1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Common header file for probe-based Dynamic events. 4 * 5 * This code was copied from kernel/trace/trace_kprobe.h written by 6 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> 7 * 8 * Updates to make this generic: 9 * Copyright (C) IBM Corporation, 2010-2011 10 * Author: Srikar Dronamraju 11 */ 12 13 #include <linux/seq_file.h> 14 #include <linux/slab.h> 15 #include <linux/smp.h> 16 #include <linux/tracefs.h> 17 #include <linux/types.h> 18 #include <linux/string.h> 19 #include <linux/ptrace.h> 20 #include <linux/perf_event.h> 21 #include <linux/kprobes.h> 22 #include <linux/stringify.h> 23 #include <linux/limits.h> 24 #include <linux/uaccess.h> 25 #include <linux/bitops.h> 26 #include <linux/btf.h> 27 #include <asm/bitsperlong.h> 28 29 #include "trace.h" 30 #include "trace_output.h" 31 32 #define MAX_TRACE_ARGS 128 33 #define MAX_ARGSTR_LEN 63 34 #define MAX_ARRAY_LEN 64 35 #define MAX_ARG_NAME_LEN 32 36 #define MAX_BTF_ARGS_LEN 128 37 #define MAX_STRING_SIZE PATH_MAX 38 #define MAX_ARG_BUF_LEN (MAX_TRACE_ARGS * MAX_ARG_NAME_LEN) 39 40 /* Reserved field names */ 41 #define FIELD_STRING_IP "__probe_ip" 42 #define FIELD_STRING_RETIP "__probe_ret_ip" 43 #define FIELD_STRING_FUNC "__probe_func" 44 45 #undef DEFINE_FIELD 46 #define DEFINE_FIELD(type, item, name, is_signed) \ 47 do { \ 48 ret = trace_define_field(event_call, #type, name, \ 49 offsetof(typeof(field), item), \ 50 sizeof(field.item), is_signed, \ 51 FILTER_OTHER); \ 52 if (ret) \ 53 return ret; \ 54 } while (0) 55 56 57 /* Flags for trace_probe */ 58 #define TP_FLAG_TRACE 1 59 #define TP_FLAG_PROFILE 2 60 61 /* data_loc: data location, compatible with u32 */ 62 #define make_data_loc(len, offs) \ 63 (((u32)(len) << 16) | ((u32)(offs) & 0xffff)) 64 #define get_loc_len(dl) ((u32)(dl) >> 16) 65 #define get_loc_offs(dl) ((u32)(dl) & 0xffff) 66 67 static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) 68 { 69 return (u8 *)ent + get_loc_offs(*dl); 70 } 71 72 static nokprobe_inline u32 update_data_loc(u32 loc, int consumed) 73 { 74 u32 maxlen = get_loc_len(loc); 75 u32 offset = get_loc_offs(loc); 76 77 return make_data_loc(maxlen - consumed, offset + consumed); 78 } 79 80 /* Printing function type */ 81 typedef int (*print_type_func_t)(struct trace_seq *, void *, void *); 82 83 enum fetch_op { 84 FETCH_OP_NOP = 0, 85 // Stage 1 (load) ops 86 FETCH_OP_REG, /* Register : .param = offset */ 87 FETCH_OP_STACK, /* Stack : .param = index */ 88 FETCH_OP_STACKP, /* Stack pointer */ 89 FETCH_OP_RETVAL, /* Return value */ 90 FETCH_OP_IMM, /* Immediate : .immediate */ 91 FETCH_OP_COMM, /* Current comm */ 92 FETCH_OP_ARG, /* Function argument : .param */ 93 FETCH_OP_FOFFS, /* File offset: .immediate */ 94 FETCH_OP_DATA, /* Allocated data: .data */ 95 // Stage 2 (dereference) op 96 FETCH_OP_DEREF, /* Dereference: .offset */ 97 FETCH_OP_UDEREF, /* User-space Dereference: .offset */ 98 // Stage 3 (store) ops 99 FETCH_OP_ST_RAW, /* Raw: .size */ 100 FETCH_OP_ST_MEM, /* Mem: .offset, .size */ 101 FETCH_OP_ST_UMEM, /* Mem: .offset, .size */ 102 FETCH_OP_ST_STRING, /* String: .offset, .size */ 103 FETCH_OP_ST_USTRING, /* User String: .offset, .size */ 104 FETCH_OP_ST_SYMSTR, /* Kernel Symbol String: .offset, .size */ 105 // Stage 4 (modify) op 106 FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ 107 // Stage 5 (loop) op 108 FETCH_OP_LP_ARRAY, /* Array: .param = loop count */ 109 FETCH_OP_TP_ARG, /* Trace Point argument */ 110 FETCH_OP_END, 111 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */ 112 }; 113 114 struct fetch_insn { 115 enum fetch_op op; 116 union { 117 unsigned int param; 118 struct { 119 unsigned int size; 120 int