| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* Copyright (c) 2018 Facebook */ |
| 3 | |
| 4 | #include <uapi/linux/btf.h> |
| 5 | #include <uapi/linux/bpf.h> |
| 6 | #include <uapi/linux/bpf_perf_event.h> |
| 7 | #include <uapi/linux/types.h> |
| 8 | #include <linux/seq_file.h> |
| 9 | #include <linux/compiler.h> |
| 10 | #include <linux/ctype.h> |
| 11 | #include <linux/errno.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/anon_inodes.h> |
| 14 | #include <linux/file.h> |
| 15 | #include <linux/uaccess.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/idr.h> |
| 18 | #include <linux/sort.h> |
| 19 | #include <linux/bpf_verifier.h> |
| 20 | #include <linux/btf.h> |
| 21 | #include <linux/btf_ids.h> |
| 22 | #include <linux/bpf_lsm.h> |
| 23 | #include <linux/skmsg.h> |
| 24 | #include <linux/perf_event.h> |
| 25 | #include <linux/bsearch.h> |
| 26 | #include <linux/kobject.h> |
| 27 | #include <linux/sysfs.h> |
| 28 | #include <net/sock.h> |
| 29 | #include "../tools/lib/bpf/relo_core.h" |
| 30 | |
| 31 | /* BTF (BPF Type Format) is the meta data format which describes |
| 32 | * the data types of BPF program/map. Hence, it basically focus |
| 33 | * on the C programming language which the modern BPF is primary |
| 34 | * using. |
| 35 | * |
| 36 | * ELF Section: |
| 37 | * ~~~~~~~~~~~ |
| 38 | * The BTF data is stored under the ".BTF" ELF section |
| 39 | * |
| 40 | * struct btf_type: |
| 41 | * ~~~~~~~~~~~~~~~ |
| 42 | * Each 'struct btf_type' object describes a C data type. |
| 43 | * Depending on the type it is describing, a 'struct btf_type' |
| 44 | * object may be followed by more data. F.e. |
| 45 | * To describe an array, 'struct btf_type' is followed by |
| 46 | * 'struct btf_array'. |
| 47 | * |
| 48 | * 'struct btf_type' and any extra data following it are |
| 49 | * 4 bytes aligned. |
| 50 | * |
| 51 | * Type section: |
| 52 | * ~~~~~~~~~~~~~ |
| 53 | * The BTF type section contains a list of 'struct btf_type' objects. |
| 54 | * Each one describes a C type. Recall from the above section |
| 55 | * that a 'struct btf_type' object could be immediately followed by extra |
| 56 | * data in order to describe some particular C types. |
| 57 | * |
| 58 | * type_id: |
| 59 | * ~~~~~~~ |
| 60 | * Each btf_type object is identified by a type_id. The type_id |
| 61 | * is implicitly implied by the location of the btf_type object in |
| 62 | * the BTF type section. The first one has type_id 1. The second |
| 63 | * one has type_id 2...etc. Hence, an earlier btf_type has |
| 64 | * a smaller type_id. |
| 65 | * |
| 66 | * A btf_type object may refer to another btf_type object by using |
| 67 | * type_id (i.e. the "type" in the "struct btf_type"). |
| 68 | * |
| 69 | * NOTE that we cannot assume any reference-order. |
| 70 | * A btf_type object can refer to an earlier btf_type object |
| 71 | * but it can also refer to a later btf_type object. |
| 72 | * |
| 73 | * For example, to describe "const void *". A btf_type |
| 74 | * object describing "const" may refer to another btf_type |
| 75 | * object describing "void *". This type-reference is done |
| 76 | * by specifying type_id: |
| 77 | * |
| 78 | * [1] CONST (anon) type_id=2 |
| 79 | * [2] PTR (anon) type_id=0 |
| 80 | * |
| 81 | * The above is the btf_verifier debug log: |
| 82 | * - Each line started with "[?]" is a btf_type object |
| 83 | * - [?] is the type_id of the btf_type object. |
| 84 | * - CONST/PTR is the BTF_KIND_XXX |
| 85 | * - "(anon)" is the name of the type. It just |
| 86 | * happens that CONST and PTR has no name. |
| 87 | * - type_id=XXX is the 'u32 type' in btf_type |
| 88 | * |
| 89 | * NOTE: "void" has type_id 0 |
| 90 | * |
| 91 | * String section: |
| 92 | * ~~~~~~~~~~~~~~ |
| 93 | * The BTF string section contains the names used by the type section. |
| 94 | * Each string is referred by an "offset" from the beginning of the |
| 95 | * string section. |
| 96 | * |
| 97 | * Each string is '\0' terminated. |
| 98 | * |
| 99 | * The first character in the string section must be '\0' |
| 100 | * which is used to mean 'anonymous'. Some btf_type may not |
| 101 | * have a name. |
| 102 | */ |
| 103 | |
| 104 | /* BTF verification: |
| 105 | * |
| 106 | * To verify BTF data, two passes are needed. |
| 107 | * |
| 108 | * Pass #1 |
| 109 | * ~~~~~~~ |
| 110 | * The first pass is to collect all btf_type objects to |
| 111 | * an array: "btf->types". |
| 112 | * |
| 113 | * Depending on the C type that a btf_type is describing, |
| 114 | * a btf_type may be followed by extra data. We don't know |
| 115 | * how many btf_type is there, and more importantly we don't |
| 116 | * know where each btf_type is located in the type section. |
| 117 | * |
| 118 | * Without knowing the location of each type_id, most verifications |
| 119 | * cannot be done. e.g. an earlier btf_type may refer to a later |
| 120 | * btf_type (recall the "const void *" above), so we cannot |
| 121 | * check this type-reference in the first pass. |
| 122 | * |
| 123 | * In the first pass, it still does some verifications (e.g. |
| 124 | * checking the name is a valid offset to the string section). |
| 125 | * |
| 126 | * Pass #2 |
| 127 | * ~~~~~~~ |
| 128 | * The main focus is to resolve a btf_type that is referring |
| 129 | * to another type. |
| 130 | * |
| 131 | * We have to ensure the referring type: |
| 132 | * 1) does exist in the BTF (i.e. in btf->types[]) |
| 133 | * 2) does not cause a loop: |
| 134 | * struct A { |
| 135 | * struct B b; |
| 136 | * }; |
| 137 | * |
| 138 | * struct B { |
| 139 | * struct A a; |
| 140 | * }; |
| 141 | * |
| 142 | * btf_type_needs_resolve() decides if a btf_type needs |
| 143 | * to be resolved. |
| 144 | * |
| 145 | * The needs_resolve type implements the "resolve()" ops which |
| 146 | * essentially does a DFS and detects backedge. |
| 147 | * |
| 148 | * During resolve (or DFS), different C types have different |
| 149 | * "RESOLVED" conditions. |
| 150 | * |
| 151 | * When resolving a BTF_KIND_STRUCT, we need to resolve all its |
| 152 | * members because a member is always referring to another |
| 153 | * type. A struct's member can be treated as "RESOLVED" if |
| 154 | * it is referring to a BTF_KIND_PTR. Otherwise, the |
| 155 | * following valid C struct would be rejected: |
| 156 | * |
| 157 | * struct A { |
| 158 | * int m; |
| 159 | * struct A *a; |
| 160 | * }; |
| 161 | * |
| 162 | * When resolving a BTF_KIND_PTR, it needs to keep resolving if |
| 163 | * it is referring to another BTF_KIND_PTR. Otherwise, we cannot |
| 164 | * detect a pointer loop, e.g.: |
| 165 | * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + |
| 166 | * ^ | |
| 167 | * +-----------------------------------------+ |
| 168 | * |
| 169 | */ |
| 170 | |
| 171 | #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
| 172 | #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
| 173 | #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) |
| 174 | #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) |
| 175 | #define BITS_ROUNDUP_BYTES(bits) \ |
| 176 | (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) |
| 177 | |
| 178 | #define BTF_INFO_MASK 0x9f00ffff |
| 179 | #define BTF_INT_MASK 0x0fffffff |
| 180 | #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) |
| 181 | #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) |
| 182 | |
| 183 | /* 16MB for 64k structs and each has 16 members and |
| 184 | * a few MB spaces for the string section. |
| 185 | * The hard limit is S32_MAX. |
| 186 | */ |
| 187 | #define BTF_MAX_SIZE (16 * 1024 * 1024) |
| 188 | |
| 189 | #define for_each_member_from(i, from, struct_type, member) \ |
| 190 | for (i = from, member = btf_type_member(struct_type) + from; \ |
| 191 | i < btf_type_vlen(struct_type); \ |
| 192 | i++, member++) |
| 193 | |
| 194 | #define for_each_vsi_from(i, from, struct_type, member) \ |
| 195 | for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ |
| 196 | i < btf_type_vlen(struct_type); \ |
| 197 | i++, member++) |
| 198 | |
| 199 | DEFINE_IDR(btf_idr); |
| 200 | DEFINE_SPINLOCK(btf_idr_lock); |
| 201 | |
| 202 | enum btf_kfunc_hook { |
| 203 | BTF_KFUNC_HOOK_COMMON, |
| 204 | BTF_KFUNC_HOOK_XDP, |
| 205 | BTF_KFUNC_HOOK_TC, |
| 206 | BTF_KFUNC_HOOK_STRUCT_OPS, |
| 207 | BTF_KFUNC_HOOK_TRACING, |
| 208 | BTF_KFUNC_HOOK_SYSCALL, |
| 209 | BTF_KFUNC_HOOK_FMODRET, |
| 210 | BTF_KFUNC_HOOK_MAX, |
| 211 | }; |
| 212 | |
| 213 | enum { |
| 214 | BTF_KFUNC_SET_MAX_CNT = 256, |
| 215 | BTF_DTOR_KFUNC_MAX_CNT = 256, |
| 216 | }; |
| 217 | |
| 218 | struct btf_kfunc_set_tab { |
| 219 | struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX]; |
| 220 | }; |
| 221 | |
| 222 | struct btf_id_dtor_kfunc_tab { |
| 223 | u32 cnt; |
| 224 | struct btf_id_dtor_kfunc dtors[]; |
| 225 | }; |
| 226 | |
| 227 | struct btf { |
| 228 | void *data; |
| 229 | struct btf_type **types; |
| 230 | u32 *resolved_ids; |
| 231 | u32 *resolved_sizes; |
| 232 | const char *strings; |
| 233 | void *nohdr_data; |
| 234 | struct btf_header hdr; |
| 235 | u32 nr_types; /* includes VOID for base BTF */ |
| 236 | u32 types_size; |
| 237 | u32 data_size; |
| 238 | refcount_t refcnt; |
| 239 | u32 id; |
| 240 | struct rcu_head rcu; |
| 241 | struct btf_kfunc_set_tab *kfunc_set_tab; |
| 242 | struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab; |
| 243 | struct btf_struct_metas *struct_meta_tab; |
| 244 | |
| 245 | /* split BTF support */ |
| 246 | struct btf *base_btf; |
| 247 | u32 start_id; /* first type ID in this BTF (0 for base BTF) */ |
| 248 | u32 start_str_off; /* first string offset (0 for base BTF) */ |
| 249 | char name[MODULE_NAME_LEN]; |
| 250 | bool kernel_btf; |
| 251 | }; |
| 252 | |
| 253 | enum verifier_phase { |
| 254 | CHECK_META, |
| 255 | CHECK_TYPE, |
| 256 | }; |
| 257 | |
| 258 | struct resolve_vertex { |
| 259 | const struct btf_type *t; |
| 260 | u32 type_id; |
| 261 | u16 next_member; |
| 262 | }; |
| 263 | |
| 264 | enum visit_state { |
| 265 | NOT_VISITED, |
| 266 | VISITED, |
| 267 | RESOLVED, |
| 268 | }; |
| 269 | |
| 270 | enum resolve_mode { |
| 271 | RESOLVE_TBD, /* To Be Determined */ |
| 272 | RESOLVE_PTR, /* Resolving for Pointer */ |
| 273 | RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union |
| 274 | * or array |
| 275 | */ |
| 276 | }; |
| 277 | |
| 278 | #define MAX_RESOLVE_DEPTH 32 |
| 279 | |
| 280 | struct btf_sec_info { |
| 281 | u32 off; |
| 282 | u32 len; |
| 283 | }; |
| 284 | |
| 285 | struct btf_verifier_env { |
| 286 | struct btf *btf; |
| 287 | u8 *visit_states; |
| 288 | struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; |
| 289 | struct bpf_verifier_log log; |
| 290 | u32 log_type_id; |
| 291 | u32 top_stack; |
| 292 | enum verifier_phase phase; |
| 293 | enum resolve_mode resolve_mode; |
| 294 | }; |
| 295 | |
| 296 | static const char * const btf_kind_str[NR_BTF_KINDS] = { |
| 297 | [BTF_KIND_UNKN] = "UNKNOWN", |
| 298 | [BTF_KIND_INT] = "INT", |
| 299 | [BTF_KIND_PTR] = "PTR", |
| 300 | [BTF_KIND_ARRAY] = "ARRAY", |
| 301 | [BTF_KIND_STRUCT] = "STRUCT", |
| 302 | [BTF_KIND_UNION] = "UNION", |
| 303 | [BTF_KIND_ENUM] = "ENUM", |
| 304 | [BTF_KIND_FWD] = "FWD", |
| 305 | [BTF_KIND_TYPEDEF] = "TYPEDEF", |
| 306 | [BTF_KIND_VOLATILE] = "VOLATILE", |
| 307 | [BTF_KIND_CONST] = "CONST", |
| 308 | [BTF_KIND_RESTRICT] = "RESTRICT", |
| 309 | [BTF_KIND_FUNC] = "FUNC", |
| 310 | [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", |
| 311 | [BTF_KIND_VAR] = "VAR", |
| 312 | [BTF_KIND_DATASEC] = "DATASEC", |
| 313 | [BTF_KIND_FLOAT] = "FLOAT", |
| 314 | [BTF_KIND_DECL_TAG] = "DECL_TAG", |
| 315 | [BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
| 316 | [BTF_KIND_ENUM64] = "ENUM64", |
| 317 | }; |
| 318 | |
| 319 | const char *btf_type_str(const struct btf_type *t) |
| 320 | { |
| 321 | return btf_kind_str[BTF_INFO_KIND(t->info)]; |
| 322 | } |
| 323 | |
| 324 | /* Chunk size we use in safe copy of data to be shown. */ |
| 325 | #define BTF_SHOW_OBJ_SAFE_SIZE 32 |
| 326 | |
| 327 | /* |
| 328 | * This is the maximum size of a base type value (equivalent to a |
| 329 | * 128-bit int); if we are at the end of our safe buffer and have |
| 330 | * less than 16 bytes space we can't be assured of being able |
| 331 | * to copy the next type safely, so in such cases we will initiate |
| 332 | * a new copy. |
| 333 | */ |
| 334 | #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 |
| 335 | |
| 336 | /* Type name size */ |
| 337 | #define BTF_SHOW_NAME_SIZE 80 |
| 338 | |
| 339 | /* |
| 340 | * The suffix of a type that indicates it cannot alias another type when |
| 341 | * comparing BTF IDs for kfunc invocations. |
| 342 | */ |
| 343 | #define NOCAST_ALIAS_SUFFIX "___init" |
| 344 | |
| 345 | /* |
| 346 | * Common data to all BTF show operations. Private show functions can add |
| 347 | * their own data to a structure containing a struct btf_show and consult it |
| 348 | * in the show callback. See btf_type_show() below. |
| 349 | * |
| 350 | * One challenge with showing nested data is we want to skip 0-valued |
| 351 | * data, but in order to figure out whether a nested object is all zeros |
| 352 | * we need to walk through it. As a result, we need to make two passes |
| 353 | * when handling structs, unions and arrays; the first path simply looks |
| 354 | * for nonzero data, while the second actually does the display. The first |
| 355 | * pass is signalled by show->state.depth_check being set, and if we |
| 356 | * encounter a non-zero value we set show->state.depth_to_show to |
| 357 | * the depth at which we encountered it. When we have completed the |
| 358 | * first pass, we will know if anything needs to be displayed if |
| 359 | * depth_to_show > depth. See btf_[struct,array]_show() for the |
| 360 | * implementation of this. |
| 361 | * |
| 362 | * Another problem is we want to ensure the data for display is safe to |
| 363 | * access. To support this, the anonymous "struct {} obj" tracks the data |
| 364 | * object and our safe copy of it. We copy portions of the data needed |
| 365 | * to the object "copy" buffer, but because its size is limited to |
| 366 | * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we |
| 367 | * traverse larger objects for display. |
| 368 | * |
| 369 | * The various data type show functions all start with a call to |
| 370 | * btf_show_start_type() which returns a pointer to the safe copy |
| 371 | * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the |
| 372 | * raw data itself). btf_show_obj_safe() is responsible for |
| 373 | * using copy_from_kernel_nofault() to update the safe data if necessary |
| 374 | * as we traverse the object's data. skbuff-like semantics are |
| 375 | * used: |
| 376 | * |
| 377 | * - obj.head points to the start of the toplevel object for display |
| 378 | * - obj.size is the size of the toplevel object |
| 379 | * - obj.data points to the current point in the original data at |
| 380 | * which our safe data starts. obj.data will advance as we copy |
| 381 | * portions of the data. |
| 382 | * |
| 383 | * In most cases a single copy will suffice, but larger data structures |
| 384 | * such as "struct task_struct" will require many copies. The logic in |
| 385 | * btf_show_obj_safe() handles the logic that determines if a new |
| 386 | * copy_from_kernel_nofault() is needed. |
| 387 | */ |
| 388 | struct btf_show { |
| 389 | u64 flags; |
| 390 | void *target; /* target of show operation (seq file, buffer) */ |
| 391 | void (*showfn)(struct btf_show *show, const char *fmt, va_list args); |
| 392 | const struct btf *btf; |
| 393 | /* below are used during iteration */ |
| 394 | struct { |
| 395 | u8 depth; |
| 396 | u8 depth_to_show; |
| 397 | u8 depth_check; |
| 398 | u8 array_member:1, |
| 399 | array_terminated:1; |
| 400 | u16 array_encoding; |
| 401 | u32 type_id; |
| 402 | int status; /* non-zero for error */ |
| 403 | const struct btf_type *type; |
| 404 | const struct btf_member *member; |
| 405 | char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ |
| 406 | } state; |
| 407 | struct { |
| 408 | u32 size; |
| 409 | void *head; |
| 410 | void *data; |
| 411 | u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; |
| 412 | } obj; |
| 413 | }; |
| 414 | |
| 415 | struct btf_kind_operations { |
| 416 | s32 (*check_meta)(struct btf_verifier_env *env, |
| 417 | const struct btf_type *t, |
| 418 | u32 meta_left); |
| 419 | int (*resolve)(struct btf_verifier_env *env, |
| 420 | const struct resolve_vertex *v); |
| 421 | int (*check_member)(struct btf_verifier_env *env, |
| 422 | const struct btf_type *struct_type, |
| 423 | const struct btf_member *member, |
| 424 | const struct btf_type *member_type); |
| 425 | int (*check_kflag_member)(struct btf_verifier_env *env, |
| 426 | const struct btf_type *struct_type, |
| 427 | const struct btf_member *member, |
| 428 | const struct btf_type *member_type); |
| 429 | void (*log_details)(struct btf_verifier_env *env, |
| 430 | const struct btf_type *t); |
| 431 | void (*show)(const struct btf *btf, const struct btf_type *t, |
| 432 | u32 type_id, void *data, u8 bits_offsets, |
| 433 | struct btf_show *show); |
| 434 | }; |
| 435 | |
| 436 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; |
| 437 | static struct btf_type btf_void; |
| 438 | |
| 439 | static int btf_resolve(struct btf_verifier_env *env, |
| 440 | const struct btf_type *t, u32 type_id); |
| 441 | |
| 442 | static int btf_func_check(struct btf_verifier_env *env, |
| 443 | const struct btf_type *t); |
| 444 | |
| 445 | static bool btf_type_is_modifier(const struct btf_type *t) |
| 446 | { |
| 447 | /* Some of them is not strictly a C modifier |
| 448 | * but they are grouped into the same bucket |
| 449 | * for BTF concern: |
| 450 | * A type (t) that refers to another |
| 451 | * type through t->type AND its size cannot |
| 452 | * be determined without following the t->type. |
| 453 | * |
| 454 | * ptr does not fall into this bucket |
| 455 | * because its size is always sizeof(void *). |
| 456 | */ |
| 457 | switch (BTF_INFO_KIND(t->info)) { |
| 458 | case BTF_KIND_TYPEDEF: |
| 459 | case BTF_KIND_VOLATILE: |
| 460 | case BTF_KIND_CONST: |
| 461 | case BTF_KIND_RESTRICT: |
| 462 | case BTF_KIND_TYPE_TAG: |
| 463 | return true; |
| 464 | } |
| 465 | |
| 466 | return false; |
| 467 | } |
| 468 | |
| 469 | bool btf_type_is_void(const struct btf_type *t) |
| 470 | { |
| 471 | return t == &btf_void; |
| 472 | } |
| 473 | |
| 474 | static bool btf_type_is_fwd(const struct btf_type *t) |
| 475 | { |
| 476 | return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; |
| 477 | } |
| 478 | |
| 479 | static bool btf_type_nosize(const struct btf_type *t) |
| 480 | { |
| 481 | return btf_type_is_void(t) || btf_type_is_fwd(t) || |
| 482 | btf_type_is_func(t) || btf_type_is_func_proto(t); |
| 483 | } |
| 484 | |
| 485 | static bool btf_type_nosize_or_null(const struct btf_type *t) |
| 486 | { |
| 487 | return !t || btf_type_nosize(t); |
| 488 | } |
| 489 | |
| 490 | static bool btf_type_is_datasec(const struct btf_type *t) |
| 491 | { |
| 492 | return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; |
| 493 | } |
| 494 | |
| 495 | static bool btf_type_is_decl_tag(const struct btf_type *t) |
| 496 | { |
| 497 | return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
| 498 | } |
| 499 | |
| 500 | static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
| 501 | { |
| 502 | return btf_type_is_func(t) || btf_type_is_struct(t) || |
| 503 | btf_type_is_var(t) || btf_type_is_typedef(t); |
| 504 | } |
| 505 | |
| 506 | u32 btf_nr_types(const struct btf *btf) |
| 507 | { |
| 508 | u32 total = 0; |
| 509 | |
| 510 | while (btf) { |
| 511 | total += btf->nr_types; |
| 512 | btf = btf->base_btf; |
| 513 | } |
| 514 | |
| 515 | return total; |
| 516 | } |
| 517 | |
| 518 | s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
| 519 | { |
| 520 | const struct btf_type *t; |
| 521 | const char *tname; |
| 522 | u32 i, total; |
| 523 | |
| 524 | total = btf_nr_types(btf); |
| 525 | for (i = 1; i < total; i++) { |
| 526 | t = btf_type_by_id(btf, i); |
| 527 | if (BTF_INFO_KIND(t->info) != kind) |
| 528 | continue; |
| 529 | |
| 530 | tname = btf_name_by_offset(btf, t->name_off); |
| 531 | if (!strcmp(tname, name)) |
| 532 | return i; |
| 533 | } |
| 534 | |
| 535 | return -ENOENT; |
| 536 | } |
| 537 | |
| 538 | static s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) |
| 539 | { |
| 540 | struct btf *btf; |
| 541 | s32 ret; |
| 542 | int id; |
| 543 | |
| 544 | btf = bpf_get_btf_vmlinux(); |
| 545 | if (IS_ERR(btf)) |
| 546 | return PTR_ERR(btf); |
| 547 | if (!btf) |
| 548 | return -EINVAL; |
| 549 | |
| 550 | ret = btf_find_by_name_kind(btf, name, kind); |
| 551 | /* ret is never zero, since btf_find_by_name_kind returns |
| 552 | * positive btf_id or negative error. |
| 553 | */ |
| 554 | if (ret > 0) { |
| 555 | btf_get(btf); |
| 556 | *btf_p = btf; |
| 557 | return ret; |
| 558 | } |
| 559 | |
| 560 | /* If name is not found in vmlinux's BTF then search in module's BTFs */ |
| 561 | spin_lock_bh(&btf_idr_lock); |
| 562 | idr_for_each_entry(&btf_idr, btf, id) { |
| 563 | if (!btf_is_module(btf)) |
| 564 | continue; |
| 565 | /* linear search could be slow hence unlock/lock |
| 566 | * the IDR to avoiding holding it for too long |
| 567 | */ |
| 568 | btf_get(btf); |
| 569 | spin_unlock_bh(&btf_idr_lock); |
| 570 | ret = btf_find_by_name_kind(btf, name, kind); |
| 571 | if (ret > 0) { |
| 572 | *btf_p = btf; |
| 573 | return ret; |
| 574 | } |
| 575 | spin_lock_bh(&btf_idr_lock); |
| 576 | btf_put(btf); |
| 577 | } |
| 578 | spin_unlock_bh(&btf_idr_lock); |
| 579 | return ret; |
| 580 | } |
| 581 | |
| 582 | const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, |
| 583 | u32 id, u32 *res_id) |
| 584 | { |
| 585 | const struct btf_type *t = btf_type_by_id(btf, id); |
| 586 | |
| 587 | while (btf_type_is_modifier(t)) { |
| 588 | id = t->type; |
| 589 | t = btf_type_by_id(btf, t->type); |
| 590 | } |
| 591 | |
| 592 | if (res_id) |
| 593 | *res_id = id; |
| 594 | |
| 595 | return t; |
| 596 | } |
| 597 | |
| 598 | const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, |
| 599 | u32 id, u32 *res_id) |
| 600 | { |
| 601 | const struct btf_type *t; |
| 602 | |
| 603 | t = btf_type_skip_modifiers(btf, id, NULL); |
| 604 | if (!btf_type_is_ptr(t)) |
| 605 | return NULL; |
| 606 | |
| 607 | return btf_type_skip_modifiers(btf, t->type, res_id); |
| 608 | } |
| 609 | |
| 610 | const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, |
| 611 | u32 id, u32 *res_id) |
| 612 | { |
| 613 | const struct btf_type *ptype; |
| 614 | |
| 615 | ptype = btf_type_resolve_ptr(btf, id, res_id); |
| 616 | if (ptype && btf_type_is_func_proto(ptype)) |
| 617 | return ptype; |
| 618 | |
| 619 | return NULL; |
| 620 | } |
| 621 | |
| 622 | /* Types that act only as a source, not sink or intermediate |
| 623 | * type when resolving. |
| 624 | */ |
| 625 | static bool btf_type_is_resolve_source_only(const struct btf_type *t) |
| 626 | { |
| 627 | return btf_type_is_var(t) || |
| 628 | btf_type_is_decl_tag(t) || |
| 629 | btf_type_is_datasec(t); |
| 630 | } |
| 631 | |
| 632 | /* What types need to be resolved? |
| 633 | * |
| 634 | * btf_type_is_modifier() is an obvious one. |
| 635 | * |
| 636 | * btf_type_is_struct() because its member refers to |
| 637 | * another type (through member->type). |
| 638 | * |
| 639 | * btf_type_is_var() because the variable refers to |
| 640 | * another type. btf_type_is_datasec() holds multiple |
| 641 | * btf_type_is_var() types that need resolving. |
| 642 | * |
| 643 | * btf_type_is_array() because its element (array->type) |
| 644 | * refers to another type. Array can be thought of a |
| 645 | * special case of struct while array just has the same |
| 646 | * member-type repeated by array->nelems of times. |
| 647 | */ |
| 648 | static bool btf_type_needs_resolve(const struct btf_type *t) |
| 649 | { |
| 650 | return btf_type_is_modifier(t) || |
| 651 | btf_type_is_ptr(t) || |
| 652 | btf_type_is_struct(t) || |
| 653 | btf_type_is_array(t) || |
| 654 | btf_type_is_var(t) || |
| 655 | btf_type_is_func(t) || |
| 656 | btf_type_is_decl_tag(t) || |
| 657 | btf_type_is_datasec(t); |
| 658 | } |
| 659 | |
| 660 | /* t->size can be used */ |
| 661 | static bool btf_type_has_size(const struct btf_type *t) |
| 662 | { |
| 663 | switch (BTF_INFO_KIND(t->info)) { |
| 664 | case BTF_KIND_INT: |
| 665 | case BTF_KIND_STRUCT: |
| 666 | case BTF_KIND_UNION: |
| 667 | case BTF_KIND_ENUM: |
| 668 | case BTF_KIND_DATASEC: |
| 669 | case BTF_KIND_FLOAT: |
| 670 | case BTF_KIND_ENUM64: |
| 671 | return true; |
| 672 | } |
| 673 | |
| 674 | return false; |
| 675 | } |
| 676 | |
| 677 | static const char *btf_int_encoding_str(u8 encoding) |
| 678 | { |
| 679 | if (encoding == 0) |
| 680 | return "(none)"; |
| 681 | else if (encoding == BTF_INT_SIGNED) |
| 682 | return "SIGNED"; |
| 683 | else if (encoding == BTF_INT_CHAR) |
| 684 | return "CHAR"; |
| 685 | else if (encoding == BTF_INT_BOOL) |
| 686 | return "BOOL"; |
| 687 | else |
| 688 | return "UNKN"; |
| 689 | } |
| 690 | |
| 691 | static u32 btf_type_int(const struct btf_type *t) |
| 692 | { |
| 693 | return *(u32 *)(t + 1); |
| 694 | } |
| 695 | |
| 696 | static const struct btf_array *btf_type_array(const struct btf_type *t) |
| 697 | { |
| 698 | return (const struct btf_array *)(t + 1); |
| 699 | } |
| 700 | |
| 701 | static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
| 702 | { |
| 703 | return (const struct btf_enum *)(t + 1); |
| 704 | } |
| 705 | |
| 706 | static const struct btf_var *btf_type_var(const struct btf_type *t) |
| 707 | { |
| 708 | return (const struct btf_var *)(t + 1); |
| 709 | } |
| 710 | |
| 711 | static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
| 712 | { |
| 713 | return (const struct btf_decl_tag *)(t + 1); |
| 714 | } |
| 715 | |
| 716 | static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t) |
| 717 | { |
| 718 | return (const struct btf_enum64 *)(t + 1); |
| 719 | } |
| 720 | |
| 721 | static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
| 722 | { |
| 723 | return kind_ops[BTF_INFO_KIND(t->info)]; |
| 724 | } |
| 725 | |
| 726 | static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
| 727 | { |
| 728 | if (!BTF_STR_OFFSET_VALID(offset)) |
| 729 | return false; |
| 730 | |
| 731 | while (offset < btf->start_str_off) |
| 732 | btf = btf->base_btf; |
| 733 | |
| 734 | offset -= btf->start_str_off; |
| 735 | return offset < btf->hdr.str_len; |
| 736 | } |
| 737 | |
| 738 | static bool __btf_name_char_ok(char c, bool first, bool dot_ok) |
| 739 | { |
| 740 | if ((first ? !isalpha(c) : |
| 741 | !isalnum(c)) && |
| 742 | c != '_' && |
| 743 | ((c == '.' && !dot_ok) || |
| 744 | c != '.')) |
| 745 | return false; |
| 746 | return true; |
| 747 | } |
| 748 | |
| 749 | static const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
| 750 | { |
| 751 | while (offset < btf->start_str_off) |
| 752 | btf = btf->base_btf; |
| 753 | |
| 754 | offset -= btf->start_str_off; |
| 755 | if (offset < btf->hdr.str_len) |
| 756 | return &btf->strings[offset]; |
| 757 | |
| 758 | return NULL; |
| 759 | } |
| 760 | |
| 761 | static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) |
| 762 | { |
| 763 | /* offset must be valid */ |
| 764 | const char *src = btf_str_by_offset(btf, offset); |
| 765 | const char *src_limit; |
| 766 | |
| 767 | if (!__btf_name_char_ok(*src, true, dot_ok)) |
| 768 | return false; |
| 769 | |
| 770 | /* set a limit on identifier length */ |
| 771 | src_limit = src + KSYM_NAME_LEN; |
| 772 | src++; |
| 773 | while (*src && src < src_limit) { |
| 774 | if (!__btf_name_char_ok(*src, false, dot_ok)) |
| 775 | return false; |
| 776 | src++; |
| 777 | } |
| 778 | |
| 779 | return !*src; |
| 780 | } |
| 781 | |
| 782 | /* Only C-style identifier is permitted. This can be relaxed if |
| 783 | * necessary. |
| 784 | */ |
| 785 | static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) |
| 786 | { |
| 787 | return __btf_name_valid(btf, offset, false); |
| 788 | } |
| 789 | |
| 790 | static bool btf_name_valid_section(const struct btf *btf, u32 offset) |
| 791 | { |
| 792 | return __btf_name_valid(btf, offset, true); |
| 793 | } |
| 794 | |
| 795 | static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
| 796 | { |
| 797 | const char *name; |
| 798 | |
| 799 | if (!offset) |
| 800 | return "(anon)"; |
| 801 | |
| 802 | name = btf_str_by_offset(btf, offset); |
| 803 | return name ?: "(invalid-name-offset)"; |
| 804 | } |
| 805 | |
| 806 | const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
| 807 | { |
| 808 | return btf_str_by_offset(btf, offset); |
| 809 | } |
| 810 | |
| 811 | const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
| 812 | { |
| 813 | while (type_id < btf->start_id) |
| 814 | btf = btf->base_btf; |
| 815 | |
| 816 | type_id -= btf->start_id; |
| 817 | if (type_id >= btf->nr_types) |
| 818 | return NULL; |
| 819 | return btf->types[type_id]; |
| 820 | } |
| 821 | EXPORT_SYMBOL_GPL(btf_type_by_id); |
| 822 | |
| 823 | /* |
| 824 | * Regular int is not a bit field and it must be either |
| 825 | * u8/u16/u32/u64 or __int128. |
| 826 | */ |
| 827 | static bool btf_type_int_is_regular(const struct btf_type *t) |
| 828 | { |
| 829 | u8 nr_bits, nr_bytes; |
| 830 | u32 int_data; |
| 831 | |
| 832 | int_data = btf_type_int(t); |
| 833 | nr_bits = BTF_INT_BITS(int_data); |
| 834 | nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); |
| 835 | if (BITS_PER_BYTE_MASKED(nr_bits) || |
| 836 | BTF_INT_OFFSET(int_data) || |
| 837 | (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && |
| 838 | nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
| 839 | nr_bytes != (2 * sizeof(u64)))) { |
| 840 | return false; |
| 841 | } |
| 842 | |
| 843 | return true; |
| 844 | } |
| 845 | |
| 846 | /* |
| 847 | * Check that given struct member is a regular int with expected |
| 848 | * offset and size. |
| 849 | */ |
| 850 | bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
| 851 | const struct btf_member *m, |
| 852 | u32 expected_offset, u32 expected_size) |
| 853 | { |
| 854 | const struct btf_type *t; |
| 855 | u32 id, int_data; |
| 856 | u8 nr_bits; |
| 857 | |
| 858 | id = m->type; |
| 859 | t = btf_type_id_size(btf, &id, NULL); |
| 860 | if (!t || !btf_type_is_int(t)) |
| 861 | return false; |
| 862 | |
| 863 | int_data = btf_type_int(t); |
| 864 | nr_bits = BTF_INT_BITS(int_data); |
| 865 | if (btf_type_kflag(s)) { |
| 866 | u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); |
| 867 | u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); |
| 868 | |
| 869 | /* if kflag set, int should be a regular int and |
| 870 | * bit offset should be at byte boundary. |
| 871 | */ |
| 872 | return !bitfield_size && |
| 873 | BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && |
| 874 | BITS_ROUNDUP_BYTES(nr_bits) == expected_size; |
| 875 | } |
| 876 | |
| 877 | if (BTF_INT_OFFSET(int_data) || |
| 878 | BITS_PER_BYTE_MASKED(m->offset) || |
| 879 | BITS_ROUNDUP_BYTES(m->offset) != expected_offset || |
| 880 | BITS_PER_BYTE_MASKED(nr_bits) || |
| 881 | BITS_ROUNDUP_BYTES(nr_bits) != expected_size) |
| 882 | return false; |
| 883 | |
| 884 | return true; |
| 885 | } |
| 886 | |
| 887 | /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
| 888 | static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, |
| 889 | u32 id) |
| 890 | { |
| 891 | const struct btf_type *t = btf_type_by_id(btf, id); |
| 892 | |
| 893 | while (btf_type_is_modifier(t) && |
| 894 | BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { |
| 895 | t = btf_type_by_id(btf, t->type); |
| 896 | } |
| 897 | |
| 898 | return t; |
| 899 | } |
| 900 | |
| 901 | #define BTF_SHOW_MAX_ITER 10 |
| 902 | |
| 903 | #define BTF_KIND_BIT(kind) (1ULL << kind) |
| 904 | |
| 905 | /* |
| 906 | * Populate show->state.name with type name information. |
| 907 | * Format of type name is |
| 908 | * |
| 909 | * [.member_name = ] (type_name) |
| 910 | */ |
| 911 | static const char *btf_show_name(struct btf_show *show) |
| 912 | { |
| 913 | /* BTF_MAX_ITER array suffixes "[]" */ |
| 914 | const char *array_suffixes = "[][][][][][][][][][]"; |
| 915 | const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; |
| 916 | /* BTF_MAX_ITER pointer suffixes "*" */ |
| 917 | const char *ptr_suffixes = "**********"; |
| 918 | const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; |
| 919 | const char *name = NULL, *prefix = "", *parens = ""; |
| 920 | const struct btf_member *m = show->state.member; |
| 921 | const struct btf_type *t; |
| 922 | const struct btf_array *array; |
| 923 | u32 id = show->state.type_id; |
| 924 | const char *member = NULL; |
| 925 | bool show_member = false; |
| 926 | u64 kinds = 0; |
| 927 | int i; |
| 928 | |
| 929 | show->state.name[0] = '\0'; |
| 930 | |
| 931 | /* |
| 932 | * Don't show type name if we're showing an array member; |
| 933 | * in that case we show the array type so don't need to repeat |
| 934 | * ourselves for each member. |
| 935 | */ |
| 936 | if (show->state.array_member) |
| 937 | return ""; |
| 938 | |
| 939 | /* Retrieve member name, if any. */ |
| 940 | if (m) { |
| 941 | member = btf_name_by_offset(show->btf, m->name_off); |
| 942 | show_member = strlen(member) > 0; |
| 943 | id = m->type; |
| 944 | } |
| 945 | |
| 946 | /* |
| 947 | * Start with type_id, as we have resolved the struct btf_type * |
| 948 | * via btf_modifier_show() past the parent typedef to the child |
| 949 | * struct, int etc it is defined as. In such cases, the type_id |
| 950 | * still represents the starting type while the struct btf_type * |
| 951 | * in our show->state points at the resolved type of the typedef. |
| 952 | */ |
| 953 | t = btf_type_by_id(show->btf, id); |
| 954 | if (!t) |
| 955 | return ""; |
| 956 | |
| 957 | /* |
| 958 | * The goal here is to build up the right number of pointer and |
| 959 | * array suffixes while ensuring the type name for a typedef |
| 960 | * is represented. Along the way we accumulate a list of |
| 961 | * BTF kinds we have encountered, since these will inform later |
| 962 | * display; for example, pointer types will not require an |
| 963 | * opening "{" for struct, we will just display the pointer value. |
| 964 | * |
| 965 | * We also want to accumulate the right number of pointer or array |
| 966 | * indices in the format string while iterating until we get to |
| 967 | * the typedef/pointee/array member target type. |
| 968 | * |
| 969 | * We start by pointing at the end of pointer and array suffix |
| 970 | * strings; as we accumulate pointers and arrays we move the pointer |
| 971 | * or array string backwards so it will show the expected number of |
| 972 | * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers |
| 973 | * and/or arrays and typedefs are supported as a precaution. |
| 974 | * |
| 975 | * We also want to get typedef name while proceeding to resolve |
| 976 | * type it points to so that we can add parentheses if it is a |
| 977 | * "typedef struct" etc. |
| 978 | */ |
| 979 | for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { |
| 980 | |
| 981 | switch (BTF_INFO_KIND(t->info)) { |
| 982 | case BTF_KIND_TYPEDEF: |
| 983 | if (!name) |
| 984 | name = btf_name_by_offset(show->btf, |
| 985 | t->name_off); |
| 986 | kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); |
| 987 | id = t->type; |
| 988 | break; |
| 989 | case BTF_KIND_ARRAY: |
| 990 | kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); |
| 991 | parens = "["; |
| 992 | if (!t) |
| 993 | return ""; |
| 994 | array = btf_type_array(t); |
| 995 | if (array_suffix > array_suffixes) |
| 996 | array_suffix -= 2; |
| 997 | id = array->type; |
| 998 | break; |
| 999 | case BTF_KIND_PTR: |
| 1000 | kinds |= BTF_KIND_BIT(BTF_KIND_PTR); |
| 1001 | if (ptr_suffix > ptr_suffixes) |
| 1002 | ptr_suffix -= 1; |
| 1003 | id = t->type; |
| 1004 | break; |
| 1005 | default: |
| 1006 | id = 0; |
| 1007 | break; |
| 1008 | } |
| 1009 | if (!id) |
| 1010 | break; |
| 1011 | t = btf_type_skip_qualifiers(show->btf, id); |
| 1012 | } |
| 1013 | /* We may not be able to represent this type; bail to be safe */ |
| 1014 | if (i == BTF_SHOW_MAX_ITER) |
| 1015 | return ""; |
| 1016 | |
| 1017 | if (!name) |
| 1018 | name = btf_name_by_offset(show->btf, t->name_off); |
