if (depth < 0) + return -EINVAL; + + local_type = skip_mods_and_typedefs(local_btf, local_id, &local_id); + targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id); + if (!local_type || !targ_type) + return -EINVAL; + + if (!btf_kind_core_compat(local_type, targ_type)) + return 0; + + switch (btf_kind(local_type)) { + case BTF_KIND_UNKN: + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + case BTF_KIND_ENUM: + case BTF_KIND_FWD: + case BTF_KIND_ENUM64: + return 1; + case BTF_KIND_INT: + /* just reject deprecated bitfield-like integers; all other + * integers are by default compatible between each other + */ + return btf_int_offset(local_type) == 0 && btf_int_offset(targ_type) == 0; + case BTF_KIND_PTR: + local_id = local_type->type; + targ_id = targ_type->type; + goto recur; + case BTF_KIND_ARRAY: + local_id = btf_array(local_type)->type; + targ_id = btf_array(targ_type)->type; + goto recur; + case BTF_KIND_FUNC_PROTO: { + struct btf_param *local_p = btf_params(local_type); + struct btf_param *targ_p = btf_params(targ_type); + __u16 local_vlen = btf_vlen(local_type); + __u16 targ_vlen = btf_vlen(targ_type); + int i, err; + + if (local_vlen != targ_vlen) + return 0; + + for (i = 0; i < local_vlen; i++, local_p++, targ_p++) { + if (level <= 0) + return -EINVAL; + + skip_mods_and_typedefs(local_btf, local_p->type, &local_id); + skip_mods_and_typedefs(targ_btf, targ_p->type, &targ_id); + err = __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, + level - 1); + if (err <= 0) + return err; + } + + /* tail recurse for return type check */ + skip_mods_and_typedefs(local_btf, local_type->type, &local_id); + skip_mods_and_typedefs(targ_btf, targ_type->type, &targ_id); + goto recur; + } + default: + pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n", + btf_kind_str(local_type), local_id, targ_id); + return 0; + } +} + /* * Turn bpf_core_relo into a low- and high-level spec representation, * validating correctness along the way, as well as calculating resulting @@ -167,11 +249,11 @@ static bool core_relo_is_enumval_based(enum bpf_core_relo_kind kind) * just a parsed access string representation): [0, 1, 2, 3]. * * High-level spec will capture only 3 points: - * - intial zero-index access by pointer (&s->... is the same as &s[0]...); + * - initial zero-index access by pointer (&s->... is the same as &s[0]...); * - field 'a' access (corresponds to '2' in low-level spec); * - array element #3 access (corresponds to '3' in low-level spec). * - * Type-based relocations (TYPE_EXISTS/TYPE_SIZE, + * Type-based relocations (TYPE_EXISTS/TYPE_MATCHES/TYPE_SIZE, * TYPE_ID_LOCAL/TYPE_ID_TARGET) don't capture any field information. Their * spec and raw_spec are kept empty. * @@ -186,7 +268,7 @@ int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, struct bpf_core_accessor *acc; const struct btf_type *t; const char *name, *spec_str; - __u32 id; + __u32 id, name_off; __s64 sz; spec_str = btf__name_by_offset(btf, relo->access_str_off); @@ -231,11 +313,13 @@ int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, spec->len++; if (core_relo_is_enumval_based(relo->kind)) { - if (!btf_is_enum(t) || spec->raw_len > 1 || access_idx >= btf_vlen(t)) + if (!btf_is_any_enum(t) || spec->raw_len > 1 || access_idx >= btf_vlen(t)) return -EINVAL; /* record enumerator name in a first accessor */ - acc->name = btf__name_by_offset(btf, btf_enum(t)[access_idx].name_off); + name_off = btf_is_enum(t) ? btf_enum(t)[access_idx].name_off + : btf_enum64(t)[access_idx].name_off; + acc->name = btf__name_by_offset(btf, name_off); return 