1 files changed, 89 insertions, 31 deletions

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 7906b9bf7ff8..0493310d981f 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3163,24 +3163,44 @@ static void btf_struct_log(struct btf_verifier_env *env,
 	btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
 }
 
+enum btf_field_type {
+	BTF_FIELD_SPIN_LOCK,
+	BTF_FIELD_TIMER,
+};
+
+struct btf_field_info {
+	u32 off;
+};
+
+static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
+			   u32 off, int sz, struct btf_field_info *info)
+{
+	if (!__btf_type_is_struct(t))
+		return 0;
+	if (t->size != sz)
+		return 0;
+	if (info->off != -ENOENT)
+		/* only one such field is allowed */
+		return -E2BIG;
+	info->off = off;
+	return 0;
+}
+
 static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t,
-				 const char *name, int sz, int align)
+				 const char *name, int sz, int align,
+				 enum btf_field_type field_type,
+				 struct btf_field_info *info)
 {
 	const struct btf_member *member;
-	u32 i, off = -ENOENT;
+	u32 i, off;
 
 	for_each_member(i, t, member) {
 		const struct btf_type *member_type = btf_type_by_id(btf,
 								    member->type);
-		if (!__btf_type_is_struct(member_type))
-			continue;
-		if (member_type->size != sz)
-			continue;
+
 		if (strcmp(__btf_name_by_offset(btf, member_type->name_off), name))
 			continue;
-		if (off != -ENOENT)
-			/* only one such field is allowed */
-			return -E2BIG;
+
 		off = __btf_member_bit_offset(t, member);
 		if (off % 8)
 			/* valid C code cannot generate such BTF */
@@ -3188,46 +3208,76 @@ static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t
 		off /= 8;
 		if (off % align)
 			return -EINVAL;
+
+		switch (field_type) {
+		case BTF_FIELD_SPIN_LOCK:
+		case BTF_FIELD_TIMER:
+			return btf_find_struct(btf, member_type, off, sz, info);
+		default:
+			return -EFAULT;
+		}
 	}
-	return off;
+	return 0;
 }
 
 static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
-				const char *name, int sz, int align)
+				const char *name, int sz, int align,
+				enum btf_field_type field_type,
+				struct btf_field_info *info)
 {
 	const struct btf_var_secinfo *vsi;
-	u32 i, off = -ENOENT;
+	u32 i, off;
 
 	for_each_vsi(i, t, vsi) {
 		const struct btf_type *var = btf_type_by_id(btf, vsi->type);
 		const struct btf_type *var_type = btf_type_by_id(btf, var->type);
 
-		if (!__btf_type_is_struct(var_type))
-			continue;
-		if (var_type->size != sz)
+		off = vsi->offset;
+
+		if (strcmp(__btf_name_by_offset(btf, var_type->name_off), name))
 			continue;
 		if (vsi->size != sz)
 			continue;
-		if (strcmp(__btf_name_by_offset(btf, var_type->name_off), name))
-			continue;
-		if (off != -ENOENT)
-			/* only one such field is allowed */
-			return -E2BIG;
-		off = vsi->offset;
 		if (off % align)
 			return -EINVAL;
+
+		switch (field_type) {
+		case BTF_FIELD_SPIN_LOCK:
+		case BTF_FIELD_TIMER:
+			return btf_find_struct(btf, var_type, off, sz, info);
+		default:
+			return -EFAULT;
+		}
 	}
-	return off;
+	return 0;
 }
 
 static int btf_find_field(const struct btf *btf, const struct btf_type *t,
-			  const char *name, int sz, int align)
+			  enum btf_field_type field_type,
+			  struct btf_field_info *info)
 {
+	const char *name;
+	int sz, align;
+
+	switch (field_type) {
+	case BTF_FIELD_SPIN_LOCK:
+		name = "bpf_spin_lock";
+		sz = sizeof(struct bpf_spin_lock);
+		align = __alignof__(struct bpf_spin_lock);
+		break;
+	case BTF_FIELD_TIMER:
+		name = "bpf_timer";
+		sz = sizeof(struct bpf_timer);
+		align = __alignof__(struct bpf_timer);
+		break;
+	default:
+		return -EFAULT;
+	}
 
 	if (__btf_type_is_struct(t))
-		return btf_find_struct_field(btf, t, name, sz, align);
+		return btf_find_struct_field(btf, t, name, sz, align, field_type, info);
 	else if (btf_type_is_datasec(t))
-		return btf_find_datasec_var(btf, t, name, sz, align);
+		return btf_find_datasec_var(btf, t, name, sz, align, field_type, info);
 	return -EINVAL;
 }
 
@@ -3237,16 +3287,24 @@ static int btf_find_field(const struct btf *btf, const struct btf_type *t,
  */
 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
 {
-	return btf_find_field(btf, t, "bpf_spin_lock",
-			      sizeof(struct bpf_spin_lock),
-			      __alignof__(struct bpf_spin_lock));
+	struct btf_field_info info = { .off = -ENOENT };
+	int ret;
+
+	ret = btf_find_field(btf, t, BTF_FIELD_SPIN_LOCK, &info);
+	if (ret < 0)
+		return ret;
+	return info.off;
 }
 
 int btf_find_timer(const struct btf *btf, const struct btf_type *t)
 {
-	return btf_find_field(btf, t, "bpf_timer",
-			      sizeof(struct bpf_timer),
-			      __alignof__(struct bpf_timer));
+	struct btf_field_info info = { .off = -ENOENT };
+	int ret;
+
+	ret = btf_find_field(btf, t, BTF_FIELD_TIMER, &info);
+	if (ret < 0)
+		return ret;
+	return info.off;
 }
 
 static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,