1 files changed, 456 insertions, 110 deletions

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 596471189176..90c4a32d89ff 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -19,6 +19,7 @@
 #include <linux/bpf_verifier.h>
 #include <linux/btf.h>
 #include <linux/btf_ids.h>
+#include <linux/bpf.h>
 #include <linux/bpf_lsm.h>
 #include <linux/skmsg.h>
 #include <linux/perf_event.h>
@@ -241,6 +242,12 @@ struct btf_id_dtor_kfunc_tab {
 	struct btf_id_dtor_kfunc dtors[];
 };
 
+struct btf_struct_ops_tab {
+	u32 cnt;
+	u32 capacity;
+	struct bpf_struct_ops_desc ops[];
+};
+
 struct btf {
 	void *data;
 	struct btf_type **types;
@@ -258,6 +265,7 @@ struct btf {
 	struct btf_kfunc_set_tab *kfunc_set_tab;
 	struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab;
 	struct btf_struct_metas *struct_meta_tab;
+	struct btf_struct_ops_tab *struct_ops_tab;
 
 	/* split BTF support */
 	struct btf *base_btf;
@@ -801,9 +809,23 @@ static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
 	return __btf_name_valid(btf, offset);
 }
 
+/* Allow any printable character in DATASEC names */
 static bool btf_name_valid_section(const struct btf *btf, u32 offset)
 {
-	return __btf_name_valid(btf, offset);
+	/* offset must be valid */
+	const char *src = btf_str_by_offset(btf, offset);
+	const char *src_limit;
+
+	/* set a limit on identifier length */
+	src_limit = src + KSYM_NAME_LEN;
+	src++;
+	while (*src && src < src_limit) {
+		if (!isprint(*src))
+			return false;
+		src++;
+	}
+
+	return !*src;
 }
 
 static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
@@ -1688,11 +1710,27 @@ static void btf_free_struct_meta_tab(struct btf *btf)
 	btf->struct_meta_tab = NULL;
 }
 
+static void btf_free_struct_ops_tab(struct btf *btf)
+{
+	struct btf_struct_ops_tab *tab = btf->struct_ops_tab;
+	u32 i;
+
+	if (!tab)
+		return;
+
+	for (i = 0; i < tab->cnt; i++)
+		bpf_struct_ops_desc_release(&tab->ops[i]);
+
+	kfree(tab);
+	btf->struct_ops_tab = NULL;
+}
+
 static void btf_free(struct btf *btf)
 {
 	btf_free_struct_meta_tab(btf);
 	btf_free_dtor_kfunc_tab(btf);
 	btf_free_kfunc_set_tab(btf);
+	btf_free_struct_ops_tab(btf);
 	kvfree(btf->types);
 	kvfree(btf->resolved_sizes);
 	kvfree(btf->resolved_ids);
@@ -1707,6 +1745,11 @@ static void btf_free_rcu(struct rcu_head *rcu)
 	btf_free(btf);
 }
 
+const char *btf_get_name(const struct btf *btf)
+{
+	return btf->name;
+}
+
 void btf_get(struct btf *btf)
 {
 	refcount_inc(&btf->refcnt);
@@ -3310,30 +3353,48 @@ static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
 	return BTF_FIELD_FOUND;
 }
 
-const char *btf_find_decl_tag_value(const struct btf *btf, const struct btf_type *pt,
-				    int comp_idx, const char *tag_key)
+int btf_find_next_decl_tag(const struct btf *btf, const struct btf_type *pt,
+			   int comp_idx, const char *tag_key, int last_id)
 {
-	const char *value = NULL;
-	int i;
+	int len = strlen(tag_key);
+	int i, n;
 
