4 files changed, 48 insertions, 24 deletions

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 7e4c5586bd87..fcec27622e7a 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -2846,8 +2846,7 @@ __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext)
 
 struct btf_dedup;
 
-static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
-				       const struct btf_dedup_opts *opts);
+static struct btf_dedup *btf_dedup_new(struct btf *btf, const struct btf_dedup_opts *opts);
 static void btf_dedup_free(struct btf_dedup *d);
 static int btf_dedup_prep(struct btf_dedup *d);
 static int btf_dedup_strings(struct btf_dedup *d);
@@ -2994,12 +2993,17 @@ static int btf_dedup_remap_types(struct btf_dedup *d);
  * deduplicating structs/unions is described in greater details in comments for
  * `btf_dedup_is_equiv` function.
  */
-int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
-	       const struct btf_dedup_opts *opts)
+
+DEFAULT_VERSION(btf__dedup_v0_6_0, btf__dedup, LIBBPF_0.6.0)
+int btf__dedup_v0_6_0(struct btf *btf, const struct btf_dedup_opts *opts)
 {
-	struct btf_dedup *d = btf_dedup_new(btf, btf_ext, opts);
+	struct btf_dedup *d;
 	int err;
 
+	if (!OPTS_VALID(opts, btf_dedup_opts))
+		return libbpf_err(-EINVAL);
+
+	d = btf_dedup_new(btf, opts);
 	if (IS_ERR(d)) {
 		pr_debug("btf_dedup_new failed: %ld", PTR_ERR(d));
 		return libbpf_err(-EINVAL);
@@ -3051,6 +3055,19 @@ done:
 	return libbpf_err(err);
 }
 
+COMPAT_VERSION(bpf__dedup_deprecated, btf__dedup, LIBBPF_0.0.2)
+int btf__dedup_deprecated(struct btf *btf, struct btf_ext *btf_ext, const void *unused_opts)
+{
+	LIBBPF_OPTS(btf_dedup_opts, opts, .btf_ext = btf_ext);
+
+	if (unused_opts) {
+		pr_warn("please use new version of btf__dedup() that supports options\n");
+		return libbpf_err(-ENOTSUP);
+	}
+
+	return btf__dedup(btf, &opts);
+}
+
 #define BTF_UNPROCESSED_ID ((__u32)-1)
 #define BTF_IN_PROGRESS_ID ((__u32)-2)
 
@@ -3163,8 +3180,7 @@ static bool btf_dedup_equal_fn(const void *k1, const void *k2, void *ctx)
 	return k1 == k2;
 }
 
-static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
-				       const struct btf_dedup_opts *opts)
+static struct btf_dedup *btf_dedup_new(struct btf *btf, const struct btf_dedup_opts *opts)
 {
 	struct btf_dedup *d = calloc(1, sizeof(struct btf_dedup));
 	hashmap_hash_fn hash_fn = btf_dedup_identity_hash_fn;
@@ -3173,13 +3189,11 @@ static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
 	if (!d)
 		return ERR_PTR(-ENOMEM);
 
-	d->opts.dont_resolve_fwds = opts && opts->dont_resolve_fwds;
-	/* dedup_table_size is now used only to force collisions in tests */
-	if (opts && opts->dedup_table_size == 1)
+	if (OPTS_GET(opts, force_collisions, false))
 		hash_fn = btf_dedup_collision_hash_fn;
 
 	d->btf = btf;
-	d->btf_ext = btf_ext;
+	d->btf_ext = OPTS_GET(opts, btf_ext, NULL);
 
 	d->dedup_table = hashmap__new(hash_fn, btf_dedup_equal_fn, NULL);
 	if (IS_ERR(d->dedup_table)) {
@@ -3708,8 +3722,6 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 				new_id = cand_id;
 				break;
 			}
-			if (d->opts.dont_resolve_fwds)
-				continue;
 			if (btf_compat_enum(t, cand)) {
 				if (btf_is_enum_fwd(t)) {
 					/* resolve fwd to full enum */
@@ -3952,8 +3964,7 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 		return 0;
 
 	/* FWD <--> STRUCT/UNION equivalence check, if enabled */
-	if (!d->opts.dont_resolve_fwds
-	    && (cand_kind == BTF_KIND_FWD || canon_kind == BTF_KIND_FWD)
+	if ((cand_kind == BTF_KIND_FWD || canon_kind == BTF_KIND_FWD)
 	    && cand_kind != canon_kind) {
 		__u16 real_kind;
 		__u16 fwd_kind;
@@ -3979,10 +3990,7 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 		return btf_equal_int_tag(cand_type, canon_type);
 
 	case BTF_KIND_ENUM:
-		if (d->opts.dont_resolve_fwds)
-			return btf_equal_enum(cand_type, canon_type);
-		else
-			return btf_compat_enum(cand_type, canon_type);
+		return btf_compat_enum(cand_type, canon_type);
 
 	case BTF_KIND_FWD:
 	case BTF_KIND_FLOAT:
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index bc005ba3ceec..6aae4f62ee0b 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -245,12 +245,24 @@ LIBBPF_API int btf__add_decl_tag(struct btf *btf, const char *value, int ref_typ
 			    int component_idx);
 
 struct btf_dedup_opts {
-	unsigned int dedup_table_size;
-	bool dont_resolve_fwds;
+	size_t sz;
+	/* optional .BTF.ext info to dedup along the main BTF info */
+	struct btf_ext *btf_ext;
+	/* force hash collisions (used for testing) */
+	bool force_collisions;
+	size_t :0;
 };
+#define btf_dedup_opts__last_field force_collisions
+
+LIBBPF_API int btf__dedup(struct btf *btf, const struct btf_dedup_opts *opts);
+
+LIBBPF_API int btf__dedup_v0_6_0(struct btf *btf, const struct btf_dedup_opts *opts);
 
-LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
-			  const struct btf_dedup_opts *opts);
+LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__dedup() instead")
+LIBBPF_API int btf__dedup_deprecated(struct btf *btf, struct btf_ext *btf_ext, const void *opts);
+#define btf__dedup(...) ___libbpf_overload(___btf_dedup, __VA_ARGS__)
+#define ___btf_dedup3(btf, btf_ext, opts) btf__dedup_deprecated(btf, btf_ext, opts)
+#define ___btf_dedup2(btf, opts) btf__dedup(btf, opts)
 
 struct btf_dump;
 
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 256d5d4be951..b8c8d14621d2 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -403,6 +403,8 @@ LIBBPF_0.6.0 {
 		bpf_program__set_extra_flags;
 		btf__add_btf;
 		btf__add_decl_tag;
+		btf__dedup;
+		btf__dedup_deprecated;
 		btf__raw_data;
 		btf__type_cnt;
 } LIBBPF_0.5.0;
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index f677dccdeae4..594b206fa674 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -2650,6 +2650,7 @@ static int emit_elf_data_sec(struct bpf_linker *linker, const char *sec_name,
 
 static int finalize_btf(struct bpf_linker *linker)
 {
+	LIBBPF_OPTS(btf_dedup_opts, opts);
 	struct btf *btf = linker->btf;
 	const void *raw_data;
 	int i, j, id, err;
@@ -2686,7 +2687,8 @@ static int finalize_btf(struct bpf_linker *linker)
 		return err;
 	}
 
-	err = btf__dedup(linker->btf, linker->btf_ext, NULL);
+	opts.btf_ext = linker->btf_ext;
+	err = btf__dedup(linker->btf, &opts);
 	if (err) {
 		pr_warn("BTF dedup failed: %d\n", err);
 		return err;