offset; 121 }; 122 struct { 123 unsigned char basesize; 124 unsigned char lshift; 125 unsigned char rshift; 126 }; 127 unsigned long immediate; 128 void *data; 129 }; 130 }; 131 132 /* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */ 133 #define FETCH_INSN_MAX 16 134 #define FETCH_TOKEN_COMM (-ECOMM) 135 136 /* Fetch type information table */ 137 struct fetch_type { 138 const char *name; /* Name of type */ 139 size_t size; /* Byte size of type */ 140 bool is_signed; /* Signed flag */ 141 bool is_string; /* String flag */ 142 print_type_func_t print; /* Print functions */ 143 const char *fmt; /* Format string */ 144 const char *fmttype; /* Name in format file */ 145 }; 146 147 /* For defining macros, define string/string_size types */ 148 typedef u32 string; 149 typedef u32 string_size; 150 151 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type 152 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type 153 154 /* Printing in basic type function template */ 155 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ 156 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\ 157 extern const char PRINT_TYPE_FMT_NAME(type)[] 158 159 DECLARE_BASIC_PRINT_TYPE_FUNC(u8); 160 DECLARE_BASIC_PRINT_TYPE_FUNC(u16); 161 DECLARE_BASIC_PRINT_TYPE_FUNC(u32); 162 DECLARE_BASIC_PRINT_TYPE_FUNC(u64); 163 DECLARE_BASIC_PRINT_TYPE_FUNC(s8); 164 DECLARE_BASIC_PRINT_TYPE_FUNC(s16); 165 DECLARE_BASIC_PRINT_TYPE_FUNC(s32); 166 DECLARE_BASIC_PRINT_TYPE_FUNC(s64); 167 DECLARE_BASIC_PRINT_TYPE_FUNC(x8); 168 DECLARE_BASIC_PRINT_TYPE_FUNC(x16); 169 DECLARE_BASIC_PRINT_TYPE_FUNC(x32); 170 DECLARE_BASIC_PRINT_TYPE_FUNC(x64); 171 172 DECLARE_BASIC_PRINT_TYPE_FUNC(char); 173 DECLARE_BASIC_PRINT_TYPE_FUNC(string); 174 DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); 175 176 /* Default (unsigned long) fetch type */ 177 #define __DEFAULT_FETCH_TYPE(t) x##t 178 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 179 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 180 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 181 182 #define __ADDR_FETCH_TYPE(t) u##t 183 #define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t) 184 #define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG) 185 186 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, str, _fmttype) \ 187 {.name = _name, \ 188 .size = _size, \ 189 .is_signed = (bool)sign, \ 190 .is_string = (bool)str, \ 191 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 192 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 193 .fmttype = _fmttype, \ 194 } 195 196 /* Non string types can use these macros */ 197 #define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 198 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, 0, #_fmttype) 199 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 200 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype) 201 202 /* If ptype is an alias of atype, use this macro (show atype in format) */ 203 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ 204 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype) 205 206 #define ASSIGN_FETCH_TYPE_END {} 207 #define MAX_ARRAY_LEN 64 208 209 #ifdef CONFIG_KPROBE_EVENTS 210 bool trace_kprobe_on_func_entry(struct trace_event_call *call); 211 bool trace_kprobe_error_injectable(struct trace_event_call *call); 212 #else 213 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) 214 { 215 return false; 216 } 217 218 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) 219 { 220 return false; 221 } 222 #endif /* CONFIG_KPROBE_EVENTS */ 223 224 struct probe_arg { 225 struct fetch_insn *code; 226 bool dynamic;/* Dynamic array (string) is used */ 227 unsigned int offset; /* Offset from argument