1 files changed, 314 insertions, 8 deletions

diff --git a/include/linux/btf.h b/include/linux/btf.h
index 5c1ea99b480f..f9aababc5d78 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -5,19 +5,86 @@
 #define _LINUX_BTF_H 1
 
 #include <linux/types.h>
+#include <linux/bpfptr.h>
 #include <uapi/linux/btf.h>
+#include <uapi/linux/bpf.h>
 
 #define BTF_TYPE_EMIT(type) ((void)(type *)0)
+#define BTF_TYPE_EMIT_ENUM(enum_val) ((void)enum_val)
+
+/* These need to be macros, as the expressions are used in assembler input */
+#define KF_ACQUIRE	(1 << 0) /* kfunc is an acquire function */
+#define KF_RELEASE	(1 << 1) /* kfunc is a release function */
+#define KF_RET_NULL	(1 << 2) /* kfunc returns a pointer that may be NULL */
+#define KF_KPTR_GET	(1 << 3) /* kfunc returns reference to a kptr */
+/* Trusted arguments are those which are meant to be referenced arguments with
+ * unchanged offset. It is used to enforce that pointers obtained from acquire
+ * kfuncs remain unmodified when being passed to helpers taking trusted args.
+ *
+ * Consider
+ *	struct foo {
+ *		int data;
+ *		struct foo *next;
+ *	};
+ *
+ *	struct bar {
+ *		int data;
+ *		struct foo f;
+ *	};
+ *
+ *	struct foo *f = alloc_foo(); // Acquire kfunc
+ *	struct bar *b = alloc_bar(); // Acquire kfunc
+ *
+ * If a kfunc set_foo_data() wants to operate only on the allocated object, it
+ * will set the KF_TRUSTED_ARGS flag, which will prevent unsafe usage like:
+ *
+ *	set_foo_data(f, 42);	   // Allowed
+ *	set_foo_data(f->next, 42); // Rejected, non-referenced pointer
+ *	set_foo_data(&f->next, 42);// Rejected, referenced, but wrong type
+ *	set_foo_data(&b->f, 42);   // Rejected, referenced, but bad offset
+ *
+ * In the final case, usually for the purposes of type matching, it is deduced
+ * by looking at the type of the member at the offset, but due to the
+ * requirement of trusted argument, this deduction will be strict and not done
+ * for this case.
+ */
+#define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer arguments */
+#define KF_SLEEPABLE    (1 << 5) /* kfunc may sleep */
+#define KF_DESTRUCTIVE  (1 << 6) /* kfunc performs destructive actions */
+
+/*
+ * Return the name of the passed struct, if exists, or halt the build if for
+ * example the structure gets renamed. In this way, developers have to revisit
+ * the code using that structure name, and update it accordingly.
+ */
+#define stringify_struct(x)			\
+	({ BUILD_BUG_ON(sizeof(struct x) < 0);	\
+	   __stringify(x); })
 
 struct btf;
 struct btf_member;
 struct btf_type;
 union bpf_attr;
+struct btf_show;
+struct btf_id_set;
+
+struct btf_kfunc_id_set {
+	struct module *owner;
+	struct btf_id_set8 *set;
+};
+
+struct btf_id_dtor_kfunc {
+	u32 btf_id;
+	u32 kfunc_btf_id;
+};
+
+typedef void (*btf_dtor_kfunc_t)(void *);
 
 extern const struct file_operations btf_fops;
 
