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