-	for (i = 1; i < btf_nr_types(btf); i++) {
+	for (i = last_id + 1, n = btf_nr_types(btf); i < n; i++) {
 		const struct btf_type *t = btf_type_by_id(btf, i);
-		int len = strlen(tag_key);
 
 		if (!btf_type_is_decl_tag(t))
 			continue;
-		if (pt != btf_type_by_id(btf, t->type) ||
-		    btf_type_decl_tag(t)->component_idx != comp_idx)
+		if (pt != btf_type_by_id(btf, t->type))
+			continue;
+		if (btf_type_decl_tag(t)->component_idx != comp_idx)
 			continue;
 		if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len))
 			continue;
-		/* Prevent duplicate entries for same type */
-		if (value)
-			return ERR_PTR(-EEXIST);
-		value = __btf_name_by_offset(btf, t->name_off) + len;
+		return i;
 	}
-	if (!value)
-		return ERR_PTR(-ENOENT);
+	return -ENOENT;
+}
+
+const char *btf_find_decl_tag_value(const struct btf *btf, const struct btf_type *pt,
+				    int comp_idx, const char *tag_key)
+{
+	const char *value = NULL;
+	const struct btf_type *t;
+	int len, id;
+
+	id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key, 0);
+	if (id < 0)
+		return ERR_PTR(id);
+
+	t = btf_type_by_id(btf, id);
+	len = strlen(tag_key);
+	value = __btf_name_by_offset(btf, t->name_off) + len;
+
+	/* Prevent duplicate entries for same type */
+	id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key, id);
+	if (id >= 0)
+		return ERR_PTR(-EEXIST);
+
 	return value;
 }
 
@@ -5647,15 +5708,29 @@ static int find_kern_ctx_type_id(enum bpf_prog_type prog_type)
 	return ctx_type->type;
 }
 
-const struct btf_type *
-btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
-		      const struct btf_type *t, enum bpf_prog_type prog_type,
-		      int arg)
+bool btf_is_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
+			  const struct btf_type *t, enum bpf_prog_type prog_type,
+			  int arg)
 {
 	const struct btf_type *ctx_type;
 	const char *tname, *ctx_tname;
 
 	t = btf_type_by_id(btf, t->type);
+
+	/* KPROBE programs allow bpf_user_pt_regs_t typedef, which we need to
+	 * check before we skip all the typedef below.
+	 */
+	if (prog_type == BPF_PROG_TYPE_KPROBE) {
+		while (btf_type_is_modifier(t) && !btf_type_is_typedef(t))
+			t = btf_type_by_id(btf, t->type);
+
+		if (btf_type_is_typedef(t)) {
+			tname = btf_name_by_offset(btf, t->name_off);
+			if (tname && strcmp(tname, "bpf_user_pt_regs_t") == 0)
+				return true;
+		}
+	}
+
 	while (btf_type_is_modifier(t))
 		t = btf_type_by_id(btf, t->type);
 	if (!btf_type_is_struct(t)) {
@@ -5664,27 +5739,30 @@ btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
 		 * is not supported yet.
 		 * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
 		 */
-		return NULL;
+		return false;
 	}
 	tname = btf_name_by_offset(btf, t->name_off);
 	if (!tname) {
 		bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
-		return NULL;
+		return false;
 	}
 
 	ctx_type = find_canonical_prog_ctx_type(prog_type);
 	if (!ctx_type) {
 		bpf_log(log, "btf_vmlinux is malformed\n");
 		/* should not happen */
-		return NULL;
+		return false;
 	}
 again:
 	ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_type->name_off);
 	if (!ctx_tname) {
 		/* should not happen */
 		bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
-		return NULL;
+		return false;
 	}
+	/* program types without named context types work only with arg:ctx tag */
+	if (ctx_tname[0] == '\0')
+		return false;
 	/* only compare that prog's ctx type name is the same as
 	 * kernel expects. No need to compare field by field.
 	 * It's ok for bpf prog to do:
@@ -5693,20 +5771,20 @@ again:
 	 * { // no fields of skb are ever used }
 	 */
 	if (strcmp(ctx_tname, "__sk_buff") == 0 && strcmp(tname, "sk_buff") == 0)
-		return ctx_type;
+		return true;
 	if (strcmp(ctx_tname, "xdp_md") == 0 && strcmp(tname, "xdp_buff") == 0)
-		return ctx_type;
+		return true;
 	if (strcmp(ctx_tname, tname)) {
 		/* bpf_user_pt_regs_t is a typedef, so resolve it to
 		 * underlying struct and check name again
 		 */
 		if (!btf_type_is_modifier(ctx_type))
-			return NULL;
+			return false;
 		while (btf_type_is_modifier(ctx_type))
 			ctx_type = btf_type_by_id(btf_vmlinux, ctx_type->type);
 		goto again;
 	}
-	return ctx_type;
+	return true;
 }
 