0; } @@ -340,7 +424,7 @@ recur: if (btf_is_composite(local_type) && btf_is_composite(targ_type)) return 1; - if (btf_kind(local_type) != btf_kind(targ_type)) + if (!btf_kind_core_compat(local_type, targ_type)) return 0; switch (btf_kind(local_type)) { @@ -348,6 +432,7 @@ recur: case BTF_KIND_FLOAT: return 1; case BTF_KIND_FWD: + case BTF_KIND_ENUM64: case BTF_KIND_ENUM: { const char *local_name, *targ_name; size_t local_len, targ_len; @@ -477,6 +562,7 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec, const struct bpf_core_accessor *local_acc; struct bpf_core_accessor *targ_acc; int i, sz, matched; + __u32 name_off; memset(targ_spec, 0, sizeof(*targ_spec)); targ_spec->btf = targ_btf; @@ -484,9 +570,14 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec, targ_spec->relo_kind = local_spec->relo_kind; if (core_relo_is_type_based(local_spec->relo_kind)) { - return bpf_core_types_are_compat(local_spec->btf, - local_spec->root_type_id, - targ_btf, targ_id); + if (local_spec->relo_kind == BPF_CORE_TYPE_MATCHES) + return bpf_core_types_match(local_spec->btf, + local_spec->root_type_id, + targ_btf, targ_id); + else + return bpf_core_types_are_compat(local_spec->btf, + local_spec->root_type_id, + targ_btf, targ_id); } local_acc = &local_spec->spec[0]; @@ -494,18 +585,22 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec, if (core_relo_is_enumval_based(local_spec->relo_kind)) { size_t local_essent_len, targ_essent_len; - const struct btf_enum *e; const char *targ_name; /* has to resolve to an enum */ targ_type = skip_mods_and_typedefs(targ_spec->btf, targ_id, &targ_id); - if (!btf_is_enum(targ_type)) + if (!btf_is_any_enum(targ_type)) return 0; local_essent_len = bpf_core_essential_name_len(local_acc->name); - for (i = 0, e = btf_enum(targ_type); i < btf_vlen(targ_type); i++, e++) { - targ_name = btf__name_by_offset(targ_spec->btf, e->name_off); + for (i = 0; i < btf_vlen(targ_type); i++) { + if (btf_is_enum(targ_type)) + name_off = btf_enum(targ_type)[i].name_off; + else + name_off = btf_enum64(targ_type)[i].name_off; + + targ_name = btf__name_by_offset(targ_spec->btf, name_off); targ_essent_len = bpf_core_essential_name_len(targ_name); if (targ_essent_len != local_essent_len) continue; @@ -583,7 +678,7 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec, static int bpf_core_calc_field_relo(const char *prog_name, const struct bpf_core_relo *relo, const struct bpf_core_spec *spec, - __u32 *val, __u32 *field_sz, __u32 *type_id, + __u64 *val, __u32 *field_sz, __u32 *type_id, bool *validate) { const struct bpf_core_accessor *acc; @@ -680,8 +775,7 @@ static int bpf_core_calc_field_relo(const char *prog_name, *val = byte_sz; break; case BPF_CORE_FIELD_SIGNED: - /* enums will be assumed unsigned */ - *val = btf_is_enum(mt) || + *val = (btf_is_any_enum(mt) && BTF_INFO_KFLAG(mt->info)) || (btf_int_encoding(mt) & BTF_INT_SIGNED); if (validate) *validate = true; /* signedness is never ambiguous */ @@ -708,7 +802,7 @@ static int bpf_core_calc_field_relo(const char *prog_name, static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo, const struct bpf_core_spec *spec, - __u32 *val, bool *validate) + __u64 *val, bool *validate) { __s64 sz; @@ -732,6 +826,7 @@ static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo, *validate = false; break; case BPF_CORE_TYPE_EXISTS: + case BPF_CORE_TYPE_MATCHES: *val = 1; break; case BPF_CORE_TYPE_SIZE: @@ -751,10 +846,9 @@ static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo, static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo, const