| 1019 | |
| 1020 | switch (BTF_INFO_KIND(t->info)) { |
| 1021 | case BTF_KIND_STRUCT: |
| 1022 | case BTF_KIND_UNION: |
| 1023 | prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? |
| 1024 | "struct" : "union"; |
| 1025 | /* if it's an array of struct/union, parens is already set */ |
| 1026 | if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) |
| 1027 | parens = "{"; |
| 1028 | break; |
| 1029 | case BTF_KIND_ENUM: |
| 1030 | case BTF_KIND_ENUM64: |
| 1031 | prefix = "enum"; |
| 1032 | break; |
| 1033 | default: |
| 1034 | break; |
| 1035 | } |
| 1036 | |
| 1037 | /* pointer does not require parens */ |
| 1038 | if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) |
| 1039 | parens = ""; |
| 1040 | /* typedef does not require struct/union/enum prefix */ |
| 1041 | if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) |
| 1042 | prefix = ""; |
| 1043 | |
| 1044 | if (!name) |
| 1045 | name = ""; |
| 1046 | |
| 1047 | /* Even if we don't want type name info, we want parentheses etc */ |
| 1048 | if (show->flags & BTF_SHOW_NONAME) |
| 1049 | snprintf(show->state.name, sizeof(show->state.name), "%s", |
| 1050 | parens); |
| 1051 | else |
| 1052 | snprintf(show->state.name, sizeof(show->state.name), |
| 1053 | "%s%s%s(%s%s%s%s%s%s)%s", |
| 1054 | /* first 3 strings comprise ".member = " */ |
| 1055 | show_member ? "." : "", |
| 1056 | show_member ? member : "", |
| 1057 | show_member ? " = " : "", |
| 1058 | /* ...next is our prefix (struct, enum, etc) */ |
| 1059 | prefix, |
| 1060 | strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", |
| 1061 | /* ...this is the type name itself */ |
| 1062 | name, |
| 1063 | /* ...suffixed by the appropriate '*', '[]' suffixes */ |
| 1064 | strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, |
| 1065 | array_suffix, parens); |
| 1066 | |
| 1067 | return show->state.name; |
| 1068 | } |
| 1069 | |
| 1070 | static const char *__btf_show_indent(struct btf_show *show) |
| 1071 | { |
| 1072 | const char *indents = " "; |
| 1073 | const char *indent = &indents[strlen(indents)]; |
| 1074 | |
| 1075 | if ((indent - show->state.depth) >= indents) |
| 1076 | return indent - show->state.depth; |
| 1077 | return indents; |
| 1078 | } |
| 1079 | |
| 1080 | static const char *btf_show_indent(struct btf_show *show) |
| 1081 | { |
| 1082 | return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); |
| 1083 | } |
| 1084 | |
| 1085 | static const char *btf_show_newline(struct btf_show *show) |
| 1086 | { |
| 1087 | return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; |
| 1088 | } |
| 1089 | |
| 1090 | static const char *btf_show_delim(struct btf_show *show) |
| 1091 | { |
| 1092 | if (show->state.depth == 0) |
| 1093 | return ""; |
| 1094 | |
| 1095 | if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && |
| 1096 | BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) |
| 1097 | return "|"; |
| 1098 | |
| 1099 | return ","; |
| 1100 | } |
| 1101 | |
| 1102 | __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) |
| 1103 | { |
| 1104 | va_list args; |
| 1105 | |
| 1106 | if (!show->state.depth_check) { |
| 1107 | va_start(args, fmt); |
| 1108 | show->showfn(show, fmt, args); |
| 1109 | va_end(args); |
| 1110 | } |
| 1111 | } |
| 1112 | |
| 1113 | /* Macros are used here as btf_show_type_value[s]() prepends and appends |
| 1114 | * format specifiers to the format specifier passed in; these do the work of |
| 1115 | * adding indentation, delimiters etc while the caller simply has to specify |
| 1116 | * the type value(s) in the format specifier + value(s). |
| 1117 | */ |
| 1118 | #define btf_show_type_value(show, fmt, value) \ |
| 1119 | do { \ |
| 1120 | if ((value) != (__typeof__(value))0 || \ |
| 1121 | (show->flags & BTF_SHOW_ZERO) || \ |
| 1122 | show->state.depth == 0) { \ |
| 1123 | btf_show(show, "%s%s" fmt "%s%s", \ |
| 1124 | btf_show_indent(show), \ |
| 1125 | btf_show_name(show), \ |
| 1126 | value, btf_show_delim(show), \ |
| 1127 | btf_show_newline(show)); \ |
| 1128 | if (show->state.depth > show->state.depth_to_show) \ |
| 1129 | show->state.depth_to_show = show->state.depth; \ |
| 1130 | } \ |
| 1131 | } while (0) |
| 1132 | |
| 1133 | #define btf_show_type_values(show, fmt, ...) \ |
| 1134 | do { \ |
| 1135 | btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ |
| 1136 | btf_show_name(show), \ |
| 1137 | __VA_ARGS__, btf_show_delim(show), \ |
| 1138 | btf_show_newline(show)); \ |
| 1139 | if (show->state.depth > show->state.depth_to_show) \ |
| 1140 | show->state.depth_to_show = show->state.depth; \ |
| 1141 | } while (0) |
| 1142 | |
| 1143 | /* How much is left to copy to safe buffer after @data? */ |
| 1144 | static int btf_show_obj_size_left(struct btf_show *show, void *data) |
| 1145 | { |
| 1146 | return show->obj.head + show->obj.size - data; |
| 1147 | } |
| 1148 | |
| 1149 | /* Is object pointed to by @data of @size already copied to our safe buffer? */ |
| 1150 | static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) |
| 1151 | { |
| 1152 | return data >= show->obj.data && |
| 1153 | (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); |
| 1154 | } |
| 1155 | |
| 1156 | /* |
| 1157 | * If object pointed to by @data of @size falls within our safe buffer, return |
| 1158 | * the equivalent pointer to the same safe data. Assumes |
| 1159 | * copy_from_kernel_nofault() has already happened and our safe buffer is |
| 1160 | * populated. |
| 1161 | */ |
| 1162 | static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) |
| 1163 | { |
| 1164 | if (btf_show_obj_is_safe(show, data, size)) |
| 1165 | return show->obj.safe + (data - show->obj.data); |
| 1166 | return NULL; |
| 1167 | } |
| 1168 | |
| 1169 | /* |
| 1170 | * Return a safe-to-access version of data pointed to by @data. |
| 1171 | * We do this by copying the relevant amount of information |
| 1172 | * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). |
| 1173 | * |
| 1174 | * If BTF_SHOW_UNSAFE is specified, just return data as-is; no |
| 1175 | * safe copy is needed. |
| 1176 | * |
| 1177 | * Otherwise we need to determine if we have the required amount |
| 1178 | * of data (determined by the @data pointer and the size of the |
| 1179 | * largest base type we can encounter (represented by |
| 1180 | * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures |
| 1181 | * that we will be able to print some of the current object, |
| 1182 | * and if more is needed a copy will be triggered. |
| 1183 | * Some objects such as structs will not fit into the buffer; |
| 1184 | * in such cases additional copies when we iterate over their |
| 1185 | * members may be needed. |
| 1186 | * |
| 1187 | * btf_show_obj_safe() is used to return a safe buffer for |
| 1188 | * btf_show_start_type(); this ensures that as we recurse into |
| 1189 | * nested types we always have safe data for the given type. |
| 1190 | * This approach is somewhat wasteful; it's possible for example |
| 1191 | * that when iterating over a large union we'll end up copying the |
| 1192 | * same data repeatedly, but the goal is safety not performance. |
| 1193 | * We use stack data as opposed to per-CPU buffers because the |
| 1194 | * iteration over a type can take some time, and preemption handling |
| 1195 | * would greatly complicate use of the safe buffer. |
| 1196 | */ |
| 1197 | static void *btf_show_obj_safe(struct btf_show *show, |
| 1198 | const struct btf_type *t, |
| 1199 | void *data) |
| 1200 | { |
| 1201 | const struct btf_type *rt; |
| 1202 | int size_left, size; |
| 1203 | void *safe = NULL; |
| 1204 | |
| 1205 | if (show->flags & BTF_SHOW_UNSAFE) |
| 1206 | return data; |
| 1207 | |
| 1208 | rt = btf_resolve_size(show->btf, t, &size); |
| 1209 | if (IS_ERR(rt)) { |
| 1210 | show->state.status = PTR_ERR(rt); |
| 1211 | return NULL; |
| 1212 | } |
| 1213 | |
| 1214 | /* |
| 1215 | * Is this toplevel object? If so, set total object size and |
| 1216 | * initialize pointers. Otherwise check if we still fall within |
| 1217 | * our safe object data. |
| 1218 | */ |
| 1219 | if (show->state.depth == 0) { |
| 1220 | show->obj.size = size; |
| 1221 | show->obj.head = data; |
| 1222 | } else { |
| 1223 | /* |
| 1224 | * If the size of the current object is > our remaining |
| 1225 | * safe buffer we _may_ need to do a new copy. However |
| 1226 | * consider the case of a nested struct; it's size pushes |
| 1227 | * us over the safe buffer limit, but showing any individual |
| 1228 | * struct members does not. In such cases, we don't need |
| 1229 | * to initiate a fresh copy yet; however we definitely need |
| 1230 | * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left |
| 1231 | * in our buffer, regardless of the current object size. |
| 1232 | * The logic here is that as we resolve types we will |
| 1233 | * hit a base type at some point, and we need to be sure |
| 1234 | * the next chunk of data is safely available to display |
| 1235 | * that type info safely. We cannot rely on the size of |
| 1236 | * the current object here because it may be much larger |
| 1237 | * than our current buffer (e.g. task_struct is 8k). |
| 1238 | * All we want to do here is ensure that we can print the |
| 1239 | * next basic type, which we can if either |
| 1240 | * - the current type size is within the safe buffer; or |
| 1241 | * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in |
| 1242 | * the safe buffer. |
| 1243 | */ |
| 1244 | safe = __btf_show_obj_safe(show, data, |
| 1245 | min(size, |
| 1246 | BTF_SHOW_OBJ_BASE_TYPE_SIZE)); |
| 1247 | } |
| 1248 | |
| 1249 | /* |
| 1250 | * We need a new copy to our safe object, either because we haven't |
| 1251 | * yet copied and are initializing safe data, or because the data |
| 1252 | * we want falls outside the boundaries of the safe object. |
| 1253 | */ |
| 1254 | if (!safe) { |
| 1255 | size_left = btf_show_obj_size_left(show, data); |
| 1256 | if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) |
| 1257 | size_left = BTF_SHOW_OBJ_SAFE_SIZE; |
| 1258 | show->state.status = copy_from_kernel_nofault(show->obj.safe, |
| 1259 | data, size_left); |
| 1260 | if (!show->state.status) { |
| 1261 | show->obj.data = data; |
| 1262 | safe = show->obj.safe; |
| 1263 | } |
| 1264 | } |
| 1265 | |
| 1266 | return safe; |
| 1267 | } |
| 1268 | |
| 1269 | /* |
| 1270 | * Set the type we are starting to show and return a safe data pointer |
| 1271 | * to be used for showing the associated data. |
| 1272 | */ |
| 1273 | static void *btf_show_start_type(struct btf_show *show, |
| 1274 | const struct btf_type *t, |
| 1275 | u32 type_id, void *data) |
| 1276 | { |
| 1277 | show->state.type = t; |
| 1278 | show->state.type_id = type_id; |
| 1279 | show->state.name[0] = '\0'; |
| 1280 | |
| 1281 | return btf_show_obj_safe(show, t, data); |
| 1282 | } |
| 1283 | |
| 1284 | static void btf_show_end_type(struct btf_show *show) |
| 1285 | { |
| 1286 | show->state.type = NULL; |
| 1287 | show->state.type_id = 0; |
| 1288 | show->state.name[0] = '\0'; |
| 1289 | } |
| 1290 | |
| 1291 | static void *btf_show_start_aggr_type(struct btf_show *show, |
| 1292 | const struct btf_type *t, |
| 1293 | u32 type_id, void *data) |
| 1294 | { |
| 1295 | void *safe_data = btf_show_start_type(show, t, type_id, data); |
| 1296 | |
| 1297 | if (!safe_data) |
| 1298 | return safe_data; |
| 1299 | |
| 1300 | btf_show(show, "%s%s%s", btf_show_indent(show), |
| 1301 | btf_show_name(show), |
| 1302 | btf_show_newline(show)); |
| 1303 | show->state.depth++; |
| 1304 | return safe_data; |
| 1305 | } |
| 1306 | |
| 1307 | static void btf_show_end_aggr_type(struct btf_show *show, |
| 1308 | const char *suffix) |
| 1309 | { |
| 1310 | show->state.depth--; |
| 1311 | btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, |
| 1312 | btf_show_delim(show), btf_show_newline(show)); |
| 1313 | btf_show_end_type(show); |
| 1314 | } |
| 1315 | |
| 1316 | static void btf_show_start_member(struct btf_show *show, |
| 1317 | const struct btf_member *m) |
| 1318 | { |
| 1319 | show->state.member = m; |
| 1320 | } |
| 1321 | |
| 1322 | static void btf_show_start_array_member(struct btf_show *show) |
| 1323 | { |
| 1324 | show->state.array_member = 1; |
| 1325 | btf_show_start_member(show, NULL); |
| 1326 | } |
| 1327 | |
| 1328 | static void btf_show_end_member(struct btf_show *show) |
| 1329 | { |
| 1330 | show->state.member = NULL; |
| 1331 | } |
| 1332 | |
| 1333 | static void btf_show_end_array_member(struct btf_show *show) |
| 1334 | { |
| 1335 | show->state.array_member = 0; |
| 1336 | btf_show_end_member(show); |
| 1337 | } |
| 1338 | |
| 1339 | static void *btf_show_start_array_type(struct btf_show *show, |
| 1340 | const struct btf_type *t, |
| 1341 | u32 type_id, |
| 1342 | u16 array_encoding, |
| 1343 | void *data) |
| 1344 | { |
| 1345 | show->state.array_encoding = array_encoding; |
| 1346 | show->state.array_terminated = 0; |
| 1347 | return btf_show_start_aggr_type(show, t, type_id, data); |
| 1348 | } |
| 1349 | |
| 1350 | static void btf_show_end_array_type(struct btf_show *show) |
| 1351 | { |
| 1352 | show->state.array_encoding = 0; |
| 1353 | show->state.array_terminated = 0; |
| 1354 | btf_show_end_aggr_type(show, "]"); |
| 1355 | } |
| 1356 | |
| 1357 | static void *btf_show_start_struct_type(struct btf_show *show, |
| 1358 | const struct btf_type *t, |
| 1359 | u32 type_id, |
| 1360 | void *data) |
| 1361 | { |
| 1362 | return btf_show_start_aggr_type(show, t, type_id, data); |
| 1363 | } |
| 1364 | |
| 1365 | static void btf_show_end_struct_type(struct btf_show *show) |
| 1366 | { |
| 1367 | btf_show_end_aggr_type(show, "}"); |
| 1368 | } |
| 1369 | |
| 1370 | __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
| 1371 | const char *fmt, ...) |
| 1372 | { |
| 1373 | va_list args; |
| 1374 | |
| 1375 | va_start(args, fmt); |
| 1376 | bpf_verifier_vlog(log, fmt, args); |
| 1377 | va_end(args); |
| 1378 | } |
| 1379 | |
| 1380 | __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, |
| 1381 | const char *fmt, ...) |
| 1382 | { |
| 1383 | struct bpf_verifier_log *log = &env->log; |
| 1384 | va_list args; |
| 1385 | |
| 1386 | if (!bpf_verifier_log_needed(log)) |
| 1387 | return; |
| 1388 | |
| 1389 | va_start(args, fmt); |
| 1390 | bpf_verifier_vlog(log, fmt, args); |
| 1391 | va_end(args); |
| 1392 | } |
| 1393 | |
| 1394 | __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, |
| 1395 | const struct btf_type *t, |
| 1396 | bool log_details, |
| 1397 | const char *fmt, ...) |
| 1398 | { |
| 1399 | struct bpf_verifier_log *log = &env->log; |
| 1400 | struct btf *btf = env->btf; |
| 1401 | va_list args; |
| 1402 | |
| 1403 | if (!bpf_verifier_log_needed(log)) |
| 1404 | return; |
| 1405 | |
| 1406 | if (log->level == BPF_LOG_KERNEL) { |
| 1407 | /* btf verifier prints all types it is processing via |
| 1408 | * btf_verifier_log_type(..., fmt = NULL). |
| 1409 | * Skip those prints for in-kernel BTF verification. |
| 1410 | */ |
| 1411 | if (!fmt) |
| 1412 | return; |
| 1413 | |
| 1414 | /* Skip logging when loading module BTF with mismatches permitted */ |
| 1415 | if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) |
| 1416 | return; |
| 1417 | } |
| 1418 | |
| 1419 | __btf_verifier_log(log, "[%u] %s %s%s", |
| 1420 | env->log_type_id, |
| 1421 | btf_type_str(t), |
| 1422 | __btf_name_by_offset(btf, t->name_off), |
| 1423 | log_details ? " " : ""); |
| 1424 | |
| 1425 | if (log_details) |
| 1426 | btf_type_ops(t)->log_details(env, t); |
| 1427 | |
| 1428 | if (fmt && *fmt) { |
| 1429 | __btf_verifier_log(log, " "); |
| 1430 | va_start(args, fmt); |
| 1431 | bpf_verifier_vlog(log, fmt, args); |
| 1432 | va_end(args); |
| 1433 | } |
| 1434 | |
| 1435 | __btf_verifier_log(log, "\n"); |
| 1436 | } |
| 1437 | |
| 1438 | #define btf_verifier_log_type(env, t, ...) \ |
| 1439 | __btf_verifier_log_type((env), (t), true, __VA_ARGS__) |
| 1440 | #define btf_verifier_log_basic(env, t, ...) \ |
| 1441 | __btf_verifier_log_type((env), (t), false, __VA_ARGS__) |
| 1442 | |
| 1443 | __printf(4, 5) |
| 1444 | static void btf_verifier_log_member(struct btf_verifier_env *env, |
| 1445 | const struct btf_type *struct_type, |
| 1446 | const struct btf_member *member, |
| 1447 | const char *fmt, ...) |
| 1448 | { |
| 1449 | struct bpf_verifier_log *log = &env->log; |
| 1450 | struct btf *btf = env->btf; |
| 1451 | va_list args; |
| 1452 | |
| 1453 | if (!bpf_verifier_log_needed(log)) |
| 1454 | return; |
| 1455 | |
| 1456 | if (log->level == BPF_LOG_KERNEL) { |
| 1457 | if (!fmt) |
| 1458 | return; |
| 1459 | |
| 1460 | /* Skip logging when loading module BTF with mismatches permitted */ |
| 1461 | if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) |
| 1462 | return; |
| 1463 | } |
| 1464 | |
| 1465 | /* The CHECK_META phase already did a btf dump. |
| 1466 | * |
| 1467 | * If member is logged again, it must hit an error in |
| 1468 | * parsing this member. It is useful to print out which |
| 1469 | * struct this member belongs to. |
| 1470 | */ |
| 1471 | if (env->phase != CHECK_META) |
| 1472 | btf_verifier_log_type(env, struct_type, NULL); |
| 1473 | |
| 1474 | if (btf_type_kflag(struct_type)) |
| 1475 | __btf_verifier_log(log, |
| 1476 | "\t%s type_id=%u bitfield_size=%u bits_offset=%u", |
| 1477 | __btf_name_by_offset(btf, member->name_off), |
| 1478 | member->type, |
| 1479 | BTF_MEMBER_BITFIELD_SIZE(member->offset), |
| 1480 | BTF_MEMBER_BIT_OFFSET(member->offset)); |
| 1481 | else |
| 1482 | __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", |
| 1483 | __btf_name_by_offset(btf, member->name_off), |
| 1484 | member->type, member->offset); |
| 1485 | |
| 1486 | if (fmt && *fmt) { |
| 1487 | __btf_verifier_log(log, " "); |
| 1488 | va_start(args, fmt); |
| 1489 | bpf_verifier_vlog(log, fmt, args); |
| 1490 | va_end(args); |
| 1491 | } |
| 1492 | |
| 1493 | __btf_verifier_log(log, "\n"); |
| 1494 | } |
| 1495 | |
| 1496 | __printf(4, 5) |
| 1497 | static void btf_verifier_log_vsi(struct btf_verifier_env *env, |
| 1498 | const struct btf_type *datasec_type, |
| 1499 | const struct btf_var_secinfo *vsi, |
| 1500 | const char *fmt, ...) |
| 1501 | { |
| 1502 | struct bpf_verifier_log *log = &env->log; |
| 1503 | va_list args; |
| 1504 | |
| 1505 | if (!bpf_verifier_log_needed(log)) |
| 1506 | return; |
| 1507 | if (log->level == BPF_LOG_KERNEL && !fmt) |
| 1508 | return; |
| 1509 | if (env->phase != CHECK_META) |
| 1510 | btf_verifier_log_type(env, datasec_type, NULL); |
| 1511 | |
| 1512 | __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", |
| 1513 | vsi->type, vsi->offset, vsi->size); |
| 1514 | if (fmt && *fmt) { |
| 1515 | __btf_verifier_log(log, " "); |
| 1516 | va_start(args, fmt); |
| 1517 | bpf_verifier_vlog(log, fmt, args); |
| 1518 | va_end(args); |
| 1519 | } |
| 1520 | |
| 1521 | __btf_verifier_log(log, "\n"); |
| 1522 | } |
| 1523 | |
| 1524 | static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
| 1525 | u32 btf_data_size) |
| 1526 | { |
| 1527 | struct bpf_verifier_log *log = &env->log; |
| 1528 | const struct btf *btf = env->btf; |
| 1529 | const struct btf_header *hdr; |
| 1530 | |
| 1531 | if (!bpf_verifier_log_needed(log)) |
| 1532 | return; |
| 1533 | |
| 1534 | if (log->level == BPF_LOG_KERNEL) |
| 1535 | return; |
| 1536 | hdr = &btf->hdr; |
| 1537 | __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
| 1538 | __btf_verifier_log(log, "version: %u\n", hdr->version); |
| 1539 | __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); |
| 1540 | __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
| 1541 | __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
| 1542 | __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
| 1543 | __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
| 1544 | __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); |
| 1545 | __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
| 1546 | } |
| 1547 | |
| 1548 | static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) |
| 1549 | { |
| 1550 | struct btf *btf = env->btf; |
| 1551 | |
| 1552 | if (btf->types_size == btf->nr_types) { |
| 1553 | /* Expand 'types' array */ |
| 1554 | |
| 1555 | struct btf_type **new_types; |
| 1556 | u32 expand_by, new_size; |
| 1557 | |
| 1558 | if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
| 1559 | btf_verifier_log(env, "Exceeded max num of types"); |
| 1560 | return -E2BIG; |
| 1561 | } |
| 1562 | |
| 1563 | expand_by = max_t(u32, btf->types_size >> 2, 16); |
| 1564 | new_size = min_t(u32, BTF_MAX_TYPE, |
| 1565 | btf->types_size + expand_by); |
| 1566 | |
| 1567 | new_types = kvcalloc(new_size, sizeof(*new_types), |
| 1568 | GFP_KERNEL | __GFP_NOWARN); |
| 1569 | if (!new_types) |
| 1570 | return -ENOMEM; |
| 1571 | |
| 1572 | if (btf->nr_types == 0) { |
| 1573 | if (!btf->base_btf) { |
| 1574 | /* lazily init VOID type */ |
| 1575 | new_types[0] = &btf_void; |
| 1576 | btf->nr_types++; |
| 1577 | } |
| 1578 | } else { |
| 1579 | memcpy(new_types, btf->types, |
| 1580 | sizeof(*btf->types) * btf->nr_types); |
| 1581 | } |
| 1582 | |
| 1583 | kvfree(btf->types); |
| 1584 | btf->types = new_types; |
| 1585 | btf->types_size = new_size; |
| 1586 | } |
| 1587 | |
| 1588 | btf->types[btf->nr_types++] = t; |
| 1589 | |
| 1590 | return 0; |
| 1591 | } |
| 1592 | |
| 1593 | static int btf_alloc_id(struct btf *btf) |
| 1594 | { |
| 1595 | int id; |
| 1596 | |
| 1597 | idr_preload(GFP_KERNEL); |
| 1598 | spin_lock_bh(&btf_idr_lock); |
| 1599 | id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); |
| 1600 | if (id > 0) |
| 1601 | btf->id = id; |
| 1602 | spin_unlock_bh(&btf_idr_lock); |
| 1603 | idr_preload_end(); |
| 1604 | |
| 1605 | if (WARN_ON_ONCE(!id)) |
| 1606 | return -ENOSPC; |
| 1607 | |
| 1608 | return id > 0 ? 0 : id; |
| 1609 | } |
| 1610 | |
| 1611 | static void btf_free_id(struct btf *btf) |
| 1612 | { |
| 1613 | unsigned long flags; |
| 1614 | |
| 1615 | /* |
| 1616 | * In map-in-map, calling map_delete_elem() on outer |
| 1617 | * map will call bpf_map_put on the inner map. |
| 1618 | * It will then eventually call btf_free_id() |
| 1619 | * on the inner map. Some of the map_delete_elem() |
| 1620 | * implementation may have irq disabled, so |
| 1621 | * we need to use the _irqsave() version instead |
| 1622 | * of the _bh() version. |
| 1623 | */ |
| 1624 | spin_lock_irqsave(&btf_idr_lock, flags); |
| 1625 | idr_remove(&btf_idr, btf->id); |
| 1626 | spin_unlock_irqrestore(&btf_idr_lock, flags); |
| 1627 | } |
| 1628 | |
| 1629 | static void btf_free_kfunc_set_tab(struct btf *btf) |
| 1630 | { |
| 1631 | struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; |
| 1632 | int hook; |
| 1633 | |
| 1634 | if (!tab) |
| 1635 | return; |
| 1636 | /* For module BTF, we directly assign the sets being registered, so |
| 1637 | * there is nothing to free except kfunc_set_tab. |
| 1638 | */ |
| 1639 | if (btf_is_module(btf)) |
| 1640 | goto free_tab; |
| 1641 | for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) |
| 1642 | kfree(tab->sets[hook]); |
| 1643 | free_tab: |
| 1644 | kfree(tab); |
| 1645 | btf->kfunc_set_tab = NULL; |
| 1646 | } |
| 1647 | |
| 1648 | static void btf_free_dtor_kfunc_tab(struct btf *btf) |
| 1649 | { |
| 1650 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; |
| 1651 | |
| 1652 | if (!tab) |
| 1653 | return; |
| 1654 | kfree(tab); |
| 1655 | btf->dtor_kfunc_tab = NULL; |
| 1656 | } |
| 1657 | |
| 1658 | static void btf_struct_metas_free(struct btf_struct_metas *tab) |
| 1659 | { |
| 1660 | int i; |
| 1661 | |
| 1662 | if (!tab) |
| 1663 | return; |
| 1664 | for (i = 0; i < tab->cnt; i++) { |
| 1665 | btf_record_free(tab->types[i].record); |
| 1666 | kfree(tab->types[i].field_offs); |
| 1667 | } |
| 1668 | kfree(tab); |
| 1669 | } |
| 1670 | |
| 1671 | static void btf_free_struct_meta_tab(struct btf *btf) |
| 1672 | { |
| 1673 | struct btf_struct_metas *tab = btf->struct_meta_tab; |
| 1674 | |
| 1675 | btf_struct_metas_free(tab); |
| 1676 | btf->struct_meta_tab = NULL; |
| 1677 | } |
| 1678 | |
| 1679 | static void btf_free(struct btf *btf) |
| 1680 | { |
| 1681 | btf_free_struct_meta_tab(btf); |
| 1682 | btf_free_dtor_kfunc_tab(btf); |
| 1683 | btf_free_kfunc_set_tab(btf); |
| 1684 | kvfree(btf->types); |
| 1685 | kvfree(btf->resolved_sizes); |
| 1686 | kvfree(btf->resolved_ids); |
| 1687 | kvfree(btf->data); |
| 1688 | kfree(btf); |
| 1689 | } |
| 1690 | |
| 1691 | static void btf_free_rcu(struct rcu_head *rcu) |
| 1692 | { |
| 1693 | struct btf *btf = container_of(rcu, struct btf, rcu); |
| 1694 | |
| 1695 | btf_free(btf); |
| 1696 | } |
| 1697 | |
| 1698 | void btf_get(struct btf *btf) |
| 1699 | { |
| 1700 | refcount_inc(&btf->refcnt); |
| 1701 | } |
| 1702 | |
| 1703 | void btf_put(struct btf *btf) |
| 1704 | { |
| 1705 | if (btf && refcount_dec_and_test(&btf->refcnt)) { |
| 1706 | btf_free_id(btf); |
| 1707 | call_rcu(&btf->rcu, btf_free_rcu); |
| 1708 | } |
| 1709 | } |
| 1710 | |
| 1711 | static int env_resolve_init(struct btf_verifier_env *env) |
| 1712 | { |
| 1713 | struct btf *btf = env->btf; |
| 1714 | u32 nr_types = btf->nr_types; |
| 1715 | u32 *resolved_sizes = NULL; |
| 1716 | u32 *resolved_ids = NULL; |
| 1717 | u8 *visit_states = NULL; |
| 1718 | |
| 1719 | resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
| 1720 | GFP_KERNEL | __GFP_NOWARN); |
| 1721 | if (!resolved_sizes) |
| 1722 | goto nomem; |
| 1723 | |
| 1724 | resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
| 1725 | GFP_KERNEL | __GFP_NOWARN); |
| 1726 | if (!resolved_ids) |
| 1727 | goto nomem; |
| 1728 | |
| 1729 | visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
| 1730 | GFP_KERNEL | __GFP_NOWARN); |
| 1731 | if (!visit_states) |
| 1732 | goto nomem; |
| 1733 | |
| 1734 | btf->resolved_sizes = resolved_sizes; |
| 1735 | btf->resolved_ids = resolved_ids; |
| 1736 | env->visit_states = visit_states; |
| 1737 | |
| 1738 | return 0; |
| 1739 | |
| 1740 | nomem: |
| 1741 | kvfree(resolved_sizes); |
| 1742 | kvfree(resolved_ids); |
| 1743 | kvfree(visit_states); |
| 1744 | return -ENOMEM; |
| 1745 | } |
| 1746 | |
| 1747 | static void btf_verifier_env_free(struct btf_verifier_env *env) |
| 1748 | { |
| 1749 | kvfree(env->visit_states); |
| 1750 | kfree(env); |
| 1751 | } |
| 1752 | |
| 1753 | static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
| 1754 | const struct btf_type *next_type) |
| 1755 | { |
| 1756 | switch (env->resolve_mode) { |
| 1757 | case RESOLVE_TBD: |
| 1758 | /* int, enum or void is a sink */ |
| 1759 | return !btf_type_needs_resolve(next_type); |
| 1760 | case RESOLVE_PTR: |
| 1761 | /* int, enum, void, struct, array, func or func_proto is a sink |
| 1762 | * for ptr |
| 1763 | */ |
| 1764 | return !btf_type_is_modifier(next_type) && |
| 1765 | !btf_type_is_ptr(next_type); |
| 1766 | case RESOLVE_STRUCT_OR_ARRAY: |
| 1767 | /* int, enum, void, ptr, func or func_proto is a sink |
| 1768 | * for struct and array |
| 1769 | */ |
| 1770 | return !btf_type_is_modifier(next_type) && |
| 1771 | !btf_type_is_array(next_type) && |
| 1772 | !btf_type_is_struct(next_type); |
| 1773 | default: |
| 1774 | BUG(); |
| 1775 | } |
| 1776 | } |
| 1777 | |
| 1778 | static bool env_type_is_resolved(const struct btf_verifier_env *env, |
| 1779 | u32 type_id) |
| 1780 | { |
| 1781 | /* base BTF types should be resolved by now */ |
| 1782 | if (type_id < env->btf->start_id) |
| 1783 | return true; |
| 1784 | |
| 1785 | return env->visit_states[type_id - env->btf->start_id] == RESOLVED; |
| 1786 | } |
| 1787 | |
| 1788 | static int env_stack_push(struct btf_verifier_env *env, |
| 1789 | const struct btf_type *t, u32 type_id) |
| 1790 | { |
| 1791 | const struct btf *btf = env->btf; |
| 1792 | struct resolve_vertex *v; |
| 1793 | |
| 1794 | if (env->top_stack == MAX_RESOLVE_DEPTH) |
| 1795 | return -E2BIG; |
| 1796 | |
| 1797 | if (type_id < btf->start_id |
| 1798 | || env->visit_states[type_id - btf->start_id] != NOT_VISITED) |
| 1799 | return -EEXIST; |
| 1800 | |
| 1801 | env->visit_states[type_id - btf->start_id] = VISITED; |
| 1802 | |
| 1803 | v = &env->stack[env->top_stack++]; |
| 1804 | v->t = t; |
| 1805 | v->type_id = type_id; |
| 1806 | v->next_member = 0; |
| 1807 | |
| 1808 | if (env->resolve_mode == RESOLVE_TBD) { |
| 1809 | if (btf_type_is_ptr(t)) |
| 1810 | env->resolve_mode = RESOLVE_PTR; |
| 1811 | else if (btf_type_is_struct(t) || btf_type_is_array(t)) |
| 1812 | env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; |
| 1813 | } |
| 1814 | |
| 1815 | return 0; |
| 1816 | } |
| 1817 | |
| 1818 | static void env_stack_set_next_member(struct btf_verifier_env *env, |
| 1819 | u16 next_member) |
| 1820 | { |
| 1821 | env->stack[env->top_stack - 1].next_member = next_member; |
| 1822 | } |
| 1823 | |
| 1824 | static void env_stack_pop_resolved(struct btf_verifier_env *env, |
| 1825 | u32 resolved_type_id, |
| 1826 | u32 resolved_size) |
| 1827 | { |
| 1828 | u32 type_id = env->stack[--(env->top_stack)].type_id; |
| 1829 | struct btf *btf = env->btf; |
| 1830 | |
| 1831 | type_id -= btf->start_id; /* adjust to local type id */ |
| 1832 | btf->resolved_sizes[type_id] = resolved_size; |
| 1833 | btf->resolved_ids[type_id] = resolved_type_id; |
| 1834 | env->visit_states[type_id] = RESOLVED; |
| 1835 | } |
| 1836 | |
| 1837 | static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) |
| 1838 | { |
| 1839 | return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; |
| 1840 | } |
| 1841 | |
| 1842 | /* Resolve the size of a passed-in "type" |
| 1843 | * |
| 1844 | * type: is an array (e.g. u32 array[x][y]) |
| 1845 | * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, |
| 1846 | * *type_size: (x * y * sizeof(u32)). Hence, *type_size always |
| 1847 | * corresponds to the return type. |
| 1848 | * *elem_type: u32 |
| 1849 | * *elem_id: id of u32 |
| 1850 | * *total_nelems: (x * y). Hence, individual elem size is |
| 1851 | * (*type_size / *total_nelems) |
| 1852 | * *type_id: id of type if it's changed within the function, 0 if not |
| 1853 | * |
| 1854 | * type: is not an array (e.g. const struct X) |
| 1855 | * return type: type "struct X" |
| 1856 | * *type_size: sizeof(struct X) |
| 1857 | * *elem_type: same as return type ("struct X") |
| 1858 | * *elem_id: 0 |
| 1859 | * *total_nelems: 1 |
| 1860 | * *type_id: id of type if it's changed within the function, 0 if not |
| 1861 | */ |
| 1862 | static const struct btf_type * |
| 1863 | __btf_resolve_size(const struct btf *btf, const struct btf_type *type, |
| 1864 | u32 *type_size, const struct btf_type **elem_type, |
| 1865 | u32 *elem_id, u32 *total_nelems, u32 *type_id) |
| 1866 | { |
| 1867 | const struct btf_type *array_type = NULL; |
| 1868 | const struct btf_array *array = NULL; |
| 1869 | u32 i, size, nelems = 1, id = 0; |
| 1870 | |
| 1871 | for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { |
| 1872 | switch (BTF_INFO_KIND(type->info)) { |
| 1873 | /* type->size can be used */ |
| 1874 | case BTF_KIND_INT: |
| 1875 | case BTF_KIND_STRUCT: |
| 1876 | case BTF_KIND_UNION: |
| 1877 | case BTF_KIND_ENUM: |
| 1878 | case BTF_KIND_FLOAT: |
| 1879 | case BTF_KIND_ENUM64: |
| 1880 | size = type->size; |
| 1881 | goto resolved; |
| 1882 | |
| 1883 | case BTF_KIND_PTR: |
| 1884 | size = sizeof(void *); |
| 1885 | goto resolved; |
| 1886 | |
| 1887 | /* Modifiers */ |
| 1888 | case BTF_KIND_TYPEDEF: |
| 1889 | case BTF_KIND_VOLATILE: |
| 1890 | case BTF_KIND_CONST: |
| 1891 | case BTF_KIND_RESTRICT: |
| 1892 | case BTF_KIND_TYPE_TAG: |
| 1893 | id = type->type; |
| 1894 | type = btf_type_by_id(btf, type->type); |
| 1895 | break; |
| 1896 | |
| 1897 | case BTF_KIND_ARRAY: |
| 1898 | if (!array_type) |
| 1899 | array_type = type; |
| 1900 | array = btf_type_array(type); |
| 1901 | if (nelems && array->nelems > U32_MAX / nelems) |
| 1902 | return ERR_PTR(-EINVAL); |
| 1903 | nelems *= array->nelems; |
| 1904 | type = btf_type_by_id(btf, array->type); |
| 1905 | break; |
| 1906 | |
| 1907 | /* type without size */ |
| 1908 | default: |
| 1909 | return ERR_PTR(-EINVAL); |
| 1910 | } |
| 1911 | } |
| 1912 | |
| 1913 | return ERR_PTR(-EINVAL); |
| 1914 | |
| 1915 | resolved: |
| 1916 | if (nelems && size > U32_MAX / nelems) |
| 1917 | return ERR_PTR(-EINVAL); |
| 1918 | |
| 1919 | *type_size = nelems * size; |
| 1920 | if (total_nelems) |
| 1921 | *total_nelems = nelems; |
| 1922 | if (elem_type) |
| 1923 | *elem_type = type; |
| 1924 | if (elem_id) |
| 1925 | *elem_id = array ? array->type : 0; |
| 1926 | if (type_id && id) |
| 1927 | *type_id = id; |
| 1928 | |
| 1929 | return array_type ? : type; |
| 1930 | } |
| 1931 | |
| 1932 | const struct btf_type * |
| 1933 | btf_resolve_size(const struct btf *btf, const struct btf_type *type, |
| 1934 | u32 *type_size) |
| 1935 | { |
| 1936 | return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
| 1937 | } |
| 1938 | |
| 1939 | static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
| 1940 | { |
| 1941 | while (type_id < btf->start_id) |
| 1942 | btf = btf->base_btf; |
| 1943 | |
| 1944 | return btf->resolved_ids[type_id - btf->start_id]; |
| 1945 | } |
| 1946 | |
| 1947 | /* The input param "type_id" must point to a needs_resolve type */ |
| 1948 | static const struct btf_type *btf_type_id_resolve(const struct btf *btf, |
| 1949 | u32 *type_id) |
| 1950 | { |
| 1951 | *type_id = btf_resolved_type_id(btf, *type_id); |
| 1952 | return btf_type_by_id(btf, *type_id); |
| 1953 | } |
| 1954 | |
| 1955 | static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
| 1956 | { |
| 1957 | while (type_id < btf->start_id) |
| 1958 | btf = btf->base_btf; |
| 1959 | |
| 1960 | return btf->resolved_sizes[type_id - btf->start_id]; |
| 1961 | } |
| 1962 | |
| 1963 | const struct btf_type *btf_type_id_size(const struct btf *btf, |
| 1964 | u32 *type_id, u32 *ret_size) |
| 1965 | { |
| 1966 | const struct btf_type *size_type; |
| 1967 | u32 size_type_id = *type_id; |
| 1968 | u32 size = 0; |
| 1969 | |
| 1970 | size_type = btf_type_by_id(btf, size_type_id); |
| 1971 | if (btf_type_nosize_or_null(size_type)) |
| 1972 | return NULL; |
| 1973 | |
| 1974 | if (btf_type_has_size(size_type)) { |
| 1975 | size = size_type->size; |
| 1976 | } else if (btf_type_is_array(size_type)) { |
| 1977 | size = btf_resolved_type_size(btf, size_type_id); |
| 1978 | } else if (btf_type_is_ptr(size_type)) { |
| 1979 | size = sizeof(void *); |
| 1980 | } else { |
| 1981 | if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
| 1982 | !btf_type_is_var(size_type))) |
| 1983 | return NULL; |
| 1984 | |
| 1985 | size_type_id = btf_resolved_type_id(btf, size_type_id); |
| 1986 | size_type = btf_type_by_id(btf, size_type_id); |
| 1987 | if (btf_type_nosize_or_null(size_type)) |
| 1988 | return NULL; |
| 1989 | else if (btf_type_has_size(size_type)) |
| 1990 | size = size_type->size; |
| 1991 | else if (btf_type_is_array(size_type)) |
| 1992 | size = btf_resolved_type_size(btf, size_type_id); |
| 1993 | else if (btf_type_is_ptr(size_type)) |
| 1994 | size = sizeof(void *); |
| 1995 | else |
| 1996 | return NULL; |
| 1997 | } |
| 1998 | |
| 1999 | *type_id = size_type_id; |
| 2000 | if (ret_size) |
| 2001 | *ret_size = size; |
| 2002 | |
| 2003 | return size_type; |
| 2004 | } |
| 2005 | |
| 2006 | static int btf_df_check_member(struct btf_verifier_env *env, |
| 2007 | const struct btf_type *struct_type, |
| 2008 | const struct btf_member *member, |
| 2009 | const struct btf_type *member_type) |
| 2010 | { |
| 2011 | btf_verifier_log_basic(env, struct_type, |
| 2012 | "Unsupported check_member"); |
| 2013 | return -EINVAL; |
| 2014 | } |
| 2015 | |
| 2016 | static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
| 2017 | const struct btf_type *struct_type, |
| 2018 | const struct btf_member *member, |
| 2019 | const struct btf_type *member_type) |
| 2020 | { |
| 2021 | btf_verifier_log_basic(env, struct_type, |
| 2022 | "Unsupported check_kflag_member"); |
| 2023 | return -EINVAL; |
| 2024 | } |
| 2025 | |
| 2026 | /* Used for ptr, array struct/union and float type members. |
| 2027 | * int, enum and modifier types have their specific callback functions. |
| 2028 | */ |
| 2029 | static int btf_generic_check_kflag_member(struct btf_verifier_env *env, |
| 2030 | const struct btf_type *struct_type, |
| 2031 | const struct btf_member *member, |
| 2032 | const struct btf_type *member_type) |
| 2033 | { |
| 2034 | if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { |
| 2035 | btf_verifier_log_member(env, struct_type, member, |
| 2036 | "Invalid member bitfield_size"); |
| 2037 | return -EINVAL; |
| 2038 | } |
| 2039 | |
| 2040 | /* bitfield size is 0, so member->offset represents bit offset only. |
| 2041 | * It is safe to call non kflag check_member variants. |
| 2042 | */ |
| 2043 | return btf_type_ops(member_type)->check_member(env, struct_type, |
| 2044 | member, |
| 2045 | member_type); |
| 2046 | } |
| 2047 | |
| 2048 | static int btf_df_resolve(struct btf_verifier_env *env, |
| 2049 | const struct resolve_vertex *v) |
| 2050 | { |
| 2051 | btf_verifier_log_basic(env, v->t, "Unsupported resolve"); |
| 2052 | return -EINVAL; |
| 2053 | } |
| 2054 | |
| 2055 | static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
| 2056 | u32 type_id, void *data, u8 bits_offsets, |
| 2057 | struct btf_show *show) |
| 2058 | { |
| 2059 | btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
| 2060 | } |
| 2061 | |
| 2062 | static int btf_int_check_member(struct btf_verifier_env *env, |
| 2063 | const struct btf_type *struct_type, |
| 2064 | const struct btf_member *member, |
| 2065 | const struct btf_type *member_type) |
| 2066 | { |
| 2067 | u32 int_data = btf_type_int(member_type); |
| 2068 | u32 struct_bits_off = member->offset; |
| 2069 | u32 struct_size = struct_type->size; |
| 2070 | u32 nr_copy_bits; |
| 2071 | u32 bytes_offset; |
| 2072 | |
| 2073 | if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { |
| 2074 | btf_verifier_log_member(env, struct_type, member, |
| 2075 | "bits_offset exceeds U32_MAX"); |
| 2076 | return -EINVAL; |
| 2077 | } |
| 2078 | |
| 2079 | struct_bits_off += BTF_INT_OFFSET(int_data); |
| 2080 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| 2081 | nr_copy_bits = BTF_INT_BITS(int_data) + |
| 2082 | BITS_PER_BYTE_MASKED(struct_bits_off); |
| 2083 | |
| 2084 | if (nr_copy_bits > BITS_PER_U128) { |
| 2085 | btf_verifier_log_member(env, struct_type, member, |
| 2086 | "nr_copy_bits exceeds 128"); |
| 2087 | return -EINVAL; |
| 2088 | } |
| 2089 | |
| 2090 | if (struct_size < bytes_offset || |
| 2091 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { |
| 2092 | btf_verifier_log_member(env, struct_type, member, |
| 2093 | "Member exceeds struct_size"); |
| 2094 | return -EINVAL; |
| 2095 | } |
| 2096 | |
| 2097 | return 0; |
| 2098 | } |
| 2099 | |
| 2100 | static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
| 2101 | const struct btf_type *struct_type, |
| 2102 | const struct btf_member *member, |
| 2103 | const struct btf_type *member_type) |
| 2104 | { |
| 2105 | u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; |
| 2106 | u32 int_data = btf_type_int(member_type); |
| 2107 | u32 struct_size = struct_type->size; |
| 2108 | u32 nr_copy_bits; |
| 2109 | |
| 2110 | /* a regular int type is required for the kflag int member */ |
| 2111 | if (!btf_type_int_is_regular(member_type)) { |
| 2112 | btf_verifier_log_member(env, struct_type, member, |
| 2113 | "Invalid member base type"); |
| 2114 | return -EINVAL; |
| 2115 | } |
| 2116 | |
| 2117 | /* check sanity of bitfield size */ |
| 2118 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); |
| 2119 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); |
| 2120 | nr_int_data_bits = BTF_INT_BITS(int_data); |
| 2121 | if (!nr_bits) { |
| 2122 | /* Not a bitfield member, member offset must be at byte |
| 2123 | * boundary. |
| 2124 | */ |
| 2125 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| 2126 | btf_verifier_log_member(env, struct_type, member, |
| 2127 | "Invalid member offset"); |
| 2128 | return -EINVAL; |
| 2129 | } |
| 2130 | |
| 2131 | nr_bits = nr_int_data_bits; |
| 2132 | } else if (nr_bits > nr_int_data_bits) { |
| 2133 | btf_verifier_log_member(env, struct_type, member, |
| 2134 | "Invalid member bitfield_size"); |
| 2135 | return -EINVAL; |
| 2136 | } |
| 2137 | |
| 2138 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| 2139 | nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); |
| 2140 | if (nr_copy_bits > BITS_PER_U128) { |
| 2141 | btf_verifier_log_member(env, struct_type, member, |
| 2142 | "nr_copy_bits exceeds 128"); |
| 2143 | return -EINVAL; |
| 2144 | } |
| 2145 | |
| 2146 | if (struct_size < bytes_offset || |
| 2147 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { |
| 2148 | btf_verifier_log_member(env, struct_type, member, |
| 2149 | "Member exceeds struct_size"); |
| 2150 | return -EINVAL; |
| 2151 | } |
| 2152 | |
| 2153 | return 0; |
| 2154 | } |
| 2155 | |
| 2156 | static s32 btf_int_check_meta(struct btf_verifier_env *env, |
| 2157 | const struct btf_type *t, |
| 2158 | u32 meta_left) |
| 2159 | { |
| 2160 | u32 int_data, nr_bits, meta_needed = sizeof(int_data); |
| 2161 | u16 encoding; |
| 2162 | |
| 2163 | if (meta_left < meta_needed) { |
| 2164 | btf_verifier_log_basic(env, t, |
| 2165 | "meta_left:%u meta_needed:%u", |
| 2166 | meta_left, meta_needed); |
| 2167 | return -EINVAL; |
| 2168 | } |
| 2169 | |
| 2170 | if (btf_type_vlen(t)) { |
| 2171 | btf_verifier_log_type(env, t, "vlen != 0"); |
| 2172 | return -EINVAL; |
| 2173 | } |
| 2174 | |
| 2175 | if (btf_type_kflag(t)) { |
| 2176 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 2177 | return -EINVAL; |
| 2178 | } |
| 2179 | |
| 2180 | int_data = btf_type_int(t); |
| 2181 | if (int_data & ~BTF_INT_MASK) { |
| 2182 | btf_verifier_log_basic(env, t, "Invalid int_data:%x", |
| 2183 | int_data); |
| 2184 | return -EINVAL; |
| 2185 | } |
| 2186 | |
| 2187 | nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
| 2188 | |
| 2189 | if (nr_bits > BITS_PER_U128) { |
| 2190 | btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
| 2191 | BITS_PER_U128); |
| 2192 | return -EINVAL; |
| 2193 | } |
| 2194 | |
| 2195 | if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { |
| 2196 | btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); |
| 2197 | return -EINVAL; |
| 2198 | } |
| 2199 | |
| 2200 | /* |
| 2201 | * Only one of the encoding bits is allowed and it |
| 2202 | * should be sufficient for the pretty print purpose (i.e. decoding). |
| 2203 | * Multiple bits can be allowed later if it is found |
| 2204 | * to be insufficient. |
| 2205 | */ |
| 2206 | encoding = BTF_INT_ENCODING(int_data); |
| 2207 | if (encoding && |
| 2208 | encoding != BTF_INT_SIGNED && |
| 2209 | encoding != BTF_INT_CHAR && |
| 2210 | encoding != BTF_INT_BOOL) { |
| 2211 | btf_verifier_log_type(env, t, "Unsupported encoding"); |
| 2212 | return -ENOTSUPP; |
| 2213 | } |
| 2214 | |
| 2215 | btf_verifier_log_type(env, t, NULL); |
| 2216 | |
| 2217 | return meta_needed; |
| 2218 | } |
| 2219 | |
| 2220 | static void btf_int_log(struct btf_verifier_env *env, |
| 2221 | const struct btf_type *t) |
| 2222 | { |
| 2223 | int int_data = btf_type_int(t); |
| 2224 | |
| 2225 | btf_verifier_log(env, |
| 2226 | "size=%u bits_offset=%u nr_bits=%u encoding=%s", |
| 2227 | t->size, BTF_INT_OFFSET(int_data), |
| 2228 | BTF_INT_BITS(int_data), |
| 2229 | btf_int_encoding_str(BTF_INT_ENCODING(int_data))); |
| 2230 | } |
| 2231 | |
| 2232 | static void btf_int128_print(struct btf_show *show, void *data) |
| 2233 | { |
| 2234 | /* data points to a __int128 number. |
| 2235 | * Suppose |
| 2236 | * int128_num = *(__int128 *)data; |
| 2237 | * The below formulas shows what upper_num and lower_num represents: |
| 2238 | * upper_num = int128_num >> 64; |
| 2239 | * lower_num = int128_num & 0xffffffffFFFFFFFFULL; |
| 2240 | */ |
| 2241 | u64 upper_num, lower_num; |
| 2242 | |
| 2243 | #ifdef __BIG_ENDIAN_BITFIELD |
| 2244 | upper_num = *(u64 *)data; |
| 2245 | lower_num = *(u64 *)(data + 8); |
| 2246 | #else |
| 2247 | upper_num = *(u64 *)(data + 8); |
| 2248 | lower_num = *(u64 *)data; |
| 2249 | #endif |
| 2250 | if (upper_num == 0) |
| 2251 | btf_show_type_value(show, "0x%llx", lower_num); |
| 2252 | else |
| 2253 | btf_show_type_values(show, "0x%llx%016llx", upper_num, |
| 2254 | lower_num); |
| 2255 | } |
| 2256 | |
| 2257 | static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, |
| 2258 | u16 right_shift_bits) |
| 2259 | { |
| 2260 | u64 upper_num, lower_num; |
| 2261 | |
| 2262 | #ifdef __BIG_ENDIAN_BITFIELD |
| 2263 | upper_num = print_num[0]; |
| 2264 | lower_num = print_num[1]; |
| 2265 | #else |
| 2266 | upper_num = print_num[1]; |
| 2267 | lower_num = print_num[0]; |
| 2268 | #endif |
| 2269 | |
| 2270 | /* shake out un-needed bits by shift/or operations */ |
| 2271 | if (left_shift_bits >= 64) { |
| 2272 | upper_num = lower_num << (left_shift_bits - 64); |
| 2273 | lower_num = 0; |
| 2274 | } else { |
| 2275 | upper_num = (upper_num << left_shift_bits) | |
| 2276 | (lower_num >> (64 - left_shift_bits)); |
| 2277 | lower_num = lower_num << left_shift_bits; |
| 2278 | } |
| 2279 | |
| 2280 | if (right_shift_bits >= 64) { |
| 2281 | lower_num = upper_num >> (right_shift_bits - 64); |
| 2282 | upper_num = 0; |
| 2283 | } else { |
| 2284 | lower_num = (lower_num >> right_shift_bits) | |
| 2285 | (upper_num << (64 - right_shift_bits)); |
| 2286 | upper_num = upper_num >> right_shift_bits; |
| 2287 | } |
| 2288 | |
| 2289 | #ifdef __BIG_ENDIAN_BITFIELD |
| 2290 | print_num[0] = upper_num; |
| 2291 | print_num[1] = lower_num; |
| 2292 | #else |
| 2293 | print_num[0] = lower_num; |
| 2294 | print_num[1] = upper_num; |
| 2295 | #endif |
| 2296 | } |
| 2297 | |
| 2298 | static void btf_bitfield_show(void *data, u8 bits_offset, |
| 2299 | u8 nr_bits, struct btf_show *show) |
| 2300 | { |
| 2301 | u16 left_shift_bits, right_shift_bits; |
| 2302 | u8 nr_copy_bytes; |
| 2303 | u8 nr_copy_bits; |
| 2304 | u64 print_num[2] = {}; |
| 2305 | |
| 2306 | nr_copy_bits = nr_bits + bits_offset; |
| 2307 | nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); |
| 2308 | |
| 2309 | memcpy(print_num, data, nr_copy_bytes); |
| 2310 | |
| 2311 | #ifdef __BIG_ENDIAN_BITFIELD |
| 2312 | left_shift_bits = bits_offset; |
| 2313 | #else |
| 2314 | left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
| 2315 | #endif |
| 2316 | right_shift_bits = BITS_PER_U128 - nr_bits; |
| 2317 | |
| 2318 | btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
| 2319 | btf_int128_print(show, print_num); |
| 2320 | } |
| 2321 | |
| 2322 | |
| 2323 | static void btf_int_bits_show(const struct btf *btf, |
| 2324 | const struct btf_type *t, |
| 2325 | void *data, u8 bits_offset, |
| 2326 | struct btf_show *show) |
| 2327 | { |
| 2328 | u32 int_data = btf_type_int(t); |
| 2329 | u8 nr_bits = BTF_INT_BITS(int_data); |
| 2330 | u8 total_bits_offset; |
| 2331 | |
| 2332 | /* |
| 2333 | * bits_offset is at most 7. |
| 2334 | * BTF_INT_OFFSET() cannot exceed 128 bits. |
| 2335 | */ |
| 2336 | total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); |
| 2337 | data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
| 2338 | bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); |
| 2339 | btf_bitfield_show(data, bits_offset, nr_bits, show); |
| 2340 | } |
| 2341 | |
| 2342 | static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
| 2343 | u32 type_id, void *data, u8 bits_offset, |
| 2344 | struct btf_show *show) |
| 2345 | { |
| 2346 | u32 int_data = btf_type_int(t); |
| 2347 | u8 encoding = BTF_INT_ENCODING(int_data); |
| 2348 | bool sign = encoding & BTF_INT_SIGNED; |
| 2349 | u8 nr_bits = BTF_INT_BITS(int_data); |
| 2350 | void *safe_data; |
| 2351 | |
| 2352 | safe_data = btf_show_start_type(show, t, type_id, data); |
| 2353 | if (!safe_data) |
| 2354 | return; |
| 2355 | |
| 2356 | if (bits_offset || BTF_INT_OFFSET(int_data) || |
| 2357 | BITS_PER_BYTE_MASKED(nr_bits)) { |
| 2358 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
| 2359 | goto out; |
| 2360 | } |
| 2361 | |
| 2362 | switch (nr_bits) { |
| 2363 | case 128: |
| 2364 | btf_int128_print(show, safe_data); |
| 2365 | break; |
| 2366 | case 64: |
| 2367 | if (sign) |
| 2368 | btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
| 2369 | else |
| 2370 | btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
| 2371 | break; |
| 2372 | case 32: |
| 2373 | if (sign) |
| 2374 | btf_show_type_value(show, "%d", *(s32 *)safe_data); |
| 2375 | else |
| 2376 | btf_show_type_value(show, "%u", *(u32 *)safe_data); |
| 2377 | break; |
| 2378 | case 16: |
| 2379 | if (sign) |
| 2380 | btf_show_type_value(show, "%d", *(s16 *)safe_data); |
| 2381 | else |
| 2382 | btf_show_type_value(show, "%u", *(u16 *)safe_data); |
| 2383 | break; |
| 2384 | case 8: |
| 2385 | if (show->state.array_encoding == BTF_INT_CHAR) { |
| 2386 | /* check for null terminator */ |
| 2387 | if (show->state.array_terminated) |
| 2388 | break; |
| 2389 | if (*(char *)data == '\0') { |
| 2390 | show->state.array_terminated = 1; |
| 2391 | break; |
| 2392 | } |
| 2393 | if (isprint(*(char *)data)) { |
| 2394 | btf_show_type_value(show, "'%c'", |
| 2395 | *(char *)safe_data); |
| 2396 | break; |
| 2397 | } |
| 2398 | } |
| 2399 | if (sign) |
| 2400 | btf_show_type_value(show, "%d", *(s8 *)safe_data); |
| 2401 | else |
| 2402 | btf_show_type_value(show, "%u", *(u8 *)safe_data); |
| 2403 | break; |
| 2404 | default: |
| 2405 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
| 2406 | break; |
| 2407 | } |
| 2408 | out: |
| 2409 | btf_show_end_type(show); |
| 2410 | } |
| 2411 | |
| 2412 | static const struct btf_kind_operations int_ops = { |
| 2413 | .check_meta = btf_int_check_meta, |
| 2414 | .resolve = btf_df_resolve, |
| 2415 | .check_member = btf_int_check_member, |
| 2416 | .check_kflag_member = btf_int_check_kflag_member, |
| 2417 | .log_details = btf_int_log, |
| 2418 | .show = btf_int_show, |
| 2419 | }; |
| 2420 | |
| 2421 | static int btf_modifier_check_member(struct btf_verifier_env *env, |
| 2422 | const struct btf_type *struct_type, |
| 2423 | const struct btf_member *member, |
| 2424 | const struct btf_type *member_type) |
| 2425 | { |
| 2426 | const struct btf_type *resolved_type; |
| 2427 | u32 resolved_type_id = member->type; |
| 2428 | struct btf_member resolved_member; |
| 2429 | struct btf *btf = env->btf; |
| 2430 | |
| 2431 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); |
| 2432 | if (!resolved_type) { |
| 2433 | btf_verifier_log_member(env, struct_type, member, |
| 2434 | "Invalid member"); |
| 2435 | return -EINVAL; |
| 2436 | } |
| 2437 | |
| 2438 | resolved_member = *member; |
| 2439 | resolved_member.type = resolved_type_id; |
| 2440 | |
| 2441 | return btf_type_ops(resolved_type)->check_member(env, struct_type, |
| 2442 | &resolved_member, |
| 2443 | resolved_type); |
| 2444 | } |
| 2445 | |
| 2446 | static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
| 2447 | const struct btf_type *struct_type, |
| 2448 | const struct btf_member *member, |
| 2449 | const struct btf_type *member_type) |
| 2450 | { |
| 2451 | const struct btf_type *resolved_type; |
| 2452 | u32 resolved_type_id = member->type; |
| 2453 | struct btf_member resolved_member; |
| 2454 | struct btf *btf = env->btf; |
| 2455 | |
| 2456 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); |
| 2457 | if (!resolved_type) { |
| 2458 | btf_verifier_log_member(env, struct_type, member, |
| 2459 | "Invalid member"); |
| 2460 | return -EINVAL; |
| 2461 | } |
| 2462 | |
| 2463 | resolved_member = *member; |
| 2464 | resolved_member.type = resolved_type_id; |
| 2465 | |
| 2466 | return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, |
| 2467 | &resolved_member, |
| 2468 | resolved_type); |
| 2469 | } |
| 2470 | |
| 2471 | static int btf_ptr_check_member(struct btf_verifier_env *env, |
| 2472 | const struct btf_type *struct_type, |
| 2473 | const struct btf_member *member, |
| 2474 | const struct btf_type *member_type) |
| 2475 | { |
| 2476 | u32 struct_size, struct_bits_off, bytes_offset; |
| 2477 | |
| 2478 | struct_size = struct_type->size; |
| 2479 | struct_bits_off = member->offset; |
| 2480 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| 2481 | |
| 2482 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| 2483 | btf_verifier_log_member(env, struct_type, member, |
| 2484 | "Member is not byte aligned"); |
| 2485 | return -EINVAL; |
| 2486 | } |
| 2487 | |
| 2488 | if (struct_size - bytes_offset < sizeof(void *)) { |
| 2489 | btf_verifier_log_member(env, struct_type, member, |
| 2490 | "Member exceeds struct_size"); |
| 2491 | return -EINVAL; |
| 2492 | } |
| 2493 | |
| 2494 | return 0; |
| 2495 | } |
| 2496 | |
| 2497 | static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
| 2498 | const struct btf_type *t, |
| 2499 | u32 meta_left) |
| 2500 | { |
| 2501 | const char *value; |
| 2502 | |
| 2503 | if (btf_type_vlen(t)) { |
| 2504 | btf_verifier_log_type(env, t, "vlen != 0"); |
| 2505 | return -EINVAL; |
| 2506 | } |
| 2507 | |
| 2508 | if (btf_type_kflag(t)) { |
| 2509 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 2510 | return -EINVAL; |
| 2511 | } |
| 2512 | |
| 2513 | if (!BTF_TYPE_ID_VALID(t->type)) { |
| 2514 | btf_verifier_log_type(env, t, "Invalid type_id"); |
| 2515 | return -EINVAL; |
| 2516 | } |
| 2517 | |
| 2518 | /* typedef/type_tag type must have a valid name, and other ref types, |
| 2519 | * volatile, const, restrict, should have a null name. |
| 2520 | */ |
| 2521 | if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { |
| 2522 | if (!t->name_off || |
| 2523 | !btf_name_valid_identifier(env->btf, t->name_off)) { |
| 2524 | btf_verifier_log_type(env, t, "Invalid name"); |
| 2525 | return -EINVAL; |
| 2526 | } |
| 2527 | } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
| 2528 | value = btf_name_by_offset(env->btf, t->name_off); |
| 2529 | if (!value || !value[0]) { |
| 2530 | btf_verifier_log_type(env, t, "Invalid name"); |
| 2531 | return -EINVAL; |
| 2532 | } |
| 2533 | } else { |
| 2534 | if (t->name_off) { |
| 2535 | btf_verifier_log_type(env, t, "Invalid name"); |
| 2536 | return -EINVAL; |
| 2537 | } |
| 2538 | } |
| 2539 | |
| 2540 | btf_verifier_log_type(env, t, NULL); |
| 2541 | |
| 2542 | return 0; |
| 2543 | } |
| 2544 | |
| 2545 | static int btf_modifier_resolve(struct btf_verifier_env *env, |
| 2546 | const struct resolve_vertex *v) |
| 2547 | { |
| 2548 | const struct btf_type *t = v->t; |
| 2549 | const struct btf_type *next_type; |
| 2550 | u32 next_type_id = t->type; |
| 2551 | struct btf *btf = env->btf; |
| 2552 | |
| 2553 | next_type = btf_type_by_id(btf, next_type_id); |
| 2554 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
| 2555 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| 2556 | return -EINVAL; |
| 2557 | } |
| 2558 | |
| 2559 | if (!env_type_is_resolve_sink(env, next_type) && |
| 2560 | !env_type_is_resolved(env, next_type_id)) |
| 2561 | return env_stack_push(env, next_type, next_type_id); |
| 2562 | |
| 2563 | /* Figure out the resolved next_type_id with size. |
| 2564 | * They will be stored in the current modifier's |
| 2565 | * resolved_ids and resolved_sizes such that it can |
| 2566 | * save us a few type-following when we use it later (e.g. in |
| 2567 | * pretty print). |
| 2568 | */ |
| 2569 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
| 2570 | if (env_type_is_resolved(env, next_type_id)) |
| 2571 | next_type = btf_type_id_resolve(btf, &next_type_id); |
| 2572 | |
| 2573 | /* "typedef void new_void", "const void"...etc */ |
| 2574 | if (!btf_type_is_void(next_type) && |
| 2575 | !btf_type_is_fwd(next_type) && |
| 2576 | !btf_type_is_func_proto(next_type)) { |
| 2577 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| 2578 | return -EINVAL; |
| 2579 | } |
| 2580 | } |
| 2581 | |
| 2582 | env_stack_pop_resolved(env, next_type_id, 0); |
| 2583 | |
| 2584 | return 0; |
| 2585 | } |
| 2586 | |
| 2587 | static int btf_var_resolve(struct btf_verifier_env *env, |
| 2588 | const struct resolve_vertex *v) |
| 2589 | { |
| 2590 | const struct btf_type *next_type; |
| 2591 | const struct btf_type *t = v->t; |
| 2592 | u32 next_type_id = t->type; |
| 2593 | struct btf *btf = env->btf; |
| 2594 | |
| 2595 | next_type = btf_type_by_id(btf, next_type_id); |
| 2596 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
| 2597 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| 2598 | return -EINVAL; |
| 2599 | } |
| 2600 | |
| 2601 | if (!env_type_is_resolve_sink(env, next_type) && |
| 2602 | !env_type_is_resolved(env, next_type_id)) |
| 2603 | return env_stack_push(env, next_type, next_type_id); |
| 2604 | |
| 2605 | if (btf_type_is_modifier(next_type)) { |
| 2606 | const struct btf_type *resolved_type; |
| 2607 | u32 resolved_type_id; |
| 2608 | |
| 2609 | resolved_type_id = next_type_id; |
| 2610 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); |
| 2611 | |
| 2612 | if (btf_type_is_ptr(resolved_type) && |
| 2613 | !env_type_is_resolve_sink(env, resolved_type) && |
| 2614 | !env_type_is_resolved(env, resolved_type_id)) |
| 2615 | return env_stack_push(env, resolved_type, |
| 2616 | resolved_type_id); |
| 2617 | } |
| 2618 | |
| 2619 | /* We must resolve to something concrete at this point, no |
| 2620 | * forward types or similar that would resolve to size of |
| 2621 | * zero is allowed. |
| 2622 | */ |
| 2623 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
| 2624 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| 2625 | return -EINVAL; |
| 2626 | } |
| 2627 | |
| 2628 | env_stack_pop_resolved(env, next_type_id, 0); |
| 2629 | |
| 2630 | return 0; |
| 2631 | } |
| 2632 | |
| 2633 | static int btf_ptr_resolve(struct btf_verifier_env *env, |
| 2634 | const struct resolve_vertex *v) |
| 2635 | { |
| 2636 | const struct btf_type *next_type; |
| 2637 | const struct btf_type *t = v->t; |
| 2638 | u32 next_type_id = t->type; |
| 2639 | struct btf *btf = env->btf; |
| 2640 | |
| 2641 | next_type = btf_type_by_id(btf, next_type_id); |
| 2642 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
| 2643 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| 2644 | return -EINVAL; |
| 2645 | } |
| 2646 | |
| 2647 | if (!env_type_is_resolve_sink(env, next_type) && |
| 2648 | !env_type_is_resolved(env, next_type_id)) |
| 2649 | return env_stack_push(env, next_type, next_type_id); |
| 2650 | |
| 2651 | /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, |
| 2652 | * the modifier may have stopped resolving when it was resolved |
| 2653 | * to a ptr (last-resolved-ptr). |
| 2654 | * |
| 2655 | * We now need to continue from the last-resolved-ptr to |
| 2656 | * ensure the last-resolved-ptr will not referring back to |
| 2657 | * the current ptr (t). |
| 2658 | */ |
| 2659 | if (btf_type_is_modifier(next_type)) { |
| 2660 | const struct btf_type *resolved_type; |
| 2661 | u32 resolved_type_id; |
| 2662 | |
| 2663 | resolved_type_id = next_type_id; |
| 2664 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); |
| 2665 | |
| 2666 | if (btf_type_is_ptr(resolved_type) && |
| 2667 | !env_type_is_resolve_sink(env, resolved_type) && |
| 2668 | !env_type_is_resolved(env, resolved_type_id)) |
| 2669 | return env_stack_push(env, resolved_type, |
| 2670 | resolved_type_id); |
| 2671 | } |
| 2672 | |
| 2673 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
| 2674 | if (env_type_is_resolved(env, next_type_id)) |
| 2675 | next_type = btf_type_id_resolve(btf, &next_type_id); |
| 2676 | |
| 2677 | if (!btf_type_is_void(next_type) && |
| 2678 | !btf_type_is_fwd(next_type) && |
| 2679 | !btf_type_is_func_proto(next_type)) { |
| 2680 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| 2681 | return -EINVAL; |
| 2682 | } |
| 2683 | } |
| 2684 | |
| 2685 | env_stack_pop_resolved(env, next_type_id, 0); |
| 2686 | |
| 2687 | return 0; |
| 2688 | } |
| 2689 | |
| 2690 | static void btf_modifier_show(const struct btf *btf, |
| 2691 | const struct btf_type *t, |
| 2692 | u32 type_id, void *data, |
| 2693 | u8 bits_offset, struct btf_show *show) |
| 2694 | { |
| 2695 | if (btf->resolved_ids) |
| 2696 | t = btf_type_id_resolve(btf, &type_id); |
| 2697 | else |
| 2698 | t = btf_type_skip_modifiers(btf, type_id, NULL); |
| 2699 | |
| 2700 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
| 2701 | } |
| 2702 | |
| 2703 | static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
| 2704 | u32 type_id, void *data, u8 bits_offset, |
| 2705 | struct btf_show *show) |
| 2706 | { |
| 2707 | t = btf_type_id_resolve(btf, &type_id); |
| 2708 | |
| 2709 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
| 2710 | } |
| 2711 | |
| 2712 | static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
| 2713 | u32 type_id, void *data, u8 bits_offset, |
| 2714 | struct btf_show *show) |
| 2715 | { |
| 2716 | void *safe_data; |
| 2717 | |
| 2718 | safe_data = btf_show_start_type(show, t, type_id, data); |
| 2719 | if (!safe_data) |
| 2720 | return; |
| 2721 | |
| 2722 | /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ |
| 2723 | if (show->flags & BTF_SHOW_PTR_RAW) |
| 2724 | btf_show_type_value(show, "0x%px", *(void **)safe_data); |
| 2725 | else |
| 2726 | btf_show_type_value(show, "0x%p", *(void **)safe_data); |
| 2727 | btf_show_end_type(show); |
| 2728 | } |
| 2729 | |
| 2730 | static void btf_ref_type_log(struct btf_verifier_env *env, |
| 2731 | const struct btf_type *t) |
| 2732 | { |
| 2733 | btf_verifier_log(env, "type_id=%u", t->type); |
| 2734 | } |
| 2735 | |
| 2736 | static struct btf_kind_operations modifier_ops = { |
| 2737 | .check_meta = btf_ref_type_check_meta, |
| 2738 | .resolve = btf_modifier_resolve, |
| 2739 | .check_member = btf_modifier_check_member, |
| 2740 | .check_kflag_member = btf_modifier_check_kflag_member, |
| 2741 | .log_details = btf_ref_type_log, |
| 2742 | .show = btf_modifier_show, |
| 2743 | }; |
| 2744 | |
| 2745 | static struct btf_kind_operations ptr_ops = { |
| 2746 | .check_meta = btf_ref_type_check_meta, |
| 2747 | .resolve = btf_ptr_resolve, |
| 2748 | .check_member = btf_ptr_check_member, |
| 2749 | .check_kflag_member = btf_generic_check_kflag_member, |
| 2750 | .log_details = btf_ref_type_log, |
| 2751 | .show = btf_ptr_show, |
| 2752 | }; |
| 2753 | |
| 2754 | static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
| 2755 | const struct btf_type *t, |
| 2756 | u32 meta_left) |
| 2757 | { |
| 2758 | if (btf_type_vlen(t)) { |
| 2759 | btf_verifier_log_type(env, t, "vlen != 0"); |
| 2760 | return -EINVAL; |
| 2761 | } |
| 2762 | |
| 2763 | if (t->type) { |
| 2764 | btf_verifier_log_type(env, t, "type != 0"); |
| 2765 | return -EINVAL; |
| 2766 | } |
| 2767 | |
| 2768 | /* fwd type must have a valid name */ |
| 2769 | if (!t->name_off || |
| 2770 | !btf_name_valid_identifier(env->btf, t->name_off)) { |
| 2771 | btf_verifier_log_type(env, t, "Invalid name"); |
| 2772 | return -EINVAL; |
| 2773 | } |
| 2774 | |
| 2775 | btf_verifier_log_type(env, t, NULL); |
| 2776 | |
| 2777 | return 0; |
| 2778 | } |
| 2779 | |
| 2780 | static void btf_fwd_type_log(struct btf_verifier_env *env, |
| 2781 | const struct btf_type *t) |
| 2782 | { |
| 2783 | btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); |
| 2784 | } |
| 2785 | |
| 2786 | static struct btf_kind_operations fwd_ops = { |
| 2787 | .check_meta = btf_fwd_check_meta, |
| 2788 | .resolve = btf_df_resolve, |
| 2789 | .check_member = btf_df_check_member, |
| 2790 | .check_kflag_member = btf_df_check_kflag_member, |
| 2791 | .log_details = btf_fwd_type_log, |
| 2792 | .show = btf_df_show, |
| 2793 | }; |
| 2794 | |
| 2795 | static int btf_array_check_member(struct btf_verifier_env *env, |
| 2796 | const struct btf_type *struct_type, |
| 2797 | const struct btf_member *member, |
| 2798 | const struct btf_type *member_type) |
| 2799 | { |
| 2800 | u32 struct_bits_off = member->offset; |
| 2801 | u32 struct_size, bytes_offset; |
| 2802 | u32 array_type_id, array_size; |
| 2803 | struct btf *btf = env->btf; |
| 2804 | |
| 2805 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| 2806 | btf_verifier_log_member(env, struct_type, member, |
| 2807 | "Member is not byte aligned"); |
| 2808 | return -EINVAL; |
| 2809 | } |
| 2810 | |
| 2811 | array_type_id = member->type; |
| 2812 | btf_type_id_size(btf, &array_type_id, &array_size); |
| 2813 | struct_size = struct_type->size; |
| 2814 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| 2815 | if (struct_size - bytes_offset < array_size) { |
| 2816 | btf_verifier_log_member(env, struct_type, member, |
| 2817 | "Member exceeds struct_size"); |
| 2818 | return -EINVAL; |
| 2819 | } |
| 2820 | |
| 2821 | return 0; |
| 2822 | } |
| 2823 | |
| 2824 | static s32 btf_array_check_meta(struct btf_verifier_env *env, |
| 2825 | const struct btf_type *t, |
| 2826 | u32 meta_left) |
| 2827 | { |
| 2828 | const struct btf_array *array = btf_type_array(t); |
| 2829 | u32 meta_needed = sizeof(*array); |
| 2830 | |
| 2831 | if (meta_left < meta_needed) { |
| 2832 | btf_verifier_log_basic(env, t, |
| 2833 | "meta_left:%u meta_needed:%u", |
| 2834 | meta_left, meta_needed); |
| 2835 | return -EINVAL; |
| 2836 | } |
| 2837 | |
| 2838 | /* array type should not have a name */ |
| 2839 | if (t->name_off) { |
| 2840 | btf_verifier_log_type(env, t, "Invalid name"); |
| 2841 | return -EINVAL; |
| 2842 | } |
| 2843 | |
| 2844 | if (btf_type_vlen(t)) { |
| 2845 | btf_verifier_log_type(env, t, "vlen != 0"); |
| 2846 | return -EINVAL; |
| 2847 | } |
| 2848 | |
| 2849 | if (btf_type_kflag(t)) { |
| 2850 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 2851 | return -EINVAL; |
| 2852 | } |
| 2853 | |
| 2854 | if (t->size) { |
| 2855 | btf_verifier_log_type(env, t, "size != 0"); |
| 2856 | return -EINVAL; |
| 2857 | } |
| 2858 | |
| 2859 | /* Array elem type and index type cannot be in type void, |
| 2860 | * so !array->type and !array->index_type are not allowed. |
| 2861 | */ |
| 2862 | if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
| 2863 | btf_verifier_log_type(env, t, "Invalid elem"); |
| 2864 | return -EINVAL; |
| 2865 | } |
| 2866 | |
| 2867 | if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
| 2868 | btf_verifier_log_type(env, t, "Invalid index"); |
| 2869 | return -EINVAL; |
| 2870 | } |
| 2871 | |
| 2872 | btf_verifier_log_type(env, t, NULL); |
| 2873 | |
| 2874 | return meta_needed; |
| 2875 | } |
| 2876 | |
| 2877 | static int btf_array_resolve(struct btf_verifier_env *env, |
| 2878 | const struct resolve_vertex *v) |
| 2879 | { |
| 2880 | const struct btf_array *array = btf_type_array(v->t); |
| 2881 | const struct btf_type *elem_type, *index_type; |
| 2882 | u32 elem_type_id, index_type_id; |
| 2883 | struct btf *btf = env->btf; |
| 2884 | u32 elem_size; |
| 2885 | |
| 2886 | /* Check array->index_type */ |
| 2887 | index_type_id = array->index_type; |
| 2888 | index_type = btf_type_by_id(btf, index_type_id); |
| 2889 | if (btf_type_nosize_or_null(index_type) || |
| 2890 | btf_type_is_resolve_source_only(index_type)) { |
| 2891 | btf_verifier_log_type(env, v->t, "Invalid index"); |
| 2892 | return -EINVAL; |
| 2893 | } |
| 2894 | |
| 2895 | if (!env_type_is_resolve_sink(env, index_type) && |
| 2896 | !env_type_is_resolved(env, index_type_id)) |
| 2897 | return env_stack_push(env, index_type, index_type_id); |
| 2898 | |
| 2899 | index_type = btf_type_id_size(btf, &index_type_id, NULL); |
| 2900 | if (!index_type || !btf_type_is_int(index_type) || |
| 2901 | !btf_type_int_is_regular(index_type)) { |
| 2902 | btf_verifier_log_type(env, v->t, "Invalid index"); |
| 2903 | return -EINVAL; |
| 2904 | } |
| 2905 | |
| 2906 | /* Check array->type */ |
| 2907 | elem_type_id = array->type; |
| 2908 | elem_type = btf_type_by_id(btf, elem_type_id); |
| 2909 | if (btf_type_nosize_or_null(elem_type) || |
| 2910 | btf_type_is_resolve_source_only(elem_type)) { |
| 2911 | btf_verifier_log_type(env, v->t, |
| 2912 | "Invalid elem"); |
| 2913 | return -EINVAL; |
| 2914 | } |
| 2915 | |
| 2916 | if (!env_type_is_resolve_sink(env, elem_type) && |
| 2917 | !env_type_is_resolved(env, elem_type_id)) |
| 2918 | return env_stack_push(env, elem_type, elem_type_id); |
| 2919 | |
| 2920 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); |
| 2921 | if (!elem_type) { |
| 2922 | btf_verifier_log_type(env, v->t, "Invalid elem"); |
| 2923 | return -EINVAL; |
| 2924 | } |
| 2925 | |
| 2926 | if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
| 2927 | btf_verifier_log_type(env, v->t, "Invalid array of int"); |
| 2928 | return -EINVAL; |
| 2929 | } |
| 2930 | |
| 2931 | if (array->nelems && elem_size > U32_MAX / array->nelems) { |
| 2932 | btf_verifier_log_type(env, v->t, |
| 2933 | "Array size overflows U32_MAX"); |
| 2934 | return -EINVAL; |
| 2935 | } |
| 2936 | |
| 2937 | env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); |
| 2938 | |
| 2939 | return 0; |
| 2940 | } |
| 2941 | |
| 2942 | static void btf_array_log(struct btf_verifier_env *env, |
| 2943 | const struct btf_type *t) |
| 2944 | { |
| 2945 | const struct btf_array *array = btf_type_array(t); |
| 2946 | |
| 2947 | btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", |
| 2948 | array->type, array->index_type, array->nelems); |
| 2949 | } |
| 2950 | |
| 2951 | static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
| 2952 | u32 type_id, void *data, u8 bits_offset, |
| 2953 | struct btf_show *show) |
| 2954 | { |
| 2955 | const struct btf_array *array = btf_type_array(t); |
| 2956 | const struct btf_kind_operations *elem_ops; |
| 2957 | const struct btf_type *elem_type; |
| 2958 | u32 i, elem_size = 0, elem_type_id; |
| 2959 | u16 encoding = 0; |
| 2960 | |
| 2961 | elem_type_id = array->type; |
| 2962 | elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
| 2963 | if (elem_type && btf_type_has_size(elem_type)) |
| 2964 | elem_size = elem_type->size; |
| 2965 | |
| 2966 | if (elem_type && btf_type_is_int(elem_type)) { |
| 2967 | u32 int_type = btf_type_int(elem_type); |
| 2968 | |
| 2969 | encoding = BTF_INT_ENCODING(int_type); |
| 2970 | |
| 2971 | /* |
| 2972 | * BTF_INT_CHAR encoding never seems to be set for |
| 2973 | * char arrays, so if size is 1 and element is |
| 2974 | * printable as a char, we'll do that. |
| 2975 | */ |
| 2976 | if (elem_size == 1) |
| 2977 | encoding = BTF_INT_CHAR; |
| 2978 | } |
| 2979 | |
| 2980 | if (!btf_show_start_array_type(show, t, type_id, encoding, data)) |
| 2981 | return; |
| 2982 | |
| 2983 | if (!elem_type) |
| 2984 | goto out; |
| 2985 | elem_ops = btf_type_ops(elem_type); |
| 2986 | |
| 2987 | for (i = 0; i < array->nelems; i++) { |
| 2988 | |
| 2989 | btf_show_start_array_member(show); |
| 2990 | |
| 2991 | elem_ops->show(btf, elem_type, elem_type_id, data, |
| 2992 | bits_offset, show); |
| 2993 | data += elem_size; |
| 2994 | |
| 2995 | btf_show_end_array_member(show); |
| 2996 | |
| 2997 | if (show->state.array_terminated) |
| 2998 | break; |
| 2999 | } |
| 3000 | out: |
| 3001 | btf_show_end_array_type(show); |
| 3002 | } |
| 3003 | |
| 3004 | static void btf_array_show(const struct btf *btf, const struct btf_type *t, |
| 3005 | u32 type_id, void *data, u8 bits_offset, |
| 3006 | struct btf_show *show) |
| 3007 | { |
| 3008 | const struct btf_member *m = show->state.member; |
| 3009 | |
| 3010 | /* |
| 3011 | * First check if any members would be shown (are non-zero). |
| 3012 | * See comments above "struct btf_show" definition for more |
| 3013 | * details on how this works at a high-level. |
| 3014 | */ |
| 3015 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { |
| 3016 | if (!show->state.depth_check) { |
| 3017 | show->state.depth_check = show->state.depth + 1; |
| 3018 | show->state.depth_to_show = 0; |
| 3019 | } |
| 3020 | __btf_array_show(btf, t, type_id, data, bits_offset, show); |
| 3021 | show->state.member = m; |
| 3022 | |
| 3023 | if (show->state.depth_check != show->state.depth + 1) |
| 3024 | return; |
| 3025 | show->state.depth_check = 0; |
| 3026 | |
| 3027 | if (show->state.depth_to_show <= show->state.depth) |
| 3028 | return; |
| 3029 | /* |
| 3030 | * Reaching here indicates we have recursed and found |
| 3031 | * non-zero array member(s). |
| 3032 | */ |
| 3033 | } |
| 3034 | __btf_array_show(btf, t, type_id, data, bits_offset, show); |
| 3035 | } |
| 3036 | |
| 3037 | static struct btf_kind_operations array_ops = { |
| 3038 | .check_meta = btf_array_check_meta, |
| 3039 | .resolve = btf_array_resolve, |
| 3040 | .check_member = btf_array_check_member, |
| 3041 | .check_kflag_member = btf_generic_check_kflag_member, |
| 3042 | .log_details = btf_array_log, |
| 3043 | .show = btf_array_show, |
| 3044 | }; |
| 3045 | |
| 3046 | static int btf_struct_check_member(struct btf_verifier_env *env, |
| 3047 | const struct btf_type *struct_type, |