 /* forward declarations for arch-specific underlying types of
@@ -5858,7 +5936,7 @@ static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
 				     enum bpf_prog_type prog_type,
 				     int arg)
 {
-	if (!btf_get_prog_ctx_type(log, btf, t, prog_type, arg))
+	if (!btf_is_prog_ctx_type(log, btf, t, prog_type, arg))
 		return -ENOENT;
 	return find_kern_ctx_type_id(prog_type);
 }
@@ -5933,8 +6011,6 @@ struct btf *btf_parse_vmlinux(void)
 	/* btf_parse_vmlinux() runs under bpf_verifier_lock */
 	bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]);
 
-	bpf_struct_ops_init(btf, log);
-
 	refcount_set(&btf->refcnt, 1);
 
 	err = btf_alloc_id(btf);
@@ -6092,6 +6168,26 @@ static bool prog_args_trusted(const struct bpf_prog *prog)
 	}
 }
 
+int btf_ctx_arg_offset(const struct btf *btf, const struct btf_type *func_proto,
+		       u32 arg_no)
+{
+	const struct btf_param *args;
+	const struct btf_type *t;
+	int off = 0, i;
+	u32 sz;
+
+	args = btf_params(func_proto);
+	for (i = 0; i < arg_no; i++) {
+		t = btf_type_by_id(btf, args[i].type);
+		t = btf_resolve_size(btf, t, &sz);
+		if (IS_ERR(t))
+			return PTR_ERR(t);
+		off += roundup(sz, 8);
+	}
+
+	return off;
+}
+
 bool btf_ctx_access(int off, int size, enum bpf_access_type type,
 		    const struct bpf_prog *prog,
 		    struct bpf_insn_access_aux *info)
@@ -6228,7 +6324,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
 			}
 
 			info->reg_type = ctx_arg_info->reg_type;
-			info->btf = btf_vmlinux;
+			info->btf = ctx_arg_info->btf ? : btf_vmlinux;
 			info->btf_id = ctx_arg_info->btf_id;
 			return true;
 		}
@@ -6284,6 +6380,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
 		__btf_name_by_offset(btf, t->name_off));
 	return true;
 }
+EXPORT_SYMBOL_GPL(btf_ctx_access);
 
 enum bpf_struct_walk_result {
 	/* < 0 error */
@@ -6946,6 +7043,81 @@ static bool btf_is_dynptr_ptr(const struct btf *btf, const struct btf_type *t)
 	return false;
 }
 