entry */ 228 unsigned int count; /* Array count */ 229 const char *name; /* Name of this argument */ 230 const char *comm; /* Command of this argument */ 231 char *fmt; /* Format string if needed */ 232 const struct fetch_type *type; /* Type of this argument */ 233 }; 234 235 struct trace_uprobe_filter { 236 rwlock_t rwlock; 237 int nr_systemwide; 238 struct list_head perf_events; 239 }; 240 241 /* Event call and class holder */ 242 struct trace_probe_event { 243 unsigned int flags; /* For TP_FLAG_* */ 244 struct trace_event_class class; 245 struct trace_event_call call; 246 struct list_head files; 247 struct list_head probes; 248 struct trace_uprobe_filter filter[]; 249 }; 250 251 struct trace_probe { 252 struct list_head list; 253 struct trace_probe_event *event; 254 ssize_t size; /* trace entry size */ 255 unsigned int nr_args; 256 struct probe_arg args[]; 257 }; 258 259 struct event_file_link { 260 struct trace_event_file *file; 261 struct list_head list; 262 }; 263 264 static inline bool trace_probe_test_flag(struct trace_probe *tp, 265 unsigned int flag) 266 { 267 return !!(tp->event->flags & flag); 268 } 269 270 static inline void trace_probe_set_flag(struct trace_probe *tp, 271 unsigned int flag) 272 { 273 tp->event->flags |= flag; 274 } 275 276 static inline void trace_probe_clear_flag(struct trace_probe *tp, 277 unsigned int flag) 278 { 279 tp->event->flags &= ~flag; 280 } 281 282 static inline bool trace_probe_is_enabled(struct trace_probe *tp) 283 { 284 return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE); 285 } 286 287 static inline const char *trace_probe_name(struct trace_probe *tp) 288 { 289 return trace_event_name(&tp->event->call); 290 } 291 292 static inline const char *trace_probe_group_name(struct trace_probe *tp) 293 { 294 return tp->event->call.class->system; 295 } 296 297 static inline struct trace_event_call * 298 trace_probe_event_call(struct trace_probe *tp) 299 { 300 return &tp->event->call; 301 } 302 303 static inline struct trace_probe_event * 304 trace_probe_event_from_call(struct trace_event_call *event_call) 305 { 306 return container_of(event_call, struct trace_probe_event, call); 307 } 308 309 static inline struct trace_probe * 310 trace_probe_primary_from_call(struct trace_event_call *call) 311 { 312 struct trace_probe_event *tpe = trace_probe_event_from_call(call); 313 314 return list_first_entry_or_null(&tpe->probes, struct trace_probe, list); 315 } 316 317 static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp) 318 { 319 return &tp->event->probes; 320 } 321 322 static inline bool trace_probe_has_sibling(struct trace_probe *tp) 323 { 324 struct list_head *list = trace_probe_probe_list(tp); 325 326 return !list_empty(list) && !list_is_singular(list); 327 } 328 329 static inline int trace_probe_unregister_event_call(struct trace_probe *tp) 330 { 331 /* tp->event is unregistered in trace_remove_event_call() */ 332 return trace_remove_event_call(&tp->event->call); 333 } 334 335 static inline bool trace_probe_has_single_file(struct trace_probe *tp) 336 { 337 return !!list_is_singular(&tp->event->files); 338 } 339 340 int trace_probe_init(struct trace_probe *tp, const char *event, 341 const char *group, bool alloc_filter); 342 void trace_probe_cleanup(struct trace_probe *tp); 343 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to); 344 void trace_probe_unlink(struct trace_probe *tp); 345 int trace_probe_register_event_call(struct trace_probe *tp); 346 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file); 347 int trace_probe_remove_file(struct trace_probe *tp, 348 struct trace_event_file *file); 349 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 350 struct trace_event_file *file); 351 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b); 352 bool trace_probe_match_command_args(struct trace_probe *tp, 353 int argc, const char **argv); 354 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)); 355 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 356 u8 *data, void *field); 357 358 #define trace_probe_for_each_link(pos, tp) \ 359 list_for_each_entry(pos, &(tp)->event->files, list) 360 #define trace_probe_for_each_link_rcu(pos, tp) \ 361 list_for_each_entry_rcu(pos, &(tp)->event->files, list) 362 363 /* 364 * The flags used for parsing trace_probe arguments. 365 * TPARG_FL_RETURN, TPARG_FL_FENTRY and TPARG_FL_TEVENT are mutually exclusive. 366 * TPARG_FL_KERNEL and TPARG_FL_USER are also mutually exclusive. 367 * TPARG_FL_FPROBE and TPARG_FL_TPOINT are optional but it should be with 368 * TPARG_FL_KERNEL. 369 */ 370 #define TPARG_FL_RETURN BIT(0) 371 #define TPARG_FL_KERNEL BIT(1) 372 #define TPARG_FL_FENTRY BIT(2) 373 #define TPARG_FL_TEVENT BIT(3) 374 #define TPARG_FL_USER BIT(4) 375 #define TPARG_FL_FPROBE BIT(5) 376 #define TPARG_FL_TPOINT BIT(6) 377 #define TPARG_FL_LOC_MASK GENMASK(4, 0) 378 379 static inline bool tparg_is_function_entry(unsigned int flags) 380 { 381 return (flags & TPARG_FL_LOC_MASK) == (TPARG_FL_KERNEL | TPARG_FL_FENTRY); 382 } 383 384 struct traceprobe_parse_context { 385 struct trace_event_call *event; 386 const struct btf_param *params; 387 s32 nr_params; 388 const char *funcname; 389 unsigned int flags; 390 int offset; 391 }; 392 393 extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, 394 const char *argv, 395 struct traceprobe_parse_context *ctx); 396 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 397 int *new_argc, char *buf, int bufsize, 398 struct traceprobe_parse_context *ctx); 399 400 extern int traceprobe_update_arg(struct probe_arg *arg); 401 extern void traceprobe_free_probe_arg(struct probe_arg *arg); 402 403 extern int traceprobe_split_symbol_offset(char *symbol, long *offset); 404 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 405 char *buf, int offset); 406 407 enum probe_print_type { 408 PROBE_PRINT_NORMAL, 409 PROBE_PRINT_RETURN, 410 PROBE_PRINT_EVENT, 411 }; 412 413 extern int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype); 414 415 #ifdef CONFIG_PERF_EVENTS 416 extern struct trace_event_call * 417 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 418 bool is_return); 419 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); 420 421 extern struct trace_event_call * 422 create_local_trace_uprobe(char *name, unsigned long offs, 423 unsigned long ref_ctr_offset, bool is_return); 424 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); 425 #endif 426 extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, 427 size_t offset, struct trace_probe *tp); 428 429 #undef ERRORS 430 #define ERRORS \ 431 C(FILE_NOT_FOUND, "Failed to find the given file"), \ 432 C(NO_REGULAR_FILE, "Not a regular file"), \ 433 C(BAD_REFCNT, "Invalid reference counter offset"), \ 434 C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \ 435 C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \ 436 C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \ 437 C(BAD_MAXACT_TYPE, "Maxactive is only for function exit"), \ 438 C(BAD_MAXACT, "Invalid maxactive number"), \ 439 C(MAXACT_TOO_BIG, "Maxactive is too big"), \ 440 C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \ 441 C(BAD_RETPROBE, "Retprobe address must be an function entry"), \ 442 C(NO_TRACEPOINT, "Tracepoint is not found"), \ 443 C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \ 444 C(NO_GROUP_NAME, "Group name is not specified"), \ 445 C(GROUP_TOO_LONG, "Group name is too