struct bpf_core_spec *spec, - __u32 *val) + __u64 *val) { const struct btf_type *t; - const struct btf_enum *e; switch (relo->kind) { case BPF_CORE_ENUMVAL_EXISTS: @@ -764,8 +858,10 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo, if (!spec) return -EUCLEAN; /* request instruction poisoning */ t = btf_type_by_id(spec->btf, spec->spec[0].type_id); - e = btf_enum(t) + spec->spec[0].idx; - *val = e->val; + if (btf_is_enum(t)) + *val = btf_enum(t)[spec->spec[0].idx].val; + else + *val = btf_enum64_value(btf_enum64(t) + spec->spec[0].idx); break; default: return -EOPNOTSUPP; @@ -929,7 +1025,7 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn, int insn_idx, const struct bpf_core_relo *relo, int relo_idx, const struct bpf_core_relo_res *res) { - __u32 orig_val, new_val; + __u64 orig_val, new_val; __u8 class; class = BPF_CLASS(insn->code); @@ -954,28 +1050,30 @@ poison: if (BPF_SRC(insn->code) != BPF_K) return -EINVAL; if (res->validate && insn->imm != orig_val) { - pr_warn("prog '%s': relo #%d: unexpected insn #%d (ALU/ALU64) value: got %u, exp %u -> %u\n", + pr_warn("prog '%s': relo #%d: unexpected insn #%d (ALU/ALU64) value: got %u, exp %llu -> %llu\n", prog_name, relo_idx, - insn_idx, insn->imm, orig_val, new_val); + insn_idx, insn->imm, (unsigned long long)orig_val, + (unsigned long long)new_val); return -EINVAL; } orig_val = insn->imm; insn->imm = new_val; - pr_debug("prog '%s': relo #%d: patched insn #%d (ALU/ALU64) imm %u -> %u\n", + pr_debug("prog '%s': relo #%d: patched insn #%d (ALU/ALU64) imm %llu -> %llu\n", prog_name, relo_idx, insn_idx, - orig_val, new_val); + (unsigned long long)orig_val, (unsigned long long)new_val); break; case BPF_LDX: case BPF_ST: case BPF_STX: if (res->validate && insn->off != orig_val) { - pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDX/ST/STX) value: got %u, exp %u -> %u\n", - prog_name, relo_idx, insn_idx, insn->off, orig_val, new_val); + pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDX/ST/STX) value: got %u, exp %llu -> %llu\n", + prog_name, relo_idx, insn_idx, insn->off, (unsigned long long)orig_val, + (unsigned long long)new_val); return -EINVAL; } if (new_val > SHRT_MAX) { - pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) value too big: %u\n", - prog_name, relo_idx, insn_idx, new_val); + pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) value too big: %llu\n", + prog_name, relo_idx, insn_idx, (unsigned long long)new_val); return -ERANGE; } if (res->fail_memsz_adjust) { @@ -987,8 +1085,9 @@ poison: orig_val = insn->off; insn->off = new_val; - pr_debug("prog '%s': relo #%d: patched insn #%d (LDX/ST/STX) off %u -> %u\n", - prog_name, relo_idx, insn_idx, orig_val, new_val); + pr_debug("prog '%s': relo #%d: patched insn #%d (LDX/ST/STX) off %llu -> %llu\n", + prog_name, relo_idx, insn_idx, (unsigned long long)orig_val, + (unsigned long long)new_val); if (res->new_sz != res->orig_sz) { int insn_bytes_sz, insn_bpf_sz; @@ -1024,20 +1123,20 @@ poison: return -EINVAL; } - imm = insn[0].imm + ((__u64)insn[1].imm << 32); + imm = (__u32)insn[0].imm | ((__u64)insn[1].imm << 32); if (res->validate && imm != orig_val) { - pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDIMM64) value: got %llu, exp %u -> %u\n", + pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDIMM64) value: got %llu, exp %llu -> %llu\n", prog_name, relo_idx, insn_idx, (unsigned long long)imm, - orig_val, new_val); + (unsigned long long)orig_val, (unsigned long long)new_val); return -EINVAL; } insn[0].imm = new_val; - insn[1].imm = 