diff options
| -rw-r--r-- | tools/lib/bpf/bpf_core_read.h | 7 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 40 |
2 files changed, 39 insertions, 8 deletions
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h index 0935cd68e7de..11461b2623b0 100644 --- a/tools/lib/bpf/bpf_core_read.h +++ b/tools/lib/bpf/bpf_core_read.h @@ -97,6 +97,13 @@ enum bpf_field_info_kind { __builtin_preserve_field_info(field, BPF_FIELD_EXISTS) /* + * Convenience macro to get byte size of a field. Works for integers, + * struct/unions, pointers, arrays, and enums. + */ +#define bpf_core_field_size(field) \ + __builtin_preserve_field_info(field, BPF_FIELD_BYTE_SIZE) + +/* * bpf_core_read() abstracts away bpf_probe_read() call and captures offset * relocation for source address using __builtin_preserve_access_index() * built-in, provided by Clang. diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 482af749f9cf..be4af95d5a2c 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2704,8 +2704,10 @@ err_out: /* Check two types for compatibility, skipping const/volatile/restrict and * typedefs, to ensure we are relocating compatible entities: * - any two STRUCTs/UNIONs are compatible and can be mixed; - * - any two FWDs are compatible; + * - any two FWDs are compatible, if their names match (modulo flavor suffix); * - any two PTRs are always compatible; + * - for ENUMs, names should be the same (ignoring flavor suffix) or at + * least one of enums should be anonymous; * - for ENUMs, check sizes, names are ignored; * - for INT, size and signedness are ignored; * - for ARRAY, dimensionality is ignored, element types are checked for @@ -2733,11 +2735,23 @@ recur: return 0; switch (btf_kind(local_type)) { - case BTF_KIND_FWD: case BTF_KIND_PTR: return 1; - case BTF_KIND_ENUM: - return local_type->size == targ_type->size; + case BTF_KIND_FWD: + case BTF_KIND_ENUM: { + const char *local_name, *targ_name; + size_t local_len, targ_len; + + local_name = btf__name_by_offset(local_btf, + local_type->name_off); + targ_name = btf__name_by_offset(targ_btf, targ_type->name_off); + local_len = bpf_core_essential_name_len(local_name); + targ_len = bpf_core_essential_name_len(targ_name); + /* one of them is anonymous or both w/ same flavor-less names */ + return local_len == 0 || targ_len == 0 || + (local_len == targ_len && + strncmp(local_name, targ_name, local_len) == 0); + } case BTF_KIND_INT: /* just reject deprecated bitfield-like integers; all other * integers are by default compatible between each other @@ -2926,16 +2940,23 @@ static int bpf_core_calc_field_relo(const struct bpf_program *prog, const struct btf_member *m; const struct btf_type *mt; bool bitfield; + __s64 sz; /* a[n] accessor needs special handling */ if (!acc->name) { - if (relo->kind != BPF_FIELD_BYTE_OFFSET) { - pr_warn("prog '%s': relo %d at insn #%d can't be applied to array access'\n", + if (relo->kind == BPF_FIELD_BYTE_OFFSET) { + *val = spec->bit_offset / 8; + } else if (relo->kind == BPF_FIELD_BYTE_SIZE) { + sz = btf__resolve_size(spec->btf, acc->type_id); + if (sz < 0) + return -EINVAL; + *val = sz; + } else { + pr_warn("prog '%s': relo %d at insn #%d can't be applied to array access\n", bpf_program__title(prog, false), relo->kind, relo->insn_off / 8); return -EINVAL; } - *val = spec->bit_offset / 8; if (validate) *validate = true; return 0; @@ -2963,7 +2984,10 @@ static int bpf_core_calc_field_relo(const struct bpf_program *prog, byte_off = bit_off / 8 / byte_sz * byte_sz; } } else { - byte_sz = mt->size; + sz = btf__resolve_size(spec->btf, m->type); + if (sz < 0) + return -EINVAL; + byte_sz = sz; byte_off = spec->bit_offset / 8; bit_sz = byte_sz * 8; } |