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