0; /* currently only 32-bit values are supported */ - pr_debug("prog '%s': relo #%d: patched insn #%d (LDIMM64) imm64 %llu -> %u\n", + insn[1].imm = new_val >> 32; + pr_debug("prog '%s': relo #%d: patched insn #%d (LDIMM64) imm64 %llu -> %llu\n", prog_name, relo_idx, insn_idx, - (unsigned long long)imm, new_val); + (unsigned long long)imm, (unsigned long long)new_val); break; } default: @@ -1057,7 +1156,6 @@ poison: int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec) { const struct btf_type *t; - const struct btf_enum *e; const char *s; __u32 type_id; int i, len = 0; @@ -1086,10 +1184,23 @@ int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *s if (core_relo_is_enumval_based(spec->relo_kind)) { t = skip_mods_and_typedefs(spec->btf, type_id, NULL); - e = btf_enum(t) + spec->raw_spec[0]; - s = btf__name_by_offset(spec->btf, e->name_off); + if (btf_is_enum(t)) { + const struct btf_enum *e; + const char *fmt_str; + + e = btf_enum(t) + spec->raw_spec[0]; + s = btf__name_by_offset(spec->btf, e->name_off); + fmt_str = BTF_INFO_KFLAG(t->info) ? "::%s = %d" : "::%s = %u"; + append_buf(fmt_str, s, e->val); + } else { + const struct btf_enum64 *e; + const char *fmt_str; - append_buf("::%s = %u", s, e->val); + e = btf_enum64(t) + spec->raw_spec[0]; + s = btf__name_by_offset(spec->btf, e->name_off); + fmt_str = BTF_INFO_KFLAG(t->info) ? "::%s = %lld" : "::%s = %llu"; + append_buf(fmt_str, s, (unsigned long long)btf_enum64_value(e)); + } return len; } @@ -1148,11 +1259,11 @@ int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *s * 3. It is supported and expected that there might be multiple flavors * matching the spec. As long as all the specs resolve to the same set of * offsets across all candidates, there is no error. If there is any - * ambiguity, CO-RE relocation will fail. This is necessary to accomodate - * imprefection of BTF deduplication, which can cause slight duplication of + * ambiguity, CO-RE relocation will fail. This is necessary to accommodate + * imperfection of BTF deduplication, which can cause slight duplication of * the same BTF type, if some directly or indirectly referenced (by * pointer) type gets resolved to different actual types in different - * object files. If such situation occurs, deduplicated BTF will end up + * object files. If such a situation occurs, deduplicated BTF will end up * with two (or more) structurally identical types, which differ only in * types they refer to through pointer. This should be OK in most cases and * is not an error. @@ -1261,10 +1372,12 @@ int bpf_core_calc_relo_insn(const char *prog_name, * decision and value, otherwise it's dangerous to * proceed due to ambiguity */ - pr_warn("prog '%s': relo #%d: relocation decision ambiguity: %s %u != %s %u\n", + pr_warn("prog '%s': relo #%d: relocation decision ambiguity: %s %llu != %s %llu\n", prog_name, relo_idx, - cand_res.poison ? "failure" : "success", cand_res.new_val, - targ_res->poison ? "failure" : "success", targ_res->new_val); + cand_res.poison ? "failure" : "success", + (unsigned long long)cand_res.new_val, + targ_res->poison ? "failure" : "success", + (unsigned long long)targ_res->new_val); return -EINVAL; } @@ -1305,3 +1418,273 @@ int bpf_core_calc_relo_insn(const char *prog_name, return 0; } + +static bool bpf_core_names_match(const struct btf *local_btf, size_t local_name_off, + const struct btf *targ_btf, size_t targ_name_off) +{ + const char *local_n, *targ_n; + size_t local_len, targ_len; + + local_n = btf__name_by_offset(local_btf, local_name_off); + targ_n = btf__name_by_offset(targ_btf, targ_name_off); + + if (str_is_empty(targ_n)) + return str_is_empty(local_n); + + targ_len = bpf_core_essential_name_len(targ_n); + local_len = bpf_core_essential_name_len(local_n); + + return targ_len == local_len && strncmp(local_n, targ_n, local_len) == 0; +} + +static int bpf_core_enums_match(const struct btf *local_btf, const struct btf_type *local_t, + const struct btf *targ_btf, const struct btf_type *targ_t) +{ + __u16 local_vlen = btf_vlen(local_t); + __u16 targ_vlen = btf_vlen(targ_t); + int i, j; + + if (local_t->size != targ_t->size) + return 0; + + if (local_vlen > targ_vlen) + return 0; + + /* iterate over the local enum's variants and make sure each has + * a symbolic name correspondent in the target + */ + for (i = 0; i < local_vlen; i++) { + bool matched = false; + __u32 local_n_off, targ_n_off; + + local_n_off = btf_is_enum(local_t) ? btf_enum(local_t)[i].name_off : + btf_enum64(local_t)[i].name_off; + + for (j = 0; j < targ_vlen; j++) { + targ_n_off = btf_is_enum(targ_t) ? btf_enum(targ_t)[j].name_off : + btf_enum64(targ_t)[j].name_off; + + if (bpf_core_names_match(local_btf, local_n_off, targ_btf, targ_n_off)) { + matched = true; + break; + } + } + + if (!matched) + return 0; + } + return 1; +} + +static int bpf_core_composites_match(const struct btf *local_btf, const struct btf_type *local_t, + const struct btf *targ_btf, const struct btf_type *targ_t, + bool behind_ptr, int level) +{ + const struct btf_member *local_m = btf_members(local_t); + __u16 local_vlen = btf_vlen(local_t); + __u16 targ_vlen = btf_vlen(targ_t); + int i, j, err; + + if (local_vlen > targ_vlen) + return 0; + + /* check that all local members have a match in the target */ + for (i = 0; i < local_vlen; i++, local_m++) { + const struct btf_member *targ_m = btf_members(targ_t); + bool matched = false; + + for (j = 0; j < targ_vlen; j++, targ_m++) { + if (!bpf_core_names_match(local_btf, local_m->name_off, + targ_btf, targ_m->name_off)) + continue; + + err = __bpf_core_types_match(local_btf, local_m->type, targ_btf, + targ_m->type, behind_ptr, level - 1); + if (err < 0) + return err; + if (err > 0) { + matched = true; + break; + } + } + + if (!matched) + return 0; + } + return 1; +} + +/* Check that two types "match". This function assumes that root types were + * already checked for name match. + * + * The matching relation is defined as follows: + * - modifiers and typedefs are stripped (and, hence, effectively ignored) + * - generally speaking types need to be of same kind (struct vs. struct, union + * vs. union, etc.) + * - exceptions are struct/union behind a pointer which could also match a + * forward declaration of a struct or union, respectively, and enum vs. + * enum64 (see below) + * Then, depending on type: + * - integers: + * - match if size and signedness match + * - arrays & pointers: + * - target types are recursively matched + * - structs & unions: + * - local members need to exist in target with the same name + * - for each member we recursively check match unless it is already behind a + * pointer, in which case we only check matching names and compatible kind + * - enums: + * - local variants have to have a match in target by symbolic name (but not + * numeric value) + * - size has to match (but enum may match enum64 and vice versa) + * - function pointers: + * - number and position of arguments in local type has to match target + * - for each argument and the return value we recursively check match + */ +int __bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, + __u32 