| 3048 | const struct btf_member *member, |
| 3049 | const struct btf_type *member_type) |
| 3050 | { |
| 3051 | u32 struct_bits_off = member->offset; |
| 3052 | u32 struct_size, bytes_offset; |
| 3053 | |
| 3054 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| 3055 | btf_verifier_log_member(env, struct_type, member, |
| 3056 | "Member is not byte aligned"); |
| 3057 | return -EINVAL; |
| 3058 | } |
| 3059 | |
| 3060 | struct_size = struct_type->size; |
| 3061 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| 3062 | if (struct_size - bytes_offset < member_type->size) { |
| 3063 | btf_verifier_log_member(env, struct_type, member, |
| 3064 | "Member exceeds struct_size"); |
| 3065 | return -EINVAL; |
| 3066 | } |
| 3067 | |
| 3068 | return 0; |
| 3069 | } |
| 3070 | |
| 3071 | static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
| 3072 | const struct btf_type *t, |
| 3073 | u32 meta_left) |
| 3074 | { |
| 3075 | bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; |
| 3076 | const struct btf_member *member; |
| 3077 | u32 meta_needed, last_offset; |
| 3078 | struct btf *btf = env->btf; |
| 3079 | u32 struct_size = t->size; |
| 3080 | u32 offset; |
| 3081 | u16 i; |
| 3082 | |
| 3083 | meta_needed = btf_type_vlen(t) * sizeof(*member); |
| 3084 | if (meta_left < meta_needed) { |
| 3085 | btf_verifier_log_basic(env, t, |
| 3086 | "meta_left:%u meta_needed:%u", |
| 3087 | meta_left, meta_needed); |
| 3088 | return -EINVAL; |
| 3089 | } |
| 3090 | |
| 3091 | /* struct type either no name or a valid one */ |
| 3092 | if (t->name_off && |
| 3093 | !btf_name_valid_identifier(env->btf, t->name_off)) { |
| 3094 | btf_verifier_log_type(env, t, "Invalid name"); |
| 3095 | return -EINVAL; |
| 3096 | } |
| 3097 | |
| 3098 | btf_verifier_log_type(env, t, NULL); |
| 3099 | |
| 3100 | last_offset = 0; |
| 3101 | for_each_member(i, t, member) { |
| 3102 | if (!btf_name_offset_valid(btf, member->name_off)) { |
| 3103 | btf_verifier_log_member(env, t, member, |
| 3104 | "Invalid member name_offset:%u", |
| 3105 | member->name_off); |
| 3106 | return -EINVAL; |
| 3107 | } |
| 3108 | |
| 3109 | /* struct member either no name or a valid one */ |
| 3110 | if (member->name_off && |
| 3111 | !btf_name_valid_identifier(btf, member->name_off)) { |
| 3112 | btf_verifier_log_member(env, t, member, "Invalid name"); |
| 3113 | return -EINVAL; |
| 3114 | } |
| 3115 | /* A member cannot be in type void */ |
| 3116 | if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
| 3117 | btf_verifier_log_member(env, t, member, |
| 3118 | "Invalid type_id"); |
| 3119 | return -EINVAL; |
| 3120 | } |
| 3121 | |
| 3122 | offset = __btf_member_bit_offset(t, member); |
| 3123 | if (is_union && offset) { |
| 3124 | btf_verifier_log_member(env, t, member, |
| 3125 | "Invalid member bits_offset"); |
| 3126 | return -EINVAL; |
| 3127 | } |
| 3128 | |
| 3129 | /* |
| 3130 | * ">" instead of ">=" because the last member could be |
| 3131 | * "char a[0];" |
| 3132 | */ |
| 3133 | if (last_offset > offset) { |
| 3134 | btf_verifier_log_member(env, t, member, |
| 3135 | "Invalid member bits_offset"); |
| 3136 | return -EINVAL; |
| 3137 | } |
| 3138 | |
| 3139 | if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
| 3140 | btf_verifier_log_member(env, t, member, |
| 3141 | "Member bits_offset exceeds its struct size"); |
| 3142 | return -EINVAL; |
| 3143 | } |
| 3144 | |
| 3145 | btf_verifier_log_member(env, t, member, NULL); |
| 3146 | last_offset = offset; |
| 3147 | } |
| 3148 | |
| 3149 | return meta_needed; |
| 3150 | } |
| 3151 | |
| 3152 | static int btf_struct_resolve(struct btf_verifier_env *env, |
| 3153 | const struct resolve_vertex *v) |
| 3154 | { |
| 3155 | const struct btf_member *member; |
| 3156 | int err; |
| 3157 | u16 i; |
| 3158 | |
| 3159 | /* Before continue resolving the next_member, |
| 3160 | * ensure the last member is indeed resolved to a |
| 3161 | * type with size info. |
| 3162 | */ |
| 3163 | if (v->next_member) { |
| 3164 | const struct btf_type *last_member_type; |
| 3165 | const struct btf_member *last_member; |
| 3166 | u32 last_member_type_id; |
| 3167 | |
| 3168 | last_member = btf_type_member(v->t) + v->next_member - 1; |
| 3169 | last_member_type_id = last_member->type; |
| 3170 | if (WARN_ON_ONCE(!env_type_is_resolved(env, |
| 3171 | last_member_type_id))) |
| 3172 | return -EINVAL; |
| 3173 | |
| 3174 | last_member_type = btf_type_by_id(env->btf, |
| 3175 | last_member_type_id); |
| 3176 | if (btf_type_kflag(v->t)) |
| 3177 | err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, |
| 3178 | last_member, |
| 3179 | last_member_type); |
| 3180 | else |
| 3181 | err = btf_type_ops(last_member_type)->check_member(env, v->t, |
| 3182 | last_member, |
| 3183 | last_member_type); |
| 3184 | if (err) |
| 3185 | return err; |
| 3186 | } |
| 3187 | |
| 3188 | for_each_member_from(i, v->next_member, v->t, member) { |
| 3189 | u32 member_type_id = member->type; |
| 3190 | const struct btf_type *member_type = btf_type_by_id(env->btf, |
| 3191 | member_type_id); |
| 3192 | |
| 3193 | if (btf_type_nosize_or_null(member_type) || |
| 3194 | btf_type_is_resolve_source_only(member_type)) { |
| 3195 | btf_verifier_log_member(env, v->t, member, |
| 3196 | "Invalid member"); |
| 3197 | return -EINVAL; |
| 3198 | } |
| 3199 | |
| 3200 | if (!env_type_is_resolve_sink(env, member_type) && |
| 3201 | !env_type_is_resolved(env, member_type_id)) { |
| 3202 | env_stack_set_next_member(env, i + 1); |
| 3203 | return env_stack_push(env, member_type, member_type_id); |
| 3204 | } |
| 3205 | |
| 3206 | if (btf_type_kflag(v->t)) |
| 3207 | err = btf_type_ops(member_type)->check_kflag_member(env, v->t, |
| 3208 | member, |
| 3209 | member_type); |
| 3210 | else |
| 3211 | err = btf_type_ops(member_type)->check_member(env, v->t, |
| 3212 | member, |
| 3213 | member_type); |
| 3214 | if (err) |
| 3215 | return err; |
| 3216 | } |
| 3217 | |
| 3218 | env_stack_pop_resolved(env, 0, 0); |
| 3219 | |
| 3220 | return 0; |
| 3221 | } |
| 3222 | |
| 3223 | static void btf_struct_log(struct btf_verifier_env *env, |
| 3224 | const struct btf_type *t) |
| 3225 | { |
| 3226 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
| 3227 | } |
| 3228 | |
| 3229 | enum btf_field_info_type { |
| 3230 | BTF_FIELD_SPIN_LOCK, |
| 3231 | BTF_FIELD_TIMER, |
| 3232 | BTF_FIELD_KPTR, |
| 3233 | }; |
| 3234 | |
| 3235 | enum { |
| 3236 | BTF_FIELD_IGNORE = 0, |
| 3237 | BTF_FIELD_FOUND = 1, |
| 3238 | }; |
| 3239 | |
| 3240 | struct btf_field_info { |
| 3241 | enum btf_field_type type; |
| 3242 | u32 off; |
| 3243 | union { |
| 3244 | struct { |
| 3245 | u32 type_id; |
| 3246 | } kptr; |
| 3247 | struct { |
| 3248 | const char *node_name; |
| 3249 | u32 value_btf_id; |
| 3250 | } graph_root; |
| 3251 | }; |
| 3252 | }; |
| 3253 | |
| 3254 | static int btf_find_struct(const struct btf *btf, const struct btf_type *t, |
| 3255 | u32 off, int sz, enum btf_field_type field_type, |
| 3256 | struct btf_field_info *info) |
| 3257 | { |
| 3258 | if (!__btf_type_is_struct(t)) |
| 3259 | return BTF_FIELD_IGNORE; |
| 3260 | if (t->size != sz) |
| 3261 | return BTF_FIELD_IGNORE; |
| 3262 | info->type = field_type; |
| 3263 | info->off = off; |
| 3264 | return BTF_FIELD_FOUND; |
| 3265 | } |
| 3266 | |
| 3267 | static int btf_find_kptr(const struct btf *btf, const struct btf_type *t, |
| 3268 | u32 off, int sz, struct btf_field_info *info) |
| 3269 | { |
| 3270 | enum btf_field_type type; |
| 3271 | u32 res_id; |
| 3272 | |
| 3273 | /* Permit modifiers on the pointer itself */ |
| 3274 | if (btf_type_is_volatile(t)) |
| 3275 | t = btf_type_by_id(btf, t->type); |
| 3276 | /* For PTR, sz is always == 8 */ |
| 3277 | if (!btf_type_is_ptr(t)) |
| 3278 | return BTF_FIELD_IGNORE; |
| 3279 | t = btf_type_by_id(btf, t->type); |
| 3280 | |
| 3281 | if (!btf_type_is_type_tag(t)) |
| 3282 | return BTF_FIELD_IGNORE; |
| 3283 | /* Reject extra tags */ |
| 3284 | if (btf_type_is_type_tag(btf_type_by_id(btf, t->type))) |
| 3285 | return -EINVAL; |
| 3286 | if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off))) |
| 3287 | type = BPF_KPTR_UNREF; |
| 3288 | else if (!strcmp("kptr_ref", __btf_name_by_offset(btf, t->name_off))) |
| 3289 | type = BPF_KPTR_REF; |
| 3290 | else |
| 3291 | return -EINVAL; |
| 3292 | |
| 3293 | /* Get the base type */ |
| 3294 | t = btf_type_skip_modifiers(btf, t->type, &res_id); |
| 3295 | /* Only pointer to struct is allowed */ |
| 3296 | if (!__btf_type_is_struct(t)) |
| 3297 | return -EINVAL; |
| 3298 | |
| 3299 | info->type = type; |
| 3300 | info->off = off; |
| 3301 | info->kptr.type_id = res_id; |
| 3302 | return BTF_FIELD_FOUND; |
| 3303 | } |
| 3304 | |
| 3305 | static const char *btf_find_decl_tag_value(const struct btf *btf, |
| 3306 | const struct btf_type *pt, |
| 3307 | int comp_idx, const char *tag_key) |
| 3308 | { |
| 3309 | int i; |
| 3310 | |
| 3311 | for (i = 1; i < btf_nr_types(btf); i++) { |
| 3312 | const struct btf_type *t = btf_type_by_id(btf, i); |
| 3313 | int len = strlen(tag_key); |
| 3314 | |
| 3315 | if (!btf_type_is_decl_tag(t)) |
| 3316 | continue; |
| 3317 | if (pt != btf_type_by_id(btf, t->type) || |
| 3318 | btf_type_decl_tag(t)->component_idx != comp_idx) |
| 3319 | continue; |
| 3320 | if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len)) |
| 3321 | continue; |
| 3322 | return __btf_name_by_offset(btf, t->name_off) + len; |
| 3323 | } |
| 3324 | return NULL; |
| 3325 | } |
| 3326 | |
| 3327 | static int btf_find_list_head(const struct btf *btf, const struct btf_type *pt, |
| 3328 | const struct btf_type *t, int comp_idx, |
| 3329 | u32 off, int sz, struct btf_field_info *info) |
| 3330 | { |
| 3331 | const char *value_type; |
| 3332 | const char *list_node; |
| 3333 | s32 id; |
| 3334 | |
| 3335 | if (!__btf_type_is_struct(t)) |
| 3336 | return BTF_FIELD_IGNORE; |
| 3337 | if (t->size != sz) |
| 3338 | return BTF_FIELD_IGNORE; |
| 3339 | value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:"); |
| 3340 | if (!value_type) |
| 3341 | return -EINVAL; |
| 3342 | list_node = strstr(value_type, ":"); |
| 3343 | if (!list_node) |
| 3344 | return -EINVAL; |
| 3345 | value_type = kstrndup(value_type, list_node - value_type, GFP_KERNEL | __GFP_NOWARN); |
| 3346 | if (!value_type) |
| 3347 | return -ENOMEM; |
| 3348 | id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT); |
| 3349 | kfree(value_type); |
| 3350 | if (id < 0) |
| 3351 | return id; |
| 3352 | list_node++; |
| 3353 | if (str_is_empty(list_node)) |
| 3354 | return -EINVAL; |
| 3355 | info->type = BPF_LIST_HEAD; |
| 3356 | info->off = off; |
| 3357 | info->graph_root.value_btf_id = id; |
| 3358 | info->graph_root.node_name = list_node; |
| 3359 | return BTF_FIELD_FOUND; |
| 3360 | } |
| 3361 | |
| 3362 | static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask, |
| 3363 | int *align, int *sz) |
| 3364 | { |
| 3365 | int type = 0; |
| 3366 | |
| 3367 | if (field_mask & BPF_SPIN_LOCK) { |
| 3368 | if (!strcmp(name, "bpf_spin_lock")) { |
| 3369 | if (*seen_mask & BPF_SPIN_LOCK) |
| 3370 | return -E2BIG; |
| 3371 | *seen_mask |= BPF_SPIN_LOCK; |
| 3372 | type = BPF_SPIN_LOCK; |
| 3373 | goto end; |
| 3374 | } |
| 3375 | } |
| 3376 | if (field_mask & BPF_TIMER) { |
| 3377 | if (!strcmp(name, "bpf_timer")) { |
| 3378 | if (*seen_mask & BPF_TIMER) |
| 3379 | return -E2BIG; |
| 3380 | *seen_mask |= BPF_TIMER; |
| 3381 | type = BPF_TIMER; |
| 3382 | goto end; |
| 3383 | } |
| 3384 | } |
| 3385 | if (field_mask & BPF_LIST_HEAD) { |
| 3386 | if (!strcmp(name, "bpf_list_head")) { |
| 3387 | type = BPF_LIST_HEAD; |
| 3388 | goto end; |
| 3389 | } |
| 3390 | } |
| 3391 | if (field_mask & BPF_LIST_NODE) { |
| 3392 | if (!strcmp(name, "bpf_list_node")) { |
| 3393 | type = BPF_LIST_NODE; |
| 3394 | goto end; |
| 3395 | } |
| 3396 | } |
| 3397 | /* Only return BPF_KPTR when all other types with matchable names fail */ |
| 3398 | if (field_mask & BPF_KPTR) { |
| 3399 | type = BPF_KPTR_REF; |
| 3400 | goto end; |
| 3401 | } |
| 3402 | return 0; |
| 3403 | end: |
| 3404 | *sz = btf_field_type_size(type); |
| 3405 | *align = btf_field_type_align(type); |
| 3406 | return type; |
| 3407 | } |
| 3408 | |
| 3409 | static int btf_find_struct_field(const struct btf *btf, |
| 3410 | const struct btf_type *t, u32 field_mask, |
| 3411 | struct btf_field_info *info, int info_cnt) |
| 3412 | { |
| 3413 | int ret, idx = 0, align, sz, field_type; |
| 3414 | const struct btf_member *member; |
| 3415 | struct btf_field_info tmp; |
| 3416 | u32 i, off, seen_mask = 0; |
| 3417 | |
| 3418 | for_each_member(i, t, member) { |
| 3419 | const struct btf_type *member_type = btf_type_by_id(btf, |
| 3420 | member->type); |
| 3421 | |
| 3422 | field_type = btf_get_field_type(__btf_name_by_offset(btf, member_type->name_off), |
| 3423 | field_mask, &seen_mask, &align, &sz); |
| 3424 | if (field_type == 0) |
| 3425 | continue; |
| 3426 | if (field_type < 0) |
| 3427 | return field_type; |
| 3428 | |
| 3429 | off = __btf_member_bit_offset(t, member); |
| 3430 | if (off % 8) |
| 3431 | /* valid C code cannot generate such BTF */ |
| 3432 | return -EINVAL; |
| 3433 | off /= 8; |
| 3434 | if (off % align) |
| 3435 | continue; |
| 3436 | |
| 3437 | switch (field_type) { |
| 3438 | case BPF_SPIN_LOCK: |
| 3439 | case BPF_TIMER: |
| 3440 | case BPF_LIST_NODE: |
| 3441 | ret = btf_find_struct(btf, member_type, off, sz, field_type, |
| 3442 | idx < info_cnt ? &info[idx] : &tmp); |
| 3443 | if (ret < 0) |
| 3444 | return ret; |
| 3445 | break; |
| 3446 | case BPF_KPTR_UNREF: |
| 3447 | case BPF_KPTR_REF: |
| 3448 | ret = btf_find_kptr(btf, member_type, off, sz, |
| 3449 | idx < info_cnt ? &info[idx] : &tmp); |
| 3450 | if (ret < 0) |
| 3451 | return ret; |
| 3452 | break; |
| 3453 | case BPF_LIST_HEAD: |
| 3454 | ret = btf_find_list_head(btf, t, member_type, i, off, sz, |
| 3455 | idx < info_cnt ? &info[idx] : &tmp); |
| 3456 | if (ret < 0) |
| 3457 | return ret; |
| 3458 | break; |
| 3459 | default: |
| 3460 | return -EFAULT; |
| 3461 | } |
| 3462 | |
| 3463 | if (ret == BTF_FIELD_IGNORE) |
| 3464 | continue; |
| 3465 | if (idx >= info_cnt) |
| 3466 | return -E2BIG; |
| 3467 | ++idx; |
| 3468 | } |
| 3469 | return idx; |
| 3470 | } |
| 3471 | |
| 3472 | static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, |
| 3473 | u32 field_mask, struct btf_field_info *info, |
| 3474 | int info_cnt) |
| 3475 | { |
| 3476 | int ret, idx = 0, align, sz, field_type; |
| 3477 | const struct btf_var_secinfo *vsi; |
| 3478 | struct btf_field_info tmp; |
| 3479 | u32 i, off, seen_mask = 0; |
| 3480 | |
| 3481 | for_each_vsi(i, t, vsi) { |
| 3482 | const struct btf_type *var = btf_type_by_id(btf, vsi->type); |
| 3483 | const struct btf_type *var_type = btf_type_by_id(btf, var->type); |
| 3484 | |
| 3485 | field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off), |
| 3486 | field_mask, &seen_mask, &align, &sz); |
| 3487 | if (field_type == 0) |
| 3488 | continue; |
| 3489 | if (field_type < 0) |
| 3490 | return field_type; |
| 3491 | |
| 3492 | off = vsi->offset; |
| 3493 | if (vsi->size != sz) |
| 3494 | continue; |
| 3495 | if (off % align) |
| 3496 | continue; |
| 3497 | |
| 3498 | switch (field_type) { |
| 3499 | case BPF_SPIN_LOCK: |
| 3500 | case BPF_TIMER: |
| 3501 | case BPF_LIST_NODE: |
| 3502 | ret = btf_find_struct(btf, var_type, off, sz, field_type, |
| 3503 | idx < info_cnt ? &info[idx] : &tmp); |
| 3504 | if (ret < 0) |
| 3505 | return ret; |
| 3506 | break; |
| 3507 | case BPF_KPTR_UNREF: |
| 3508 | case BPF_KPTR_REF: |
| 3509 | ret = btf_find_kptr(btf, var_type, off, sz, |
| 3510 | idx < info_cnt ? &info[idx] : &tmp); |
| 3511 | if (ret < 0) |
| 3512 | return ret; |
| 3513 | break; |
| 3514 | case BPF_LIST_HEAD: |
| 3515 | ret = btf_find_list_head(btf, var, var_type, -1, off, sz, |
| 3516 | idx < info_cnt ? &info[idx] : &tmp); |
| 3517 | if (ret < 0) |
| 3518 | return ret; |
| 3519 | break; |
| 3520 | default: |
| 3521 | return -EFAULT; |
| 3522 | } |
| 3523 | |
| 3524 | if (ret == BTF_FIELD_IGNORE) |
| 3525 | continue; |
| 3526 | if (idx >= info_cnt) |
| 3527 | return -E2BIG; |
| 3528 | ++idx; |
| 3529 | } |
| 3530 | return idx; |
| 3531 | } |
| 3532 | |
| 3533 | static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
| 3534 | u32 field_mask, struct btf_field_info *info, |
| 3535 | int info_cnt) |
| 3536 | { |
| 3537 | if (__btf_type_is_struct(t)) |
| 3538 | return btf_find_struct_field(btf, t, field_mask, info, info_cnt); |
| 3539 | else if (btf_type_is_datasec(t)) |
| 3540 | return btf_find_datasec_var(btf, t, field_mask, info, info_cnt); |
| 3541 | return -EINVAL; |
| 3542 | } |
| 3543 | |
| 3544 | static int btf_parse_kptr(const struct btf *btf, struct btf_field *field, |
| 3545 | struct btf_field_info *info) |
| 3546 | { |
| 3547 | struct module *mod = NULL; |
| 3548 | const struct btf_type *t; |
| 3549 | struct btf *kernel_btf; |
| 3550 | int ret; |
| 3551 | s32 id; |
| 3552 | |
| 3553 | /* Find type in map BTF, and use it to look up the matching type |
| 3554 | * in vmlinux or module BTFs, by name and kind. |
| 3555 | */ |
| 3556 | t = btf_type_by_id(btf, info->kptr.type_id); |
| 3557 | id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info), |
| 3558 | &kernel_btf); |
| 3559 | if (id < 0) |
| 3560 | return id; |
| 3561 | |
| 3562 | /* Find and stash the function pointer for the destruction function that |
| 3563 | * needs to be eventually invoked from the map free path. |
| 3564 | */ |
| 3565 | if (info->type == BPF_KPTR_REF) { |
| 3566 | const struct btf_type *dtor_func; |
| 3567 | const char *dtor_func_name; |
| 3568 | unsigned long addr; |
| 3569 | s32 dtor_btf_id; |
| 3570 | |
| 3571 | /* This call also serves as a whitelist of allowed objects that |
| 3572 | * can be used as a referenced pointer and be stored in a map at |
| 3573 | * the same time. |
| 3574 | */ |
| 3575 | dtor_btf_id = btf_find_dtor_kfunc(kernel_btf, id); |
| 3576 | if (dtor_btf_id < 0) { |
| 3577 | ret = dtor_btf_id; |
| 3578 | goto end_btf; |
| 3579 | } |
| 3580 | |
| 3581 | dtor_func = btf_type_by_id(kernel_btf, dtor_btf_id); |
| 3582 | if (!dtor_func) { |
| 3583 | ret = -ENOENT; |
| 3584 | goto end_btf; |
| 3585 | } |
| 3586 | |
| 3587 | if (btf_is_module(kernel_btf)) { |
| 3588 | mod = btf_try_get_module(kernel_btf); |
| 3589 | if (!mod) { |
| 3590 | ret = -ENXIO; |
| 3591 | goto end_btf; |
| 3592 | } |
| 3593 | } |
| 3594 | |
| 3595 | /* We already verified dtor_func to be btf_type_is_func |
| 3596 | * in register_btf_id_dtor_kfuncs. |
| 3597 | */ |
| 3598 | dtor_func_name = __btf_name_by_offset(kernel_btf, dtor_func->name_off); |
| 3599 | addr = kallsyms_lookup_name(dtor_func_name); |
| 3600 | if (!addr) { |
| 3601 | ret = -EINVAL; |
| 3602 | goto end_mod; |
| 3603 | } |
| 3604 | field->kptr.dtor = (void *)addr; |
| 3605 | } |
| 3606 | |
| 3607 | field->kptr.btf_id = id; |
| 3608 | field->kptr.btf = kernel_btf; |
| 3609 | field->kptr.module = mod; |
| 3610 | return 0; |
| 3611 | end_mod: |
| 3612 | module_put(mod); |
| 3613 | end_btf: |
| 3614 | btf_put(kernel_btf); |
| 3615 | return ret; |
| 3616 | } |
| 3617 | |
| 3618 | static int btf_parse_list_head(const struct btf *btf, struct btf_field *field, |
| 3619 | struct btf_field_info *info) |
| 3620 | { |
| 3621 | const struct btf_type *t, *n = NULL; |
| 3622 | const struct btf_member *member; |
| 3623 | u32 offset; |
| 3624 | int i; |
| 3625 | |
| 3626 | t = btf_type_by_id(btf, info->graph_root.value_btf_id); |
| 3627 | /* We've already checked that value_btf_id is a struct type. We |
| 3628 | * just need to figure out the offset of the list_node, and |
| 3629 | * verify its type. |
| 3630 | */ |
| 3631 | for_each_member(i, t, member) { |
| 3632 | if (strcmp(info->graph_root.node_name, |
| 3633 | __btf_name_by_offset(btf, member->name_off))) |
| 3634 | continue; |
| 3635 | /* Invalid BTF, two members with same name */ |
| 3636 | if (n) |
| 3637 | return -EINVAL; |
| 3638 | n = btf_type_by_id(btf, member->type); |
| 3639 | if (!__btf_type_is_struct(n)) |
| 3640 | return -EINVAL; |
| 3641 | if (strcmp("bpf_list_node", __btf_name_by_offset(btf, n->name_off))) |
| 3642 | return -EINVAL; |
| 3643 | offset = __btf_member_bit_offset(n, member); |
| 3644 | if (offset % 8) |
| 3645 | return -EINVAL; |
| 3646 | offset /= 8; |
| 3647 | if (offset % __alignof__(struct bpf_list_node)) |
| 3648 | return -EINVAL; |
| 3649 | |
| 3650 | field->graph_root.btf = (struct btf *)btf; |
| 3651 | field->graph_root.value_btf_id = info->graph_root.value_btf_id; |
| 3652 | field->graph_root.node_offset = offset; |
| 3653 | } |
| 3654 | if (!n) |
| 3655 | return -ENOENT; |
| 3656 | return 0; |
| 3657 | } |
| 3658 | |
| 3659 | struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t, |
| 3660 | u32 field_mask, u32 value_size) |
| 3661 | { |
| 3662 | struct btf_field_info info_arr[BTF_FIELDS_MAX]; |
| 3663 | struct btf_record *rec; |
| 3664 | u32 next_off = 0; |
| 3665 | int ret, i, cnt; |
| 3666 | |
| 3667 | ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr)); |
| 3668 | if (ret < 0) |
| 3669 | return ERR_PTR(ret); |
| 3670 | if (!ret) |
| 3671 | return NULL; |
| 3672 | |
| 3673 | cnt = ret; |
| 3674 | /* This needs to be kzalloc to zero out padding and unused fields, see |
| 3675 | * comment in btf_record_equal. |
| 3676 | */ |
| 3677 | rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN); |
| 3678 | if (!rec) |
| 3679 | return ERR_PTR(-ENOMEM); |
| 3680 | |
| 3681 | rec->spin_lock_off = -EINVAL; |
| 3682 | rec->timer_off = -EINVAL; |
| 3683 | for (i = 0; i < cnt; i++) { |
| 3684 | if (info_arr[i].off + btf_field_type_size(info_arr[i].type) > value_size) { |
| 3685 | WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size); |
| 3686 | ret = -EFAULT; |
| 3687 | goto end; |
| 3688 | } |
| 3689 | if (info_arr[i].off < next_off) { |
| 3690 | ret = -EEXIST; |
| 3691 | goto end; |
| 3692 | } |
| 3693 | next_off = info_arr[i].off + btf_field_type_size(info_arr[i].type); |
| 3694 | |
| 3695 | rec->field_mask |= info_arr[i].type; |
| 3696 | rec->fields[i].offset = info_arr[i].off; |
| 3697 | rec->fields[i].type = info_arr[i].type; |
| 3698 | |
| 3699 | switch (info_arr[i].type) { |
| 3700 | case BPF_SPIN_LOCK: |
| 3701 | WARN_ON_ONCE(rec->spin_lock_off >= 0); |
| 3702 | /* Cache offset for faster lookup at runtime */ |
| 3703 | rec->spin_lock_off = rec->fields[i].offset; |
| 3704 | break; |
| 3705 | case BPF_TIMER: |
| 3706 | WARN_ON_ONCE(rec->timer_off >= 0); |
| 3707 | /* Cache offset for faster lookup at runtime */ |
| 3708 | rec->timer_off = rec->fields[i].offset; |
| 3709 | break; |
| 3710 | case BPF_KPTR_UNREF: |
| 3711 | case BPF_KPTR_REF: |
| 3712 | ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]); |
| 3713 | if (ret < 0) |
| 3714 | goto end; |
| 3715 | break; |
| 3716 | case BPF_LIST_HEAD: |
| 3717 | ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]); |
| 3718 | if (ret < 0) |
| 3719 | goto end; |
| 3720 | break; |
| 3721 | case BPF_LIST_NODE: |
| 3722 | break; |
| 3723 | default: |
| 3724 | ret = -EFAULT; |
| 3725 | goto end; |
| 3726 | } |
| 3727 | rec->cnt++; |
| 3728 | } |
| 3729 | |
| 3730 | /* bpf_list_head requires bpf_spin_lock */ |
| 3731 | if (btf_record_has_field(rec, BPF_LIST_HEAD) && rec->spin_lock_off < 0) { |
| 3732 | ret = -EINVAL; |
| 3733 | goto end; |
| 3734 | } |
| 3735 | |
| 3736 | return rec; |
| 3737 | end: |
| 3738 | btf_record_free(rec); |
| 3739 | return ERR_PTR(ret); |
| 3740 | } |
| 3741 | |
| 3742 | int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec) |
| 3743 | { |
| 3744 | int i; |
| 3745 | |
| 3746 | /* There are two owning types, kptr_ref and bpf_list_head. The former |
| 3747 | * only supports storing kernel types, which can never store references |
| 3748 | * to program allocated local types, atleast not yet. Hence we only need |
| 3749 | * to ensure that bpf_list_head ownership does not form cycles. |
| 3750 | */ |
| 3751 | if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & BPF_LIST_HEAD)) |
| 3752 | return 0; |
| 3753 | for (i = 0; i < rec->cnt; i++) { |
| 3754 | struct btf_struct_meta *meta; |
| 3755 | u32 btf_id; |
| 3756 | |
| 3757 | if (!(rec->fields[i].type & BPF_LIST_HEAD)) |
| 3758 | continue; |
| 3759 | btf_id = rec->fields[i].graph_root.value_btf_id; |
| 3760 | meta = btf_find_struct_meta(btf, btf_id); |
| 3761 | if (!meta) |
| 3762 | return -EFAULT; |
| 3763 | rec->fields[i].graph_root.value_rec = meta->record; |
| 3764 | |
| 3765 | if (!(rec->field_mask & BPF_LIST_NODE)) |
| 3766 | continue; |
| 3767 | |
| 3768 | /* We need to ensure ownership acyclicity among all types. The |
| 3769 | * proper way to do it would be to topologically sort all BTF |
| 3770 | * IDs based on the ownership edges, since there can be multiple |
| 3771 | * bpf_list_head in a type. Instead, we use the following |
| 3772 | * reasoning: |
| 3773 | * |
| 3774 | * - A type can only be owned by another type in user BTF if it |
| 3775 | * has a bpf_list_node. |
| 3776 | * - A type can only _own_ another type in user BTF if it has a |
| 3777 | * bpf_list_head. |
| 3778 | * |
| 3779 | * We ensure that if a type has both bpf_list_head and |
| 3780 | * bpf_list_node, its element types cannot be owning types. |
| 3781 | * |
| 3782 | * To ensure acyclicity: |
| 3783 | * |
| 3784 | * When A only has bpf_list_head, ownership chain can be: |
| 3785 | * A -> B -> C |
| 3786 | * Where: |
| 3787 | * - B has both bpf_list_head and bpf_list_node. |
| 3788 | * - C only has bpf_list_node. |
| 3789 | * |
| 3790 | * When A has both bpf_list_head and bpf_list_node, some other |
| 3791 | * type already owns it in the BTF domain, hence it can not own |
| 3792 | * another owning type through any of the bpf_list_head edges. |
| 3793 | * A -> B |
| 3794 | * Where: |
| 3795 | * - B only has bpf_list_node. |
| 3796 | */ |
| 3797 | if (meta->record->field_mask & BPF_LIST_HEAD) |
| 3798 | return -ELOOP; |
| 3799 | } |
| 3800 | return 0; |
| 3801 | } |
| 3802 | |
| 3803 | static int btf_field_offs_cmp(const void *_a, const void *_b, const void *priv) |
| 3804 | { |
| 3805 | const u32 a = *(const u32 *)_a; |
| 3806 | const u32 b = *(const u32 *)_b; |
| 3807 | |
| 3808 | if (a < b) |
| 3809 | return -1; |
| 3810 | else if (a > b) |
| 3811 | return 1; |
| 3812 | return 0; |
| 3813 | } |
| 3814 | |
| 3815 | static void btf_field_offs_swap(void *_a, void *_b, int size, const void *priv) |
| 3816 | { |
| 3817 | struct btf_field_offs *foffs = (void *)priv; |
| 3818 | u32 *off_base = foffs->field_off; |
| 3819 | u32 *a = _a, *b = _b; |
| 3820 | u8 *sz_a, *sz_b; |
| 3821 | |
| 3822 | sz_a = foffs->field_sz + (a - off_base); |
| 3823 | sz_b = foffs->field_sz + (b - off_base); |
| 3824 | |
| 3825 | swap(*a, *b); |
| 3826 | swap(*sz_a, *sz_b); |
| 3827 | } |
| 3828 | |
| 3829 | struct btf_field_offs *btf_parse_field_offs(struct btf_record *rec) |
| 3830 | { |
| 3831 | struct btf_field_offs *foffs; |
| 3832 | u32 i, *off; |
| 3833 | u8 *sz; |
| 3834 | |
| 3835 | BUILD_BUG_ON(ARRAY_SIZE(foffs->field_off) != ARRAY_SIZE(foffs->field_sz)); |
| 3836 | if (IS_ERR_OR_NULL(rec)) |
| 3837 | return NULL; |
| 3838 | |
| 3839 | foffs = kzalloc(sizeof(*foffs), GFP_KERNEL | __GFP_NOWARN); |
| 3840 | if (!foffs) |
| 3841 | return ERR_PTR(-ENOMEM); |
| 3842 | |
| 3843 | off = foffs->field_off; |
| 3844 | sz = foffs->field_sz; |
| 3845 | for (i = 0; i < rec->cnt; i++) { |
| 3846 | off[i] = rec->fields[i].offset; |
| 3847 | sz[i] = btf_field_type_size(rec->fields[i].type); |
| 3848 | } |
| 3849 | foffs->cnt = rec->cnt; |
| 3850 | |
| 3851 | if (foffs->cnt == 1) |
| 3852 | return foffs; |
| 3853 | sort_r(foffs->field_off, foffs->cnt, sizeof(foffs->field_off[0]), |
| 3854 | btf_field_offs_cmp, btf_field_offs_swap, foffs); |
| 3855 | return foffs; |
| 3856 | } |
| 3857 | |
| 3858 | static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
| 3859 | u32 type_id, void *data, u8 bits_offset, |
| 3860 | struct btf_show *show) |
| 3861 | { |
| 3862 | const struct btf_member *member; |
| 3863 | void *safe_data; |
| 3864 | u32 i; |
| 3865 | |
| 3866 | safe_data = btf_show_start_struct_type(show, t, type_id, data); |
| 3867 | if (!safe_data) |
| 3868 | return; |
| 3869 | |
| 3870 | for_each_member(i, t, member) { |
| 3871 | const struct btf_type *member_type = btf_type_by_id(btf, |
| 3872 | member->type); |
| 3873 | const struct btf_kind_operations *ops; |
| 3874 | u32 member_offset, bitfield_size; |
| 3875 | u32 bytes_offset; |
| 3876 | u8 bits8_offset; |
| 3877 | |
| 3878 | btf_show_start_member(show, member); |
| 3879 | |
| 3880 | member_offset = __btf_member_bit_offset(t, member); |
| 3881 | bitfield_size = __btf_member_bitfield_size(t, member); |
| 3882 | bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
| 3883 | bits8_offset = BITS_PER_BYTE_MASKED(member_offset); |
| 3884 | if (bitfield_size) { |
| 3885 | safe_data = btf_show_start_type(show, member_type, |
| 3886 | member->type, |
| 3887 | data + bytes_offset); |
| 3888 | if (safe_data) |
| 3889 | btf_bitfield_show(safe_data, |
| 3890 | bits8_offset, |
| 3891 | bitfield_size, show); |
| 3892 | btf_show_end_type(show); |
| 3893 | } else { |
| 3894 | ops = btf_type_ops(member_type); |
| 3895 | ops->show(btf, member_type, member->type, |
| 3896 | data + bytes_offset, bits8_offset, show); |
| 3897 | } |
| 3898 | |
| 3899 | btf_show_end_member(show); |
| 3900 | } |
| 3901 | |
| 3902 | btf_show_end_struct_type(show); |
| 3903 | } |
| 3904 | |
| 3905 | static void btf_struct_show(const struct btf *btf, const struct btf_type *t, |
| 3906 | u32 type_id, void *data, u8 bits_offset, |
| 3907 | struct btf_show *show) |
| 3908 | { |
| 3909 | const struct btf_member *m = show->state.member; |
| 3910 | |
| 3911 | /* |
| 3912 | * First check if any members would be shown (are non-zero). |
| 3913 | * See comments above "struct btf_show" definition for more |
| 3914 | * details on how this works at a high-level. |
| 3915 | */ |
| 3916 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { |
| 3917 | if (!show->state.depth_check) { |
| 3918 | show->state.depth_check = show->state.depth + 1; |
| 3919 | show->state.depth_to_show = 0; |
| 3920 | } |
| 3921 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); |
| 3922 | /* Restore saved member data here */ |
| 3923 | show->state.member = m; |
| 3924 | if (show->state.depth_check != show->state.depth + 1) |
| 3925 | return; |
| 3926 | show->state.depth_check = 0; |
| 3927 | |
| 3928 | if (show->state.depth_to_show <= show->state.depth) |
| 3929 | return; |
| 3930 | /* |
| 3931 | * Reaching here indicates we have recursed and found |
| 3932 | * non-zero child values. |
| 3933 | */ |
| 3934 | } |
| 3935 | |
| 3936 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); |
| 3937 | } |
| 3938 | |
| 3939 | static struct btf_kind_operations struct_ops = { |
| 3940 | .check_meta = btf_struct_check_meta, |
| 3941 | .resolve = btf_struct_resolve, |
| 3942 | .check_member = btf_struct_check_member, |
| 3943 | .check_kflag_member = btf_generic_check_kflag_member, |
| 3944 | .log_details = btf_struct_log, |
| 3945 | .show = btf_struct_show, |
| 3946 | }; |
| 3947 | |
| 3948 | static int btf_enum_check_member(struct btf_verifier_env *env, |
| 3949 | const struct btf_type *struct_type, |
| 3950 | const struct btf_member *member, |
| 3951 | const struct btf_type *member_type) |
| 3952 | { |
| 3953 | u32 struct_bits_off = member->offset; |
| 3954 | u32 struct_size, bytes_offset; |
| 3955 | |
| 3956 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| 3957 | btf_verifier_log_member(env, struct_type, member, |
| 3958 | "Member is not byte aligned"); |
| 3959 | return -EINVAL; |
| 3960 | } |
| 3961 | |
| 3962 | struct_size = struct_type->size; |
| 3963 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| 3964 | if (struct_size - bytes_offset < member_type->size) { |
| 3965 | btf_verifier_log_member(env, struct_type, member, |
| 3966 | "Member exceeds struct_size"); |
| 3967 | return -EINVAL; |
| 3968 | } |
| 3969 | |
| 3970 | return 0; |
| 3971 | } |
| 3972 | |
| 3973 | static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
| 3974 | const struct btf_type *struct_type, |
| 3975 | const struct btf_member *member, |
| 3976 | const struct btf_type *member_type) |
| 3977 | { |
| 3978 | u32 struct_bits_off, nr_bits, bytes_end, struct_size; |
| 3979 | u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; |
| 3980 | |
| 3981 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); |
| 3982 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); |
| 3983 | if (!nr_bits) { |
| 3984 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| 3985 | btf_verifier_log_member(env, struct_type, member, |
| 3986 | "Member is not byte aligned"); |
| 3987 | return -EINVAL; |
| 3988 | } |
| 3989 | |
| 3990 | nr_bits = int_bitsize; |
| 3991 | } else if (nr_bits > int_bitsize) { |
| 3992 | btf_verifier_log_member(env, struct_type, member, |
| 3993 | "Invalid member bitfield_size"); |
| 3994 | return -EINVAL; |
| 3995 | } |
| 3996 | |
| 3997 | struct_size = struct_type->size; |
| 3998 | bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); |
| 3999 | if (struct_size < bytes_end) { |
| 4000 | btf_verifier_log_member(env, struct_type, member, |
| 4001 | "Member exceeds struct_size"); |
| 4002 | return -EINVAL; |
| 4003 | } |
| 4004 | |
| 4005 | return 0; |
| 4006 | } |
| 4007 | |
| 4008 | static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
| 4009 | const struct btf_type *t, |
| 4010 | u32 meta_left) |
| 4011 | { |
| 4012 | const struct btf_enum *enums = btf_type_enum(t); |
| 4013 | struct btf *btf = env->btf; |
| 4014 | const char *fmt_str; |
| 4015 | u16 i, nr_enums; |
| 4016 | u32 meta_needed; |
| 4017 | |
| 4018 | nr_enums = btf_type_vlen(t); |
| 4019 | meta_needed = nr_enums * sizeof(*enums); |
| 4020 | |
| 4021 | if (meta_left < meta_needed) { |
| 4022 | btf_verifier_log_basic(env, t, |
| 4023 | "meta_left:%u meta_needed:%u", |
| 4024 | meta_left, meta_needed); |
| 4025 | return -EINVAL; |
| 4026 | } |
| 4027 | |
| 4028 | if (t->size > 8 || !is_power_of_2(t->size)) { |
| 4029 | btf_verifier_log_type(env, t, "Unexpected size"); |
| 4030 | return -EINVAL; |
| 4031 | } |
| 4032 | |
| 4033 | /* enum type either no name or a valid one */ |
| 4034 | if (t->name_off && |
| 4035 | !btf_name_valid_identifier(env->btf, t->name_off)) { |
| 4036 | btf_verifier_log_type(env, t, "Invalid name"); |
| 4037 | return -EINVAL; |
| 4038 | } |
| 4039 | |
| 4040 | btf_verifier_log_type(env, t, NULL); |
| 4041 | |
| 4042 | for (i = 0; i < nr_enums; i++) { |
| 4043 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
| 4044 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
| 4045 | enums[i].name_off); |
| 4046 | return -EINVAL; |
| 4047 | } |
| 4048 | |
| 4049 | /* enum member must have a valid name */ |
| 4050 | if (!enums[i].name_off || |
| 4051 | !btf_name_valid_identifier(btf, enums[i].name_off)) { |
| 4052 | btf_verifier_log_type(env, t, "Invalid name"); |
| 4053 | return -EINVAL; |
| 4054 | } |
| 4055 | |
| 4056 | if (env->log.level == BPF_LOG_KERNEL) |
| 4057 | continue; |
| 4058 | fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n"; |
| 4059 | btf_verifier_log(env, fmt_str, |
| 4060 | __btf_name_by_offset(btf, enums[i].name_off), |
| 4061 | enums[i].val); |
| 4062 | } |
| 4063 | |
| 4064 | return meta_needed; |
| 4065 | } |
| 4066 | |
| 4067 | static void btf_enum_log(struct btf_verifier_env *env, |
| 4068 | const struct btf_type *t) |
| 4069 | { |
| 4070 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
| 4071 | } |
| 4072 | |
| 4073 | static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
| 4074 | u32 type_id, void *data, u8 bits_offset, |
| 4075 | struct btf_show *show) |
| 4076 | { |
| 4077 | const struct btf_enum *enums = btf_type_enum(t); |
| 4078 | u32 i, nr_enums = btf_type_vlen(t); |
| 4079 | void *safe_data; |
| 4080 | int v; |
| 4081 | |
| 4082 | safe_data = btf_show_start_type(show, t, type_id, data); |
| 4083 | if (!safe_data) |
| 4084 | return; |
| 4085 | |
| 4086 | v = *(int *)safe_data; |
| 4087 | |
| 4088 | for (i = 0; i < nr_enums; i++) { |
| 4089 | if (v != enums[i].val) |
| 4090 | continue; |
| 4091 | |
| 4092 | btf_show_type_value(show, "%s", |
| 4093 | __btf_name_by_offset(btf, |
| 4094 | enums[i].name_off)); |
| 4095 | |
| 4096 | btf_show_end_type(show); |
| 4097 | return; |
| 4098 | } |
| 4099 | |
| 4100 | if (btf_type_kflag(t)) |
| 4101 | btf_show_type_value(show, "%d", v); |