+struct bpf_cand_cache {
+	const char *name;
+	u32 name_len;
+	u16 kind;
+	u16 cnt;
+	struct {
+		const struct btf *btf;
+		u32 id;
+	} cands[];
+};
+
+static DEFINE_MUTEX(cand_cache_mutex);
+
+static struct bpf_cand_cache *
+bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id);
+
+static int btf_get_ptr_to_btf_id(struct bpf_verifier_log *log, int arg_idx,
+				 const struct btf *btf, const struct btf_type *t)
+{
+	struct bpf_cand_cache *cc;
+	struct bpf_core_ctx ctx = {
+		.btf = btf,
+		.log = log,
+	};
+	u32 kern_type_id, type_id;
+	int err = 0;
+
+	/* skip PTR and modifiers */
+	type_id = t->type;
+	t = btf_type_by_id(btf, t->type);
+	while (btf_type_is_modifier(t)) {
+		type_id = t->type;
+		t = btf_type_by_id(btf, t->type);
+	}
+
+	mutex_lock(&cand_cache_mutex);
+	cc = bpf_core_find_cands(&ctx, type_id);
+	if (IS_ERR(cc)) {
+		err = PTR_ERR(cc);
+		bpf_log(log, "arg#%d reference type('%s %s') candidate matching error: %d\n",
+			arg_idx, btf_type_str(t), __btf_name_by_offset(btf, t->name_off),
+			err);
+		goto cand_cache_unlock;
+	}
+	if (cc->cnt != 1) {
+		bpf_log(log, "arg#%d reference type('%s %s') %s\n",
+			arg_idx, btf_type_str(t), __btf_name_by_offset(btf, t->name_off),
+			cc->cnt == 0 ? "has no matches" : "is ambiguous");
+		err = cc->cnt == 0 ? -ENOENT : -ESRCH;
+		goto cand_cache_unlock;
+	}
+	if (btf_is_module(cc->cands[0].btf)) {
+		bpf_log(log, "arg#%d reference type('%s %s') points to kernel module type (unsupported)\n",
+			arg_idx, btf_type_str(t), __btf_name_by_offset(btf, t->name_off));
+		err = -EOPNOTSUPP;
+		goto cand_cache_unlock;
+	}
+	kern_type_id = cc->cands[0].id;
+
+cand_cache_unlock:
+	mutex_unlock(&cand_cache_mutex);
+	if (err)
+		return err;
+
+	return kern_type_id;
+}
+
+enum btf_arg_tag {
+	ARG_TAG_CTX	 = BIT_ULL(0),
+	ARG_TAG_NONNULL  = BIT_ULL(1),
+	ARG_TAG_TRUSTED  = BIT_ULL(2),
+	ARG_TAG_NULLABLE = BIT_ULL(3),
+	ARG_TAG_ARENA	 = BIT_ULL(4),
+};
+
 /* Process BTF of a function to produce high-level expectation of function
  * arguments (like ARG_PTR_TO_CTX, or ARG_PTR_TO_MEM, etc). This information
  * is cached in subprog info for reuse.
@@ -7009,6 +7181,8 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
 	args = (const struct btf_param *)(t + 1);
 	nargs = btf_type_vlen(t);
 	if (nargs > MAX_BPF_FUNC_REG_ARGS) {
+		if (!is_global)
+			return -EINVAL;
 		bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n",
 			tname, nargs, MAX_BPF_FUNC_REG_ARGS);
 		return -EINVAL;
@@ -7018,6 +7192,8 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
 	while (btf_type_is_modifier(t))
 		t = btf_type_by_id(btf, t->type);
 	if (!btf_type_is_int(t) && !btf_is_any_enum(t)) {
+		if (!is_global)
+			return -EINVAL;
 		bpf_log(log,
 			"Global function %s() doesn't return scalar. Only those are supported.\n",
 			tname);
@@ -7027,92 +7203,134 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
 	 * Only PTR_TO_CTX and SCALAR are supported atm.
 	 */
 	for (i = 0; i < nargs; i++) {
-		bool is_nonnull = false;
-		const char *tag;
+		u32 tags = 0;
+		int id = 0;
 
-		t = btf_type_by_id(btf, args[i].type);
-
-		tag = btf_find_decl_tag_value(btf, fn_t, i, "arg:");
-		if (IS_ERR(tag) && PTR_ERR(tag) == -ENOENT) {
-			tag = NULL;
-		} else if (IS_ERR(tag)) {
-			bpf_log(log, "arg#%d type's tag fetching failure: %ld\n", i, PTR_ERR(tag));
-			return PTR_ERR(tag);
-		}
 		/* 'arg:<tag>' decl_tag takes precedence over derivation of
 		 * register type from BTF type itself
 		 */
-		if (tag) {
+		while ((id = btf_find_next_decl_tag(btf, fn_t, i, "arg:", id)) > 0) {
+			const struct btf_type *tag_t = btf_type_by_id(btf, id);
+			const char *tag = __btf_name_by_offset(btf, tag_t->name_off) + 4;
+
 			/* disallow arg tags in static subprogs */
 			if (!is_global) {
 				bpf_log(log, "arg#%d type tag is not supported in static functions\n", i);
 				return -EOPNOTSUPP;
 			}
+
 			if (strcmp(tag, "ctx") == 0) {
-				sub->args[i].arg_type = ARG_PTR_TO_CTX;
-				continue;
+				tags |= ARG_TAG_CTX;
+			} else if (strcmp(tag, "trusted") == 0) {
+				tags |= ARG_TAG_TRUSTED;
+			} else if (strcmp(tag, "nonnull") == 0) {
+				tags |= ARG_TAG_NONNULL;
+			} else if (strcmp(tag, "nullable") == 0) {
+				tags |= ARG_TAG_NULLABLE;
+			} else if (strcmp(tag, "arena") == 0) {
+				tags |= ARG_TAG_ARENA;
+			} else {
+				bpf_log(log, "arg#%d has unsupported set of tags\n", i);
+				return -EOPNOTSUPP;
 			}
-			if (strcmp(tag, "nonnull") == 0)
-				is_nonnull = true;
+		}
+		if (id != -ENOENT) {
+			bpf_log(log, "arg#%d type tag fetching failure: %d\n", i, id);
+			return id;
 		}
 
