diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index 3b57ba095ab6..7d2af1ff3c8d 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -50,6 +50,7 @@ struct sort_datum { int type_rank; const char *sort_name; const char *own_name; + __u64 disambig_hash; }; static const char *btf_int_enc_str(__u8 encoding) @@ -584,20 +585,88 @@ static const char *btf_type_sort_name(const struct btf *btf, __u32 index, bool f return NULL; } +static __u64 hasher(__u64 hash, __u64 val) +{ + return hash * 31 + val; +} + +static __u64 btf_name_hasher(__u64 hash, const struct btf *btf, __u32 name_off) +{ + if (!name_off) + return hash; + + return hasher(hash, str_hash(btf__name_by_offset(btf, name_off))); +} + +static __u64 btf_type_disambig_hash(const struct btf *btf, __u32 id, bool include_members) +{ + const struct btf_type *t = btf__type_by_id(btf, id); + int i; + size_t hash = 0; + + hash = btf_name_hasher(hash, btf, t->name_off); + + switch (btf_kind(t)) { + case BTF_KIND_ENUM: + case BTF_KIND_ENUM64: + for (i = 0; i < btf_vlen(t); i++) { + __u32 name_off = btf_is_enum(t) ? + btf_enum(t)[i].name_off : + btf_enum64(t)[i].name_off; + + hash = btf_name_hasher(hash, btf, name_off); + } + break; + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + if (!include_members) + break; + for (i = 0; i < btf_vlen(t); i++) { + const struct btf_member *m = btf_members(t) + i; + + hash = btf_name_hasher(hash, btf, m->name_off); + /* resolve field type's name and hash it as well */ + hash = hasher(hash, btf_type_disambig_hash(btf, m->type, false)); + } + break; + case BTF_KIND_TYPE_TAG: + case BTF_KIND_CONST: + case BTF_KIND_PTR: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_TYPEDEF: + case BTF_KIND_DECL_TAG: + hash = hasher(hash, btf_type_disambig_hash(btf, t->type, include_members)); + break; + case BTF_KIND_ARRAY: { + struct btf_array *arr = btf_array(t); + + hash = hasher(hash, arr->nelems); + hash = hasher(hash, btf_type_disambig_hash(btf, arr->type, include_members)); + break; + } + default: + break; + } + return hash; +} + static int btf_type_compare(const void *left, const void *right) { const struct sort_datum *d1 = (const struct sort_datum *)left; const struct sort_datum *d2 = (const struct sort_datum *)right; int r; - if (d1->type_rank != d2->type_rank) - return d1->type_rank < d2->type_rank ? -1 : 1; - - r = strcmp(d1->sort_name, d2->sort_name); + r = d1->type_rank - d2->type_rank; + r = r ?: strcmp(d1->sort_name, d2->sort_name); + r = r ?: strcmp(d1->own_name, d2->own_name); if (r) return r; - return strcmp(d1->own_name, d2->own_name); + if (d1->disambig_hash != d2->disambig_hash) + return d1->disambig_hash < d2->disambig_hash ? -1 : 1; + + return d1->index - d2->index; } static struct sort_datum *sort_btf_c(const struct btf *btf) @@ -618,6 +687,7 @@ static struct sort_datum *sort_btf_c(const struct btf *btf) d->type_rank = btf_type_rank(btf, i, false); d->sort_name = btf_type_sort_name(btf, i, false); d->own_name = btf__name_by_offset(btf, t->name_off); + d->disambig_hash = btf_type_disambig_hash(btf, i, true); } qsort(datums, n, sizeof(struct sort_datum), btf_type_compare);