| 4102 | else |
| 4103 | btf_show_type_value(show, "%u", v); |
| 4104 | btf_show_end_type(show); |
| 4105 | } |
| 4106 | |
| 4107 | static struct btf_kind_operations enum_ops = { |
| 4108 | .check_meta = btf_enum_check_meta, |
| 4109 | .resolve = btf_df_resolve, |
| 4110 | .check_member = btf_enum_check_member, |
| 4111 | .check_kflag_member = btf_enum_check_kflag_member, |
| 4112 | .log_details = btf_enum_log, |
| 4113 | .show = btf_enum_show, |
| 4114 | }; |
| 4115 | |
| 4116 | static s32 btf_enum64_check_meta(struct btf_verifier_env *env, |
| 4117 | const struct btf_type *t, |
| 4118 | u32 meta_left) |
| 4119 | { |
| 4120 | const struct btf_enum64 *enums = btf_type_enum64(t); |
| 4121 | struct btf *btf = env->btf; |
| 4122 | const char *fmt_str; |
| 4123 | u16 i, nr_enums; |
| 4124 | u32 meta_needed; |
| 4125 | |
| 4126 | nr_enums = btf_type_vlen(t); |
| 4127 | meta_needed = nr_enums * sizeof(*enums); |
| 4128 | |
| 4129 | if (meta_left < meta_needed) { |
| 4130 | btf_verifier_log_basic(env, t, |
| 4131 | "meta_left:%u meta_needed:%u", |
| 4132 | meta_left, meta_needed); |
| 4133 | return -EINVAL; |
| 4134 | } |
| 4135 | |
| 4136 | if (t->size > 8 || !is_power_of_2(t->size)) { |
| 4137 | btf_verifier_log_type(env, t, "Unexpected size"); |
| 4138 | return -EINVAL; |
| 4139 | } |
| 4140 | |
| 4141 | /* enum type either no name or a valid one */ |
| 4142 | if (t->name_off && |
| 4143 | !btf_name_valid_identifier(env->btf, t->name_off)) { |
| 4144 | btf_verifier_log_type(env, t, "Invalid name"); |
| 4145 | return -EINVAL; |
| 4146 | } |
| 4147 | |
| 4148 | btf_verifier_log_type(env, t, NULL); |
| 4149 | |
| 4150 | for (i = 0; i < nr_enums; i++) { |
| 4151 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
| 4152 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
| 4153 | enums[i].name_off); |
| 4154 | return -EINVAL; |
| 4155 | } |
| 4156 | |
| 4157 | /* enum member must have a valid name */ |
| 4158 | if (!enums[i].name_off || |
| 4159 | !btf_name_valid_identifier(btf, enums[i].name_off)) { |
| 4160 | btf_verifier_log_type(env, t, "Invalid name"); |
| 4161 | return -EINVAL; |
| 4162 | } |
| 4163 | |
| 4164 | if (env->log.level == BPF_LOG_KERNEL) |
| 4165 | continue; |
| 4166 | |
| 4167 | fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n"; |
| 4168 | btf_verifier_log(env, fmt_str, |
| 4169 | __btf_name_by_offset(btf, enums[i].name_off), |
| 4170 | btf_enum64_value(enums + i)); |
| 4171 | } |
| 4172 | |
| 4173 | return meta_needed; |
| 4174 | } |
| 4175 | |
| 4176 | static void btf_enum64_show(const struct btf *btf, const struct btf_type *t, |
| 4177 | u32 type_id, void *data, u8 bits_offset, |
| 4178 | struct btf_show *show) |
| 4179 | { |
| 4180 | const struct btf_enum64 *enums = btf_type_enum64(t); |
| 4181 | u32 i, nr_enums = btf_type_vlen(t); |
| 4182 | void *safe_data; |
| 4183 | s64 v; |
| 4184 | |
| 4185 | safe_data = btf_show_start_type(show, t, type_id, data); |
| 4186 | if (!safe_data) |
| 4187 | return; |
| 4188 | |
| 4189 | v = *(u64 *)safe_data; |
| 4190 | |
| 4191 | for (i = 0; i < nr_enums; i++) { |
| 4192 | if (v != btf_enum64_value(enums + i)) |
| 4193 | continue; |
| 4194 | |
| 4195 | btf_show_type_value(show, "%s", |
| 4196 | __btf_name_by_offset(btf, |
| 4197 | enums[i].name_off)); |
| 4198 | |
| 4199 | btf_show_end_type(show); |
| 4200 | return; |
| 4201 | } |
| 4202 | |
| 4203 | if (btf_type_kflag(t)) |
| 4204 | btf_show_type_value(show, "%lld", v); |
| 4205 | else |
| 4206 | btf_show_type_value(show, "%llu", v); |
| 4207 | btf_show_end_type(show); |
| 4208 | } |
| 4209 | |
| 4210 | static struct btf_kind_operations enum64_ops = { |
| 4211 | .check_meta = btf_enum64_check_meta, |
| 4212 | .resolve = btf_df_resolve, |
| 4213 | .check_member = btf_enum_check_member, |
| 4214 | .check_kflag_member = btf_enum_check_kflag_member, |
| 4215 | .log_details = btf_enum_log, |
| 4216 | .show = btf_enum64_show, |
| 4217 | }; |
| 4218 | |
| 4219 | static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
| 4220 | const struct btf_type *t, |
| 4221 | u32 meta_left) |
| 4222 | { |
| 4223 | u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); |
| 4224 | |
| 4225 | if (meta_left < meta_needed) { |
| 4226 | btf_verifier_log_basic(env, t, |
| 4227 | "meta_left:%u meta_needed:%u", |
| 4228 | meta_left, meta_needed); |
| 4229 | return -EINVAL; |
| 4230 | } |
| 4231 | |
| 4232 | if (t->name_off) { |
| 4233 | btf_verifier_log_type(env, t, "Invalid name"); |
| 4234 | return -EINVAL; |
| 4235 | } |
| 4236 | |
| 4237 | if (btf_type_kflag(t)) { |
| 4238 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 4239 | return -EINVAL; |
| 4240 | } |
| 4241 | |
| 4242 | btf_verifier_log_type(env, t, NULL); |
| 4243 | |
| 4244 | return meta_needed; |
| 4245 | } |
| 4246 | |
| 4247 | static void btf_func_proto_log(struct btf_verifier_env *env, |
| 4248 | const struct btf_type *t) |
| 4249 | { |
| 4250 | const struct btf_param *args = (const struct btf_param *)(t + 1); |
| 4251 | u16 nr_args = btf_type_vlen(t), i; |
| 4252 | |
| 4253 | btf_verifier_log(env, "return=%u args=(", t->type); |
| 4254 | if (!nr_args) { |
| 4255 | btf_verifier_log(env, "void"); |
| 4256 | goto done; |
| 4257 | } |
| 4258 | |
| 4259 | if (nr_args == 1 && !args[0].type) { |
| 4260 | /* Only one vararg */ |
| 4261 | btf_verifier_log(env, "vararg"); |
| 4262 | goto done; |
| 4263 | } |
| 4264 | |
| 4265 | btf_verifier_log(env, "%u %s", args[0].type, |
| 4266 | __btf_name_by_offset(env->btf, |
| 4267 | args[0].name_off)); |
| 4268 | for (i = 1; i < nr_args - 1; i++) |
| 4269 | btf_verifier_log(env, ", %u %s", args[i].type, |
| 4270 | __btf_name_by_offset(env->btf, |
| 4271 | args[i].name_off)); |
| 4272 | |
| 4273 | if (nr_args > 1) { |
| 4274 | const struct btf_param *last_arg = &args[nr_args - 1]; |
| 4275 | |
| 4276 | if (last_arg->type) |
| 4277 | btf_verifier_log(env, ", %u %s", last_arg->type, |
| 4278 | __btf_name_by_offset(env->btf, |
| 4279 | last_arg->name_off)); |
| 4280 | else |
| 4281 | btf_verifier_log(env, ", vararg"); |
| 4282 | } |
| 4283 | |
| 4284 | done: |
| 4285 | btf_verifier_log(env, ")"); |
| 4286 | } |
| 4287 | |
| 4288 | static struct btf_kind_operations func_proto_ops = { |
| 4289 | .check_meta = btf_func_proto_check_meta, |
| 4290 | .resolve = btf_df_resolve, |
| 4291 | /* |
| 4292 | * BTF_KIND_FUNC_PROTO cannot be directly referred by |
| 4293 | * a struct's member. |
| 4294 | * |
| 4295 | * It should be a function pointer instead. |
| 4296 | * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
| 4297 | * |
| 4298 | * Hence, there is no btf_func_check_member(). |
| 4299 | */ |
| 4300 | .check_member = btf_df_check_member, |
| 4301 | .check_kflag_member = btf_df_check_kflag_member, |
| 4302 | .log_details = btf_func_proto_log, |
| 4303 | .show = btf_df_show, |
| 4304 | }; |
| 4305 | |
| 4306 | static s32 btf_func_check_meta(struct btf_verifier_env *env, |
| 4307 | const struct btf_type *t, |
| 4308 | u32 meta_left) |
| 4309 | { |
| 4310 | if (!t->name_off || |
| 4311 | !btf_name_valid_identifier(env->btf, t->name_off)) { |
| 4312 | btf_verifier_log_type(env, t, "Invalid name"); |
| 4313 | return -EINVAL; |
| 4314 | } |
| 4315 | |
| 4316 | if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
| 4317 | btf_verifier_log_type(env, t, "Invalid func linkage"); |
| 4318 | return -EINVAL; |
| 4319 | } |
| 4320 | |
| 4321 | if (btf_type_kflag(t)) { |
| 4322 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 4323 | return -EINVAL; |
| 4324 | } |
| 4325 | |
| 4326 | btf_verifier_log_type(env, t, NULL); |
| 4327 | |
| 4328 | return 0; |
| 4329 | } |
| 4330 | |
| 4331 | static int btf_func_resolve(struct btf_verifier_env *env, |
| 4332 | const struct resolve_vertex *v) |
| 4333 | { |
| 4334 | const struct btf_type *t = v->t; |
| 4335 | u32 next_type_id = t->type; |
| 4336 | int err; |
| 4337 | |
| 4338 | err = btf_func_check(env, t); |
| 4339 | if (err) |
| 4340 | return err; |
| 4341 | |
| 4342 | env_stack_pop_resolved(env, next_type_id, 0); |
| 4343 | return 0; |
| 4344 | } |
| 4345 | |
| 4346 | static struct btf_kind_operations func_ops = { |
| 4347 | .check_meta = btf_func_check_meta, |
| 4348 | .resolve = btf_func_resolve, |
| 4349 | .check_member = btf_df_check_member, |
| 4350 | .check_kflag_member = btf_df_check_kflag_member, |
| 4351 | .log_details = btf_ref_type_log, |
| 4352 | .show = btf_df_show, |
| 4353 | }; |
| 4354 | |
| 4355 | static s32 btf_var_check_meta(struct btf_verifier_env *env, |
| 4356 | const struct btf_type *t, |
| 4357 | u32 meta_left) |
| 4358 | { |
| 4359 | const struct btf_var *var; |
| 4360 | u32 meta_needed = sizeof(*var); |
| 4361 | |
| 4362 | if (meta_left < meta_needed) { |
| 4363 | btf_verifier_log_basic(env, t, |
| 4364 | "meta_left:%u meta_needed:%u", |
| 4365 | meta_left, meta_needed); |
| 4366 | return -EINVAL; |
| 4367 | } |
| 4368 | |
| 4369 | if (btf_type_vlen(t)) { |
| 4370 | btf_verifier_log_type(env, t, "vlen != 0"); |
| 4371 | return -EINVAL; |
| 4372 | } |
| 4373 | |
| 4374 | if (btf_type_kflag(t)) { |
| 4375 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 4376 | return -EINVAL; |
| 4377 | } |
| 4378 | |
| 4379 | if (!t->name_off || |
| 4380 | !__btf_name_valid(env->btf, t->name_off, true)) { |
| 4381 | btf_verifier_log_type(env, t, "Invalid name"); |
| 4382 | return -EINVAL; |
| 4383 | } |
| 4384 | |
| 4385 | /* A var cannot be in type void */ |
| 4386 | if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { |
| 4387 | btf_verifier_log_type(env, t, "Invalid type_id"); |
| 4388 | return -EINVAL; |
| 4389 | } |
| 4390 | |
| 4391 | var = btf_type_var(t); |
| 4392 | if (var->linkage != BTF_VAR_STATIC && |
| 4393 | var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { |
| 4394 | btf_verifier_log_type(env, t, "Linkage not supported"); |
| 4395 | return -EINVAL; |
| 4396 | } |
| 4397 | |
| 4398 | btf_verifier_log_type(env, t, NULL); |
| 4399 | |
| 4400 | return meta_needed; |
| 4401 | } |
| 4402 | |
| 4403 | static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) |
| 4404 | { |
| 4405 | const struct btf_var *var = btf_type_var(t); |
| 4406 | |
| 4407 | btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); |
| 4408 | } |
| 4409 | |
| 4410 | static const struct btf_kind_operations var_ops = { |
| 4411 | .check_meta = btf_var_check_meta, |
| 4412 | .resolve = btf_var_resolve, |
| 4413 | .check_member = btf_df_check_member, |
| 4414 | .check_kflag_member = btf_df_check_kflag_member, |
| 4415 | .log_details = btf_var_log, |
| 4416 | .show = btf_var_show, |
| 4417 | }; |
| 4418 | |
| 4419 | static s32 btf_datasec_check_meta(struct btf_verifier_env *env, |
| 4420 | const struct btf_type *t, |
| 4421 | u32 meta_left) |
| 4422 | { |
| 4423 | const struct btf_var_secinfo *vsi; |
| 4424 | u64 last_vsi_end_off = 0, sum = 0; |
| 4425 | u32 i, meta_needed; |
| 4426 | |
| 4427 | meta_needed = btf_type_vlen(t) * sizeof(*vsi); |
| 4428 | if (meta_left < meta_needed) { |
| 4429 | btf_verifier_log_basic(env, t, |
| 4430 | "meta_left:%u meta_needed:%u", |
| 4431 | meta_left, meta_needed); |
| 4432 | return -EINVAL; |
| 4433 | } |
| 4434 | |
| 4435 | if (!t->size) { |
| 4436 | btf_verifier_log_type(env, t, "size == 0"); |
| 4437 | return -EINVAL; |
| 4438 | } |
| 4439 | |
| 4440 | if (btf_type_kflag(t)) { |
| 4441 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 4442 | return -EINVAL; |
| 4443 | } |
| 4444 | |
| 4445 | if (!t->name_off || |
| 4446 | !btf_name_valid_section(env->btf, t->name_off)) { |
| 4447 | btf_verifier_log_type(env, t, "Invalid name"); |
| 4448 | return -EINVAL; |
| 4449 | } |
| 4450 | |
| 4451 | btf_verifier_log_type(env, t, NULL); |
| 4452 | |
| 4453 | for_each_vsi(i, t, vsi) { |
| 4454 | /* A var cannot be in type void */ |
| 4455 | if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { |
| 4456 | btf_verifier_log_vsi(env, t, vsi, |
| 4457 | "Invalid type_id"); |
| 4458 | return -EINVAL; |
| 4459 | } |
| 4460 | |
| 4461 | if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { |
| 4462 | btf_verifier_log_vsi(env, t, vsi, |
| 4463 | "Invalid offset"); |
| 4464 | return -EINVAL; |
| 4465 | } |
| 4466 | |
| 4467 | if (!vsi->size || vsi->size > t->size) { |
| 4468 | btf_verifier_log_vsi(env, t, vsi, |
| 4469 | "Invalid size"); |
| 4470 | return -EINVAL; |
| 4471 | } |
| 4472 | |
| 4473 | last_vsi_end_off = vsi->offset + vsi->size; |
| 4474 | if (last_vsi_end_off > t->size) { |
| 4475 | btf_verifier_log_vsi(env, t, vsi, |
| 4476 | "Invalid offset+size"); |
| 4477 | return -EINVAL; |
| 4478 | } |
| 4479 | |
| 4480 | btf_verifier_log_vsi(env, t, vsi, NULL); |
| 4481 | sum += vsi->size; |
| 4482 | } |
| 4483 | |
| 4484 | if (t->size < sum) { |
| 4485 | btf_verifier_log_type(env, t, "Invalid btf_info size"); |
| 4486 | return -EINVAL; |
| 4487 | } |
| 4488 | |
| 4489 | return meta_needed; |
| 4490 | } |
| 4491 | |
| 4492 | static int btf_datasec_resolve(struct btf_verifier_env *env, |
| 4493 | const struct resolve_vertex *v) |
| 4494 | { |
| 4495 | const struct btf_var_secinfo *vsi; |
| 4496 | struct btf *btf = env->btf; |
| 4497 | u16 i; |
| 4498 | |
| 4499 | for_each_vsi_from(i, v->next_member, v->t, vsi) { |
| 4500 | u32 var_type_id = vsi->type, type_id, type_size = 0; |
| 4501 | const struct btf_type *var_type = btf_type_by_id(env->btf, |
| 4502 | var_type_id); |
| 4503 | if (!var_type || !btf_type_is_var(var_type)) { |
| 4504 | btf_verifier_log_vsi(env, v->t, vsi, |
| 4505 | "Not a VAR kind member"); |
| 4506 | return -EINVAL; |
| 4507 | } |
| 4508 | |
| 4509 | if (!env_type_is_resolve_sink(env, var_type) && |
| 4510 | !env_type_is_resolved(env, var_type_id)) { |
| 4511 | env_stack_set_next_member(env, i + 1); |
| 4512 | return env_stack_push(env, var_type, var_type_id); |
| 4513 | } |
| 4514 | |
| 4515 | type_id = var_type->type; |
| 4516 | if (!btf_type_id_size(btf, &type_id, &type_size)) { |
| 4517 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); |
| 4518 | return -EINVAL; |
| 4519 | } |
| 4520 | |
| 4521 | if (vsi->size < type_size) { |
| 4522 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); |
| 4523 | return -EINVAL; |
| 4524 | } |
| 4525 | } |
| 4526 | |
| 4527 | env_stack_pop_resolved(env, 0, 0); |
| 4528 | return 0; |
| 4529 | } |
| 4530 | |
| 4531 | static void btf_datasec_log(struct btf_verifier_env *env, |
| 4532 | const struct btf_type *t) |
| 4533 | { |
| 4534 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
| 4535 | } |
| 4536 | |
| 4537 | static void btf_datasec_show(const struct btf *btf, |
| 4538 | const struct btf_type *t, u32 type_id, |
| 4539 | void *data, u8 bits_offset, |
| 4540 | struct btf_show *show) |
| 4541 | { |
| 4542 | const struct btf_var_secinfo *vsi; |
| 4543 | const struct btf_type *var; |
| 4544 | u32 i; |
| 4545 | |
| 4546 | if (!btf_show_start_type(show, t, type_id, data)) |
| 4547 | return; |
| 4548 | |
| 4549 | btf_show_type_value(show, "section (\"%s\") = {", |
| 4550 | __btf_name_by_offset(btf, t->name_off)); |
| 4551 | for_each_vsi(i, t, vsi) { |
| 4552 | var = btf_type_by_id(btf, vsi->type); |
| 4553 | if (i) |
| 4554 | btf_show(show, ","); |
| 4555 | btf_type_ops(var)->show(btf, var, vsi->type, |
| 4556 | data + vsi->offset, bits_offset, show); |
| 4557 | } |
| 4558 | btf_show_end_type(show); |
| 4559 | } |
| 4560 | |
| 4561 | static const struct btf_kind_operations datasec_ops = { |
| 4562 | .check_meta = btf_datasec_check_meta, |
| 4563 | .resolve = btf_datasec_resolve, |
| 4564 | .check_member = btf_df_check_member, |
| 4565 | .check_kflag_member = btf_df_check_kflag_member, |
| 4566 | .log_details = btf_datasec_log, |
| 4567 | .show = btf_datasec_show, |
| 4568 | }; |
| 4569 | |
| 4570 | static s32 btf_float_check_meta(struct btf_verifier_env *env, |
| 4571 | const struct btf_type *t, |
| 4572 | u32 meta_left) |
| 4573 | { |
| 4574 | if (btf_type_vlen(t)) { |
| 4575 | btf_verifier_log_type(env, t, "vlen != 0"); |
| 4576 | return -EINVAL; |
| 4577 | } |
| 4578 | |
| 4579 | if (btf_type_kflag(t)) { |
| 4580 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 4581 | return -EINVAL; |
| 4582 | } |
| 4583 | |
| 4584 | if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && |
| 4585 | t->size != 16) { |
| 4586 | btf_verifier_log_type(env, t, "Invalid type_size"); |
| 4587 | return -EINVAL; |
| 4588 | } |
| 4589 | |
| 4590 | btf_verifier_log_type(env, t, NULL); |
| 4591 | |
| 4592 | return 0; |
| 4593 | } |
| 4594 | |
| 4595 | static int btf_float_check_member(struct btf_verifier_env *env, |
| 4596 | const struct btf_type *struct_type, |
| 4597 | const struct btf_member *member, |
| 4598 | const struct btf_type *member_type) |
| 4599 | { |
| 4600 | u64 start_offset_bytes; |
| 4601 | u64 end_offset_bytes; |
| 4602 | u64 misalign_bits; |
| 4603 | u64 align_bytes; |
| 4604 | u64 align_bits; |
| 4605 | |
| 4606 | /* Different architectures have different alignment requirements, so |
| 4607 | * here we check only for the reasonable minimum. This way we ensure |
| 4608 | * that types after CO-RE can pass the kernel BTF verifier. |
| 4609 | */ |
| 4610 | align_bytes = min_t(u64, sizeof(void *), member_type->size); |
| 4611 | align_bits = align_bytes * BITS_PER_BYTE; |
| 4612 | div64_u64_rem(member->offset, align_bits, &misalign_bits); |
| 4613 | if (misalign_bits) { |
| 4614 | btf_verifier_log_member(env, struct_type, member, |
| 4615 | "Member is not properly aligned"); |
| 4616 | return -EINVAL; |
| 4617 | } |
| 4618 | |
| 4619 | start_offset_bytes = member->offset / BITS_PER_BYTE; |
| 4620 | end_offset_bytes = start_offset_bytes + member_type->size; |
| 4621 | if (end_offset_bytes > struct_type->size) { |
| 4622 | btf_verifier_log_member(env, struct_type, member, |
| 4623 | "Member exceeds struct_size"); |
| 4624 | return -EINVAL; |
| 4625 | } |
| 4626 | |
| 4627 | return 0; |
| 4628 | } |
| 4629 | |
| 4630 | static void btf_float_log(struct btf_verifier_env *env, |
| 4631 | const struct btf_type *t) |
| 4632 | { |
| 4633 | btf_verifier_log(env, "size=%u", t->size); |
| 4634 | } |
| 4635 | |
| 4636 | static const struct btf_kind_operations float_ops = { |
| 4637 | .check_meta = btf_float_check_meta, |
| 4638 | .resolve = btf_df_resolve, |
| 4639 | .check_member = btf_float_check_member, |
| 4640 | .check_kflag_member = btf_generic_check_kflag_member, |
| 4641 | .log_details = btf_float_log, |
| 4642 | .show = btf_df_show, |
| 4643 | }; |
| 4644 | |
| 4645 | static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
| 4646 | const struct btf_type *t, |
| 4647 | u32 meta_left) |
| 4648 | { |
| 4649 | const struct btf_decl_tag *tag; |
| 4650 | u32 meta_needed = sizeof(*tag); |
| 4651 | s32 component_idx; |
| 4652 | const char *value; |
| 4653 | |
| 4654 | if (meta_left < meta_needed) { |
| 4655 | btf_verifier_log_basic(env, t, |
| 4656 | "meta_left:%u meta_needed:%u", |
| 4657 | meta_left, meta_needed); |
| 4658 | return -EINVAL; |
| 4659 | } |
| 4660 | |
| 4661 | value = btf_name_by_offset(env->btf, t->name_off); |
| 4662 | if (!value || !value[0]) { |
| 4663 | btf_verifier_log_type(env, t, "Invalid value"); |
| 4664 | return -EINVAL; |
| 4665 | } |
| 4666 | |
| 4667 | if (btf_type_vlen(t)) { |
| 4668 | btf_verifier_log_type(env, t, "vlen != 0"); |
| 4669 | return -EINVAL; |
| 4670 | } |
| 4671 | |
| 4672 | if (btf_type_kflag(t)) { |
| 4673 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| 4674 | return -EINVAL; |
| 4675 | } |
| 4676 | |
| 4677 | component_idx = btf_type_decl_tag(t)->component_idx; |
| 4678 | if (component_idx < -1) { |
| 4679 | btf_verifier_log_type(env, t, "Invalid component_idx"); |
| 4680 | return -EINVAL; |
| 4681 | } |
| 4682 | |
| 4683 | btf_verifier_log_type(env, t, NULL); |
| 4684 | |
| 4685 | return meta_needed; |
| 4686 | } |
| 4687 | |
| 4688 | static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
| 4689 | const struct resolve_vertex *v) |
| 4690 | { |
| 4691 | const struct btf_type *next_type; |
| 4692 | const struct btf_type *t = v->t; |
| 4693 | u32 next_type_id = t->type; |
| 4694 | struct btf *btf = env->btf; |
| 4695 | s32 component_idx; |
| 4696 | u32 vlen; |
| 4697 | |
| 4698 | next_type = btf_type_by_id(btf, next_type_id); |
| 4699 | if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
| 4700 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| 4701 | return -EINVAL; |
| 4702 | } |
| 4703 | |
| 4704 | if (!env_type_is_resolve_sink(env, next_type) && |
| 4705 | !env_type_is_resolved(env, next_type_id)) |
| 4706 | return env_stack_push(env, next_type, next_type_id); |
| 4707 | |
| 4708 | component_idx = btf_type_decl_tag(t)->component_idx; |
| 4709 | if (component_idx != -1) { |
| 4710 | if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
| 4711 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
| 4712 | return -EINVAL; |
| 4713 | } |
| 4714 | |
| 4715 | if (btf_type_is_struct(next_type)) { |
| 4716 | vlen = btf_type_vlen(next_type); |
| 4717 | } else { |
| 4718 | /* next_type should be a function */ |
| 4719 | next_type = btf_type_by_id(btf, next_type->type); |
| 4720 | vlen = btf_type_vlen(next_type); |
| 4721 | } |
| 4722 | |
| 4723 | if ((u32)component_idx >= vlen) { |
| 4724 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
| 4725 | return -EINVAL; |
| 4726 | } |
| 4727 | } |
| 4728 | |
| 4729 | env_stack_pop_resolved(env, next_type_id, 0); |
| 4730 | |
| 4731 | return 0; |
| 4732 | } |
| 4733 | |
| 4734 | static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
| 4735 | { |
| 4736 | btf_verifier_log(env, "type=%u component_idx=%d", t->type, |
| 4737 | btf_type_decl_tag(t)->component_idx); |
| 4738 | } |
| 4739 | |
| 4740 | static const struct btf_kind_operations decl_tag_ops = { |
| 4741 | .check_meta = btf_decl_tag_check_meta, |
| 4742 | .resolve = btf_decl_tag_resolve, |
| 4743 | .check_member = btf_df_check_member, |
| 4744 | .check_kflag_member = btf_df_check_kflag_member, |
| 4745 | .log_details = btf_decl_tag_log, |
| 4746 | .show = btf_df_show, |
| 4747 | }; |
| 4748 | |
| 4749 | static int btf_func_proto_check(struct btf_verifier_env *env, |
| 4750 | const struct btf_type *t) |
| 4751 | { |
| 4752 | const struct btf_type *ret_type; |
| 4753 | const struct btf_param *args; |
| 4754 | const struct btf *btf; |
| 4755 | u16 nr_args, i; |
| 4756 | int err; |
| 4757 | |
| 4758 | btf = env->btf; |
| 4759 | args = (const struct btf_param *)(t + 1); |
| 4760 | nr_args = btf_type_vlen(t); |
| 4761 | |
| 4762 | /* Check func return type which could be "void" (t->type == 0) */ |
| 4763 | if (t->type) { |
| 4764 | u32 ret_type_id = t->type; |
| 4765 | |
| 4766 | ret_type = btf_type_by_id(btf, ret_type_id); |
| 4767 | if (!ret_type) { |
| 4768 | btf_verifier_log_type(env, t, "Invalid return type"); |
| 4769 | return -EINVAL; |
| 4770 | } |
| 4771 | |
| 4772 | if (btf_type_is_resolve_source_only(ret_type)) { |
| 4773 | btf_verifier_log_type(env, t, "Invalid return type"); |
| 4774 | return -EINVAL; |
| 4775 | } |
| 4776 | |
| 4777 | if (btf_type_needs_resolve(ret_type) && |
| 4778 | !env_type_is_resolved(env, ret_type_id)) { |
| 4779 | err = btf_resolve(env, ret_type, ret_type_id); |
| 4780 | if (err) |
| 4781 | return err; |
| 4782 | } |
| 4783 | |
| 4784 | /* Ensure the return type is a type that has a size */ |
| 4785 | if (!btf_type_id_size(btf, &ret_type_id, NULL)) { |
| 4786 | btf_verifier_log_type(env, t, "Invalid return type"); |
| 4787 | return -EINVAL; |
| 4788 | } |
| 4789 | } |
| 4790 | |
| 4791 | if (!nr_args) |
| 4792 | return 0; |
| 4793 | |
| 4794 | /* Last func arg type_id could be 0 if it is a vararg */ |
| 4795 | if (!args[nr_args - 1].type) { |
| 4796 | if (args[nr_args - 1].name_off) { |
| 4797 | btf_verifier_log_type(env, t, "Invalid arg#%u", |
| 4798 | nr_args); |
| 4799 | return -EINVAL; |
| 4800 | } |
| 4801 | nr_args--; |
| 4802 | } |
| 4803 | |
| 4804 | for (i = 0; i < nr_args; i++) { |
| 4805 | const struct btf_type *arg_type; |
| 4806 | u32 arg_type_id; |
| 4807 | |
| 4808 | arg_type_id = args[i].type; |
| 4809 | arg_type = btf_type_by_id(btf, arg_type_id); |
| 4810 | if (!arg_type) { |
| 4811 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
| 4812 | return -EINVAL; |
| 4813 | } |
| 4814 | |
| 4815 | if (btf_type_is_resolve_source_only(arg_type)) { |
| 4816 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
| 4817 | return -EINVAL; |
| 4818 | } |
| 4819 | |
| 4820 | if (args[i].name_off && |
| 4821 | (!btf_name_offset_valid(btf, args[i].name_off) || |
| 4822 | !btf_name_valid_identifier(btf, args[i].name_off))) { |
| 4823 | btf_verifier_log_type(env, t, |
| 4824 | "Invalid arg#%u", i + 1); |
| 4825 | return -EINVAL; |
| 4826 | } |
| 4827 | |
| 4828 | if (btf_type_needs_resolve(arg_type) && |
| 4829 | !env_type_is_resolved(env, arg_type_id)) { |
| 4830 | err = btf_resolve(env, arg_type, arg_type_id); |
| 4831 | if (err) |
| 4832 | return err; |
| 4833 | } |
| 4834 | |
| 4835 | if (!btf_type_id_size(btf, &arg_type_id, NULL)) { |
| 4836 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
| 4837 | return -EINVAL; |
| 4838 | } |
| 4839 | } |
| 4840 | |
| 4841 | return 0; |
| 4842 | } |
| 4843 | |
| 4844 | static int btf_func_check(struct btf_verifier_env *env, |
| 4845 | const struct btf_type *t) |
| 4846 | { |
| 4847 | const struct btf_type *proto_type; |
| 4848 | const struct btf_param *args; |
| 4849 | const struct btf *btf; |
| 4850 | u16 nr_args, i; |
| 4851 | |
| 4852 | btf = env->btf; |
| 4853 | proto_type = btf_type_by_id(btf, t->type); |
| 4854 | |
| 4855 | if (!proto_type || !btf_type_is_func_proto(proto_type)) { |
| 4856 | btf_verifier_log_type(env, t, "Invalid type_id"); |
| 4857 | return -EINVAL; |
| 4858 | } |
| 4859 | |
| 4860 | args = (const struct btf_param *)(proto_type + 1); |
| 4861 | nr_args = btf_type_vlen(proto_type); |
| 4862 | for (i = 0; i < nr_args; i++) { |
| 4863 | if (!args[i].name_off && args[i].type) { |
| 4864 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
| 4865 | return -EINVAL; |
| 4866 | } |
| 4867 | } |
| 4868 | |
| 4869 | return 0; |
| 4870 | } |
| 4871 | |
| 4872 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
| 4873 | [BTF_KIND_INT] = &int_ops, |
| 4874 | [BTF_KIND_PTR] = &ptr_ops, |
| 4875 | [BTF_KIND_ARRAY] = &array_ops, |
| 4876 | [BTF_KIND_STRUCT] = &struct_ops, |
| 4877 | [BTF_KIND_UNION] = &struct_ops, |
| 4878 | [BTF_KIND_ENUM] = &enum_ops, |
| 4879 | [BTF_KIND_FWD] = &fwd_ops, |
| 4880 | [BTF_KIND_TYPEDEF] = &modifier_ops, |
| 4881 | [BTF_KIND_VOLATILE] = &modifier_ops, |
| 4882 | [BTF_KIND_CONST] = &modifier_ops, |
| 4883 | [BTF_KIND_RESTRICT] = &modifier_ops, |
| 4884 | [BTF_KIND_FUNC] = &func_ops, |
| 4885 | [BTF_KIND_FUNC_PROTO] = &func_proto_ops, |
| 4886 | [BTF_KIND_VAR] = &var_ops, |
| 4887 | [BTF_KIND_DATASEC] = &datasec_ops, |
| 4888 | [BTF_KIND_FLOAT] = &float_ops, |
| 4889 | [BTF_KIND_DECL_TAG] = &decl_tag_ops, |
| 4890 | [BTF_KIND_TYPE_TAG] = &modifier_ops, |
| 4891 | [BTF_KIND_ENUM64] = &enum64_ops, |
| 4892 | }; |
| 4893 | |
| 4894 | static s32 btf_check_meta(struct btf_verifier_env *env, |
| 4895 | const struct btf_type *t, |
| 4896 | u32 meta_left) |
| 4897 | { |
| 4898 | u32 saved_meta_left = meta_left; |
| 4899 | s32 var_meta_size; |
| 4900 | |
| 4901 | if (meta_left < sizeof(*t)) { |
| 4902 | btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", |
| 4903 | env->log_type_id, meta_left, sizeof(*t)); |
| 4904 | return -EINVAL; |
| 4905 | } |
| 4906 | meta_left -= sizeof(*t); |
| 4907 | |
| 4908 | if (t->info & ~BTF_INFO_MASK) { |
| 4909 | btf_verifier_log(env, "[%u] Invalid btf_info:%x", |
| 4910 | env->log_type_id, t->info); |
| 4911 | return -EINVAL; |
| 4912 | } |
| 4913 | |
| 4914 | if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
| 4915 | BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { |
| 4916 | btf_verifier_log(env, "[%u] Invalid kind:%u", |
| 4917 | env->log_type_id, BTF_INFO_KIND(t->info)); |
| 4918 | return -EINVAL; |
| 4919 | } |
| 4920 | |
| 4921 | if (!btf_name_offset_valid(env->btf, t->name_off)) { |
| 4922 | btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
| 4923 | env->log_type_id, t->name_off); |
| 4924 | return -EINVAL; |
| 4925 | } |
| 4926 | |
| 4927 | var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); |
| 4928 | if (var_meta_size < 0) |
| 4929 | return var_meta_size; |
| 4930 | |
| 4931 | meta_left -= var_meta_size; |
| 4932 | |
| 4933 | return saved_meta_left - meta_left; |
| 4934 | } |
| 4935 | |
| 4936 | static int btf_check_all_metas(struct btf_verifier_env *env) |
| 4937 | { |
| 4938 | struct btf *btf = env->btf; |
| 4939 | struct btf_header *hdr; |
| 4940 | void *cur, *end; |
| 4941 | |
| 4942 | hdr = &btf->hdr; |
| 4943 | cur = btf->nohdr_data + hdr->type_off; |
| 4944 | end = cur + hdr->type_len; |
| 4945 | |
| 4946 | env->log_type_id = btf->base_btf ? btf->start_id : 1; |
| 4947 | while (cur < end) { |
| 4948 | struct btf_type *t = cur; |
| 4949 | s32 meta_size; |
| 4950 | |
| 4951 | meta_size = btf_check_meta(env, t, end - cur); |
| 4952 | if (meta_size < 0) |
| 4953 | return meta_size; |
| 4954 | |
| 4955 | btf_add_type(env, t); |
| 4956 | cur += meta_size; |
| 4957 | env->log_type_id++; |
| 4958 | } |
| 4959 | |
| 4960 | return 0; |
| 4961 | } |
| 4962 | |
| 4963 | static bool btf_resolve_valid(struct btf_verifier_env *env, |
| 4964 | const struct btf_type *t, |
| 4965 | u32 type_id) |
| 4966 | { |
| 4967 | struct btf *btf = env->btf; |
| 4968 | |
| 4969 | if (!env_type_is_resolved(env, type_id)) |
| 4970 | return false; |
| 4971 | |
| 4972 | if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
| 4973 | return !btf_resolved_type_id(btf, type_id) && |
| 4974 | !btf_resolved_type_size(btf, type_id); |
| 4975 | |
| 4976 | if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
| 4977 | return btf_resolved_type_id(btf, type_id) && |
| 4978 | !btf_resolved_type_size(btf, type_id); |
| 4979 | |
| 4980 | if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
| 4981 | btf_type_is_var(t)) { |
| 4982 | t = btf_type_id_resolve(btf, &type_id); |
| 4983 | return t && |
| 4984 | !btf_type_is_modifier(t) && |
| 4985 | !btf_type_is_var(t) && |
| 4986 | !btf_type_is_datasec(t); |
| 4987 | } |
| 4988 | |
| 4989 | if (btf_type_is_array(t)) { |
| 4990 | const struct btf_array *array = btf_type_array(t); |
| 4991 | const struct btf_type *elem_type; |
| 4992 | u32 elem_type_id = array->type; |
| 4993 | u32 elem_size; |
| 4994 | |
| 4995 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); |
| 4996 | return elem_type && !btf_type_is_modifier(elem_type) && |
| 4997 | (array->nelems * elem_size == |
| 4998 | btf_resolved_type_size(btf, type_id)); |
| 4999 | } |
| 5000 | |
| 5001 | return false; |
| 5002 | } |
| 5003 | |
| 5004 | static int btf_resolve(struct btf_verifier_env *env, |
| 5005 | const struct btf_type *t, u32 type_id) |
| 5006 | { |
| 5007 | u32 save_log_type_id = env->log_type_id; |
| 5008 | const struct resolve_vertex *v; |
| 5009 | int err = 0; |
| 5010 | |
| 5011 | env->resolve_mode = RESOLVE_TBD; |
| 5012 | env_stack_push(env, t, type_id); |
| 5013 | while (!err && (v = env_stack_peak(env))) { |
| 5014 | env->log_type_id = v->type_id; |
| 5015 | err = btf_type_ops(v->t)->resolve(env, v); |
| 5016 | } |
| 5017 | |
| 5018 | env->log_type_id = type_id; |
| 5019 | if (err == -E2BIG) { |
| 5020 | btf_verifier_log_type(env, t, |
| 5021 | "Exceeded max resolving depth:%u", |
| 5022 | MAX_RESOLVE_DEPTH); |
| 5023 | } else if (err == -EEXIST) { |
| 5024 | btf_verifier_log_type(env, t, "Loop detected"); |
| 5025 | } |
| 5026 | |
| 5027 | /* Final sanity check */ |
| 5028 | if (!err && !btf_resolve_valid(env, t, type_id)) { |
| 5029 | btf_verifier_log_type(env, t, "Invalid resolve state"); |
| 5030 | err = -EINVAL; |
| 5031 | } |
| 5032 | |
| 5033 | env->log_type_id = save_log_type_id; |
| 5034 | return err; |
| 5035 | } |
| 5036 | |
| 5037 | static int btf_check_all_types(struct btf_verifier_env *env) |
| 5038 | { |
| 5039 | struct btf *btf = env->btf; |
| 5040 | const struct btf_type *t; |
| 5041 | u32 type_id, i; |
| 5042 | int err; |
| 5043 | |
| 5044 | err = env_resolve_init(env); |
| 5045 | if (err) |
| 5046 | return err; |
| 5047 | |
| 5048 | env->phase++; |
| 5049 | for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
| 5050 | type_id = btf->start_id + i; |
| 5051 | t = btf_type_by_id(btf, type_id); |
| 5052 | |
| 5053 | env->log_type_id = type_id; |
| 5054 | if (btf_type_needs_resolve(t) && |
| 5055 | !env_type_is_resolved(env, type_id)) { |
| 5056 | err = btf_resolve(env, t, type_id); |
| 5057 | if (err) |
| 5058 | return err; |
| 5059 | } |
| 5060 | |
| 5061 | if (btf_type_is_func_proto(t)) { |
| 5062 | err = btf_func_proto_check(env, t); |
| 5063 | if (err) |
| 5064 | return err; |
| 5065 | } |
| 5066 | } |
| 5067 | |
| 5068 | return 0; |
| 5069 | } |
| 5070 | |
| 5071 | static int btf_parse_type_sec(struct btf_verifier_env *env) |
| 5072 | { |
| 5073 | const struct btf_header *hdr = &env->btf->hdr; |
| 5074 | int err; |
| 5075 | |
| 5076 | /* Type section must align to 4 bytes */ |
| 5077 | if (hdr->type_off & (sizeof(u32) - 1)) { |
| 5078 | btf_verifier_log(env, "Unaligned type_off"); |
| 5079 | return -EINVAL; |
| 5080 | } |
| 5081 | |
| 5082 | if (!env->btf->base_btf && !hdr->type_len) { |
| 5083 | btf_verifier_log(env, "No type found"); |
| 5084 | return -EINVAL; |
| 5085 | } |
| 5086 | |
| 5087 | err = btf_check_all_metas(env); |
| 5088 | if (err) |
| 5089 | return err; |
| 5090 | |
| 5091 | return btf_check_all_types(env); |
| 5092 | } |
| 5093 | |
| 5094 | static int btf_parse_str_sec(struct btf_verifier_env *env) |
| 5095 | { |
| 5096 | const struct btf_header *hdr; |
| 5097 | struct btf *btf = env->btf; |
| 5098 | const char *start, *end; |
| 5099 | |
| 5100 | hdr = &btf->hdr; |
| 5101 | start = btf->nohdr_data + hdr->str_off; |
| 5102 | end = start + hdr->str_len; |
| 5103 | |
| 5104 | if (end != btf->data + btf->data_size) { |
| 5105 | btf_verifier_log(env, "String section is not at the end"); |
| 5106 | return -EINVAL; |
| 5107 | } |
| 5108 | |
| 5109 | btf->strings = start; |
| 5110 | |
| 5111 | if (btf->base_btf && !hdr->str_len) |
| 5112 | return 0; |
| 5113 | if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { |
| 5114 | btf_verifier_log(env, "Invalid string section"); |
| 5115 | return -EINVAL; |
| 5116 | } |
| 5117 | if (!btf->base_btf && start[0]) { |
| 5118 | btf_verifier_log(env, "Invalid string section"); |
| 5119 | return -EINVAL; |
| 5120 | } |
| 5121 | |
| 5122 | return 0; |
| 5123 | } |
| 5124 | |
| 5125 | static const size_t btf_sec_info_offset[] = { |
| 5126 | offsetof(struct btf_header, type_off), |
| 5127 | offsetof(struct btf_header, str_off), |
| 5128 | }; |
| 5129 | |
| 5130 | static int btf_sec_info_cmp(const void *a, const void *b) |
| 5131 | { |
| 5132 | const struct btf_sec_info *x = a; |
| 5133 | const struct btf_sec_info *y = b; |
| 5134 | |
| 5135 | return (int)(x->off - y->off) ? : (int)(x->len - y->len); |
| 5136 | } |
| 5137 | |
| 5138 | static int btf_check_sec_info(struct btf_verifier_env *env, |
| 5139 | u32 btf_data_size) |
| 5140 | { |
| 5141 | struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
| 5142 | u32 total, expected_total, i; |
| 5143 | const struct btf_header *hdr; |
| 5144 | const struct btf *btf; |
| 5145 | |
| 5146 | btf = env->btf; |
| 5147 | hdr = &btf->hdr; |
| 5148 | |
| 5149 | /* Populate the secs from hdr */ |
| 5150 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
| 5151 | secs[i] = *(struct btf_sec_info *)((void *)hdr + |
| 5152 | btf_sec_info_offset[i]); |
| 5153 | |
| 5154 | sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
| 5155 | sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); |
| 5156 | |
| 5157 | /* Check for gaps and overlap among sections */ |
| 5158 | total = 0; |
| 5159 | expected_total = btf_data_size - hdr->hdr_len; |
| 5160 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
| 5161 | if (expected_total < secs[i].off) { |
| 5162 | btf_verifier_log(env, "Invalid section offset"); |
| 5163 | return -EINVAL; |
| 5164 | } |
| 5165 | if (total < secs[i].off) { |
| 5166 | /* gap */ |
| 5167 | btf_verifier_log(env, "Unsupported section found"); |
| 5168 | return -EINVAL; |
| 5169 | } |
| 5170 | if (total > secs[i].off) { |
| 5171 | btf_verifier_log(env, "Section overlap found"); |
| 5172 | return -EINVAL; |
| 5173 | } |
| 5174 | if (expected_total - total < secs[i].len) { |
| 5175 | btf_verifier_log(env, |
| 5176 | "Total section length too long"); |
| 5177 | return -EINVAL; |
| 5178 | } |
| 5179 | total += secs[i].len; |