+		t = btf_type_by_id(btf, args[i].type);
 		while (btf_type_is_modifier(t))
 			t = btf_type_by_id(btf, t->type);
-		if (btf_type_is_int(t) || btf_is_any_enum(t)) {
-			sub->args[i].arg_type = ARG_ANYTHING;
-			continue;
-		}
-		if (btf_type_is_ptr(t) && btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
+		if (!btf_type_is_ptr(t))
+			goto skip_pointer;
+
+		if ((tags & ARG_TAG_CTX) || btf_is_prog_ctx_type(log, btf, t, prog_type, i)) {
+			if (tags & ~ARG_TAG_CTX) {
+				bpf_log(log, "arg#%d has invalid combination of tags\n", i);
+				return -EINVAL;
+			}
+			if ((tags & ARG_TAG_CTX) &&
+			    btf_validate_prog_ctx_type(log, btf, t, i, prog_type,
+						       prog->expected_attach_type))
+				return -EINVAL;
 			sub->args[i].arg_type = ARG_PTR_TO_CTX;
 			continue;
 		}
-		if (btf_type_is_ptr(t) && btf_is_dynptr_ptr(btf, t)) {
+		if (btf_is_dynptr_ptr(btf, t)) {
+			if (tags) {
+				bpf_log(log, "arg#%d has invalid combination of tags\n", i);
+				return -EINVAL;
+			}
 			sub->args[i].arg_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY;
 			continue;
 		}
-		if (is_global && btf_type_is_ptr(t)) {
+		if (tags & ARG_TAG_TRUSTED) {
+			int kern_type_id;
+
+			if (tags & ARG_TAG_NONNULL) {
+				bpf_log(log, "arg#%d has invalid combination of tags\n", i);
+				return -EINVAL;
+			}
+
+			kern_type_id = btf_get_ptr_to_btf_id(log, i, btf, t);
+			if (kern_type_id < 0)
+				return kern_type_id;
+
+			sub->args[i].arg_type = ARG_PTR_TO_BTF_ID | PTR_TRUSTED;
+			if (tags & ARG_TAG_NULLABLE)
+				sub->args[i].arg_type |= PTR_MAYBE_NULL;
+			sub->args[i].btf_id = kern_type_id;
+			continue;
+		}
+		if (tags & ARG_TAG_ARENA) {
+			if (tags & ~ARG_TAG_ARENA) {
+				bpf_log(log, "arg#%d arena cannot be combined with any other tags\n", i);
+				return -EINVAL;
+			}
+			sub->args[i].arg_type = ARG_PTR_TO_ARENA;
+			continue;
+		}
+		if (is_global) { /* generic user data pointer */
 			u32 mem_size;
 
+			if (tags & ARG_TAG_NULLABLE) {
+				bpf_log(log, "arg#%d has invalid combination of tags\n", i);
+				return -EINVAL;
+			}
+
 			t = btf_type_skip_modifiers(btf, t->type, NULL);
 			ref_t = btf_resolve_size(btf, t, &mem_size);
 			if (IS_ERR(ref_t)) {
-				bpf_log(log,
-				    "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
-				    i, btf_type_str(t), btf_name_by_offset(btf, t->name_off),
+				bpf_log(log, "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
+					i, btf_type_str(t), btf_name_by_offset(btf, t->name_off),
 					PTR_ERR(ref_t));
 				return -EINVAL;
 			}
 
-			sub->args[i].arg_type = is_nonnull ? ARG_PTR_TO_MEM : ARG_PTR_TO_MEM_OR_NULL;
+			sub->args[i].arg_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL;
+			if (tags & ARG_TAG_NONNULL)
+				sub->args[i].arg_type &= ~PTR_MAYBE_NULL;
 			sub->args[i].mem_size = mem_size;
 			continue;
 		}
-		if (is_nonnull) {
-			bpf_log(log, "arg#%d marked as non-null, but is not a pointer type\n", i);
+
+skip_pointer:
+		if (tags) {
+			bpf_log(log, "arg#%d has pointer tag, but is not a pointer type\n", i);
 			return -EINVAL;
 		}
+		if (btf_type_is_int(t) || btf_is_any_enum(t)) {
+			sub->args[i].arg_type = ARG_ANYTHING;
+			continue;
+		}
+		if (!is_global)
+			return -EINVAL;
 		bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
 			i, btf_type_str(t), tname);
 		return -EINVAL;
 	}
 