targ_id, bool behind_ptr, int level) +{ + const struct btf_type *local_t, *targ_t; + int depth = 32; /* max recursion depth */ + __u16 local_k, targ_k; + + if (level <= 0) + return -EINVAL; + + local_t = btf_type_by_id(local_btf, local_id); + targ_t = btf_type_by_id(targ_btf, targ_id); + +recur: + depth--; + if (depth < 0) + return -EINVAL; + + local_t = skip_mods_and_typedefs(local_btf, local_id, &local_id); + targ_t = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id); + if (!local_t || !targ_t) + return -EINVAL; + + /* While the name check happens after typedefs are skipped, root-level + * typedefs would still be name-matched as that's the contract with + * callers. + */ + if (!bpf_core_names_match(local_btf, local_t->name_off, targ_btf, targ_t->name_off)) + return 0; + + local_k = btf_kind(local_t); + targ_k = btf_kind(targ_t); + + switch (local_k) { + case BTF_KIND_UNKN: + return local_k == targ_k; + case BTF_KIND_FWD: { + bool local_f = BTF_INFO_KFLAG(local_t->info); + + if (behind_ptr) { + if (local_k == targ_k) + return local_f == BTF_INFO_KFLAG(targ_t->info); + + /* for forward declarations kflag dictates whether the + * target is a struct (0) or union (1) + */ + return (targ_k == BTF_KIND_STRUCT && !local_f) || + (targ_k == BTF_KIND_UNION && local_f); + } else { + if (local_k != targ_k) + return 0; + + /* match if the forward declaration is for the same kind */ + return local_f == BTF_INFO_KFLAG(targ_t->info); + } + } + case BTF_KIND_ENUM: + case BTF_KIND_ENUM64: + if (!btf_is_any_enum(targ_t)) + return 0; + + return bpf_core_enums_match(local_btf, local_t, targ_btf, targ_t); + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + if (behind_ptr) { + bool targ_f = BTF_INFO_KFLAG(targ_t->info); + + if (local_k == targ_k) + return 1; + + if (targ_k != BTF_KIND_FWD) + return 0; + + return (local_k == BTF_KIND_UNION) == targ_f; + } else { + if (local_k != targ_k) + return 0; + + return bpf_core_composites_match(local_btf, local_t, targ_btf, targ_t, + behind_ptr, level); + } + case BTF_KIND_INT: { + __u8 local_sgn; + __u8 targ_sgn; + + if (local_k != targ_k) + return 0; + + local_sgn = btf_int_encoding(local_t) & BTF_INT_SIGNED; + targ_sgn = btf_int_encoding(targ_t) & BTF_INT_SIGNED; + + return local_t->size == targ_t->size && local_sgn == targ_sgn; + } + case BTF_KIND_PTR: + if (local_k != targ_k) + return 0; + + behind_ptr = true; + + local_id = local_t->type; + targ_id = targ_t->type; + goto recur; + case BTF_KIND_ARRAY: { + const struct btf_array *local_array = btf_array(local_t); + const struct btf_array *targ_array = btf_array(targ_t); + + if (local_k != targ_k) + return 0; + + if (local_array->nelems != targ_array->nelems) + return 0; + + local_id = local_array->type; + targ_id = targ_array->type; + goto recur; + } + case BTF_KIND_FUNC_PROTO: { + struct btf_param *local_p = btf_params(local_t); + struct btf_param *targ_p = btf_params(targ_t); + __u16 local_vlen = btf_vlen(local_t); + __u16 targ_vlen = btf_vlen(targ_t); + int i, err; + + if (local_k != targ_k) + return 0; + + if (local_vlen != targ_vlen) + return 0; + + for (i = 0; i < local_vlen; i++, local_p++, targ_p++) { + err = __bpf_core_types_match(local_btf, local_p->type, targ_btf, + targ_p->type, behind_ptr, level - 1); + if (err <= 0) + return err; + } + + /* tail recurse for return type check */ + local_id = local_t->type; + targ_id = targ_t->type; + goto recur; + } + default: + pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n", + btf_kind_str(local_t), local_id, targ_id); + return 0; + } +} |