+void btf_get(struct btf *btf);
 void btf_put(struct btf *btf);
-int btf_new_fd(const union bpf_attr *attr);
+int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr);
 struct btf *btf_get_by_fd(int fd);
 int btf_get_info_by_fd(const struct btf *btf,
 		       const union bpf_attr *attr,
@@ -46,14 +113,58 @@ int btf_get_info_by_fd(const struct btf *btf,
 const struct btf_type *btf_type_id_size(const struct btf *btf,
 					u32 *type_id,
 					u32 *ret_size);
+
+/*
+ * Options to control show behaviour.
+ *	- BTF_SHOW_COMPACT: no formatting around type information
+ *	- BTF_SHOW_NONAME: no struct/union member names/types
+ *	- BTF_SHOW_PTR_RAW: show raw (unobfuscated) pointer values;
+ *	  equivalent to %px.
+ *	- BTF_SHOW_ZERO: show zero-valued struct/union members; they
+ *	  are not displayed by default
+ *	- BTF_SHOW_UNSAFE: skip use of bpf_probe_read() to safely read
+ *	  data before displaying it.
+ */
+#define BTF_SHOW_COMPACT	BTF_F_COMPACT
+#define BTF_SHOW_NONAME		BTF_F_NONAME
+#define BTF_SHOW_PTR_RAW	BTF_F_PTR_RAW
+#define BTF_SHOW_ZERO		BTF_F_ZERO
+#define BTF_SHOW_UNSAFE		(1ULL << 4)
+
 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
 		       struct seq_file *m);
+int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, void *obj,
+			    struct seq_file *m, u64 flags);
+
+/*
+ * Copy len bytes of string representation of obj of BTF type_id into buf.
+ *
+ * @btf: struct btf object
+ * @type_id: type id of type obj points to
+ * @obj: pointer to typed data
+ * @buf: buffer to write to
+ * @len: maximum length to write to buf
+ * @flags: show options (see above)
+ *
+ * Return: length that would have been/was copied as per snprintf, or
+ *	   negative error.
+ */
+int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
+			   char *buf, int len, u64 flags);
+
 int btf_get_fd_by_id(u32 id);
-u32 btf_id(const struct btf *btf);
+u32 btf_obj_id(const struct btf *btf);
+bool btf_is_kernel(const struct btf *btf);
+bool btf_is_module(const struct btf *btf);
+struct module *btf_try_get_module(const struct btf *btf);
+u32 btf_nr_types(const struct btf *btf);
 bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
 			   const struct btf_member *m,
 			   u32 expected_offset, u32 expected_size);
 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
+int btf_find_timer(const struct btf *btf, const struct btf_type *t);
+struct bpf_map_value_off *btf_parse_kptrs(const struct btf *btf,
+					  const struct btf_type *t);
 bool btf_type_is_void(const struct btf_type *t);
 s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
 const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
@@ -64,14 +175,19 @@ const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
 						 u32 id, u32 *res_id);
 const struct btf_type *
 btf_resolve_size(const struct btf *btf, const struct btf_type *type,
-		 u32 *type_size, const struct btf_type **elem_type,
-		 u32 *total_nelems);
+		 u32 *type_size);
+const char *btf_type_str(const struct btf_type *t);
 
 #define for_each_member(i, struct_type, member)			\
 	for (i = 0, member = btf_type_member(struct_type);	\
 	     i < btf_type_vlen(struct_type);			\
 	     i++, member++)
 
+#define for_each_vsi(i, datasec_type, member)			\
+	for (i = 0, member = btf_type_var_secinfo(datasec_type);	\
+	     i < btf_type_vlen(datasec_type);			\
+	     i++, member++)
+
 static inline bool btf_type_is_ptr(const struct btf_type *t)
 {
 	return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
@@ -82,11 +198,91 @@ static inline bool btf_type_is_int(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
 }
 
+static inline bool btf_type_is_small_int(const struct btf_type *t)
+{
+	return btf_type_is_int(t) && t->size <= sizeof(u64);
+}
+
 static inline bool btf_type_is_enum(const struct btf_type *t)
 {
 	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
 }
 
+static inline bool btf_is_any_enum(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM ||
+	       BTF_INFO_KIND(t->info) == BTF_KIND_ENUM64;
+}
+
+static inline bool btf_kind_core_compat(const struct btf_type *t1,
+					const struct btf_type *t2)
+{
+	return BTF_INFO_KIND(t1->info) == BTF_INFO_KIND(t2->info) ||
+	       (btf_is_any_enum(t1) && btf_is_any_enum(t2));
+}
+
+static inline bool str_is_empty(const char *s)
+{
+	return !s || !s[0];
+}
+
+static inline u16 btf_kind(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info);
+}
+
+static inline bool btf_is_enum(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_ENUM;
+}
+
+static inline bool btf_is_enum64(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_ENUM64;
+}
+
+static inline u64 btf_enum64_value(const struct btf_enum64 *e)
+{
+	return ((u64)e->val_hi32 << 32) | e->val_lo32;
+}
+
+static inline bool btf_is_composite(const struct btf_type *t)
+{
+	u16 kind = btf_kind(t);
+
+	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
+}
+
+static inline bool btf_is_array(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_ARRAY;
+}
+
+static inline bool btf_is_int(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_INT;
+}
+
+static inline bool btf_is_ptr(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_PTR;
+}
+
+static inline u8 btf_int_offset(const struct btf_type *t)
+{
+	return BTF_INT_OFFSET(*(u32 *)(t + 1));
+}
+
+static inline u8 btf_int_encoding(const struct btf_type *t)
+{
+	return BTF_INT_ENCODING(*(u32 *)(t + 1));
+}
+
+static inline bool btf_type_is_scalar(const struct btf_type *t)
+{
+	return btf_type_is_int(t) || btf_type_is_enum(t);
+}
+
 static inline bool btf_type_is_typedef(const struct btf_type *t)
 {
 	return BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF;
@@ -102,11 +298,36 @@ static inline bool btf_type_is_func_proto(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
 }
 