-	for (i = 0; i < nargs; i++) {
-		const char *tag;
-
-		if (sub->args[i].arg_type != ARG_PTR_TO_CTX)
-			continue;
-
-		/* check if arg has "arg:ctx" tag */
-		t = btf_type_by_id(btf, args[i].type);
-		tag = btf_find_decl_tag_value(btf, fn_t, i, "arg:");
-		if (IS_ERR_OR_NULL(tag) || strcmp(tag, "ctx") != 0)
-			continue;
-
-		if (btf_validate_prog_ctx_type(log, btf, t, i, prog_type,
-					       prog->expected_attach_type))
-			return -EINVAL;
-	}
-
 	sub->arg_cnt = nargs;
 	sub->args_cached = true;
 
@@ -7589,6 +7807,17 @@ static struct btf *btf_get_module_btf(const struct module *module)
 	return btf;
 }
 
+static int check_btf_kconfigs(const struct module *module, const char *feature)
+{
+	if (!module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
+		pr_err("missing vmlinux BTF, cannot register %s\n", feature);
+		return -ENOENT;
+	}
+	if (module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
+		pr_warn("missing module BTF, cannot register %s\n", feature);
+	return 0;
+}
+
 BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags)
 {
 	struct btf *btf = NULL;
@@ -7949,15 +8178,8 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
 	int ret, i;
 
 	btf = btf_get_module_btf(kset->owner);
-	if (!btf) {
-		if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
-			pr_err("missing vmlinux BTF, cannot register kfuncs\n");
-			return -ENOENT;
-		}
-		if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
-			pr_warn("missing module BTF, cannot register kfuncs\n");
-		return 0;
-	}
+	if (!btf)
+		return check_btf_kconfigs(kset->owner, "kfunc");
 	if (IS_ERR(btf))
 		return PTR_ERR(btf);
 
@@ -7981,6 +8203,14 @@ int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
 {
 	enum btf_kfunc_hook hook;
 
+	/* All kfuncs need to be tagged as such in BTF.
+	 * WARN() for initcall registrations that do not check errors.
+	 */
+	if (!(kset->set->flags & BTF_SET8_KFUNCS)) {
+		WARN_ON(!kset->owner);
+		return -EINVAL;
+	}
+
 	hook = bpf_prog_type_to_kfunc_hook(prog_type);
 	return __register_btf_kfunc_id_set(hook, kset);
 }
@@ -8057,17 +8287,8 @@ int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_c
 	int ret;
 
 	btf = btf_get_module_btf(owner);
-	if (!btf) {
-		if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
-			pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n");
-			return -ENOENT;
-		}
-		if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
-			pr_err("missing module BTF, cannot register dtor kfuncs\n");
-			return -ENOENT;
-		}
-		return 0;
-	}
+	if (!btf)
+		return check_btf_kconfigs(owner, "dtor kfuncs");
 	if (IS_ERR(btf))
 		return PTR_ERR(btf);
 
@@ -8182,17 +8403,6 @@ size_t bpf_core_essential_name_len(const char *name)
 	return n;
 }
 
-struct bpf_cand_cache {
-	const char *name;
-	u32 name_len;
-	u16 kind;
-	u16 cnt;
-	struct {
-		const struct btf *btf;
-		u32 id;
-	} cands[];
-};
-
 static void bpf_free_cands(struct bpf_cand_cache *cands)
 {
 	if (!cands->cnt)
@@ -8213,8 +8423,6 @@ static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE];
 #define MODULE_CAND_CACHE_SIZE 31
 static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE];
 
