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/ctype.h> 20 #include <linux/ptrace.h> 21 #include <linux/perf_event.h> 22 #include <linux/kprobes.h> 23 #include <linux/stringify.h> 24 #include <linux/limits.h> 25 #include <linux/uaccess.h> 26 #include <linux/bitops.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 // Stage 4 (modify) op 103 FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ 104 // Stage 5 (loop) op 105 FETCH_OP_LP_ARRAY, /* Array: .param = loop count */ 106 FETCH_OP_END, 107 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */ 108 }; 109 110 struct fetch_insn { 111 enum fetch_op op; 112 union { 113 unsigned int param; 114 struct { 115 unsigned int size; 116 int offset; 117 }; 118 struct { 119 unsigned char basesize; 120 unsigned char lshift; 121 unsigned char rshift; 122 }; 123 unsigned long immediate; 124 void *data; 125 }; 126 }; 127 128 /* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */ 129 #define FETCH_INSN_MAX 16 130 #define FETCH_TOKEN_COMM (-ECOMM) 131 132 /* Fetch type information table */ 133 struct fetch_type { 134 const char *name; /* Name of type */ 135 size_t size; /* Byte size of type */ 136 int is_signed; /* Signed flag */ 137 print_type_func_t print; /* Print functions */ 138 const char *fmt; /* Fromat string */ 139 const char *fmttype; /* Name in format file */ 140 }; 141 142 /* For defining macros, define string/string_size types */ 143 typedef u32 string; 144 typedef u32 string_size; 145 146 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type 147 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type 148 149 /* Printing in basic type function template */ 150 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ 151 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\ 152 extern const char PRINT_TYPE_FMT_NAME(type)[] 153 154 DECLARE_BASIC_PRINT_TYPE_FUNC(u8); 155 DECLARE_BASIC_PRINT_TYPE_FUNC(u16); 156 DECLARE_BASIC_PRINT_TYPE_FUNC(u32); 157 DECLARE_BASIC_PRINT_TYPE_FUNC(u64); 158 DECLARE_BASIC_PRINT_TYPE_FUNC(s8); 159 DECLARE_BASIC_PRINT_TYPE_FUNC(s16); 160 DECLARE_BASIC_PRINT_TYPE_FUNC(s32); 161 DECLARE_BASIC_PRINT_TYPE_FUNC(s64); 162 DECLARE_BASIC_PRINT_TYPE_FUNC(x8); 163 DECLARE_BASIC_PRINT_TYPE_FUNC(x16); 164 DECLARE_BASIC_PRINT_TYPE_FUNC(x32); 165 DECLARE_BASIC_PRINT_TYPE_FUNC(x64); 166 167 DECLARE_BASIC_PRINT_TYPE_FUNC(string); 168 DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); 169 170 /* Default (unsigned long) fetch type */ 171 #define __DEFAULT_FETCH_TYPE(t) x##t 172 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 173 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 174 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 175 176 #define __ADDR_FETCH_TYPE(t) u##t 177 #define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t) 178 #define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG) 179 180 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 181 {.name = _name, \ 182 .size = _size, \ 183 .is_signed = sign, \ 184 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 185 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 186 .fmttype = _fmttype, \ 187 } 188 #define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 189 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype) 190 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 191 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype) 192 193 /* If ptype is an alias of atype, use this macro (show atype in format) */ 194 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ 195 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype) 196 197 #define ASSIGN_FETCH_TYPE_END {} 198 #define MAX_ARRAY_LEN 64 199 200 #ifdef CONFIG_KPROBE_EVENTS 201 bool trace_kprobe_on_func_entry(struct trace_event_call *call); 202 bool trace_kprobe_error_injectable(struct trace_event_call *call); 203 #else 204 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) 205 { 206 return false; 207 } 208 209 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) 210 { 211 return false; 212 } 213 #endif /* CONFIG_KPROBE_EVENTS */ 214 215 struct probe_arg { 216 struct fetch_insn *code; 217 bool dynamic;/* Dynamic array (string) is used */ 218 unsigned int offset; /* Offset from argument entry */ 219 unsigned int count; /* Array count */ 220 const char *name; /* Name of this argument */ 221 const char *comm; /* Command of this argument */ 222 char *fmt; /* Format string if needed */ 223 const struct