| 5180 | } |
| 5181 | |
| 5182 | /* There is data other than hdr and known sections */ |
| 5183 | if (expected_total != total) { |
| 5184 | btf_verifier_log(env, "Unsupported section found"); |
| 5185 | return -EINVAL; |
| 5186 | } |
| 5187 | |
| 5188 | return 0; |
| 5189 | } |
| 5190 | |
| 5191 | static int btf_parse_hdr(struct btf_verifier_env *env) |
| 5192 | { |
| 5193 | u32 hdr_len, hdr_copy, btf_data_size; |
| 5194 | const struct btf_header *hdr; |
| 5195 | struct btf *btf; |
| 5196 | |
| 5197 | btf = env->btf; |
| 5198 | btf_data_size = btf->data_size; |
| 5199 | |
| 5200 | if (btf_data_size < offsetofend(struct btf_header, hdr_len)) { |
| 5201 | btf_verifier_log(env, "hdr_len not found"); |
| 5202 | return -EINVAL; |
| 5203 | } |
| 5204 | |
| 5205 | hdr = btf->data; |
| 5206 | hdr_len = hdr->hdr_len; |
| 5207 | if (btf_data_size < hdr_len) { |
| 5208 | btf_verifier_log(env, "btf_header not found"); |
| 5209 | return -EINVAL; |
| 5210 | } |
| 5211 | |
| 5212 | /* Ensure the unsupported header fields are zero */ |
| 5213 | if (hdr_len > sizeof(btf->hdr)) { |
| 5214 | u8 *expected_zero = btf->data + sizeof(btf->hdr); |
| 5215 | u8 *end = btf->data + hdr_len; |
| 5216 | |
| 5217 | for (; expected_zero < end; expected_zero++) { |
| 5218 | if (*expected_zero) { |
| 5219 | btf_verifier_log(env, "Unsupported btf_header"); |
| 5220 | return -E2BIG; |
| 5221 | } |
| 5222 | } |
| 5223 | } |
| 5224 | |
| 5225 | hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); |
| 5226 | memcpy(&btf->hdr, btf->data, hdr_copy); |
| 5227 | |
| 5228 | hdr = &btf->hdr; |
| 5229 | |
| 5230 | btf_verifier_log_hdr(env, btf_data_size); |
| 5231 | |
| 5232 | if (hdr->magic != BTF_MAGIC) { |
| 5233 | btf_verifier_log(env, "Invalid magic"); |
| 5234 | return -EINVAL; |
| 5235 | } |
| 5236 | |
| 5237 | if (hdr->version != BTF_VERSION) { |
| 5238 | btf_verifier_log(env, "Unsupported version"); |
| 5239 | return -ENOTSUPP; |
| 5240 | } |
| 5241 | |
| 5242 | if (hdr->flags) { |
| 5243 | btf_verifier_log(env, "Unsupported flags"); |
| 5244 | return -ENOTSUPP; |
| 5245 | } |
| 5246 | |
| 5247 | if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
| 5248 | btf_verifier_log(env, "No data"); |
| 5249 | return -EINVAL; |
| 5250 | } |
| 5251 | |
| 5252 | return btf_check_sec_info(env, btf_data_size); |
| 5253 | } |
| 5254 | |
| 5255 | static const char *alloc_obj_fields[] = { |
| 5256 | "bpf_spin_lock", |
| 5257 | "bpf_list_head", |
| 5258 | "bpf_list_node", |
| 5259 | }; |
| 5260 | |
| 5261 | static struct btf_struct_metas * |
| 5262 | btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf) |
| 5263 | { |
| 5264 | union { |
| 5265 | struct btf_id_set set; |
| 5266 | struct { |
| 5267 | u32 _cnt; |
| 5268 | u32 _ids[ARRAY_SIZE(alloc_obj_fields)]; |
| 5269 | } _arr; |
| 5270 | } aof; |
| 5271 | struct btf_struct_metas *tab = NULL; |
| 5272 | int i, n, id, ret; |
| 5273 | |
| 5274 | BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0); |
| 5275 | BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32)); |
| 5276 | |
| 5277 | memset(&aof, 0, sizeof(aof)); |
| 5278 | for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) { |
| 5279 | /* Try to find whether this special type exists in user BTF, and |
| 5280 | * if so remember its ID so we can easily find it among members |
| 5281 | * of structs that we iterate in the next loop. |
| 5282 | */ |
| 5283 | id = btf_find_by_name_kind(btf, alloc_obj_fields[i], BTF_KIND_STRUCT); |
| 5284 | if (id < 0) |
| 5285 | continue; |
| 5286 | aof.set.ids[aof.set.cnt++] = id; |
| 5287 | } |
| 5288 | |
| 5289 | if (!aof.set.cnt) |
| 5290 | return NULL; |
| 5291 | sort(&aof.set.ids, aof.set.cnt, sizeof(aof.set.ids[0]), btf_id_cmp_func, NULL); |
| 5292 | |
| 5293 | n = btf_nr_types(btf); |
| 5294 | for (i = 1; i < n; i++) { |
| 5295 | struct btf_struct_metas *new_tab; |
| 5296 | const struct btf_member *member; |
| 5297 | struct btf_field_offs *foffs; |
| 5298 | struct btf_struct_meta *type; |
| 5299 | struct btf_record *record; |
| 5300 | const struct btf_type *t; |
| 5301 | int j, tab_cnt; |
| 5302 | |
| 5303 | t = btf_type_by_id(btf, i); |
| 5304 | if (!t) { |
| 5305 | ret = -EINVAL; |
| 5306 | goto free; |
| 5307 | } |
| 5308 | if (!__btf_type_is_struct(t)) |
| 5309 | continue; |
| 5310 | |
| 5311 | cond_resched(); |
| 5312 | |
| 5313 | for_each_member(j, t, member) { |
| 5314 | if (btf_id_set_contains(&aof.set, member->type)) |
| 5315 | goto parse; |
| 5316 | } |
| 5317 | continue; |
| 5318 | parse: |
| 5319 | tab_cnt = tab ? tab->cnt : 0; |
| 5320 | new_tab = krealloc(tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]), |
| 5321 | GFP_KERNEL | __GFP_NOWARN); |
| 5322 | if (!new_tab) { |
| 5323 | ret = -ENOMEM; |
| 5324 | goto free; |
| 5325 | } |
| 5326 | if (!tab) |
| 5327 | new_tab->cnt = 0; |
| 5328 | tab = new_tab; |
| 5329 | |
| 5330 | type = &tab->types[tab->cnt]; |
| 5331 | type->btf_id = i; |
| 5332 | record = btf_parse_fields(btf, t, BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE, t->size); |
| 5333 | /* The record cannot be unset, treat it as an error if so */ |
| 5334 | if (IS_ERR_OR_NULL(record)) { |
| 5335 | ret = PTR_ERR_OR_ZERO(record) ?: -EFAULT; |
| 5336 | goto free; |
| 5337 | } |
| 5338 | foffs = btf_parse_field_offs(record); |
| 5339 | /* We need the field_offs to be valid for a valid record, |
| 5340 | * either both should be set or both should be unset. |
| 5341 | */ |
| 5342 | if (IS_ERR_OR_NULL(foffs)) { |
| 5343 | btf_record_free(record); |
| 5344 | ret = -EFAULT; |
| 5345 | goto free; |
| 5346 | } |
| 5347 | type->record = record; |
| 5348 | type->field_offs = foffs; |
| 5349 | tab->cnt++; |
| 5350 | } |
| 5351 | return tab; |
| 5352 | free: |
| 5353 | btf_struct_metas_free(tab); |
| 5354 | return ERR_PTR(ret); |
| 5355 | } |
| 5356 | |
| 5357 | struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id) |
| 5358 | { |
| 5359 | struct btf_struct_metas *tab; |
| 5360 | |
| 5361 | BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0); |
| 5362 | tab = btf->struct_meta_tab; |
| 5363 | if (!tab) |
| 5364 | return NULL; |
| 5365 | return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func); |
| 5366 | } |
| 5367 | |
| 5368 | static int btf_check_type_tags(struct btf_verifier_env *env, |
| 5369 | struct btf *btf, int start_id) |
| 5370 | { |
| 5371 | int i, n, good_id = start_id - 1; |
| 5372 | bool in_tags; |
| 5373 | |
| 5374 | n = btf_nr_types(btf); |
| 5375 | for (i = start_id; i < n; i++) { |
| 5376 | const struct btf_type *t; |
| 5377 | int chain_limit = 32; |
| 5378 | u32 cur_id = i; |
| 5379 | |
| 5380 | t = btf_type_by_id(btf, i); |
| 5381 | if (!t) |
| 5382 | return -EINVAL; |
| 5383 | if (!btf_type_is_modifier(t)) |
| 5384 | continue; |
| 5385 | |
| 5386 | cond_resched(); |
| 5387 | |
| 5388 | in_tags = btf_type_is_type_tag(t); |
| 5389 | while (btf_type_is_modifier(t)) { |
| 5390 | if (!chain_limit--) { |
| 5391 | btf_verifier_log(env, "Max chain length or cycle detected"); |
| 5392 | return -ELOOP; |
| 5393 | } |
| 5394 | if (btf_type_is_type_tag(t)) { |
| 5395 | if (!in_tags) { |
| 5396 | btf_verifier_log(env, "Type tags don't precede modifiers"); |
| 5397 | return -EINVAL; |
| 5398 | } |
| 5399 | } else if (in_tags) { |
| 5400 | in_tags = false; |
| 5401 | } |
| 5402 | if (cur_id <= good_id) |
| 5403 | break; |
| 5404 | /* Move to next type */ |
| 5405 | cur_id = t->type; |
| 5406 | t = btf_type_by_id(btf, cur_id); |
| 5407 | if (!t) |
| 5408 | return -EINVAL; |
| 5409 | } |
| 5410 | good_id = i; |
| 5411 | } |
| 5412 | return 0; |
| 5413 | } |
| 5414 | |
| 5415 | static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, |
| 5416 | u32 log_level, char __user *log_ubuf, u32 log_size) |
| 5417 | { |
| 5418 | struct btf_struct_metas *struct_meta_tab; |
| 5419 | struct btf_verifier_env *env = NULL; |
| 5420 | struct bpf_verifier_log *log; |
| 5421 | struct btf *btf = NULL; |
| 5422 | u8 *data; |
| 5423 | int err; |
| 5424 | |
| 5425 | if (btf_data_size > BTF_MAX_SIZE) |
| 5426 | return ERR_PTR(-E2BIG); |
| 5427 | |
| 5428 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
| 5429 | if (!env) |
| 5430 | return ERR_PTR(-ENOMEM); |
| 5431 | |
| 5432 | log = &env->log; |
| 5433 | if (log_level || log_ubuf || log_size) { |
| 5434 | /* user requested verbose verifier output |
| 5435 | * and supplied buffer to store the verification trace |
| 5436 | */ |
| 5437 | log->level = log_level; |
| 5438 | log->ubuf = log_ubuf; |
| 5439 | log->len_total = log_size; |
| 5440 | |
| 5441 | /* log attributes have to be sane */ |
| 5442 | if (!bpf_verifier_log_attr_valid(log)) { |
| 5443 | err = -EINVAL; |
| 5444 | goto errout; |
| 5445 | } |
| 5446 | } |
| 5447 | |
| 5448 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
| 5449 | if (!btf) { |
| 5450 | err = -ENOMEM; |
| 5451 | goto errout; |
| 5452 | } |
| 5453 | env->btf = btf; |
| 5454 | |
| 5455 | data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN); |
| 5456 | if (!data) { |
| 5457 | err = -ENOMEM; |
| 5458 | goto errout; |
| 5459 | } |
| 5460 | |
| 5461 | btf->data = data; |
| 5462 | btf->data_size = btf_data_size; |
| 5463 | |
| 5464 | if (copy_from_bpfptr(data, btf_data, btf_data_size)) { |
| 5465 | err = -EFAULT; |
| 5466 | goto errout; |
| 5467 | } |
| 5468 | |
| 5469 | err = btf_parse_hdr(env); |
| 5470 | if (err) |
| 5471 | goto errout; |
| 5472 | |
| 5473 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
| 5474 | |
| 5475 | err = btf_parse_str_sec(env); |
| 5476 | if (err) |
| 5477 | goto errout; |
| 5478 | |
| 5479 | err = btf_parse_type_sec(env); |
| 5480 | if (err) |
| 5481 | goto errout; |
| 5482 | |
| 5483 | err = btf_check_type_tags(env, btf, 1); |
| 5484 | if (err) |
| 5485 | goto errout; |
| 5486 | |
| 5487 | struct_meta_tab = btf_parse_struct_metas(log, btf); |
| 5488 | if (IS_ERR(struct_meta_tab)) { |
| 5489 | err = PTR_ERR(struct_meta_tab); |
| 5490 | goto errout; |
| 5491 | } |
| 5492 | btf->struct_meta_tab = struct_meta_tab; |
| 5493 | |
| 5494 | if (struct_meta_tab) { |
| 5495 | int i; |
| 5496 | |
| 5497 | for (i = 0; i < struct_meta_tab->cnt; i++) { |
| 5498 | err = btf_check_and_fixup_fields(btf, struct_meta_tab->types[i].record); |
| 5499 | if (err < 0) |
| 5500 | goto errout_meta; |
| 5501 | } |
| 5502 | } |
| 5503 | |
| 5504 | if (log->level && bpf_verifier_log_full(log)) { |
| 5505 | err = -ENOSPC; |
| 5506 | goto errout_meta; |
| 5507 | } |
| 5508 | |
| 5509 | btf_verifier_env_free(env); |
| 5510 | refcount_set(&btf->refcnt, 1); |
| 5511 | return btf; |
| 5512 | |
| 5513 | errout_meta: |
| 5514 | btf_free_struct_meta_tab(btf); |
| 5515 | errout: |
| 5516 | btf_verifier_env_free(env); |
| 5517 | if (btf) |
| 5518 | btf_free(btf); |
| 5519 | return ERR_PTR(err); |
| 5520 | } |
| 5521 | |
| 5522 | extern char __weak __start_BTF[]; |
| 5523 | extern char __weak __stop_BTF[]; |
| 5524 | extern struct btf *btf_vmlinux; |
| 5525 | |
| 5526 | #define BPF_MAP_TYPE(_id, _ops) |
| 5527 | #define BPF_LINK_TYPE(_id, _name) |
| 5528 | static union { |
| 5529 | struct bpf_ctx_convert { |
| 5530 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
| 5531 | prog_ctx_type _id##_prog; \ |
| 5532 | kern_ctx_type _id##_kern; |
| 5533 | #include <linux/bpf_types.h> |
| 5534 | #undef BPF_PROG_TYPE |
| 5535 | } *__t; |
| 5536 | /* 't' is written once under lock. Read many times. */ |
| 5537 | const struct btf_type *t; |
| 5538 | } bpf_ctx_convert; |
| 5539 | enum { |
| 5540 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
| 5541 | __ctx_convert##_id, |
| 5542 | #include <linux/bpf_types.h> |
| 5543 | #undef BPF_PROG_TYPE |
| 5544 | __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
| 5545 | }; |
| 5546 | static u8 bpf_ctx_convert_map[] = { |
| 5547 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
| 5548 | [_id] = __ctx_convert##_id, |
| 5549 | #include <linux/bpf_types.h> |
| 5550 | #undef BPF_PROG_TYPE |
| 5551 | 0, /* avoid empty array */ |
| 5552 | }; |
| 5553 | #undef BPF_MAP_TYPE |
| 5554 | #undef BPF_LINK_TYPE |
| 5555 | |
| 5556 | const struct btf_member * |
| 5557 | btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
| 5558 | const struct btf_type *t, enum bpf_prog_type prog_type, |
| 5559 | int arg) |
| 5560 | { |
| 5561 | const struct btf_type *conv_struct; |
| 5562 | const struct btf_type *ctx_struct; |
| 5563 | const struct btf_member *ctx_type; |
| 5564 | const char *tname, *ctx_tname; |
| 5565 | |
| 5566 | conv_struct = bpf_ctx_convert.t; |
| 5567 | if (!conv_struct) { |
| 5568 | bpf_log(log, "btf_vmlinux is malformed\n"); |
| 5569 | return NULL; |
| 5570 | } |
| 5571 | t = btf_type_by_id(btf, t->type); |
| 5572 | while (btf_type_is_modifier(t)) |
| 5573 | t = btf_type_by_id(btf, t->type); |
| 5574 | if (!btf_type_is_struct(t)) { |
| 5575 | /* Only pointer to struct is supported for now. |
| 5576 | * That means that BPF_PROG_TYPE_TRACEPOINT with BTF |
| 5577 | * is not supported yet. |
| 5578 | * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. |
| 5579 | */ |
| 5580 | return NULL; |
| 5581 | } |
| 5582 | tname = btf_name_by_offset(btf, t->name_off); |
| 5583 | if (!tname) { |
| 5584 | bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
| 5585 | return NULL; |
| 5586 | } |
| 5587 | /* prog_type is valid bpf program type. No need for bounds check. */ |
| 5588 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; |
| 5589 | /* ctx_struct is a pointer to prog_ctx_type in vmlinux. |
| 5590 | * Like 'struct __sk_buff' |
| 5591 | */ |
| 5592 | ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type); |
| 5593 | if (!ctx_struct) |
| 5594 | /* should not happen */ |
| 5595 | return NULL; |
| 5596 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off); |
| 5597 | if (!ctx_tname) { |
| 5598 | /* should not happen */ |
| 5599 | bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); |
| 5600 | return NULL; |
| 5601 | } |
| 5602 | /* only compare that prog's ctx type name is the same as |
| 5603 | * kernel expects. No need to compare field by field. |
| 5604 | * It's ok for bpf prog to do: |
| 5605 | * struct __sk_buff {}; |
| 5606 | * int socket_filter_bpf_prog(struct __sk_buff *skb) |
| 5607 | * { // no fields of skb are ever used } |
| 5608 | */ |
| 5609 | if (strcmp(ctx_tname, tname)) |
| 5610 | return NULL; |
| 5611 | return ctx_type; |
| 5612 | } |
| 5613 | |
| 5614 | static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
| 5615 | struct btf *btf, |
| 5616 | const struct btf_type *t, |
| 5617 | enum bpf_prog_type prog_type, |
| 5618 | int arg) |
| 5619 | { |
| 5620 | const struct btf_member *prog_ctx_type, *kern_ctx_type; |
| 5621 | |
| 5622 | prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg); |
| 5623 | if (!prog_ctx_type) |
| 5624 | return -ENOENT; |
| 5625 | kern_ctx_type = prog_ctx_type + 1; |
| 5626 | return kern_ctx_type->type; |
| 5627 | } |
| 5628 | |
| 5629 | int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type) |
| 5630 | { |
| 5631 | const struct btf_member *kctx_member; |
| 5632 | const struct btf_type *conv_struct; |
| 5633 | const struct btf_type *kctx_type; |
| 5634 | u32 kctx_type_id; |
| 5635 | |
| 5636 | conv_struct = bpf_ctx_convert.t; |
| 5637 | /* get member for kernel ctx type */ |
| 5638 | kctx_member = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1; |
| 5639 | kctx_type_id = kctx_member->type; |
| 5640 | kctx_type = btf_type_by_id(btf_vmlinux, kctx_type_id); |
| 5641 | if (!btf_type_is_struct(kctx_type)) { |
| 5642 | bpf_log(log, "kern ctx type id %u is not a struct\n", kctx_type_id); |
| 5643 | return -EINVAL; |
| 5644 | } |
| 5645 | |
| 5646 | return kctx_type_id; |
| 5647 | } |
| 5648 | |
| 5649 | BTF_ID_LIST(bpf_ctx_convert_btf_id) |
| 5650 | BTF_ID(struct, bpf_ctx_convert) |
| 5651 | |
| 5652 | struct btf *btf_parse_vmlinux(void) |
| 5653 | { |
| 5654 | struct btf_verifier_env *env = NULL; |
| 5655 | struct bpf_verifier_log *log; |
| 5656 | struct btf *btf = NULL; |
| 5657 | int err; |
| 5658 | |
| 5659 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
| 5660 | if (!env) |
| 5661 | return ERR_PTR(-ENOMEM); |
| 5662 | |
| 5663 | log = &env->log; |
| 5664 | log->level = BPF_LOG_KERNEL; |
| 5665 | |
| 5666 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
| 5667 | if (!btf) { |
| 5668 | err = -ENOMEM; |
| 5669 | goto errout; |
| 5670 | } |
| 5671 | env->btf = btf; |
| 5672 | |
| 5673 | btf->data = __start_BTF; |
| 5674 | btf->data_size = __stop_BTF - __start_BTF; |
| 5675 | btf->kernel_btf = true; |
| 5676 | snprintf(btf->name, sizeof(btf->name), "vmlinux"); |
| 5677 | |
| 5678 | err = btf_parse_hdr(env); |
| 5679 | if (err) |
| 5680 | goto errout; |
| 5681 | |
| 5682 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
| 5683 | |
| 5684 | err = btf_parse_str_sec(env); |
| 5685 | if (err) |
| 5686 | goto errout; |
| 5687 | |
| 5688 | err = btf_check_all_metas(env); |
| 5689 | if (err) |
| 5690 | goto errout; |
| 5691 | |
| 5692 | err = btf_check_type_tags(env, btf, 1); |
| 5693 | if (err) |
| 5694 | goto errout; |
| 5695 | |
| 5696 | /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
| 5697 | bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
| 5698 | |
| 5699 | bpf_struct_ops_init(btf, log); |
| 5700 | |
| 5701 | refcount_set(&btf->refcnt, 1); |
| 5702 | |
| 5703 | err = btf_alloc_id(btf); |
| 5704 | if (err) |
| 5705 | goto errout; |
| 5706 | |
| 5707 | btf_verifier_env_free(env); |
| 5708 | return btf; |
| 5709 | |
| 5710 | errout: |
| 5711 | btf_verifier_env_free(env); |
| 5712 | if (btf) { |
| 5713 | kvfree(btf->types); |
| 5714 | kfree(btf); |
| 5715 | } |
| 5716 | return ERR_PTR(err); |
| 5717 | } |
| 5718 | |
| 5719 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| 5720 | |
| 5721 | static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size) |
| 5722 | { |
| 5723 | struct btf_verifier_env *env = NULL; |
| 5724 | struct bpf_verifier_log *log; |
| 5725 | struct btf *btf = NULL, *base_btf; |
| 5726 | int err; |
| 5727 | |
| 5728 | base_btf = bpf_get_btf_vmlinux(); |
| 5729 | if (IS_ERR(base_btf)) |
| 5730 | return base_btf; |
| 5731 | if (!base_btf) |
| 5732 | return ERR_PTR(-EINVAL); |
| 5733 | |
| 5734 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
| 5735 | if (!env) |
| 5736 | return ERR_PTR(-ENOMEM); |
| 5737 | |
| 5738 | log = &env->log; |
| 5739 | log->level = BPF_LOG_KERNEL; |
| 5740 | |
| 5741 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
| 5742 | if (!btf) { |
| 5743 | err = -ENOMEM; |
| 5744 | goto errout; |
| 5745 | } |
| 5746 | env->btf = btf; |
| 5747 | |
| 5748 | btf->base_btf = base_btf; |
| 5749 | btf->start_id = base_btf->nr_types; |
| 5750 | btf->start_str_off = base_btf->hdr.str_len; |
| 5751 | btf->kernel_btf = true; |
| 5752 | snprintf(btf->name, sizeof(btf->name), "%s", module_name); |
| 5753 | |
| 5754 | btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN); |
| 5755 | if (!btf->data) { |
| 5756 | err = -ENOMEM; |
| 5757 | goto errout; |
| 5758 | } |
| 5759 | memcpy(btf->data, data, data_size); |
| 5760 | btf->data_size = data_size; |
| 5761 | |
| 5762 | err = btf_parse_hdr(env); |
| 5763 | if (err) |
| 5764 | goto errout; |
| 5765 | |
| 5766 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
| 5767 | |
| 5768 | err = btf_parse_str_sec(env); |
| 5769 | if (err) |
| 5770 | goto errout; |
| 5771 | |
| 5772 | err = btf_check_all_metas(env); |
| 5773 | if (err) |
| 5774 | goto errout; |
| 5775 | |
| 5776 | err = btf_check_type_tags(env, btf, btf_nr_types(base_btf)); |
| 5777 | if (err) |
| 5778 | goto errout; |
| 5779 | |
| 5780 | btf_verifier_env_free(env); |
| 5781 | refcount_set(&btf->refcnt, 1); |
| 5782 | return btf; |
| 5783 | |
| 5784 | errout: |
| 5785 | btf_verifier_env_free(env); |
| 5786 | if (btf) { |
| 5787 | kvfree(btf->data); |
| 5788 | kvfree(btf->types); |
| 5789 | kfree(btf); |
| 5790 | } |
| 5791 | return ERR_PTR(err); |
| 5792 | } |
| 5793 | |
| 5794 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
| 5795 | |
| 5796 | struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
| 5797 | { |
| 5798 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
| 5799 | |
| 5800 | if (tgt_prog) |
| 5801 | return tgt_prog->aux->btf; |
| 5802 | else |
| 5803 | return prog->aux->attach_btf; |
| 5804 | } |
| 5805 | |
| 5806 | static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
| 5807 | { |
| 5808 | /* t comes in already as a pointer */ |
| 5809 | t = btf_type_by_id(btf, t->type); |
| 5810 | |
| 5811 | /* allow const */ |
| 5812 | if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST) |
| 5813 | t = btf_type_by_id(btf, t->type); |
| 5814 | |
| 5815 | return btf_type_is_int(t); |
| 5816 | } |
| 5817 | |
| 5818 | static u32 get_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, |
| 5819 | int off) |
| 5820 | { |
| 5821 | const struct btf_param *args; |
| 5822 | const struct btf_type *t; |
| 5823 | u32 offset = 0, nr_args; |
| 5824 | int i; |
| 5825 | |
| 5826 | if (!func_proto) |
| 5827 | return off / 8; |
| 5828 | |
| 5829 | nr_args = btf_type_vlen(func_proto); |
| 5830 | args = (const struct btf_param *)(func_proto + 1); |
| 5831 | for (i = 0; i < nr_args; i++) { |
| 5832 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
| 5833 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); |
| 5834 | if (off < offset) |
| 5835 | return i; |
| 5836 | } |
| 5837 | |
| 5838 | t = btf_type_skip_modifiers(btf, func_proto->type, NULL); |
| 5839 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); |
| 5840 | if (off < offset) |
| 5841 | return nr_args; |
| 5842 | |
| 5843 | return nr_args + 1; |
| 5844 | } |
| 5845 | |
| 5846 | static bool prog_args_trusted(const struct bpf_prog *prog) |
| 5847 | { |
| 5848 | enum bpf_attach_type atype = prog->expected_attach_type; |
| 5849 | |
| 5850 | switch (prog->type) { |
| 5851 | case BPF_PROG_TYPE_TRACING: |
| 5852 | return atype == BPF_TRACE_RAW_TP || atype == BPF_TRACE_ITER; |
| 5853 | case BPF_PROG_TYPE_LSM: |
| 5854 | return bpf_lsm_is_trusted(prog); |
| 5855 | case BPF_PROG_TYPE_STRUCT_OPS: |
| 5856 | return true; |
| 5857 | default: |
| 5858 | return false; |
| 5859 | } |
| 5860 | } |
| 5861 | |
| 5862 | bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
| 5863 | const struct bpf_prog *prog, |
| 5864 | struct bpf_insn_access_aux *info) |
| 5865 | { |
| 5866 | const struct btf_type *t = prog->aux->attach_func_proto; |
| 5867 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
| 5868 | struct btf *btf = bpf_prog_get_target_btf(prog); |
| 5869 | const char *tname = prog->aux->attach_func_name; |
| 5870 | struct bpf_verifier_log *log = info->log; |
| 5871 | const struct btf_param *args; |
| 5872 | const char *tag_value; |
| 5873 | u32 nr_args, arg; |
| 5874 | int i, ret; |
| 5875 | |
| 5876 | if (off % 8) { |
| 5877 | bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
| 5878 | tname, off); |
| 5879 | return false; |
| 5880 | } |
| 5881 | arg = get_ctx_arg_idx(btf, t, off); |
| 5882 | args = (const struct btf_param *)(t + 1); |
| 5883 | /* if (t == NULL) Fall back to default BPF prog with |
| 5884 | * MAX_BPF_FUNC_REG_ARGS u64 arguments. |
| 5885 | */ |
| 5886 | nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; |
| 5887 | if (prog->aux->attach_btf_trace) { |
| 5888 | /* skip first 'void *__data' argument in btf_trace_##name typedef */ |
| 5889 | args++; |
| 5890 | nr_args--; |
| 5891 | } |
| 5892 | |
| 5893 | if (arg > nr_args) { |
| 5894 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", |
| 5895 | tname, arg + 1); |
| 5896 | return false; |
| 5897 | } |
| 5898 | |
| 5899 | if (arg == nr_args) { |
| 5900 | switch (prog->expected_attach_type) { |
| 5901 | case BPF_LSM_CGROUP: |
| 5902 | case BPF_LSM_MAC: |
| 5903 | case BPF_TRACE_FEXIT: |
| 5904 | /* When LSM programs are attached to void LSM hooks |
| 5905 | * they use FEXIT trampolines and when attached to |
| 5906 | * int LSM hooks, they use MODIFY_RETURN trampolines. |
| 5907 | * |
| 5908 | * While the LSM programs are BPF_MODIFY_RETURN-like |
| 5909 | * the check: |
| 5910 | * |
| 5911 | * if (ret_type != 'int') |
| 5912 | * return -EINVAL; |
| 5913 | * |
| 5914 | * is _not_ done here. This is still safe as LSM hooks |
| 5915 | * have only void and int return types. |
| 5916 | */ |
| 5917 | if (!t) |
| 5918 | return true; |
| 5919 | t = btf_type_by_id(btf, t->type); |
| 5920 | break; |
| 5921 | case BPF_MODIFY_RETURN: |
| 5922 | /* For now the BPF_MODIFY_RETURN can only be attached to |
| 5923 | * functions that return an int. |
| 5924 | */ |
| 5925 | if (!t) |
| 5926 | return false; |
| 5927 | |
| 5928 | t = btf_type_skip_modifiers(btf, t->type, NULL); |
| 5929 | if (!btf_type_is_small_int(t)) { |
| 5930 | bpf_log(log, |
| 5931 | "ret type %s not allowed for fmod_ret\n", |
| 5932 | btf_type_str(t)); |
| 5933 | return false; |
| 5934 | } |
| 5935 | break; |
| 5936 | default: |
| 5937 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", |
| 5938 | tname, arg + 1); |
| 5939 | return false; |
| 5940 | } |
| 5941 | } else { |
| 5942 | if (!t) |
| 5943 | /* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
| 5944 | return true; |
| 5945 | t = btf_type_by_id(btf, args[arg].type); |
| 5946 | } |
| 5947 | |
| 5948 | /* skip modifiers */ |
| 5949 | while (btf_type_is_modifier(t)) |
| 5950 | t = btf_type_by_id(btf, t->type); |
| 5951 | if (btf_type_is_small_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
| 5952 | /* accessing a scalar */ |
| 5953 | return true; |
| 5954 | if (!btf_type_is_ptr(t)) { |
| 5955 | bpf_log(log, |
| 5956 | "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
| 5957 | tname, arg, |
| 5958 | __btf_name_by_offset(btf, t->name_off), |
| 5959 | btf_type_str(t)); |
| 5960 | return false; |
| 5961 | } |
| 5962 | |
| 5963 | /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ |
| 5964 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
| 5965 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; |
| 5966 | u32 type, flag; |
| 5967 | |
| 5968 | type = base_type(ctx_arg_info->reg_type); |
| 5969 | flag = type_flag(ctx_arg_info->reg_type); |
| 5970 | if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
| 5971 | (flag & PTR_MAYBE_NULL)) { |
| 5972 | info->reg_type = ctx_arg_info->reg_type; |
| 5973 | return true; |
| 5974 | } |
| 5975 | } |
| 5976 | |
| 5977 | if (t->type == 0) |
| 5978 | /* This is a pointer to void. |
| 5979 | * It is the same as scalar from the verifier safety pov. |
| 5980 | * No further pointer walking is allowed. |
| 5981 | */ |
| 5982 | return true; |
| 5983 | |
| 5984 | if (is_int_ptr(btf, t)) |
| 5985 | return true; |
| 5986 | |
| 5987 | /* this is a pointer to another type */ |
| 5988 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
| 5989 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; |
| 5990 | |
| 5991 | if (ctx_arg_info->offset == off) { |
| 5992 | if (!ctx_arg_info->btf_id) { |
| 5993 | bpf_log(log,"invalid btf_id for context argument offset %u\n", off); |
| 5994 | return false; |
| 5995 | } |
| 5996 | |
| 5997 | info->reg_type = ctx_arg_info->reg_type; |
| 5998 | info->btf = btf_vmlinux; |
| 5999 | info->btf_id = ctx_arg_info->btf_id; |
| 6000 | return true; |
| 6001 | } |
| 6002 | } |
| 6003 | |
| 6004 | info->reg_type = PTR_TO_BTF_ID; |
| 6005 | if (prog_args_trusted(prog)) |
| 6006 | info->reg_type |= PTR_TRUSTED; |
| 6007 | |
| 6008 | if (tgt_prog) { |
| 6009 | enum bpf_prog_type tgt_type; |
| 6010 | |
| 6011 | if (tgt_prog->type == BPF_PROG_TYPE_EXT) |
| 6012 | tgt_type = tgt_prog->aux->saved_dst_prog_type; |
| 6013 | else |
| 6014 | tgt_type = tgt_prog->type; |
| 6015 | |
| 6016 | ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); |
| 6017 | if (ret > 0) { |
| 6018 | info->btf = btf_vmlinux; |
| 6019 | info->btf_id = ret; |
| 6020 | return true; |
| 6021 | } else { |
| 6022 | return false; |
| 6023 | } |
| 6024 | } |
| 6025 | |
| 6026 | info->btf = btf; |
| 6027 | info->btf_id = t->type; |
| 6028 | t = btf_type_by_id(btf, t->type); |
| 6029 | |
| 6030 | if (btf_type_is_type_tag(t)) { |
| 6031 | tag_value = __btf_name_by_offset(btf, t->name_off); |
| 6032 | if (strcmp(tag_value, "user") == 0) |
| 6033 | info->reg_type |= MEM_USER; |
| 6034 | if (strcmp(tag_value, "percpu") == 0) |
| 6035 | info->reg_type |= MEM_PERCPU; |
| 6036 | } |
| 6037 | |
| 6038 | /* skip modifiers */ |
| 6039 | while (btf_type_is_modifier(t)) { |
| 6040 | info->btf_id = t->type; |
| 6041 | t = btf_type_by_id(btf, t->type); |
| 6042 | } |
| 6043 | if (!btf_type_is_struct(t)) { |
| 6044 | bpf_log(log, |
| 6045 | "func '%s' arg%d type %s is not a struct\n", |
| 6046 | tname, arg, btf_type_str(t)); |
| 6047 | return false; |
| 6048 | } |
| 6049 | bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
| 6050 | tname, arg, info->btf_id, btf_type_str(t), |
| 6051 | __btf_name_by_offset(btf, t->name_off)); |
| 6052 | return true; |
| 6053 | } |
| 6054 | |
| 6055 | enum bpf_struct_walk_result { |
| 6056 | /* < 0 error */ |
| 6057 | WALK_SCALAR = 0, |
| 6058 | WALK_PTR, |
| 6059 | WALK_STRUCT, |
| 6060 | }; |
| 6061 | |
| 6062 | static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
| 6063 | const struct btf_type *t, int off, int size, |
| 6064 | u32 *next_btf_id, enum bpf_type_flag *flag) |
| 6065 | { |
| 6066 | u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
| 6067 | const struct btf_type *mtype, *elem_type = NULL; |
| 6068 | const struct btf_member *member; |
| 6069 | const char *tname, *mname, *tag_value; |
| 6070 | u32 vlen, elem_id, mid; |
| 6071 | |
| 6072 | again: |
| 6073 | tname = __btf_name_by_offset(btf, t->name_off); |
| 6074 | if (!btf_type_is_struct(t)) { |
| 6075 | bpf_log(log, "Type '%s' is not a struct\n", tname); |
| 6076 | return -EINVAL; |
| 6077 | } |
| 6078 | |
| 6079 | vlen = btf_type_vlen(t); |
| 6080 | if (off + size > t->size) { |
| 6081 | /* If the last element is a variable size array, we may |
| 6082 | * need to relax the rule. |
| 6083 | */ |
| 6084 | struct btf_array *array_elem; |
| 6085 | |
| 6086 | if (vlen == 0) |
| 6087 | goto error; |
| 6088 | |
| 6089 | member = btf_type_member(t) + vlen - 1; |
| 6090 | mtype = btf_type_skip_modifiers(btf, member->type, |
| 6091 | NULL); |
| 6092 | if (!btf_type_is_array(mtype)) |
| 6093 | goto error; |
| 6094 | |
| 6095 | array_elem = (struct btf_array *)(mtype + 1); |
| 6096 | if (array_elem->nelems != 0) |
| 6097 | goto error; |
| 6098 | |
| 6099 | moff = __btf_member_bit_offset(t, member) / 8; |
| 6100 | if (off < moff) |
| 6101 | goto error; |
| 6102 | |
| 6103 | /* Only allow structure for now, can be relaxed for |
| 6104 | * other types later. |
| 6105 | */ |
| 6106 | t = btf_type_skip_modifiers(btf, array_elem->type, |
| 6107 | NULL); |
| 6108 | if (!btf_type_is_struct(t)) |
| 6109 | goto error; |
| 6110 | |
| 6111 | off = (off - moff) % t->size; |
| 6112 | goto again; |
| 6113 | |
| 6114 | error: |
| 6115 | bpf_log(log, "access beyond struct %s at off %u size %u\n", |
| 6116 | tname, off, size); |
| 6117 | return -EACCES; |
| 6118 | } |
| 6119 | |
| 6120 | for_each_member(i, t, member) { |
| 6121 | /* offset of the field in bytes */ |
| 6122 | moff = __btf_member_bit_offset(t, member) / 8; |
| 6123 | if (off + size <= moff) |
| 6124 | /* won't find anything, field is already too far */ |
| 6125 | break; |
| 6126 | |
| 6127 | if (__btf_member_bitfield_size(t, member)) { |
| 6128 | u32 end_bit = __btf_member_bit_offset(t, member) + |
| 6129 | __btf_member_bitfield_size(t, member); |
| 6130 | |
| 6131 | /* off <= moff instead of off == moff because clang |
| 6132 | * does not generate a BTF member for anonymous |
| 6133 | * bitfield like the ":16" here: |
| 6134 | * struct { |
| 6135 | * int :16; |
| 6136 | * int x:8; |
| 6137 | * }; |
| 6138 | */ |
| 6139 | if (off <= moff && |
| 6140 | BITS_ROUNDUP_BYTES(end_bit) <= off + size) |
| 6141 | return WALK_SCALAR; |
| 6142 | |
| 6143 | /* off may be accessing a following member |
| 6144 | * |
| 6145 | * or |
| 6146 | * |
| 6147 | * Doing partial access at either end of this |
| 6148 | * bitfield. Continue on this case also to |
| 6149 | * treat it as not accessing this bitfield |
| 6150 | * and eventually error out as field not |
| 6151 | * found to keep it simple. |
| 6152 | * It could be relaxed if there was a legit |
| 6153 | * partial access case later. |
| 6154 | */ |
| 6155 | continue; |
| 6156 | } |
| 6157 | |
| 6158 | /* In case of "off" is pointing to holes of a struct */ |
| 6159 | if (off < moff) |
| 6160 | break; |
| 6161 | |
| 6162 | /* type of the field */ |
| 6163 | mid = member->type; |
| 6164 | mtype = btf_type_by_id(btf, member->type); |
| 6165 | mname = __btf_name_by_offset(btf, member->name_off); |
| 6166 | |
| 6167 | mtype = __btf_resolve_size(btf, mtype, &msize, |
| 6168 | &elem_type, &elem_id, &total_nelems, |
| 6169 | &mid); |
| 6170 | if (IS_ERR(mtype)) { |
| 6171 | bpf_log(log, "field %s doesn't have size\n", mname); |
| 6172 | return -EFAULT; |
| 6173 | } |
| 6174 | |
| 6175 | mtrue_end = moff + msize; |
| 6176 | if (off >= mtrue_end) |
| 6177 | /* no overlap with member, keep iterating */ |
| 6178 | continue; |
| 6179 | |
| 6180 | if (btf_type_is_array(mtype)) { |
| 6181 | u32 elem_idx; |
| 6182 | |
| 6183 | /* __btf_resolve_size() above helps to |
| 6184 | * linearize a multi-dimensional array. |
| 6185 | * |
| 6186 | * The logic here is treating an array |
| 6187 | * in a struct as the following way: |
| 6188 | * |
| 6189 | * struct outer { |
| 6190 | * struct inner array[2][2]; |
| 6191 | * }; |
| 6192 | * |
| 6193 | * looks like: |
| 6194 | * |
| 6195 | * struct outer { |
| 6196 | * struct inner array_elem0; |
| 6197 | * struct inner array_elem1; |
| 6198 | * struct inner array_elem2; |
| 6199 | * struct inner array_elem3; |
| 6200 | * }; |
| 6201 | * |
| 6202 | * When accessing outer->array[1][0], it moves |
| 6203 | * moff to "array_elem2", set mtype to |
| 6204 | * "struct inner", and msize also becomes |
| 6205 | * sizeof(struct inner). Then most of the |
| 6206 | * remaining logic will fall through without |
| 6207 | * caring the current member is an array or |
| 6208 | * not. |
| 6209 | * |
| 6210 | * Unlike mtype/msize/moff, mtrue_end does not |
| 6211 | * change. The naming difference ("_true") tells |
| 6212 | * that it is not always corresponding to |
| 6213 | * the current mtype/msize/moff. |
| 6214 | * It is the true end of the current |
| 6215 | * member (i.e. array in this case). That |
| 6216 | * will allow an int array to be accessed like |
| 6217 | * a scratch space, |
| 6218 | * i.e. allow access beyond the size of |
| 6219 | * the array's element as long as it is |
| 6220 | * within the mtrue_end boundary. |
| 6221 | */ |
| 6222 | |
| 6223 | /* skip empty array */ |
| 6224 | if (moff == mtrue_end) |
| 6225 | continue; |
| 6226 | |
| 6227 | msize /= total_nelems; |
| 6228 | elem_idx = (off - moff) / msize; |
| 6229 | moff += elem_idx * msize; |
| 6230 | mtype = elem_type; |
| 6231 | mid = elem_id; |
| 6232 | } |
| 6233 | |
| 6234 | /* the 'off' we're looking for is either equal to start |
| 6235 | * of this field or inside of this struct |
| 6236 | */ |
| 6237 | if (btf_type_is_struct(mtype)) { |
| 6238 | /* our field must be inside that union or struct */ |
| 6239 | t = mtype; |
| 6240 | |
| 6241 | /* return if the offset matches the member offset */ |
| 6242 | if (off == moff) { |
| 6243 | *next_btf_id = mid; |
| 6244 | return WALK_STRUCT; |
| 6245 | } |
| 6246 | |
| 6247 | /* adjust offset we're looking for */ |
| 6248 | off -= moff; |
| 6249 | goto again; |
| 6250 | } |
| 6251 | |
| 6252 | if (btf_type_is_ptr(mtype)) { |
| 6253 | const struct btf_type *stype, *t; |
| 6254 | enum bpf_type_flag tmp_flag = 0; |
| 6255 | u32 id; |
| 6256 | |
| 6257 | if (msize != size || off != moff) { |
| 6258 | bpf_log(log, |
| 6259 | "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", |
| 6260 | mname, moff, tname, off, size); |
| 6261 | return -EACCES; |
| 6262 | } |
| 6263 | |
| 6264 | /* check type tag */ |
| 6265 | t = btf_type_by_id(btf, mtype->type); |
| 6266 | if (btf_type_is_type_tag(t)) { |
| 6267 | tag_value = __btf_name_by_offset(btf, t->name_off); |
| 6268 | /* check __user tag */ |
| 6269 | if (strcmp(tag_value, "user") == 0) |
| 6270 | tmp_flag = MEM_USER; |
| 6271 | /* check __percpu tag */ |
| 6272 | if (strcmp(tag_value, "percpu") == 0) |
| 6273 | tmp_flag = MEM_PERCPU; |
| 6274 | /* check __rcu tag */ |
| 6275 | if (strcmp(tag_value, "rcu") == 0) |
| 6276 | tmp_flag = MEM_RCU; |
| 6277 | } |
| 6278 | |