-static DEFINE_MUTEX(cand_cache_mutex);
-
 static void __print_cand_cache(struct bpf_verifier_log *log,
 			       struct bpf_cand_cache **cache,
 			       int cache_size)
@@ -8645,3 +8853,141 @@ bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log,
 
 	return !strncmp(reg_name, arg_name, cmp_len);
 }
+
+#ifdef CONFIG_BPF_JIT
+static int
+btf_add_struct_ops(struct btf *btf, struct bpf_struct_ops *st_ops,
+		   struct bpf_verifier_log *log)
+{
+	struct btf_struct_ops_tab *tab, *new_tab;
+	int i, err;
+
+	tab = btf->struct_ops_tab;
+	if (!tab) {
+		tab = kzalloc(offsetof(struct btf_struct_ops_tab, ops[4]),
+			      GFP_KERNEL);
+		if (!tab)
+			return -ENOMEM;
+		tab->capacity = 4;
+		btf->struct_ops_tab = tab;
+	}
+
+	for (i = 0; i < tab->cnt; i++)
+		if (tab->ops[i].st_ops == st_ops)
+			return -EEXIST;
+
+	if (tab->cnt == tab->capacity) {
+		new_tab = krealloc(tab,
+				   offsetof(struct btf_struct_ops_tab,
+					    ops[tab->capacity * 2]),
+				   GFP_KERNEL);
+		if (!new_tab)
+			return -ENOMEM;
+		tab = new_tab;
+		tab->capacity *= 2;
+		btf->struct_ops_tab = tab;
+	}
+
+	tab->ops[btf->struct_ops_tab->cnt].st_ops = st_ops;
+
+	err = bpf_struct_ops_desc_init(&tab->ops[btf->struct_ops_tab->cnt], btf, log);
+	if (err)
+		return err;
+
+	btf->struct_ops_tab->cnt++;
+
+	return 0;
+}
+
+const struct bpf_struct_ops_desc *
+bpf_struct_ops_find_value(struct btf *btf, u32 value_id)
+{
+	const struct bpf_struct_ops_desc *st_ops_list;
+	unsigned int i;
+	u32 cnt;
+
+	if (!value_id)
+		return NULL;
+	if (!btf->struct_ops_tab)
+		return NULL;
+
+	cnt = btf->struct_ops_tab->cnt;
+	st_ops_list = btf->struct_ops_tab->ops;
+	for (i = 0; i < cnt; i++) {
+		if (st_ops_list[i].value_id == value_id)
+			return &st_ops_list[i];
+	}
+
+	return NULL;
+}
+
+const struct bpf_struct_ops_desc *
+bpf_struct_ops_find(struct btf *btf, u32 type_id)
+{
+	const struct bpf_struct_ops_desc *st_ops_list;
+	unsigned int i;
+	u32 cnt;
+
+	if (!type_id)
+		return NULL;
+	if (!btf->struct_ops_tab)
+		return NULL;
+
+	cnt = btf->struct_ops_tab->cnt;
+	st_ops_list = btf->struct_ops_tab->ops;
+	for (i = 0; i < cnt; i++) {
+		if (st_ops_list[i].type_id == type_id)
+			return &st_ops_list[i];
+	}
+
+	return NULL;
+}
+
+int __register_bpf_struct_ops(struct bpf_struct_ops *st_ops)
+{
+	struct bpf_verifier_log *log;
+	struct btf *btf;
+	int err = 0;
+
+	btf = btf_get_module_btf(st_ops->owner);
+	if (!btf)
+		return check_btf_kconfigs(st_ops->owner, "struct_ops");
+	if (IS_ERR(btf))
+		return PTR_ERR(btf);
+
+	log = kzalloc(sizeof(*log), GFP_KERNEL | __GFP_NOWARN);
+	if (!log) {
+		err = -ENOMEM;
+		goto errout;
+	}
+
+	log->level = BPF_LOG_KERNEL;
+
+	err = btf_add_struct_ops(btf, st_ops, log);
+
+errout:
+	kfree(log);
+	btf_put(btf);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(__register_bpf_struct_ops);
+#endif
+
+bool btf_param_match_suffix(const struct btf *btf,
+			    const struct btf_param *arg,
+			    const char *suffix)
+{
+	int suffix_len = strlen(suffix), len;
+	const char *param_name;
+
+	/* In the future, this can be ported to use BTF tagging */
+	param_name = btf_name_by_offset(btf, arg->name_off);
+	if (str_is_empty(param_name))
+		return false;
+	len = strlen(param_name);
+	if (len <= suffix_len)
+		return false;
+	param_name += len - suffix_len;
+	return !strncmp(param_name, suffix, suffix_len);
+}