+static inline bool btf_type_is_var(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
+}
+
+static inline bool btf_type_is_type_tag(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG;
+}
+
+/* union is only a special case of struct:
+ * all its offsetof(member) == 0
+ */
+static inline bool btf_type_is_struct(const struct btf_type *t)
+{
+	u8 kind = BTF_INFO_KIND(t->info);
+
+	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
+}
+
 static inline u16 btf_type_vlen(const struct btf_type *t)
 {
 	return BTF_INFO_VLEN(t->info);
 }
 
+static inline u16 btf_vlen(const struct btf_type *t)
+{
+	return btf_type_vlen(t);
+}
+
 static inline u16 btf_func_linkage(const struct btf_type *t)
 {
 	return BTF_INFO_VLEN(t->info);
@@ -117,30 +338,85 @@ static inline bool btf_type_kflag(const struct btf_type *t)
 	return BTF_INFO_KFLAG(t->info);
 }
 
-static inline u32 btf_member_bit_offset(const struct btf_type *struct_type,
-					const struct btf_member *member)
+static inline u32 __btf_member_bit_offset(const struct btf_type *struct_type,
+					  const struct btf_member *member)
 {
 	return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
 					   : member->offset;
 }
 
-static inline u32 btf_member_bitfield_size(const struct btf_type *struct_type,
-					   const struct btf_member *member)
+static inline u32 __btf_member_bitfield_size(const struct btf_type *struct_type,
+					     const struct btf_member *member)
 {
 	return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
 					   : 0;
 }
 
+static inline struct btf_member *btf_members(const struct btf_type *t)
+{
+	return (struct btf_member *)(t + 1);
+}
+
+static inline u32 btf_member_bit_offset(const struct btf_type *t, u32 member_idx)
+{
+	const struct btf_member *m = btf_members(t) + member_idx;
+
+	return __btf_member_bit_offset(t, m);
+}
+
+static inline u32 btf_member_bitfield_size(const struct btf_type *t, u32 member_idx)
+{
+	const struct btf_member *m = btf_members(t) + member_idx;
+
+	return __btf_member_bitfield_size(t, m);
+}
+
 static inline const struct btf_member *btf_type_member(const struct btf_type *t)
 {
 	return (const struct btf_member *)(t + 1);
 }
 
+static inline struct btf_array *btf_array(const struct btf_type *t)
+{
+	return (struct btf_array *)(t + 1);
+}
+
+static inline struct btf_enum *btf_enum(const struct btf_type *t)
+{
+	return (struct btf_enum *)(t + 1);
+}
+
+static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
+{
+	return (struct btf_enum64 *)(t + 1);
+}
+
+static inline const struct btf_var_secinfo *btf_type_var_secinfo(
+		const struct btf_type *t)
+{
+	return (const struct btf_var_secinfo *)(t + 1);
+}
+
+static inline struct btf_param *btf_params(const struct btf_type *t)
+{
+	return (struct btf_param *)(t + 1);
+}
+
 #ifdef CONFIG_BPF_SYSCALL
+struct bpf_prog;
+
 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
 const char *btf_name_by_offset(const struct btf *btf, u32 offset);
 struct btf *btf_parse_vmlinux(void);
 struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
+u32 *btf_kfunc_id_set_contains(const struct btf *btf,
+			       enum bpf_prog_type prog_type,
+			       u32 kfunc_btf_id);
+int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
+			      const struct btf_kfunc_id_set *s);
+s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id);
+int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt,
+				struct module *owner);
 #else
 static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
 						    u32 type_id)
@@ -152,6 +428,36 @@ static inline const char *btf_name_by_offset(const struct btf *btf,
 {
 	return NULL;
 }
+static inline u32 *btf_kfunc_id_set_contains(const struct btf *btf,
+					     enum bpf_prog_type prog_type,
+					     u32 kfunc_btf_id)
+{
+	return NULL;
+}
+static inline int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
+					    const struct btf_kfunc_id_set *s)
+{
+	return 0;
+}
+static inline s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id)
+{
+	return -ENOENT;
+}
+static inline int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors,
+					      u32 add_cnt, struct module *owner)
+{
+	return 0;
+}
 #endif
 
+static inline bool btf_type_is_struct_ptr(struct btf *btf, const struct btf_type *t)
+{
+	if (!btf_type_is_ptr(t))
+		return false;
+
+	t = btf_type_skip_modifiers(btf, t->type, NULL);
+
+	return btf_type_is_struct(t);
+}
+
 #endif