fetch_type *type; /* Type of this argument */ 224 }; 225 226 struct trace_uprobe_filter { 227 rwlock_t rwlock; 228 int nr_systemwide; 229 struct list_head perf_events; 230 }; 231 232 /* Event call and class holder */ 233 struct trace_probe_event { 234 unsigned int flags; /* For TP_FLAG_* */ 235 struct trace_event_class class; 236 struct trace_event_call call; 237 struct list_head files; 238 struct list_head probes; 239 struct trace_uprobe_filter filter[0]; 240 }; 241 242 struct trace_probe { 243 struct list_head list; 244 struct trace_probe_event *event; 245 ssize_t size; /* trace entry size */ 246 unsigned int nr_args; 247 struct probe_arg args[]; 248 }; 249 250 struct event_file_link { 251 struct trace_event_file *file; 252 struct list_head list; 253 }; 254 255 static inline bool trace_probe_test_flag(struct trace_probe *tp, 256 unsigned int flag) 257 { 258 return !!(tp->event->flags & flag); 259 } 260 261 static inline void trace_probe_set_flag(struct trace_probe *tp, 262 unsigned int flag) 263 { 264 tp->event->flags |= flag; 265 } 266 267 static inline void trace_probe_clear_flag(struct trace_probe *tp, 268 unsigned int flag) 269 { 270 tp->event->flags &= ~flag; 271 } 272 273 static inline bool trace_probe_is_enabled(struct trace_probe *tp) 274 { 275 return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE); 276 } 277 278 static inline const char *trace_probe_name(struct trace_probe *tp) 279 { 280 return trace_event_name(&tp->event->call); 281 } 282 283 static inline const char *trace_probe_group_name(struct trace_probe *tp) 284 { 285 return tp->event->call.class->system; 286 } 287 288 static inline struct trace_event_call * 289 trace_probe_event_call(struct trace_probe *tp) 290 { 291 return &tp->event->call; 292 } 293 294 static inline struct trace_probe_event * 295 trace_probe_event_from_call(struct trace_event_call *event_call) 296 { 297 return container_of(event_call, struct trace_probe_event, call); 298 } 299 300 static inline struct trace_probe * 301 trace_probe_primary_from_call(struct trace_event_call *call) 302 { 303 struct trace_probe_event *tpe = trace_probe_event_from_call(call); 304 305 return list_first_entry(&tpe->probes, struct trace_probe, list); 306 } 307 308 static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp) 309 { 310 return &tp->event->probes; 311 } 312 313 static inline bool trace_probe_has_sibling(struct trace_probe *tp) 314 { 315 struct list_head *list = trace_probe_probe_list(tp); 316 317 return !list_empty(list) && !list_is_singular(list); 318 } 319 320 static inline int trace_probe_unregister_event_call(struct trace_probe *tp) 321 { 322 /* tp->event is unregistered in trace_remove_event_call() */ 323 return trace_remove_event_call(&tp->event->call); 324 } 325 326 static inline bool trace_probe_has_single_file(struct trace_probe *tp) 327 { 328 return !!list_is_singular(&tp->event->files); 329 } 330 331 int trace_probe_init(struct trace_probe *tp, const char *event, 332 const char *group, bool alloc_filter); 333 void trace_probe_cleanup(struct trace_probe *tp); 334 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to); 335 void trace_probe_unlink(struct trace_probe *tp); 336 int trace_probe_register_event_call(struct trace_probe *tp); 337 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file); 338 int trace_probe_remove_file(struct trace_probe *tp, 339 struct trace_event_file *file); 340 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 341 struct trace_event_file *file); 342 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b); 343 bool trace_probe_match_command_args(struct trace_probe *tp, 344 int argc, const char **argv); 345 346 #define trace_probe_for_each_link(pos, tp) \ 347 list_for_each_entry(pos, &(tp)->event->files, list) 348 #define trace_probe_for_each_link_rcu(pos, tp) \ 349 list_for_each_entry_rcu(pos, &(tp)->event->files, list) 350 351 /* Check the name is good for event/group/fields */ 352 static inline bool is_good_name(const char *name) 353 { 354 if (!isalpha(*name) && *name != '_') 355 return false; 356 while (*++name != '\0') { 357 if (!isalpha(*name) && !isdigit(*name) && *name != '_') 358 return false; 359 } 360 return true; 361 } 362 363 #define TPARG_FL_RETURN BIT(0) 364 #define TPARG_FL_KERNEL BIT(1) 365 #define TPARG_FL_FENTRY BIT(2) 366 #define TPARG_FL_MASK GENMASK(2, 0) 367 368 extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, 369 char *arg, unsigned int flags); 