| 6279 | stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
| 6280 | if (btf_type_is_struct(stype)) { |
| 6281 | *next_btf_id = id; |
| 6282 | *flag = tmp_flag; |
| 6283 | return WALK_PTR; |
| 6284 | } |
| 6285 | } |
| 6286 | |
| 6287 | /* Allow more flexible access within an int as long as |
| 6288 | * it is within mtrue_end. |
| 6289 | * Since mtrue_end could be the end of an array, |
| 6290 | * that also allows using an array of int as a scratch |
| 6291 | * space. e.g. skb->cb[]. |
| 6292 | */ |
| 6293 | if (off + size > mtrue_end) { |
| 6294 | bpf_log(log, |
| 6295 | "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", |
| 6296 | mname, mtrue_end, tname, off, size); |
| 6297 | return -EACCES; |
| 6298 | } |
| 6299 | |
| 6300 | return WALK_SCALAR; |
| 6301 | } |
| 6302 | bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); |
| 6303 | return -EINVAL; |
| 6304 | } |
| 6305 | |
| 6306 | int btf_struct_access(struct bpf_verifier_log *log, |
| 6307 | const struct bpf_reg_state *reg, |
| 6308 | int off, int size, enum bpf_access_type atype __maybe_unused, |
| 6309 | u32 *next_btf_id, enum bpf_type_flag *flag) |
| 6310 | { |
| 6311 | const struct btf *btf = reg->btf; |
| 6312 | enum bpf_type_flag tmp_flag = 0; |
| 6313 | const struct btf_type *t; |
| 6314 | u32 id = reg->btf_id; |
| 6315 | int err; |
| 6316 | |
| 6317 | while (type_is_alloc(reg->type)) { |
| 6318 | struct btf_struct_meta *meta; |
| 6319 | struct btf_record *rec; |
| 6320 | int i; |
| 6321 | |
| 6322 | meta = btf_find_struct_meta(btf, id); |
| 6323 | if (!meta) |
| 6324 | break; |
| 6325 | rec = meta->record; |
| 6326 | for (i = 0; i < rec->cnt; i++) { |
| 6327 | struct btf_field *field = &rec->fields[i]; |
| 6328 | u32 offset = field->offset; |
| 6329 | if (off < offset + btf_field_type_size(field->type) && offset < off + size) { |
| 6330 | bpf_log(log, |
| 6331 | "direct access to %s is disallowed\n", |
| 6332 | btf_field_type_name(field->type)); |
| 6333 | return -EACCES; |
| 6334 | } |
| 6335 | } |
| 6336 | break; |
| 6337 | } |
| 6338 | |
| 6339 | t = btf_type_by_id(btf, id); |
| 6340 | do { |
| 6341 | err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag); |
| 6342 | |
| 6343 | switch (err) { |
| 6344 | case WALK_PTR: |
| 6345 | /* For local types, the destination register cannot |
| 6346 | * become a pointer again. |
| 6347 | */ |
| 6348 | if (type_is_alloc(reg->type)) |
| 6349 | return SCALAR_VALUE; |
| 6350 | /* If we found the pointer or scalar on t+off, |
| 6351 | * we're done. |
| 6352 | */ |
| 6353 | *next_btf_id = id; |
| 6354 | *flag = tmp_flag; |
| 6355 | return PTR_TO_BTF_ID; |
| 6356 | case WALK_SCALAR: |
| 6357 | return SCALAR_VALUE; |
| 6358 | case WALK_STRUCT: |
| 6359 | /* We found nested struct, so continue the search |
| 6360 | * by diving in it. At this point the offset is |
| 6361 | * aligned with the new type, so set it to 0. |
| 6362 | */ |
| 6363 | t = btf_type_by_id(btf, id); |
| 6364 | off = 0; |
| 6365 | break; |
| 6366 | default: |
| 6367 | /* It's either error or unknown return value.. |
| 6368 | * scream and leave. |
| 6369 | */ |
| 6370 | if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) |
| 6371 | return -EINVAL; |
| 6372 | return err; |
| 6373 | } |
| 6374 | } while (t); |
| 6375 | |
| 6376 | return -EINVAL; |
| 6377 | } |
| 6378 | |
| 6379 | /* Check that two BTF types, each specified as an BTF object + id, are exactly |
| 6380 | * the same. Trivial ID check is not enough due to module BTFs, because we can |
| 6381 | * end up with two different module BTFs, but IDs point to the common type in |
| 6382 | * vmlinux BTF. |
| 6383 | */ |
| 6384 | bool btf_types_are_same(const struct btf *btf1, u32 id1, |
| 6385 | const struct btf *btf2, u32 id2) |
| 6386 | { |
| 6387 | if (id1 != id2) |
| 6388 | return false; |
| 6389 | if (btf1 == btf2) |
| 6390 | return true; |
| 6391 | return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); |
| 6392 | } |
| 6393 | |
| 6394 | bool btf_struct_ids_match(struct bpf_verifier_log *log, |
| 6395 | const struct btf *btf, u32 id, int off, |
| 6396 | const struct btf *need_btf, u32 need_type_id, |
| 6397 | bool strict) |
| 6398 | { |
| 6399 | const struct btf_type *type; |
| 6400 | enum bpf_type_flag flag; |
| 6401 | int err; |
| 6402 | |
| 6403 | /* Are we already done? */ |
| 6404 | if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
| 6405 | return true; |
| 6406 | /* In case of strict type match, we do not walk struct, the top level |
| 6407 | * type match must succeed. When strict is true, off should have already |
| 6408 | * been 0. |
| 6409 | */ |
| 6410 | if (strict) |
| 6411 | return false; |
| 6412 | again: |
| 6413 | type = btf_type_by_id(btf, id); |
| 6414 | if (!type) |
| 6415 | return false; |
| 6416 | err = btf_struct_walk(log, btf, type, off, 1, &id, &flag); |
| 6417 | if (err != WALK_STRUCT) |
| 6418 | return false; |
| 6419 | |
| 6420 | /* We found nested struct object. If it matches |
| 6421 | * the requested ID, we're done. Otherwise let's |
| 6422 | * continue the search with offset 0 in the new |
| 6423 | * type. |
| 6424 | */ |
| 6425 | if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
| 6426 | off = 0; |
| 6427 | goto again; |
| 6428 | } |
| 6429 | |
| 6430 | return true; |
| 6431 | } |
| 6432 | |
| 6433 | static int __get_type_size(struct btf *btf, u32 btf_id, |
| 6434 | const struct btf_type **ret_type) |
| 6435 | { |
| 6436 | const struct btf_type *t; |
| 6437 | |
| 6438 | *ret_type = btf_type_by_id(btf, 0); |
| 6439 | if (!btf_id) |
| 6440 | /* void */ |
| 6441 | return 0; |
| 6442 | t = btf_type_by_id(btf, btf_id); |
| 6443 | while (t && btf_type_is_modifier(t)) |
| 6444 | t = btf_type_by_id(btf, t->type); |
| 6445 | if (!t) |
| 6446 | return -EINVAL; |
| 6447 | *ret_type = t; |
| 6448 | if (btf_type_is_ptr(t)) |
| 6449 | /* kernel size of pointer. Not BPF's size of pointer*/ |
| 6450 | return sizeof(void *); |
| 6451 | if (btf_type_is_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
| 6452 | return t->size; |
| 6453 | return -EINVAL; |
| 6454 | } |
| 6455 | |
| 6456 | int btf_distill_func_proto(struct bpf_verifier_log *log, |
| 6457 | struct btf *btf, |
| 6458 | const struct btf_type *func, |
| 6459 | const char *tname, |
| 6460 | struct btf_func_model *m) |
| 6461 | { |
| 6462 | const struct btf_param *args; |
| 6463 | const struct btf_type *t; |
| 6464 | u32 i, nargs; |
| 6465 | int ret; |
| 6466 | |
| 6467 | if (!func) { |
| 6468 | /* BTF function prototype doesn't match the verifier types. |
| 6469 | * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
| 6470 | */ |
| 6471 | for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { |
| 6472 | m->arg_size[i] = 8; |
| 6473 | m->arg_flags[i] = 0; |
| 6474 | } |
| 6475 | m->ret_size = 8; |
| 6476 | m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
| 6477 | return 0; |
| 6478 | } |
| 6479 | args = (const struct btf_param *)(func + 1); |
| 6480 | nargs = btf_type_vlen(func); |
| 6481 | if (nargs > MAX_BPF_FUNC_ARGS) { |
| 6482 | bpf_log(log, |
| 6483 | "The function %s has %d arguments. Too many.\n", |
| 6484 | tname, nargs); |
| 6485 | return -EINVAL; |
| 6486 | } |
| 6487 | ret = __get_type_size(btf, func->type, &t); |
| 6488 | if (ret < 0 || __btf_type_is_struct(t)) { |
| 6489 | bpf_log(log, |
| 6490 | "The function %s return type %s is unsupported.\n", |
| 6491 | tname, btf_type_str(t)); |
| 6492 | return -EINVAL; |
| 6493 | } |
| 6494 | m->ret_size = ret; |
| 6495 | |
| 6496 | for (i = 0; i < nargs; i++) { |
| 6497 | if (i == nargs - 1 && args[i].type == 0) { |
| 6498 | bpf_log(log, |
| 6499 | "The function %s with variable args is unsupported.\n", |
| 6500 | tname); |
| 6501 | return -EINVAL; |
| 6502 | } |
| 6503 | ret = __get_type_size(btf, args[i].type, &t); |
| 6504 | |
| 6505 | /* No support of struct argument size greater than 16 bytes */ |
| 6506 | if (ret < 0 || ret > 16) { |
| 6507 | bpf_log(log, |
| 6508 | "The function %s arg%d type %s is unsupported.\n", |
| 6509 | tname, i, btf_type_str(t)); |
| 6510 | return -EINVAL; |
| 6511 | } |
| 6512 | if (ret == 0) { |
| 6513 | bpf_log(log, |
| 6514 | "The function %s has malformed void argument.\n", |
| 6515 | tname); |
| 6516 | return -EINVAL; |
| 6517 | } |
| 6518 | m->arg_size[i] = ret; |
| 6519 | m->arg_flags[i] = __btf_type_is_struct(t) ? BTF_FMODEL_STRUCT_ARG : 0; |
| 6520 | } |
| 6521 | m->nr_args = nargs; |
| 6522 | return 0; |
| 6523 | } |
| 6524 | |
| 6525 | /* Compare BTFs of two functions assuming only scalars and pointers to context. |
| 6526 | * t1 points to BTF_KIND_FUNC in btf1 |
| 6527 | * t2 points to BTF_KIND_FUNC in btf2 |
| 6528 | * Returns: |
| 6529 | * EINVAL - function prototype mismatch |
| 6530 | * EFAULT - verifier bug |
| 6531 | * 0 - 99% match. The last 1% is validated by the verifier. |
| 6532 | */ |
| 6533 | static int btf_check_func_type_match(struct bpf_verifier_log *log, |
| 6534 | struct btf *btf1, const struct btf_type *t1, |
| 6535 | struct btf *btf2, const struct btf_type *t2) |
| 6536 | { |
| 6537 | const struct btf_param *args1, *args2; |
| 6538 | const char *fn1, *fn2, *s1, *s2; |
| 6539 | u32 nargs1, nargs2, i; |
| 6540 | |
| 6541 | fn1 = btf_name_by_offset(btf1, t1->name_off); |
| 6542 | fn2 = btf_name_by_offset(btf2, t2->name_off); |
| 6543 | |
| 6544 | if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { |
| 6545 | bpf_log(log, "%s() is not a global function\n", fn1); |
| 6546 | return -EINVAL; |
| 6547 | } |
| 6548 | if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { |
| 6549 | bpf_log(log, "%s() is not a global function\n", fn2); |
| 6550 | return -EINVAL; |
| 6551 | } |
| 6552 | |
| 6553 | t1 = btf_type_by_id(btf1, t1->type); |
| 6554 | if (!t1 || !btf_type_is_func_proto(t1)) |
| 6555 | return -EFAULT; |
| 6556 | t2 = btf_type_by_id(btf2, t2->type); |
| 6557 | if (!t2 || !btf_type_is_func_proto(t2)) |
| 6558 | return -EFAULT; |
| 6559 | |
| 6560 | args1 = (const struct btf_param *)(t1 + 1); |
| 6561 | nargs1 = btf_type_vlen(t1); |
| 6562 | args2 = (const struct btf_param *)(t2 + 1); |
| 6563 | nargs2 = btf_type_vlen(t2); |
| 6564 | |
| 6565 | if (nargs1 != nargs2) { |
| 6566 | bpf_log(log, "%s() has %d args while %s() has %d args\n", |
| 6567 | fn1, nargs1, fn2, nargs2); |
| 6568 | return -EINVAL; |
| 6569 | } |
| 6570 | |
| 6571 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); |
| 6572 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); |
| 6573 | if (t1->info != t2->info) { |
| 6574 | bpf_log(log, |
| 6575 | "Return type %s of %s() doesn't match type %s of %s()\n", |
| 6576 | btf_type_str(t1), fn1, |
| 6577 | btf_type_str(t2), fn2); |
| 6578 | return -EINVAL; |
| 6579 | } |
| 6580 | |
| 6581 | for (i = 0; i < nargs1; i++) { |
| 6582 | t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); |
| 6583 | t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); |
| 6584 | |
| 6585 | if (t1->info != t2->info) { |
| 6586 | bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", |
| 6587 | i, fn1, btf_type_str(t1), |
| 6588 | fn2, btf_type_str(t2)); |
| 6589 | return -EINVAL; |
| 6590 | } |
| 6591 | if (btf_type_has_size(t1) && t1->size != t2->size) { |
| 6592 | bpf_log(log, |
| 6593 | "arg%d in %s() has size %d while %s() has %d\n", |
| 6594 | i, fn1, t1->size, |
| 6595 | fn2, t2->size); |
| 6596 | return -EINVAL; |
| 6597 | } |
| 6598 | |
| 6599 | /* global functions are validated with scalars and pointers |
| 6600 | * to context only. And only global functions can be replaced. |
| 6601 | * Hence type check only those types. |
| 6602 | */ |
| 6603 | if (btf_type_is_int(t1) || btf_is_any_enum(t1)) |
| 6604 | continue; |
| 6605 | if (!btf_type_is_ptr(t1)) { |
| 6606 | bpf_log(log, |
| 6607 | "arg%d in %s() has unrecognized type\n", |
| 6608 | i, fn1); |
| 6609 | return -EINVAL; |
| 6610 | } |
| 6611 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); |
| 6612 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); |
| 6613 | if (!btf_type_is_struct(t1)) { |
| 6614 | bpf_log(log, |
| 6615 | "arg%d in %s() is not a pointer to context\n", |
| 6616 | i, fn1); |
| 6617 | return -EINVAL; |
| 6618 | } |
| 6619 | if (!btf_type_is_struct(t2)) { |
| 6620 | bpf_log(log, |
| 6621 | "arg%d in %s() is not a pointer to context\n", |
| 6622 | i, fn2); |
| 6623 | return -EINVAL; |
| 6624 | } |
| 6625 | /* This is an optional check to make program writing easier. |
| 6626 | * Compare names of structs and report an error to the user. |
| 6627 | * btf_prepare_func_args() already checked that t2 struct |
| 6628 | * is a context type. btf_prepare_func_args() will check |
| 6629 | * later that t1 struct is a context type as well. |
| 6630 | */ |
| 6631 | s1 = btf_name_by_offset(btf1, t1->name_off); |
| 6632 | s2 = btf_name_by_offset(btf2, t2->name_off); |
| 6633 | if (strcmp(s1, s2)) { |
| 6634 | bpf_log(log, |
| 6635 | "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", |
| 6636 | i, fn1, s1, fn2, s2); |
| 6637 | return -EINVAL; |
| 6638 | } |
| 6639 | } |
| 6640 | return 0; |
| 6641 | } |
| 6642 | |
| 6643 | /* Compare BTFs of given program with BTF of target program */ |
| 6644 | int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
| 6645 | struct btf *btf2, const struct btf_type *t2) |
| 6646 | { |
| 6647 | struct btf *btf1 = prog->aux->btf; |
| 6648 | const struct btf_type *t1; |
| 6649 | u32 btf_id = 0; |
| 6650 | |
| 6651 | if (!prog->aux->func_info) { |
| 6652 | bpf_log(log, "Program extension requires BTF\n"); |
| 6653 | return -EINVAL; |
| 6654 | } |
| 6655 | |
| 6656 | btf_id = prog->aux->func_info[0].type_id; |
| 6657 | if (!btf_id) |
| 6658 | return -EFAULT; |
| 6659 | |
| 6660 | t1 = btf_type_by_id(btf1, btf_id); |
| 6661 | if (!t1 || !btf_type_is_func(t1)) |
| 6662 | return -EFAULT; |
| 6663 | |
| 6664 | return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
| 6665 | } |
| 6666 | |
| 6667 | static int btf_check_func_arg_match(struct bpf_verifier_env *env, |
| 6668 | const struct btf *btf, u32 func_id, |
| 6669 | struct bpf_reg_state *regs, |
| 6670 | bool ptr_to_mem_ok, |
| 6671 | bool processing_call) |
| 6672 | { |
| 6673 | enum bpf_prog_type prog_type = resolve_prog_type(env->prog); |
| 6674 | struct bpf_verifier_log *log = &env->log; |
| 6675 | const char *func_name, *ref_tname; |
| 6676 | const struct btf_type *t, *ref_t; |
| 6677 | const struct btf_param *args; |
| 6678 | u32 i, nargs, ref_id; |
| 6679 | int ret; |
| 6680 | |
| 6681 | t = btf_type_by_id(btf, func_id); |
| 6682 | if (!t || !btf_type_is_func(t)) { |
| 6683 | /* These checks were already done by the verifier while loading |
| 6684 | * struct bpf_func_info or in add_kfunc_call(). |
| 6685 | */ |
| 6686 | bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n", |
| 6687 | func_id); |
| 6688 | return -EFAULT; |
| 6689 | } |
| 6690 | func_name = btf_name_by_offset(btf, t->name_off); |
| 6691 | |
| 6692 | t = btf_type_by_id(btf, t->type); |
| 6693 | if (!t || !btf_type_is_func_proto(t)) { |
| 6694 | bpf_log(log, "Invalid BTF of func %s\n", func_name); |
| 6695 | return -EFAULT; |
| 6696 | } |
| 6697 | args = (const struct btf_param *)(t + 1); |
| 6698 | nargs = btf_type_vlen(t); |
| 6699 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
| 6700 | bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs, |
| 6701 | MAX_BPF_FUNC_REG_ARGS); |
| 6702 | return -EINVAL; |
| 6703 | } |
| 6704 | |
| 6705 | /* check that BTF function arguments match actual types that the |
| 6706 | * verifier sees. |
| 6707 | */ |
| 6708 | for (i = 0; i < nargs; i++) { |
| 6709 | enum bpf_arg_type arg_type = ARG_DONTCARE; |
| 6710 | u32 regno = i + 1; |
| 6711 | struct bpf_reg_state *reg = ®s[regno]; |
| 6712 | |
| 6713 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
| 6714 | if (btf_type_is_scalar(t)) { |
| 6715 | if (reg->type == SCALAR_VALUE) |
| 6716 | continue; |
| 6717 | bpf_log(log, "R%d is not a scalar\n", regno); |
| 6718 | return -EINVAL; |
| 6719 | } |
| 6720 | |
| 6721 | if (!btf_type_is_ptr(t)) { |
| 6722 | bpf_log(log, "Unrecognized arg#%d type %s\n", |
| 6723 | i, btf_type_str(t)); |
| 6724 | return -EINVAL; |
| 6725 | } |
| 6726 | |
| 6727 | ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); |
| 6728 | ref_tname = btf_name_by_offset(btf, ref_t->name_off); |
| 6729 | |
| 6730 | ret = check_func_arg_reg_off(env, reg, regno, arg_type); |
| 6731 | if (ret < 0) |
| 6732 | return ret; |
| 6733 | |
| 6734 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { |
| 6735 | /* If function expects ctx type in BTF check that caller |
| 6736 | * is passing PTR_TO_CTX. |
| 6737 | */ |
| 6738 | if (reg->type != PTR_TO_CTX) { |
| 6739 | bpf_log(log, |
| 6740 | "arg#%d expected pointer to ctx, but got %s\n", |
| 6741 | i, btf_type_str(t)); |
| 6742 | return -EINVAL; |
| 6743 | } |
| 6744 | } else if (ptr_to_mem_ok && processing_call) { |
| 6745 | const struct btf_type *resolve_ret; |
| 6746 | u32 type_size; |
| 6747 | |
| 6748 | resolve_ret = btf_resolve_size(btf, ref_t, &type_size); |
| 6749 | if (IS_ERR(resolve_ret)) { |
| 6750 | bpf_log(log, |
| 6751 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
| 6752 | i, btf_type_str(ref_t), ref_tname, |
| 6753 | PTR_ERR(resolve_ret)); |
| 6754 | return -EINVAL; |
| 6755 | } |
| 6756 | |
| 6757 | if (check_mem_reg(env, reg, regno, type_size)) |
| 6758 | return -EINVAL; |
| 6759 | } else { |
| 6760 | bpf_log(log, "reg type unsupported for arg#%d function %s#%d\n", i, |
| 6761 | func_name, func_id); |
| 6762 | return -EINVAL; |
| 6763 | } |
| 6764 | } |
| 6765 | |
| 6766 | return 0; |
| 6767 | } |
| 6768 | |
| 6769 | /* Compare BTF of a function declaration with given bpf_reg_state. |
| 6770 | * Returns: |
| 6771 | * EFAULT - there is a verifier bug. Abort verification. |
| 6772 | * EINVAL - there is a type mismatch or BTF is not available. |
| 6773 | * 0 - BTF matches with what bpf_reg_state expects. |
| 6774 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. |
| 6775 | */ |
| 6776 | int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, |
| 6777 | struct bpf_reg_state *regs) |
| 6778 | { |
| 6779 | struct bpf_prog *prog = env->prog; |
| 6780 | struct btf *btf = prog->aux->btf; |
| 6781 | bool is_global; |
| 6782 | u32 btf_id; |
| 6783 | int err; |
| 6784 | |
| 6785 | if (!prog->aux->func_info) |
| 6786 | return -EINVAL; |
| 6787 | |
| 6788 | btf_id = prog->aux->func_info[subprog].type_id; |
| 6789 | if (!btf_id) |
| 6790 | return -EFAULT; |
| 6791 | |
| 6792 | if (prog->aux->func_info_aux[subprog].unreliable) |
| 6793 | return -EINVAL; |
| 6794 | |
| 6795 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; |
| 6796 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, false); |
| 6797 | |
| 6798 | /* Compiler optimizations can remove arguments from static functions |
| 6799 | * or mismatched type can be passed into a global function. |
| 6800 | * In such cases mark the function as unreliable from BTF point of view. |
| 6801 | */ |
| 6802 | if (err) |
| 6803 | prog->aux->func_info_aux[subprog].unreliable = true; |
| 6804 | return err; |
| 6805 | } |
| 6806 | |
| 6807 | /* Compare BTF of a function call with given bpf_reg_state. |
| 6808 | * Returns: |
| 6809 | * EFAULT - there is a verifier bug. Abort verification. |
| 6810 | * EINVAL - there is a type mismatch or BTF is not available. |
| 6811 | * 0 - BTF matches with what bpf_reg_state expects. |
| 6812 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. |
| 6813 | * |
| 6814 | * NOTE: the code is duplicated from btf_check_subprog_arg_match() |
| 6815 | * because btf_check_func_arg_match() is still doing both. Once that |
| 6816 | * function is split in 2, we can call from here btf_check_subprog_arg_match() |
| 6817 | * first, and then treat the calling part in a new code path. |
| 6818 | */ |
| 6819 | int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, |
| 6820 | struct bpf_reg_state *regs) |
| 6821 | { |
| 6822 | struct bpf_prog *prog = env->prog; |
| 6823 | struct btf *btf = prog->aux->btf; |
| 6824 | bool is_global; |
| 6825 | u32 btf_id; |
| 6826 | int err; |
| 6827 | |
| 6828 | if (!prog->aux->func_info) |
| 6829 | return -EINVAL; |
| 6830 | |
| 6831 | btf_id = prog->aux->func_info[subprog].type_id; |
| 6832 | if (!btf_id) |
| 6833 | return -EFAULT; |
| 6834 | |
| 6835 | if (prog->aux->func_info_aux[subprog].unreliable) |
| 6836 | return -EINVAL; |
| 6837 | |
| 6838 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; |
| 6839 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, true); |
| 6840 | |
| 6841 | /* Compiler optimizations can remove arguments from static functions |
| 6842 | * or mismatched type can be passed into a global function. |
| 6843 | * In such cases mark the function as unreliable from BTF point of view. |
| 6844 | */ |
| 6845 | if (err) |
| 6846 | prog->aux->func_info_aux[subprog].unreliable = true; |
| 6847 | return err; |
| 6848 | } |
| 6849 | |
| 6850 | /* Convert BTF of a function into bpf_reg_state if possible |
| 6851 | * Returns: |
| 6852 | * EFAULT - there is a verifier bug. Abort verification. |
| 6853 | * EINVAL - cannot convert BTF. |
| 6854 | * 0 - Successfully converted BTF into bpf_reg_state |
| 6855 | * (either PTR_TO_CTX or SCALAR_VALUE). |
| 6856 | */ |
| 6857 | int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, |
| 6858 | struct bpf_reg_state *regs) |
| 6859 | { |
| 6860 | struct bpf_verifier_log *log = &env->log; |
| 6861 | struct bpf_prog *prog = env->prog; |
| 6862 | enum bpf_prog_type prog_type = prog->type; |
| 6863 | struct btf *btf = prog->aux->btf; |
| 6864 | const struct btf_param *args; |
| 6865 | const struct btf_type *t, *ref_t; |
| 6866 | u32 i, nargs, btf_id; |
| 6867 | const char *tname; |
| 6868 | |
| 6869 | if (!prog->aux->func_info || |
| 6870 | prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) { |
| 6871 | bpf_log(log, "Verifier bug\n"); |
| 6872 | return -EFAULT; |
| 6873 | } |
| 6874 | |
| 6875 | btf_id = prog->aux->func_info[subprog].type_id; |
| 6876 | if (!btf_id) { |
| 6877 | bpf_log(log, "Global functions need valid BTF\n"); |
| 6878 | return -EFAULT; |
| 6879 | } |
| 6880 | |
| 6881 | t = btf_type_by_id(btf, btf_id); |
| 6882 | if (!t || !btf_type_is_func(t)) { |
| 6883 | /* These checks were already done by the verifier while loading |
| 6884 | * struct bpf_func_info |
| 6885 | */ |
| 6886 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", |
| 6887 | subprog); |
| 6888 | return -EFAULT; |
| 6889 | } |
| 6890 | tname = btf_name_by_offset(btf, t->name_off); |
| 6891 | |
| 6892 | if (log->level & BPF_LOG_LEVEL) |
| 6893 | bpf_log(log, "Validating %s() func#%d...\n", |
| 6894 | tname, subprog); |
| 6895 | |
| 6896 | if (prog->aux->func_info_aux[subprog].unreliable) { |
| 6897 | bpf_log(log, "Verifier bug in function %s()\n", tname); |
| 6898 | return -EFAULT; |
| 6899 | } |
| 6900 | if (prog_type == BPF_PROG_TYPE_EXT) |
| 6901 | prog_type = prog->aux->dst_prog->type; |
| 6902 | |
| 6903 | t = btf_type_by_id(btf, t->type); |
| 6904 | if (!t || !btf_type_is_func_proto(t)) { |
| 6905 | bpf_log(log, "Invalid type of function %s()\n", tname); |
| 6906 | return -EFAULT; |
| 6907 | } |
| 6908 | args = (const struct btf_param *)(t + 1); |
| 6909 | nargs = btf_type_vlen(t); |
| 6910 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
| 6911 | bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", |
| 6912 | tname, nargs, MAX_BPF_FUNC_REG_ARGS); |
| 6913 | return -EINVAL; |
| 6914 | } |
| 6915 | /* check that function returns int */ |
| 6916 | t = btf_type_by_id(btf, t->type); |
| 6917 | while (btf_type_is_modifier(t)) |
| 6918 | t = btf_type_by_id(btf, t->type); |
| 6919 | if (!btf_type_is_int(t) && !btf_is_any_enum(t)) { |
| 6920 | bpf_log(log, |
| 6921 | "Global function %s() doesn't return scalar. Only those are supported.\n", |
| 6922 | tname); |
| 6923 | return -EINVAL; |
| 6924 | } |
| 6925 | /* Convert BTF function arguments into verifier types. |
| 6926 | * Only PTR_TO_CTX and SCALAR are supported atm. |
| 6927 | */ |
| 6928 | for (i = 0; i < nargs; i++) { |
| 6929 | struct bpf_reg_state *reg = ®s[i + 1]; |
| 6930 | |
| 6931 | t = btf_type_by_id(btf, args[i].type); |
| 6932 | while (btf_type_is_modifier(t)) |
| 6933 | t = btf_type_by_id(btf, t->type); |
| 6934 | if (btf_type_is_int(t) || btf_is_any_enum(t)) { |
| 6935 | reg->type = SCALAR_VALUE; |
| 6936 | continue; |
| 6937 | } |
| 6938 | if (btf_type_is_ptr(t)) { |
| 6939 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { |
| 6940 | reg->type = PTR_TO_CTX; |
| 6941 | continue; |
| 6942 | } |
| 6943 | |
| 6944 | t = btf_type_skip_modifiers(btf, t->type, NULL); |
| 6945 | |
| 6946 | ref_t = btf_resolve_size(btf, t, ®->mem_size); |
| 6947 | if (IS_ERR(ref_t)) { |
| 6948 | bpf_log(log, |
| 6949 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
| 6950 | i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), |
| 6951 | PTR_ERR(ref_t)); |
| 6952 | return -EINVAL; |
| 6953 | } |
| 6954 | |
| 6955 | reg->type = PTR_TO_MEM | PTR_MAYBE_NULL; |
| 6956 | reg->id = ++env->id_gen; |
| 6957 | |
| 6958 | continue; |
| 6959 | } |
| 6960 | bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", |
| 6961 | i, btf_type_str(t), tname); |
| 6962 | return -EINVAL; |
| 6963 | } |
| 6964 | return 0; |
| 6965 | } |
| 6966 | |
| 6967 | static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
| 6968 | struct btf_show *show) |
| 6969 | { |
| 6970 | const struct btf_type *t = btf_type_by_id(btf, type_id); |
| 6971 | |
| 6972 | show->btf = btf; |
| 6973 | memset(&show->state, 0, sizeof(show->state)); |
| 6974 | memset(&show->obj, 0, sizeof(show->obj)); |
| 6975 | |
| 6976 | btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); |
| 6977 | } |
| 6978 | |
| 6979 | static void btf_seq_show(struct btf_show *show, const char *fmt, |
| 6980 | va_list args) |
| 6981 | { |
| 6982 | seq_vprintf((struct seq_file *)show->target, fmt, args); |
| 6983 | } |
| 6984 | |
| 6985 | int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
| 6986 | void *obj, struct seq_file *m, u64 flags) |
| 6987 | { |
| 6988 | struct btf_show sseq; |
| 6989 | |
| 6990 | sseq.target = m; |
| 6991 | sseq.showfn = btf_seq_show; |
| 6992 | sseq.flags = flags; |
| 6993 | |
| 6994 | btf_type_show(btf, type_id, obj, &sseq); |
| 6995 | |
| 6996 | return sseq.state.status; |
| 6997 | } |
| 6998 | |
| 6999 | void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
| 7000 | struct seq_file *m) |
| 7001 | { |
| 7002 | (void) btf_type_seq_show_flags(btf, type_id, obj, m, |
| 7003 | BTF_SHOW_NONAME | BTF_SHOW_COMPACT | |
| 7004 | BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); |
| 7005 | } |
| 7006 | |
| 7007 | struct btf_show_snprintf { |
| 7008 | struct btf_show show; |
| 7009 | int len_left; /* space left in string */ |
| 7010 | int len; /* length we would have written */ |
| 7011 | }; |
| 7012 | |
| 7013 | static void btf_snprintf_show(struct btf_show *show, const char *fmt, |
| 7014 | va_list args) |
| 7015 | { |
| 7016 | struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; |
| 7017 | int len; |
| 7018 | |
| 7019 | len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); |
| 7020 | |
| 7021 | if (len < 0) { |
| 7022 | ssnprintf->len_left = 0; |
| 7023 | ssnprintf->len = len; |
| 7024 | } else if (len >= ssnprintf->len_left) { |
| 7025 | /* no space, drive on to get length we would have written */ |
| 7026 | ssnprintf->len_left = 0; |
| 7027 | ssnprintf->len += len; |
| 7028 | } else { |
| 7029 | ssnprintf->len_left -= len; |
| 7030 | ssnprintf->len += len; |
| 7031 | show->target += len; |
| 7032 | } |
| 7033 | } |
| 7034 | |
| 7035 | int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, |
| 7036 | char *buf, int len, u64 flags) |
| 7037 | { |
| 7038 | struct btf_show_snprintf ssnprintf; |
| 7039 | |
| 7040 | ssnprintf.show.target = buf; |
| 7041 | ssnprintf.show.flags = flags; |
| 7042 | ssnprintf.show.showfn = btf_snprintf_show; |
| 7043 | ssnprintf.len_left = len; |
| 7044 | ssnprintf.len = 0; |
| 7045 | |
| 7046 | btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); |
| 7047 | |
| 7048 | /* If we encountered an error, return it. */ |
| 7049 | if (ssnprintf.show.state.status) |
| 7050 | return ssnprintf.show.state.status; |
| 7051 | |
| 7052 | /* Otherwise return length we would have written */ |
| 7053 | return ssnprintf.len; |
| 7054 | } |
| 7055 | |
| 7056 | #ifdef CONFIG_PROC_FS |
| 7057 | static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) |
| 7058 | { |
| 7059 | const struct btf *btf = filp->private_data; |
| 7060 | |
| 7061 | seq_printf(m, "btf_id:\t%u\n", btf->id); |
| 7062 | } |
| 7063 | #endif |
| 7064 | |
| 7065 | static int btf_release(struct inode *inode, struct file *filp) |
| 7066 | { |
| 7067 | btf_put(filp->private_data); |
| 7068 | return 0; |
| 7069 | } |
| 7070 | |
| 7071 | const struct file_operations btf_fops = { |
| 7072 | #ifdef CONFIG_PROC_FS |
| 7073 | .show_fdinfo = bpf_btf_show_fdinfo, |
| 7074 | #endif |
| 7075 | .release = btf_release, |
| 7076 | }; |
| 7077 | |
| 7078 | static int __btf_new_fd(struct btf *btf) |
| 7079 | { |
| 7080 | return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); |
| 7081 | } |
| 7082 | |
| 7083 | int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr) |
| 7084 | { |
| 7085 | struct btf *btf; |
| 7086 | int ret; |
| 7087 | |
| 7088 | btf = btf_parse(make_bpfptr(attr->btf, uattr.is_kernel), |
| 7089 | attr->btf_size, attr->btf_log_level, |
| 7090 | u64_to_user_ptr(attr->btf_log_buf), |
| 7091 | attr->btf_log_size); |
| 7092 | if (IS_ERR(btf)) |
| 7093 | return PTR_ERR(btf); |
| 7094 | |
| 7095 | ret = btf_alloc_id(btf); |
| 7096 | if (ret) { |
| 7097 | btf_free(btf); |
| 7098 | return ret; |
| 7099 | } |
| 7100 | |
| 7101 | /* |
| 7102 | * The BTF ID is published to the userspace. |
| 7103 | * All BTF free must go through call_rcu() from |
| 7104 | * now on (i.e. free by calling btf_put()). |
| 7105 | */ |
| 7106 | |
| 7107 | ret = __btf_new_fd(btf); |
| 7108 | if (ret < 0) |
| 7109 | btf_put(btf); |
| 7110 | |
| 7111 | return ret; |
| 7112 | } |
| 7113 | |
| 7114 | struct btf *btf_get_by_fd(int fd) |
| 7115 | { |
| 7116 | struct btf *btf; |
| 7117 | struct fd f; |
| 7118 | |
| 7119 | f = fdget(fd); |
| 7120 | |
| 7121 | if (!f.file) |
| 7122 | return ERR_PTR(-EBADF); |
| 7123 | |
| 7124 | if (f.file->f_op != &btf_fops) { |
| 7125 | fdput(f); |
| 7126 | return ERR_PTR(-EINVAL); |
| 7127 | } |
| 7128 | |
| 7129 | btf = f.file->private_data; |
| 7130 | refcount_inc(&btf->refcnt); |
| 7131 | fdput(f); |
| 7132 | |
| 7133 | return btf; |
| 7134 | } |
| 7135 | |
| 7136 | int btf_get_info_by_fd(const struct btf *btf, |
| 7137 | const union bpf_attr *attr, |
| 7138 | union bpf_attr __user *uattr) |
| 7139 | { |
| 7140 | struct bpf_btf_info __user *uinfo; |
| 7141 | struct bpf_btf_info info; |
| 7142 | u32 info_copy, btf_copy; |
| 7143 | void __user *ubtf; |
| 7144 | char __user *uname; |
| 7145 | u32 uinfo_len, uname_len, name_len; |
| 7146 | int ret = 0; |
| 7147 | |
| 7148 | uinfo = u64_to_user_ptr(attr->info.info); |
| 7149 | uinfo_len = attr->info.info_len; |
| 7150 | |
| 7151 | info_copy = min_t(u32, uinfo_len, sizeof(info)); |
| 7152 | memset(&info, 0, sizeof(info)); |
| 7153 | if (copy_from_user(&info, uinfo, info_copy)) |
| 7154 | return -EFAULT; |
| 7155 | |
| 7156 | info.id = btf->id; |
| 7157 | ubtf = u64_to_user_ptr(info.btf); |
| 7158 | btf_copy = min_t(u32, btf->data_size, info.btf_size); |
| 7159 | if (copy_to_user(ubtf, btf->data, btf_copy)) |
| 7160 | return -EFAULT; |
| 7161 | info.btf_size = btf->data_size; |
| 7162 | |
| 7163 | info.kernel_btf = btf->kernel_btf; |
| 7164 | |
| 7165 | uname = u64_to_user_ptr(info.name); |
| 7166 | uname_len = info.name_len; |
| 7167 | if (!uname ^ !uname_len) |
| 7168 | return -EINVAL; |
| 7169 | |
| 7170 | name_len = strlen(btf->name); |
| 7171 | info.name_len = name_len; |
| 7172 | |
| 7173 | if (uname) { |
| 7174 | if (uname_len >= name_len + 1) { |
| 7175 | if (copy_to_user(uname, btf->name, name_len + 1)) |
| 7176 | return -EFAULT; |
| 7177 | } else { |
| 7178 | char zero = '\0'; |
| 7179 | |
| 7180 | if (copy_to_user(uname, btf->name, uname_len - 1)) |
| 7181 | return -EFAULT; |
| 7182 | if (put_user(zero, uname + uname_len - 1)) |
| 7183 | return -EFAULT; |
| 7184 | /* let user-space know about too short buffer */ |
| 7185 | ret = -ENOSPC; |
| 7186 | } |
| 7187 | } |
| 7188 | |
| 7189 | if (copy_to_user(uinfo, &info, info_copy) || |
| 7190 | put_user(info_copy, &uattr->info.info_len)) |
| 7191 | return -EFAULT; |
| 7192 | |
| 7193 | return ret; |
| 7194 | } |
| 7195 | |
| 7196 | int btf_get_fd_by_id(u32 id) |
| 7197 | { |
| 7198 | struct btf *btf; |
| 7199 | int fd; |
| 7200 | |
| 7201 | rcu_read_lock(); |
| 7202 | btf = idr_find(&btf_idr, id); |
| 7203 | if (!btf || !refcount_inc_not_zero(&btf->refcnt)) |
| 7204 | btf = ERR_PTR(-ENOENT); |
| 7205 | rcu_read_unlock(); |
| 7206 | |
| 7207 | if (IS_ERR(btf)) |
| 7208 | return PTR_ERR(btf); |
| 7209 | |
| 7210 | fd = __btf_new_fd(btf); |
| 7211 | if (fd < 0) |
| 7212 | btf_put(btf); |
| 7213 | |
| 7214 | return fd; |
| 7215 | } |
| 7216 | |
| 7217 | u32 btf_obj_id(const struct btf *btf) |
| 7218 | { |
| 7219 | return btf->id; |
| 7220 | } |
| 7221 | |
| 7222 | bool btf_is_kernel(const struct btf *btf) |
| 7223 | { |
| 7224 | return btf->kernel_btf; |
| 7225 | } |
| 7226 | |
| 7227 | bool btf_is_module(const struct btf *btf) |
| 7228 | { |
| 7229 | return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; |
| 7230 | } |
| 7231 | |
| 7232 | enum { |
| 7233 | BTF_MODULE_F_LIVE = (1 << 0), |
| 7234 | }; |
| 7235 | |
| 7236 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| 7237 | struct btf_module { |
| 7238 | struct list_head list; |
| 7239 | struct module *module; |
| 7240 | struct btf *btf; |
| 7241 | struct bin_attribute *sysfs_attr; |
| 7242 | int flags; |
| 7243 | }; |
| 7244 | |
| 7245 | static LIST_HEAD(btf_modules); |
| 7246 | static DEFINE_MUTEX(btf_module_mutex); |
| 7247 | |
| 7248 | static ssize_t |
| 7249 | btf_module_read(struct file *file, struct kobject *kobj, |
| 7250 | struct bin_attribute *bin_attr, |
| 7251 | char *buf, loff_t off, size_t len) |
| 7252 | { |
| 7253 | const struct btf *btf = bin_attr->private; |
| 7254 | |
| 7255 | memcpy(buf, btf->data + off, len); |
| 7256 | return len; |
| 7257 | } |
| 7258 | |
| 7259 | static void purge_cand_cache(struct btf *btf); |
| 7260 | |
| 7261 | static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
| 7262 | void *module) |
| 7263 | { |
| 7264 | struct btf_module *btf_mod, *tmp; |
| 7265 | struct module *mod = module; |
| 7266 | struct btf *btf; |
| 7267 | int err = 0; |
| 7268 | |
| 7269 | if (mod->btf_data_size == 0 || |
| 7270 | (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
| 7271 | op != MODULE_STATE_GOING)) |
| 7272 | goto out; |
| 7273 | |
| 7274 | switch (op) { |
| 7275 | case MODULE_STATE_COMING: |
| 7276 | btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); |
| 7277 | if (!btf_mod) { |
| 7278 | err = -ENOMEM; |
| 7279 | goto out; |
| 7280 | } |
| 7281 | btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size); |
| 7282 | if (IS_ERR(btf)) { |
| 7283 | kfree(btf_mod); |
| 7284 | if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) { |
| 7285 | pr_warn("failed to validate module [%s] BTF: %ld\n", |
| 7286 | mod->name, PTR_ERR(btf)); |
| 7287 | err = PTR_ERR(btf); |
| 7288 | } else { |
| 7289 | pr_warn_once("Kernel module BTF mismatch detected, BTF debug info may be unavailable for some modules\n"); |
| 7290 | } |
| 7291 | goto out; |
| 7292 | } |
| 7293 | err = btf_alloc_id(btf); |
| 7294 | if (err) { |
| 7295 | btf_free(btf); |
| 7296 | kfree(btf_mod); |
| 7297 | goto out; |
| 7298 | } |
| 7299 | |
| 7300 | purge_cand_cache(NULL); |
| 7301 | mutex_lock(&btf_module_mutex); |
| 7302 | btf_mod->module = module; |
| 7303 | btf_mod->btf = btf; |
| 7304 | list_add(&btf_mod->list, &btf_modules); |
| 7305 | mutex_unlock(&btf_module_mutex); |
| 7306 | |
| 7307 | if (IS_ENABLED(CONFIG_SYSFS)) { |
| 7308 | struct bin_attribute *attr; |
| 7309 | |
| 7310 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); |
| 7311 | if (!attr) |
| 7312 | goto out; |
| 7313 | |
| 7314 | sysfs_bin_attr_init(attr); |
| 7315 | attr->attr.name = btf->name; |
| 7316 | attr->attr.mode = 0444; |
| 7317 | attr->size = btf->data_size; |
| 7318 | attr->private = btf; |
| 7319 | attr->read = btf_module_read; |
| 7320 | |
| 7321 | err = sysfs_create_bin_file(btf_kobj, attr); |
| 7322 | if (err) { |