long"), \ 446 C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \ 447 C(NO_EVENT_NAME, "Event name is not specified"), \ 448 C(EVENT_TOO_LONG, "Event name is too long"), \ 449 C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \ 450 C(EVENT_EXIST, "Given group/event name is already used by another event"), \ 451 C(RETVAL_ON_PROBE, "$retval is not available on probe"), \ 452 C(NO_RETVAL, "This function returns 'void' type"), \ 453 C(BAD_STACK_NUM, "Invalid stack number"), \ 454 C(BAD_ARG_NUM, "Invalid argument number"), \ 455 C(BAD_VAR, "Invalid $-valiable specified"), \ 456 C(BAD_REG_NAME, "Invalid register name"), \ 457 C(BAD_MEM_ADDR, "Invalid memory address"), \ 458 C(BAD_IMM, "Invalid immediate value"), \ 459 C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \ 460 C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \ 461 C(BAD_FILE_OFFS, "Invalid file offset value"), \ 462 C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \ 463 C(TOO_MANY_OPS, "Dereference is too much nested"), \ 464 C(DEREF_NEED_BRACE, "Dereference needs a brace"), \ 465 C(BAD_DEREF_OFFS, "Invalid dereference offset"), \ 466 C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \ 467 C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \ 468 C(BAD_FETCH_ARG, "Invalid fetch argument"), \ 469 C(ARRAY_NO_CLOSE, "Array is not closed"), \ 470 C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \ 471 C(BAD_ARRAY_NUM, "Invalid array size"), \ 472 C(ARRAY_TOO_BIG, "Array number is too big"), \ 473 C(BAD_TYPE, "Unknown type is specified"), \ 474 C(BAD_STRING, "String accepts only memory argument"), \ 475 C(BAD_SYMSTRING, "Symbol String doesn't accept data/userdata"), \ 476 C(BAD_BITFIELD, "Invalid bitfield"), \ 477 C(ARG_NAME_TOO_LONG, "Argument name is too long"), \ 478 C(NO_ARG_NAME, "Argument name is not specified"), \ 479 C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \ 480 C(USED_ARG_NAME, "This argument name is already used"), \ 481 C(ARG_TOO_LONG, "Argument expression is too long"), \ 482 C(NO_ARG_BODY, "No argument expression"), \ 483 C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\ 484 C(FAIL_REG_PROBE, "Failed to register probe event"),\ 485 C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\ 486 C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\ 487 C(SAME_PROBE, "There is already the exact same probe event"),\ 488 C(NO_EVENT_INFO, "This requires both group and event name to attach"),\ 489 C(BAD_ATTACH_EVENT, "Attached event does not exist"),\ 490 C(BAD_ATTACH_ARG, "Attached event does not have this field"),\ 491 C(NO_EP_FILTER, "No filter rule after 'if'"), \ 492 C(NOSUP_BTFARG, "BTF is not available or not supported"), \ 493 C(NO_BTFARG, "This variable is not found at this probe point"),\ 494 C(NO_BTF_ENTRY, "No BTF entry for this probe point"), \ 495 C(BAD_VAR_ARGS, "$arg* must be an independent parameter without name etc."),\ 496 C(NOFENTRY_ARGS, "$arg* can be used only on function entry"), \ 497 C(DOUBLE_ARGS, "$arg* can be used only once in the parameters"), \ 498 C(ARGS_2LONG, "$arg* failed because the argument list is too long"), 499 500 #undef C 501 #define C(a, b) TP_ERR_##a 502 503 /* Define TP_ERR_ */ 504 enum { ERRORS }; 505 506 /* Error text is defined in trace_probe.c */ 507 508 struct trace_probe_log { 509 const char *subsystem; 510 const char **argv; 511 int argc; 512 int index; 513 }; 514 515 void trace_probe_log_init(const char *subsystem, int argc, const char **argv); 516 void trace_probe_log_set_index(int index); 517 void trace_probe_log_clear(void); 518 void __trace_probe_log_err(int offset, int err); 519 520 #define trace_probe_log_err(offs, err) \ 521 __trace_probe_log_err(offs, TP_ERR_##err) 522