370 371 extern int traceprobe_update_arg(struct probe_arg *arg); 372 extern void traceprobe_free_probe_arg(struct probe_arg *arg); 373 374 extern int traceprobe_split_symbol_offset(char *symbol, long *offset); 375 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 376 char *buf, int offset); 377 378 extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return); 379 380 #ifdef CONFIG_PERF_EVENTS 381 extern struct trace_event_call * 382 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 383 bool is_return); 384 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); 385 386 extern struct trace_event_call * 387 create_local_trace_uprobe(char *name, unsigned long offs, 388 unsigned long ref_ctr_offset, bool is_return); 389 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); 390 #endif 391 extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, 392 size_t offset, struct trace_probe *tp); 393 394 #undef ERRORS 395 #define ERRORS \ 396 C(FILE_NOT_FOUND, "Failed to find the given file"), \ 397 C(NO_REGULAR_FILE, "Not a regular file"), \ 398 C(BAD_REFCNT, "Invalid reference counter offset"), \ 399 C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \ 400 C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \ 401 C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \ 402 C(MAXACT_NO_KPROBE, "Maxactive is not for kprobe"), \ 403 C(BAD_MAXACT, "Invalid maxactive number"), \ 404 C(MAXACT_TOO_BIG, "Maxactive is too big"), \ 405 C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \ 406 C(BAD_RETPROBE, "Retprobe address must be an function entry"), \ 407 C(NO_GROUP_NAME, "Group name is not specified"), \ 408 C(GROUP_TOO_LONG, "Group name is too long"), \ 409 C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \ 410 C(NO_EVENT_NAME, "Event name is not specified"), \ 411 C(EVENT_TOO_LONG, "Event name is too long"), \ 412 C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \ 413 C(RETVAL_ON_PROBE, "$retval is not available on probe"), \ 414 C(BAD_STACK_NUM, "Invalid stack number"), \ 415 C(BAD_ARG_NUM, "Invalid argument number"), \ 416 C(BAD_VAR, "Invalid $-valiable specified"), \ 417 C(BAD_REG_NAME, "Invalid register name"), \ 418 C(BAD_MEM_ADDR, "Invalid memory address"), \ 419 C(BAD_IMM, "Invalid immediate value"), \ 420 C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \ 421 C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \ 422 C(BAD_FILE_OFFS, "Invalid file offset value"), \ 423 C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \ 424 C(TOO_MANY_OPS, "Dereference is too much nested"), \ 425 C(DEREF_NEED_BRACE, "Dereference needs a brace"), \ 426 C(BAD_DEREF_OFFS, "Invalid dereference offset"), \ 427 C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \ 428 C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \ 429 C(BAD_FETCH_ARG, "Invalid fetch argument"), \ 430 C(ARRAY_NO_CLOSE, "Array is not closed"), \ 431 C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \ 432 C(BAD_ARRAY_NUM, "Invalid array size"), \ 433 C(ARRAY_TOO_BIG, "Array number is too big"), \ 434 C(BAD_TYPE, "Unknown type is specified"), \ 435 C(BAD_STRING, "String accepts only memory argument"), \ 436 C(BAD_BITFIELD, "Invalid bitfield"), \ 437 C(ARG_NAME_TOO_LONG, "Argument name is too long"), \ 438 C(NO_ARG_NAME, "Argument name is not specified"), \ 439 C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \ 440 C(USED_ARG_NAME, "This argument name is already used"), \ 441 C(ARG_TOO_LONG, "Argument expression is too long"), \ 442 C(NO_ARG_BODY, "No argument expression"), \ 443 C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\ 444 C(FAIL_REG_PROBE, "Failed to register probe event"),\ 445 C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\ 446 C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\ 447 C(SAME_PROBE, "There is already the exact same probe event"), 448 449 #undef C 450 #define C(a, b) TP_ERR_##a 451 452 /* Define TP_ERR_ */ 453 enum { ERRORS }; 454 455 /* Error text is defined in trace_probe.c */ 456 457 struct trace_probe_log { 458 const char *subsystem; 459 const char **argv; 460 int argc; 461 int index; 462 }; 463 464 void trace_probe_log_init(const char *subsystem, int argc, const char **argv); 465 void trace_probe_log_set_index(int index); 466 void trace_probe_log_clear(void); 467 void __trace_probe_log_err(int offset, int err); 468 469 #define trace_probe_log_err(offs, err) \ 470 __trace_probe_log_err(offs, TP_ERR_##err) 471