| 7323 | pr_warn("failed to register module [%s] BTF in sysfs: %d\n", |
| 7324 | mod->name, err); |
| 7325 | kfree(attr); |
| 7326 | err = 0; |
| 7327 | goto out; |
| 7328 | } |
| 7329 | |
| 7330 | btf_mod->sysfs_attr = attr; |
| 7331 | } |
| 7332 | |
| 7333 | break; |
| 7334 | case MODULE_STATE_LIVE: |
| 7335 | mutex_lock(&btf_module_mutex); |
| 7336 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
| 7337 | if (btf_mod->module != module) |
| 7338 | continue; |
| 7339 | |
| 7340 | btf_mod->flags |= BTF_MODULE_F_LIVE; |
| 7341 | break; |
| 7342 | } |
| 7343 | mutex_unlock(&btf_module_mutex); |
| 7344 | break; |
| 7345 | case MODULE_STATE_GOING: |
| 7346 | mutex_lock(&btf_module_mutex); |
| 7347 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
| 7348 | if (btf_mod->module != module) |
| 7349 | continue; |
| 7350 | |
| 7351 | list_del(&btf_mod->list); |
| 7352 | if (btf_mod->sysfs_attr) |
| 7353 | sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); |
| 7354 | purge_cand_cache(btf_mod->btf); |
| 7355 | btf_put(btf_mod->btf); |
| 7356 | kfree(btf_mod->sysfs_attr); |
| 7357 | kfree(btf_mod); |
| 7358 | break; |
| 7359 | } |
| 7360 | mutex_unlock(&btf_module_mutex); |
| 7361 | break; |
| 7362 | } |
| 7363 | out: |
| 7364 | return notifier_from_errno(err); |
| 7365 | } |
| 7366 | |
| 7367 | static struct notifier_block btf_module_nb = { |
| 7368 | .notifier_call = btf_module_notify, |
| 7369 | }; |
| 7370 | |
| 7371 | static int __init btf_module_init(void) |
| 7372 | { |
| 7373 | register_module_notifier(&btf_module_nb); |
| 7374 | return 0; |
| 7375 | } |
| 7376 | |
| 7377 | fs_initcall(btf_module_init); |
| 7378 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
| 7379 | |
| 7380 | struct module *btf_try_get_module(const struct btf *btf) |
| 7381 | { |
| 7382 | struct module *res = NULL; |
| 7383 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| 7384 | struct btf_module *btf_mod, *tmp; |
| 7385 | |
| 7386 | mutex_lock(&btf_module_mutex); |
| 7387 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
| 7388 | if (btf_mod->btf != btf) |
| 7389 | continue; |
| 7390 | |
| 7391 | /* We must only consider module whose __init routine has |
| 7392 | * finished, hence we must check for BTF_MODULE_F_LIVE flag, |
| 7393 | * which is set from the notifier callback for |
| 7394 | * MODULE_STATE_LIVE. |
| 7395 | */ |
| 7396 | if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) |
| 7397 | res = btf_mod->module; |
| 7398 | |
| 7399 | break; |
| 7400 | } |
| 7401 | mutex_unlock(&btf_module_mutex); |
| 7402 | #endif |
| 7403 | |
| 7404 | return res; |
| 7405 | } |
| 7406 | |
| 7407 | /* Returns struct btf corresponding to the struct module. |
| 7408 | * This function can return NULL or ERR_PTR. |
| 7409 | */ |
| 7410 | static struct btf *btf_get_module_btf(const struct module *module) |
| 7411 | { |
| 7412 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| 7413 | struct btf_module *btf_mod, *tmp; |
| 7414 | #endif |
| 7415 | struct btf *btf = NULL; |
| 7416 | |
| 7417 | if (!module) { |
| 7418 | btf = bpf_get_btf_vmlinux(); |
| 7419 | if (!IS_ERR_OR_NULL(btf)) |
| 7420 | btf_get(btf); |
| 7421 | return btf; |
| 7422 | } |
| 7423 | |
| 7424 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| 7425 | mutex_lock(&btf_module_mutex); |
| 7426 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
| 7427 | if (btf_mod->module != module) |
| 7428 | continue; |
| 7429 | |
| 7430 | btf_get(btf_mod->btf); |
| 7431 | btf = btf_mod->btf; |
| 7432 | break; |
| 7433 | } |
| 7434 | mutex_unlock(&btf_module_mutex); |
| 7435 | #endif |
| 7436 | |
| 7437 | return btf; |
| 7438 | } |
| 7439 | |
| 7440 | BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
| 7441 | { |
| 7442 | struct btf *btf = NULL; |
| 7443 | int btf_obj_fd = 0; |
| 7444 | long ret; |
| 7445 | |
| 7446 | if (flags) |
| 7447 | return -EINVAL; |
| 7448 | |
| 7449 | if (name_sz <= 1 || name[name_sz - 1]) |
| 7450 | return -EINVAL; |
| 7451 | |
| 7452 | ret = bpf_find_btf_id(name, kind, &btf); |
| 7453 | if (ret > 0 && btf_is_module(btf)) { |
| 7454 | btf_obj_fd = __btf_new_fd(btf); |
| 7455 | if (btf_obj_fd < 0) { |
| 7456 | btf_put(btf); |
| 7457 | return btf_obj_fd; |
| 7458 | } |
| 7459 | return ret | (((u64)btf_obj_fd) << 32); |
| 7460 | } |
| 7461 | if (ret > 0) |
| 7462 | btf_put(btf); |
| 7463 | return ret; |
| 7464 | } |
| 7465 | |
| 7466 | const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { |
| 7467 | .func = bpf_btf_find_by_name_kind, |
| 7468 | .gpl_only = false, |
| 7469 | .ret_type = RET_INTEGER, |
| 7470 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 7471 | .arg2_type = ARG_CONST_SIZE, |
| 7472 | .arg3_type = ARG_ANYTHING, |
| 7473 | .arg4_type = ARG_ANYTHING, |
| 7474 | }; |
| 7475 | |
| 7476 | BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
| 7477 | #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) |
| 7478 | BTF_TRACING_TYPE_xxx |
| 7479 | #undef BTF_TRACING_TYPE |
| 7480 | |
| 7481 | /* Kernel Function (kfunc) BTF ID set registration API */ |
| 7482 | |
| 7483 | static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
| 7484 | struct btf_id_set8 *add_set) |
| 7485 | { |
| 7486 | bool vmlinux_set = !btf_is_module(btf); |
| 7487 | struct btf_kfunc_set_tab *tab; |
| 7488 | struct btf_id_set8 *set; |
| 7489 | u32 set_cnt; |
| 7490 | int ret; |
| 7491 | |
| 7492 | if (hook >= BTF_KFUNC_HOOK_MAX) { |
| 7493 | ret = -EINVAL; |
| 7494 | goto end; |
| 7495 | } |
| 7496 | |
| 7497 | if (!add_set->cnt) |
| 7498 | return 0; |
| 7499 | |
| 7500 | tab = btf->kfunc_set_tab; |
| 7501 | if (!tab) { |
| 7502 | tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); |
| 7503 | if (!tab) |
| 7504 | return -ENOMEM; |
| 7505 | btf->kfunc_set_tab = tab; |
| 7506 | } |
| 7507 | |
| 7508 | set = tab->sets[hook]; |
| 7509 | /* Warn when register_btf_kfunc_id_set is called twice for the same hook |
| 7510 | * for module sets. |
| 7511 | */ |
| 7512 | if (WARN_ON_ONCE(set && !vmlinux_set)) { |
| 7513 | ret = -EINVAL; |
| 7514 | goto end; |
| 7515 | } |
| 7516 | |
| 7517 | /* We don't need to allocate, concatenate, and sort module sets, because |
| 7518 | * only one is allowed per hook. Hence, we can directly assign the |
| 7519 | * pointer and return. |
| 7520 | */ |
| 7521 | if (!vmlinux_set) { |
| 7522 | tab->sets[hook] = add_set; |
| 7523 | return 0; |
| 7524 | } |
| 7525 | |
| 7526 | /* In case of vmlinux sets, there may be more than one set being |
| 7527 | * registered per hook. To create a unified set, we allocate a new set |
| 7528 | * and concatenate all individual sets being registered. While each set |
| 7529 | * is individually sorted, they may become unsorted when concatenated, |
| 7530 | * hence re-sorting the final set again is required to make binary |
| 7531 | * searching the set using btf_id_set8_contains function work. |
| 7532 | */ |
| 7533 | set_cnt = set ? set->cnt : 0; |
| 7534 | |
| 7535 | if (set_cnt > U32_MAX - add_set->cnt) { |
| 7536 | ret = -EOVERFLOW; |
| 7537 | goto end; |
| 7538 | } |
| 7539 | |
| 7540 | if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { |
| 7541 | ret = -E2BIG; |
| 7542 | goto end; |
| 7543 | } |
| 7544 | |
| 7545 | /* Grow set */ |
| 7546 | set = krealloc(tab->sets[hook], |
| 7547 | offsetof(struct btf_id_set8, pairs[set_cnt + add_set->cnt]), |
| 7548 | GFP_KERNEL | __GFP_NOWARN); |
| 7549 | if (!set) { |
| 7550 | ret = -ENOMEM; |
| 7551 | goto end; |
| 7552 | } |
| 7553 | |
| 7554 | /* For newly allocated set, initialize set->cnt to 0 */ |
| 7555 | if (!tab->sets[hook]) |
| 7556 | set->cnt = 0; |
| 7557 | tab->sets[hook] = set; |
| 7558 | |
| 7559 | /* Concatenate the two sets */ |
| 7560 | memcpy(set->pairs + set->cnt, add_set->pairs, add_set->cnt * sizeof(set->pairs[0])); |
| 7561 | set->cnt += add_set->cnt; |
| 7562 | |
| 7563 | sort(set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func, NULL); |
| 7564 | |
| 7565 | return 0; |
| 7566 | end: |
| 7567 | btf_free_kfunc_set_tab(btf); |
| 7568 | return ret; |
| 7569 | } |
| 7570 | |
| 7571 | static u32 *__btf_kfunc_id_set_contains(const struct btf *btf, |
| 7572 | enum btf_kfunc_hook hook, |
| 7573 | u32 kfunc_btf_id) |
| 7574 | { |
| 7575 | struct btf_id_set8 *set; |
| 7576 | u32 *id; |
| 7577 | |
| 7578 | if (hook >= BTF_KFUNC_HOOK_MAX) |
| 7579 | return NULL; |
| 7580 | if (!btf->kfunc_set_tab) |
| 7581 | return NULL; |
| 7582 | set = btf->kfunc_set_tab->sets[hook]; |
| 7583 | if (!set) |
| 7584 | return NULL; |
| 7585 | id = btf_id_set8_contains(set, kfunc_btf_id); |
| 7586 | if (!id) |
| 7587 | return NULL; |
| 7588 | /* The flags for BTF ID are located next to it */ |
| 7589 | return id + 1; |
| 7590 | } |
| 7591 | |
| 7592 | static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) |
| 7593 | { |
| 7594 | switch (prog_type) { |
| 7595 | case BPF_PROG_TYPE_UNSPEC: |
| 7596 | return BTF_KFUNC_HOOK_COMMON; |
| 7597 | case BPF_PROG_TYPE_XDP: |
| 7598 | return BTF_KFUNC_HOOK_XDP; |
| 7599 | case BPF_PROG_TYPE_SCHED_CLS: |
| 7600 | return BTF_KFUNC_HOOK_TC; |
| 7601 | case BPF_PROG_TYPE_STRUCT_OPS: |
| 7602 | return BTF_KFUNC_HOOK_STRUCT_OPS; |
| 7603 | case BPF_PROG_TYPE_TRACING: |
| 7604 | case BPF_PROG_TYPE_LSM: |
| 7605 | return BTF_KFUNC_HOOK_TRACING; |
| 7606 | case BPF_PROG_TYPE_SYSCALL: |
| 7607 | return BTF_KFUNC_HOOK_SYSCALL; |
| 7608 | default: |
| 7609 | return BTF_KFUNC_HOOK_MAX; |
| 7610 | } |
| 7611 | } |
| 7612 | |
| 7613 | /* Caution: |
| 7614 | * Reference to the module (obtained using btf_try_get_module) corresponding to |
| 7615 | * the struct btf *MUST* be held when calling this function from verifier |
| 7616 | * context. This is usually true as we stash references in prog's kfunc_btf_tab; |
| 7617 | * keeping the reference for the duration of the call provides the necessary |
| 7618 | * protection for looking up a well-formed btf->kfunc_set_tab. |
| 7619 | */ |
| 7620 | u32 *btf_kfunc_id_set_contains(const struct btf *btf, |
| 7621 | enum bpf_prog_type prog_type, |
| 7622 | u32 kfunc_btf_id) |
| 7623 | { |
| 7624 | enum btf_kfunc_hook hook; |
| 7625 | u32 *kfunc_flags; |
| 7626 | |
| 7627 | kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id); |
| 7628 | if (kfunc_flags) |
| 7629 | return kfunc_flags; |
| 7630 | |
| 7631 | hook = bpf_prog_type_to_kfunc_hook(prog_type); |
| 7632 | return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id); |
| 7633 | } |
| 7634 | |
| 7635 | u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id) |
| 7636 | { |
| 7637 | return __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id); |
| 7638 | } |
| 7639 | |
| 7640 | static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook, |
| 7641 | const struct btf_kfunc_id_set *kset) |
| 7642 | { |
| 7643 | struct btf *btf; |
| 7644 | int ret; |
| 7645 | |
| 7646 | btf = btf_get_module_btf(kset->owner); |
| 7647 | if (!btf) { |
| 7648 | if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { |
| 7649 | pr_err("missing vmlinux BTF, cannot register kfuncs\n"); |
| 7650 | return -ENOENT; |
| 7651 | } |
| 7652 | if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { |
| 7653 | pr_err("missing module BTF, cannot register kfuncs\n"); |
| 7654 | return -ENOENT; |
| 7655 | } |
| 7656 | return 0; |
| 7657 | } |
| 7658 | if (IS_ERR(btf)) |
| 7659 | return PTR_ERR(btf); |
| 7660 | |
| 7661 | ret = btf_populate_kfunc_set(btf, hook, kset->set); |
| 7662 | btf_put(btf); |
| 7663 | return ret; |
| 7664 | } |
| 7665 | |
| 7666 | /* This function must be invoked only from initcalls/module init functions */ |
| 7667 | int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, |
| 7668 | const struct btf_kfunc_id_set *kset) |
| 7669 | { |
| 7670 | enum btf_kfunc_hook hook; |
| 7671 | |
| 7672 | hook = bpf_prog_type_to_kfunc_hook(prog_type); |
| 7673 | return __register_btf_kfunc_id_set(hook, kset); |
| 7674 | } |
| 7675 | EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); |
| 7676 | |
| 7677 | /* This function must be invoked only from initcalls/module init functions */ |
| 7678 | int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset) |
| 7679 | { |
| 7680 | return __register_btf_kfunc_id_set(BTF_KFUNC_HOOK_FMODRET, kset); |
| 7681 | } |
| 7682 | EXPORT_SYMBOL_GPL(register_btf_fmodret_id_set); |
| 7683 | |
| 7684 | s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id) |
| 7685 | { |
| 7686 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; |
| 7687 | struct btf_id_dtor_kfunc *dtor; |
| 7688 | |
| 7689 | if (!tab) |
| 7690 | return -ENOENT; |
| 7691 | /* Even though the size of tab->dtors[0] is > sizeof(u32), we only need |
| 7692 | * to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func. |
| 7693 | */ |
| 7694 | BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0); |
| 7695 | dtor = bsearch(&btf_id, tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func); |
| 7696 | if (!dtor) |
| 7697 | return -ENOENT; |
| 7698 | return dtor->kfunc_btf_id; |
| 7699 | } |
| 7700 | |
| 7701 | static int btf_check_dtor_kfuncs(struct btf *btf, const struct btf_id_dtor_kfunc *dtors, u32 cnt) |
| 7702 | { |
| 7703 | const struct btf_type *dtor_func, *dtor_func_proto, *t; |
| 7704 | const struct btf_param *args; |
| 7705 | s32 dtor_btf_id; |
| 7706 | u32 nr_args, i; |
| 7707 | |
| 7708 | for (i = 0; i < cnt; i++) { |
| 7709 | dtor_btf_id = dtors[i].kfunc_btf_id; |
| 7710 | |
| 7711 | dtor_func = btf_type_by_id(btf, dtor_btf_id); |
| 7712 | if (!dtor_func || !btf_type_is_func(dtor_func)) |
| 7713 | return -EINVAL; |
| 7714 | |
| 7715 | dtor_func_proto = btf_type_by_id(btf, dtor_func->type); |
| 7716 | if (!dtor_func_proto || !btf_type_is_func_proto(dtor_func_proto)) |
| 7717 | return -EINVAL; |
| 7718 | |
| 7719 | /* Make sure the prototype of the destructor kfunc is 'void func(type *)' */ |
| 7720 | t = btf_type_by_id(btf, dtor_func_proto->type); |
| 7721 | if (!t || !btf_type_is_void(t)) |
| 7722 | return -EINVAL; |
| 7723 | |
| 7724 | nr_args = btf_type_vlen(dtor_func_proto); |
| 7725 | if (nr_args != 1) |
| 7726 | return -EINVAL; |
| 7727 | args = btf_params(dtor_func_proto); |
| 7728 | t = btf_type_by_id(btf, args[0].type); |
| 7729 | /* Allow any pointer type, as width on targets Linux supports |
| 7730 | * will be same for all pointer types (i.e. sizeof(void *)) |
| 7731 | */ |
| 7732 | if (!t || !btf_type_is_ptr(t)) |
| 7733 | return -EINVAL; |
| 7734 | } |
| 7735 | return 0; |
| 7736 | } |
| 7737 | |
| 7738 | /* This function must be invoked only from initcalls/module init functions */ |
| 7739 | int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, |
| 7740 | struct module *owner) |
| 7741 | { |
| 7742 | struct btf_id_dtor_kfunc_tab *tab; |
| 7743 | struct btf *btf; |
| 7744 | u32 tab_cnt; |
| 7745 | int ret; |
| 7746 | |
| 7747 | btf = btf_get_module_btf(owner); |
| 7748 | if (!btf) { |
| 7749 | if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { |
| 7750 | pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n"); |
| 7751 | return -ENOENT; |
| 7752 | } |
| 7753 | if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { |
| 7754 | pr_err("missing module BTF, cannot register dtor kfuncs\n"); |
| 7755 | return -ENOENT; |
| 7756 | } |
| 7757 | return 0; |
| 7758 | } |
| 7759 | if (IS_ERR(btf)) |
| 7760 | return PTR_ERR(btf); |
| 7761 | |
| 7762 | if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { |
| 7763 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); |
| 7764 | ret = -E2BIG; |
| 7765 | goto end; |
| 7766 | } |
| 7767 | |
| 7768 | /* Ensure that the prototype of dtor kfuncs being registered is sane */ |
| 7769 | ret = btf_check_dtor_kfuncs(btf, dtors, add_cnt); |
| 7770 | if (ret < 0) |
| 7771 | goto end; |
| 7772 | |
| 7773 | tab = btf->dtor_kfunc_tab; |
| 7774 | /* Only one call allowed for modules */ |
| 7775 | if (WARN_ON_ONCE(tab && btf_is_module(btf))) { |
| 7776 | ret = -EINVAL; |
| 7777 | goto end; |
| 7778 | } |
| 7779 | |
| 7780 | tab_cnt = tab ? tab->cnt : 0; |
| 7781 | if (tab_cnt > U32_MAX - add_cnt) { |
| 7782 | ret = -EOVERFLOW; |
| 7783 | goto end; |
| 7784 | } |
| 7785 | if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { |
| 7786 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); |
| 7787 | ret = -E2BIG; |
| 7788 | goto end; |
| 7789 | } |
| 7790 | |
| 7791 | tab = krealloc(btf->dtor_kfunc_tab, |
| 7792 | offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]), |
| 7793 | GFP_KERNEL | __GFP_NOWARN); |
| 7794 | if (!tab) { |
| 7795 | ret = -ENOMEM; |
| 7796 | goto end; |
| 7797 | } |
| 7798 | |
| 7799 | if (!btf->dtor_kfunc_tab) |
| 7800 | tab->cnt = 0; |
| 7801 | btf->dtor_kfunc_tab = tab; |
| 7802 | |
| 7803 | memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0])); |
| 7804 | tab->cnt += add_cnt; |
| 7805 | |
| 7806 | sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL); |
| 7807 | |
| 7808 | return 0; |
| 7809 | end: |
| 7810 | btf_free_dtor_kfunc_tab(btf); |
| 7811 | btf_put(btf); |
| 7812 | return ret; |
| 7813 | } |
| 7814 | EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs); |
| 7815 | |
| 7816 | #define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
| 7817 | |
| 7818 | /* Check local and target types for compatibility. This check is used for |
| 7819 | * type-based CO-RE relocations and follow slightly different rules than |
| 7820 | * field-based relocations. This function assumes that root types were already |
| 7821 | * checked for name match. Beyond that initial root-level name check, names |
| 7822 | * are completely ignored. Compatibility rules are as follows: |
| 7823 | * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but |
| 7824 | * kind should match for local and target types (i.e., STRUCT is not |
| 7825 | * compatible with UNION); |
| 7826 | * - for ENUMs/ENUM64s, the size is ignored; |
| 7827 | * - for INT, size and signedness are ignored; |
| 7828 | * - for ARRAY, dimensionality is ignored, element types are checked for |
| 7829 | * compatibility recursively; |
| 7830 | * - CONST/VOLATILE/RESTRICT modifiers are ignored; |
| 7831 | * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; |
| 7832 | * - FUNC_PROTOs are compatible if they have compatible signature: same |
| 7833 | * number of input args and compatible return and argument types. |
| 7834 | * These rules are not set in stone and probably will be adjusted as we get |
| 7835 | * more experience with using BPF CO-RE relocations. |
| 7836 | */ |
| 7837 | int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
| 7838 | const struct btf *targ_btf, __u32 targ_id) |
| 7839 | { |
| 7840 | return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, |
| 7841 | MAX_TYPES_ARE_COMPAT_DEPTH); |
| 7842 | } |
| 7843 | |
| 7844 | #define MAX_TYPES_MATCH_DEPTH 2 |
| 7845 | |
| 7846 | int bpf_core_types_match(const struct btf *local_btf, u32 local_id, |
| 7847 | const struct btf *targ_btf, u32 targ_id) |
| 7848 | { |
| 7849 | return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, |
| 7850 | MAX_TYPES_MATCH_DEPTH); |
| 7851 | } |
| 7852 | |
| 7853 | static bool bpf_core_is_flavor_sep(const char *s) |
| 7854 | { |
| 7855 | /* check X___Y name pattern, where X and Y are not underscores */ |
| 7856 | return s[0] != '_' && /* X */ |
| 7857 | s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ |
| 7858 | s[4] != '_'; /* Y */ |
| 7859 | } |
| 7860 | |
| 7861 | size_t bpf_core_essential_name_len(const char *name) |
| 7862 | { |
| 7863 | size_t n = strlen(name); |
| 7864 | int i; |
| 7865 | |
| 7866 | for (i = n - 5; i >= 0; i--) { |
| 7867 | if (bpf_core_is_flavor_sep(name + i)) |
| 7868 | return i + 1; |
| 7869 | } |
| 7870 | return n; |
| 7871 | } |
| 7872 | |
| 7873 | struct bpf_cand_cache { |
| 7874 | const char *name; |
| 7875 | u32 name_len; |
| 7876 | u16 kind; |
| 7877 | u16 cnt; |
| 7878 | struct { |
| 7879 | const struct btf *btf; |
| 7880 | u32 id; |
| 7881 | } cands[]; |
| 7882 | }; |
| 7883 | |
| 7884 | static void bpf_free_cands(struct bpf_cand_cache *cands) |
| 7885 | { |
| 7886 | if (!cands->cnt) |
| 7887 | /* empty candidate array was allocated on stack */ |
| 7888 | return; |
| 7889 | kfree(cands); |
| 7890 | } |
| 7891 | |
| 7892 | static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) |
| 7893 | { |
| 7894 | kfree(cands->name); |
| 7895 | kfree(cands); |
| 7896 | } |
| 7897 | |
| 7898 | #define VMLINUX_CAND_CACHE_SIZE 31 |
| 7899 | static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; |
| 7900 | |
| 7901 | #define MODULE_CAND_CACHE_SIZE 31 |
| 7902 | static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; |
| 7903 | |
| 7904 | static DEFINE_MUTEX(cand_cache_mutex); |
| 7905 | |
| 7906 | static void __print_cand_cache(struct bpf_verifier_log *log, |
| 7907 | struct bpf_cand_cache **cache, |
| 7908 | int cache_size) |
| 7909 | { |
| 7910 | struct bpf_cand_cache *cc; |
| 7911 | int i, j; |
| 7912 | |
| 7913 | for (i = 0; i < cache_size; i++) { |
| 7914 | cc = cache[i]; |
| 7915 | if (!cc) |
| 7916 | continue; |
| 7917 | bpf_log(log, "[%d]%s(", i, cc->name); |
| 7918 | for (j = 0; j < cc->cnt; j++) { |
| 7919 | bpf_log(log, "%d", cc->cands[j].id); |
| 7920 | if (j < cc->cnt - 1) |
| 7921 | bpf_log(log, " "); |
| 7922 | } |
| 7923 | bpf_log(log, "), "); |
| 7924 | } |
| 7925 | } |
| 7926 | |
| 7927 | static void print_cand_cache(struct bpf_verifier_log *log) |
| 7928 | { |
| 7929 | mutex_lock(&cand_cache_mutex); |
| 7930 | bpf_log(log, "vmlinux_cand_cache:"); |
| 7931 | __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
| 7932 | bpf_log(log, "\nmodule_cand_cache:"); |
| 7933 | __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
| 7934 | bpf_log(log, "\n"); |
| 7935 | mutex_unlock(&cand_cache_mutex); |
| 7936 | } |
| 7937 | |
| 7938 | static u32 hash_cands(struct bpf_cand_cache *cands) |
| 7939 | { |
| 7940 | return jhash(cands->name, cands->name_len, 0); |
| 7941 | } |
| 7942 | |
| 7943 | static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, |
| 7944 | struct bpf_cand_cache **cache, |
| 7945 | int cache_size) |
| 7946 | { |
| 7947 | struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; |
| 7948 | |
| 7949 | if (cc && cc->name_len == cands->name_len && |
| 7950 | !strncmp(cc->name, cands->name, cands->name_len)) |
| 7951 | return cc; |
| 7952 | return NULL; |
| 7953 | } |
| 7954 | |
| 7955 | static size_t sizeof_cands(int cnt) |
| 7956 | { |
| 7957 | return offsetof(struct bpf_cand_cache, cands[cnt]); |
| 7958 | } |
| 7959 | |
| 7960 | static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, |
| 7961 | struct bpf_cand_cache **cache, |
| 7962 | int cache_size) |
| 7963 | { |
| 7964 | struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; |
| 7965 | |
| 7966 | if (*cc) { |
| 7967 | bpf_free_cands_from_cache(*cc); |
| 7968 | *cc = NULL; |
| 7969 | } |
| 7970 | new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
| 7971 | if (!new_cands) { |
| 7972 | bpf_free_cands(cands); |
| 7973 | return ERR_PTR(-ENOMEM); |
| 7974 | } |
| 7975 | /* strdup the name, since it will stay in cache. |
| 7976 | * the cands->name points to strings in prog's BTF and the prog can be unloaded. |
| 7977 | */ |
| 7978 | new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); |
| 7979 | bpf_free_cands(cands); |
| 7980 | if (!new_cands->name) { |
| 7981 | kfree(new_cands); |
| 7982 | return ERR_PTR(-ENOMEM); |
| 7983 | } |
| 7984 | *cc = new_cands; |
| 7985 | return new_cands; |
| 7986 | } |
| 7987 | |
| 7988 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| 7989 | static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
| 7990 | int cache_size) |
| 7991 | { |
| 7992 | struct bpf_cand_cache *cc; |
| 7993 | int i, j; |
| 7994 | |
| 7995 | for (i = 0; i < cache_size; i++) { |
| 7996 | cc = cache[i]; |
| 7997 | if (!cc) |
| 7998 | continue; |
| 7999 | if (!btf) { |
| 8000 | /* when new module is loaded purge all of module_cand_cache, |
| 8001 | * since new module might have candidates with the name |
| 8002 | * that matches cached cands. |
| 8003 | */ |
| 8004 | bpf_free_cands_from_cache(cc); |
| 8005 | cache[i] = NULL; |
| 8006 | continue; |
| 8007 | } |
| 8008 | /* when module is unloaded purge cache entries |
| 8009 | * that match module's btf |
| 8010 | */ |
| 8011 | for (j = 0; j < cc->cnt; j++) |
| 8012 | if (cc->cands[j].btf == btf) { |
| 8013 | bpf_free_cands_from_cache(cc); |
| 8014 | cache[i] = NULL; |
| 8015 | break; |
| 8016 | } |
| 8017 | } |
| 8018 | |
| 8019 | } |
| 8020 | |
| 8021 | static void purge_cand_cache(struct btf *btf) |
| 8022 | { |
| 8023 | mutex_lock(&cand_cache_mutex); |
| 8024 | __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
| 8025 | mutex_unlock(&cand_cache_mutex); |
| 8026 | } |
| 8027 | #endif |
| 8028 | |
| 8029 | static struct bpf_cand_cache * |
| 8030 | bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, |
| 8031 | int targ_start_id) |
| 8032 | { |
| 8033 | struct bpf_cand_cache *new_cands; |
| 8034 | const struct btf_type *t; |
| 8035 | const char *targ_name; |
| 8036 | size_t targ_essent_len; |
| 8037 | int n, i; |
| 8038 | |
| 8039 | n = btf_nr_types(targ_btf); |
| 8040 | for (i = targ_start_id; i < n; i++) { |
| 8041 | t = btf_type_by_id(targ_btf, i); |
| 8042 | if (btf_kind(t) != cands->kind) |
| 8043 | continue; |
| 8044 | |
| 8045 | targ_name = btf_name_by_offset(targ_btf, t->name_off); |
| 8046 | if (!targ_name) |
| 8047 | continue; |
| 8048 | |
| 8049 | /* the resched point is before strncmp to make sure that search |
| 8050 | * for non-existing name will have a chance to schedule(). |
| 8051 | */ |
| 8052 | cond_resched(); |
| 8053 | |
| 8054 | if (strncmp(cands->name, targ_name, cands->name_len) != 0) |
| 8055 | continue; |
| 8056 | |
| 8057 | targ_essent_len = bpf_core_essential_name_len(targ_name); |
| 8058 | if (targ_essent_len != cands->name_len) |
| 8059 | continue; |
| 8060 | |
| 8061 | /* most of the time there is only one candidate for a given kind+name pair */ |
| 8062 | new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); |
| 8063 | if (!new_cands) { |
| 8064 | bpf_free_cands(cands); |
| 8065 | return ERR_PTR(-ENOMEM); |
| 8066 | } |
| 8067 | |
| 8068 | memcpy(new_cands, cands, sizeof_cands(cands->cnt)); |
| 8069 | bpf_free_cands(cands); |
| 8070 | cands = new_cands; |
| 8071 | cands->cands[cands->cnt].btf = targ_btf; |
| 8072 | cands->cands[cands->cnt].id = i; |
| 8073 | cands->cnt++; |
| 8074 | } |
| 8075 | return cands; |
| 8076 | } |
| 8077 | |
| 8078 | static struct bpf_cand_cache * |
| 8079 | bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) |
| 8080 | { |
| 8081 | struct bpf_cand_cache *cands, *cc, local_cand = {}; |
| 8082 | const struct btf *local_btf = ctx->btf; |
| 8083 | const struct btf_type *local_type; |
| 8084 | const struct btf *main_btf; |
| 8085 | size_t local_essent_len; |
| 8086 | struct btf *mod_btf; |
| 8087 | const char *name; |
| 8088 | int id; |
| 8089 | |
| 8090 | main_btf = bpf_get_btf_vmlinux(); |
| 8091 | if (IS_ERR(main_btf)) |
| 8092 | return ERR_CAST(main_btf); |
| 8093 | if (!main_btf) |
| 8094 | return ERR_PTR(-EINVAL); |
| 8095 | |
| 8096 | local_type = btf_type_by_id(local_btf, local_type_id); |
| 8097 | if (!local_type) |
| 8098 | return ERR_PTR(-EINVAL); |
| 8099 | |
| 8100 | name = btf_name_by_offset(local_btf, local_type->name_off); |
| 8101 | if (str_is_empty(name)) |
| 8102 | return ERR_PTR(-EINVAL); |
| 8103 | local_essent_len = bpf_core_essential_name_len(name); |
| 8104 | |
| 8105 | cands = &local_cand; |
| 8106 | cands->name = name; |
| 8107 | cands->kind = btf_kind(local_type); |
| 8108 | cands->name_len = local_essent_len; |
| 8109 | |
| 8110 | cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
| 8111 | /* cands is a pointer to stack here */ |
| 8112 | if (cc) { |
| 8113 | if (cc->cnt) |
| 8114 | return cc; |
| 8115 | goto check_modules; |
| 8116 | } |
| 8117 | |
| 8118 | /* Attempt to find target candidates in vmlinux BTF first */ |
| 8119 | cands = bpf_core_add_cands(cands, main_btf, 1); |
| 8120 | if (IS_ERR(cands)) |
| 8121 | return ERR_CAST(cands); |
| 8122 | |
| 8123 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ |
| 8124 | |
| 8125 | /* populate cache even when cands->cnt == 0 */ |
| 8126 | cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
| 8127 | if (IS_ERR(cc)) |
| 8128 | return ERR_CAST(cc); |
| 8129 | |
| 8130 | /* if vmlinux BTF has any candidate, don't go for module BTFs */ |
| 8131 | if (cc->cnt) |
| 8132 | return cc; |
| 8133 | |
| 8134 | check_modules: |
| 8135 | /* cands is a pointer to stack here and cands->cnt == 0 */ |
| 8136 | cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
| 8137 | if (cc) |
| 8138 | /* if cache has it return it even if cc->cnt == 0 */ |
| 8139 | return cc; |
| 8140 | |
| 8141 | /* If candidate is not found in vmlinux's BTF then search in module's BTFs */ |
| 8142 | spin_lock_bh(&btf_idr_lock); |
| 8143 | idr_for_each_entry(&btf_idr, mod_btf, id) { |
| 8144 | if (!btf_is_module(mod_btf)) |
| 8145 | continue; |
| 8146 | /* linear search could be slow hence unlock/lock |
| 8147 | * the IDR to avoiding holding it for too long |
| 8148 | */ |
| 8149 | btf_get(mod_btf); |
| 8150 | spin_unlock_bh(&btf_idr_lock); |
| 8151 | cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); |
| 8152 | if (IS_ERR(cands)) { |
| 8153 | btf_put(mod_btf); |
| 8154 | return ERR_CAST(cands); |
| 8155 | } |
| 8156 | spin_lock_bh(&btf_idr_lock); |
| 8157 | btf_put(mod_btf); |
| 8158 | } |
| 8159 | spin_unlock_bh(&btf_idr_lock); |
| 8160 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 |
| 8161 | * or pointer to stack if cands->cnd == 0. |
| 8162 | * Copy it into the cache even when cands->cnt == 0 and |
| 8163 | * return the result. |
| 8164 | */ |
| 8165 | return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
| 8166 | } |
| 8167 | |
| 8168 | int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
| 8169 | int relo_idx, void *insn) |
| 8170 | { |
| 8171 | bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
| 8172 | struct bpf_core_cand_list cands = {}; |
| 8173 | struct bpf_core_relo_res targ_res; |
| 8174 | struct bpf_core_spec *specs; |
| 8175 | int err; |
| 8176 | |
| 8177 | /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
| 8178 | * into arrays of btf_ids of struct fields and array indices. |
| 8179 | */ |
| 8180 | specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); |
| 8181 | if (!specs) |
| 8182 | return -ENOMEM; |
| 8183 | |
| 8184 | if (need_cands) { |
| 8185 | struct bpf_cand_cache *cc; |
| 8186 | int i; |
| 8187 | |
| 8188 | mutex_lock(&cand_cache_mutex); |
| 8189 | cc = bpf_core_find_cands(ctx, relo->type_id); |
| 8190 | if (IS_ERR(cc)) { |
| 8191 | bpf_log(ctx->log, "target candidate search failed for %d\n", |
| 8192 | relo->type_id); |
| 8193 | err = PTR_ERR(cc); |
| 8194 | goto out; |
| 8195 | } |
| 8196 | if (cc->cnt) { |
| 8197 | cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); |
| 8198 | if (!cands.cands) { |
| 8199 | err = -ENOMEM; |
| 8200 | goto out; |
| 8201 | } |
| 8202 | } |
| 8203 | for (i = 0; i < cc->cnt; i++) { |
| 8204 | bpf_log(ctx->log, |
| 8205 | "CO-RE relocating %s %s: found target candidate [%d]\n", |
| 8206 | btf_kind_str[cc->kind], cc->name, cc->cands[i].id); |
| 8207 | cands.cands[i].btf = cc->cands[i].btf; |
| 8208 | cands.cands[i].id = cc->cands[i].id; |
| 8209 | } |
| 8210 | cands.len = cc->cnt; |
| 8211 | /* cand_cache_mutex needs to span the cache lookup and |
| 8212 | * copy of btf pointer into bpf_core_cand_list, |
| 8213 | * since module can be unloaded while bpf_core_calc_relo_insn |
| 8214 | * is working with module's btf. |
| 8215 | */ |
| 8216 | } |
| 8217 | |
| 8218 | err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
| 8219 | &targ_res); |
| 8220 | if (err) |
| 8221 | goto out; |
| 8222 | |
| 8223 | err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, |
| 8224 | &targ_res); |
| 8225 | |
| 8226 | out: |
| 8227 | kfree(specs); |
| 8228 | if (need_cands) { |
| 8229 | kfree(cands.cands); |
| 8230 | mutex_unlock(&cand_cache_mutex); |
| 8231 | if (ctx->log->level & BPF_LOG_LEVEL2) |
| 8232 | print_cand_cache(ctx->log); |
| 8233 | } |
| 8234 | return err; |
| 8235 | } |
| 8236 | |
| 8237 | bool btf_nested_type_is_trusted(struct bpf_verifier_log *log, |
| 8238 | const struct bpf_reg_state *reg, |
| 8239 | int off) |
| 8240 | { |
| 8241 | struct btf *btf = reg->btf; |
| 8242 | const struct btf_type *walk_type, *safe_type; |
| 8243 | const char *tname; |
| 8244 | char safe_tname[64]; |
| 8245 | long ret, safe_id; |
| 8246 | const struct btf_member *member, *m_walk = NULL; |
| 8247 | u32 i; |
| 8248 | const char *walk_name; |
| 8249 | |
| 8250 | walk_type = btf_type_by_id(btf, reg->btf_id); |
| 8251 | if (!walk_type) |
| 8252 | return false; |
| 8253 | |
| 8254 | tname = btf_name_by_offset(btf, walk_type->name_off); |
| 8255 | |
| 8256 | ret = snprintf(safe_tname, sizeof(safe_tname), "%s__safe_fields", tname); |
| 8257 | if (ret < 0) |
| 8258 | return false; |
| 8259 | |
| 8260 | safe_id = btf_find_by_name_kind(btf, safe_tname, BTF_INFO_KIND(walk_type->info)); |
| 8261 | if (safe_id < 0) |
| 8262 | return false; |
| 8263 | |
| 8264 | safe_type = btf_type_by_id(btf, safe_id); |
| 8265 | if (!safe_type) |
| 8266 | return false; |
| 8267 | |
| 8268 | for_each_member(i, walk_type, member) { |
| 8269 | u32 moff; |
| 8270 | |
| 8271 | /* We're looking for the PTR_TO_BTF_ID member in the struct |
| 8272 | * type we're walking which matches the specified offset. |
| 8273 | * Below, we'll iterate over the fields in the safe variant of |
| 8274 | * the struct and see if any of them has a matching type / |
| 8275 | * name. |
| 8276 | */ |
| 8277 | moff = __btf_member_bit_offset(walk_type, member) / 8; |
| 8278 | if (off == moff) { |
| 8279 | m_walk = member; |
| 8280 | break; |
| 8281 | } |
| 8282 | } |
| 8283 | if (m_walk == NULL) |
| 8284 | return false; |
| 8285 | |
| 8286 | walk_name = __btf_name_by_offset(btf, m_walk->name_off); |
| 8287 | for_each_member(i, safe_type, member) { |
| 8288 | const char *m_name = __btf_name_by_offset(btf, member->name_off); |
| 8289 | |
| 8290 | /* If we match on both type and name, the field is considered trusted. */ |
| 8291 | if (m_walk->type == member->type && !strcmp(walk_name, m_name)) |
| 8292 | return true; |
| 8293 | } |
| 8294 | |
| 8295 | return false; |
| 8296 | } |
| 8297 | |
| 8298 | bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log, |
| 8299 | const struct btf *reg_btf, u32 reg_id, |
| 8300 | const struct btf *arg_btf, u32 arg_id) |
| 8301 | { |
| 8302 | const char *reg_name, *arg_name, *search_needle; |
| 8303 | const struct btf_type *reg_type, *arg_type; |
| 8304 | int reg_len, arg_len, cmp_len; |
| 8305 | size_t pattern_len = sizeof(NOCAST_ALIAS_SUFFIX) - sizeof(char); |
| 8306 | |
| 8307 | reg_type = btf_type_by_id(reg_btf, reg_id); |
| 8308 | if (!reg_type) |
| 8309 | return false; |
| 8310 | |
| 8311 | arg_type = btf_type_by_id(arg_btf, arg_id); |
| 8312 | if (!arg_type) |
| 8313 | return false; |
| 8314 | |
| 8315 | reg_name = btf_name_by_offset(reg_btf, reg_type->name_off); |
| 8316 | arg_name = btf_name_by_offset(arg_btf, arg_type->name_off); |
| 8317 | |
| 8318 | reg_len = strlen(reg_name); |
| 8319 | arg_len = strlen(arg_name); |
| 8320 | |
| 8321 | /* Exactly one of the two type names may be suffixed with ___init, so |
| 8322 | * if the strings are the same size, they can't possibly be no-cast |
| 8323 | * aliases of one another. If you have two of the same type names, e.g. |
| 8324 | * they're both nf_conn___init, it would be improper to return true |
| 8325 | * because they are _not_ no-cast aliases, they are the same type. |
| 8326 | */ |
| 8327 | if (reg_len == arg_len) |
| 8328 | return false; |
| 8329 | |
| 8330 | /* Either of the two names must be the other name, suffixed with ___init. */ |
| 8331 | if ((reg_len != arg_len + pattern_len) && |
| 8332 | (arg_len != reg_len + pattern_len)) |
| 8333 | return false; |
| 8334 | |
| 8335 | if (reg_len < arg_len) { |
| 8336 | search_needle = strstr(arg_name, NOCAST_ALIAS_SUFFIX); |
| 8337 | cmp_len = reg_len; |
| 8338 | } else { |
| 8339 | search_needle = strstr(reg_name, NOCAST_ALIAS_SUFFIX); |
| 8340 | cmp_len = arg_len; |
| 8341 | } |
| 8342 | |
| 8343 | if (!search_needle) |
| 8344 | return false; |
| 8345 | |
| 8346 | /* ___init suffix must come at the end of the name */ |
| 8347 | if (*(search_needle + pattern_len) != '\0') |
| 8348 | return false; |
| 8349 | |
| 8350 | return !strncmp(reg_name, arg_name, cmp_len); |
| 8351 | } |