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 <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_STRING_SIZE PATH_MAX 34 35 /* Reserved field names */ 36 #define FIELD_STRING_IP "__probe_ip" 37 #define FIELD_STRING_RETIP "__probe_ret_ip" 38 #define FIELD_STRING_FUNC "__probe_func" 39 40 #undef DEFINE_FIELD 41 #define DEFINE_FIELD(type, item, name, is_signed) \ 42 do { \ 43 ret = trace_define_field(event_call, #type, name, \ 44 offsetof(typeof(field), item), \ 45 sizeof(field.item), is_signed, \ 46 FILTER_OTHER); \ 47 if (ret) \ 48 return ret; \ 49 } while (0) 50 51 52 /* Flags for trace_probe */ 53 #define TP_FLAG_TRACE 1 54 #define TP_FLAG_PROFILE 2 55 #define TP_FLAG_REGISTERED 4 56 57 58 /* data_rloc: data relative location, compatible with u32 */ 59 #define make_data_rloc(len, roffs) \ 60 (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) 61 #define get_rloc_len(dl) ((u32)(dl) >> 16) 62 #define get_rloc_offs(dl) ((u32)(dl) & 0xffff) 63 64 /* 65 * Convert data_rloc to data_loc: 66 * data_rloc stores the offset from data_rloc itself, but data_loc 67 * stores the offset from event entry. 68 */ 69 #define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) 70 71 static nokprobe_inline void *get_rloc_data(u32 *dl) 72 { 73 return (u8 *)dl + get_rloc_offs(*dl); 74 } 75 76 /* For data_loc conversion */ 77 static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) 78 { 79 return (u8 *)ent + get_rloc_offs(*dl); 80 } 81 82 /* Data fetch function type */ 83 typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); 84 /* Printing function type */ 85 typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); 86 87 /* Fetch types */ 88 enum { 89 FETCH_MTD_reg = 0, 90 FETCH_MTD_stack, 91 FETCH_MTD_retval, 92 FETCH_MTD_comm, 93 FETCH_MTD_memory, 94 FETCH_MTD_symbol, 95 FETCH_MTD_deref, 96 FETCH_MTD_bitfield, 97 FETCH_MTD_file_offset, 98 FETCH_MTD_END, 99 }; 100 101 /* Fetch type information table */ 102 struct fetch_type { 103 const char *name; /* Name of type */ 104 size_t size; /* Byte size of type */ 105 int is_signed; /* Signed flag */ 106 print_type_func_t print; /* Print functions */ 107 const char *fmt; /* Fromat string */ 108 const char *fmttype; /* Name in format file */ 109 /* Fetch functions */ 110 fetch_func_t fetch[FETCH_MTD_END]; 111 }; 112 113 struct fetch_param { 114 fetch_func_t fn; 115 void *data; 116 }; 117 118 /* For defining macros, define string/string_size types */ 119 typedef u32 string; 120 typedef u32 string_size; 121 122 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type 123 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type 124 125 /* Printing in basic type function template */ 126 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ 127 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ 128 void *data, void *ent); \ 129 extern const char PRINT_TYPE_FMT_NAME(type)[] 130 131 DECLARE_BASIC_PRINT_TYPE_FUNC(u8); 132 DECLARE_BASIC_PRINT_TYPE_FUNC(u16); 133 DECLARE_BASIC_PRINT_TYPE_FUNC(u32); 134 DECLARE_BASIC_PRINT_TYPE_FUNC(u64); 135 DECLARE_BASIC_PRINT_TYPE_FUNC(s8); 136 DECLARE_BASIC_PRINT_TYPE_FUNC(s16); 137 DECLARE_BASIC_PRINT_TYPE_FUNC(s32); 138 DECLARE_BASIC_PRINT_TYPE_FUNC(s64); 139 DECLARE_BASIC_PRINT_TYPE_FUNC(x8); 140 DECLARE_BASIC_PRINT_TYPE_FUNC(x16); 141 DECLARE_BASIC_PRINT_TYPE_FUNC(x32); 142 DECLARE_BASIC_PRINT_TYPE_FUNC(x64); 143 144 DECLARE_BASIC_PRINT_TYPE_FUNC(string); 145 146 #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type 147 148 /* Declare macro for basic types */ 149 #define DECLARE_FETCH_FUNC(method, type) \ 150 extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \ 151 void *data, void *dest) 152 153 #define DECLARE_BASIC_FETCH_FUNCS(method) \ 154 DECLARE_FETCH_FUNC(method, u8); \ 155 DECLARE_FETCH_FUNC(method, u16); \ 156 DECLARE_FETCH_FUNC(method, u32); \ 157 DECLARE_FETCH_FUNC(method, u64) 158 159 DECLARE_BASIC_FETCH_FUNCS(reg); 160 #define fetch_reg_string NULL 161 #define fetch_reg_string_size NULL 162 163 DECLARE_BASIC_FETCH_FUNCS(retval); 164 #define fetch_retval_string NULL 165 #define fetch_retval_string_size NULL 166 167 DECLARE_BASIC_FETCH_FUNCS(symbol); 168 DECLARE_FETCH_FUNC(symbol, string); 169 DECLARE_FETCH_FUNC(symbol, string_size); 170 171 DECLARE_BASIC_FETCH_FUNCS(deref); 172 DECLARE_FETCH_FUNC(deref, string); 173 DECLARE_FETCH_FUNC(deref, string_size); 174 175 DECLARE_BASIC_FETCH_FUNCS(bitfield); 176 #define fetch_bitfield_string NULL 177 #define fetch_bitfield_string_size NULL 178 179 /* comm only makes sense as a string */ 180 #define fetch_comm_u8 NULL 181 #define fetch_comm_u16 NULL 182 #define fetch_comm_u32 NULL 183 #define fetch_comm_u64 NULL 184 DECLARE_FETCH_FUNC(comm, string); 185 DECLARE_FETCH_FUNC(comm, string_size); 186 187 /* 188 * Define macro for basic types - we don't need to define s* types, because 189 * we have to care only about bitwidth at recording time. 190 */ 191 #define DEFINE_BASIC_FETCH_FUNCS(method) \ 192 DEFINE_FETCH_##method(u8) \ 193 DEFINE_FETCH_##method(u16) \ 194 DEFINE_FETCH_##method(u32) \ 195 DEFINE_FETCH_##method(u64) 196 197 /* Default (unsigned long) fetch type */ 198 #define __DEFAULT_FETCH_TYPE(t) x##t 199 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 200 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 201 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 202 203 #define ASSIGN_FETCH_FUNC(method, type) \ 204 [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) 205 206 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 207 {.name = _name, \ 208 .size = _size, \ 209 .is_signed = sign, \ 210 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 211 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 212 .fmttype = _fmttype, \ 213 .fetch = { \ 214 ASSIGN_FETCH_FUNC(reg, ftype), \ 215 ASSIGN_FETCH_FUNC(stack, ftype), \ 216 ASSIGN_FETCH_FUNC(retval, ftype), \ 217 ASSIGN_FETCH_FUNC(comm, ftype), \ 218 ASSIGN_FETCH_FUNC(memory, ftype), \ 219 ASSIGN_FETCH_FUNC(symbol, ftype), \ 220 ASSIGN_FETCH_FUNC(deref, ftype), \ 221 ASSIGN_FETCH_FUNC(bitfield, ftype), \ 222 ASSIGN_FETCH_FUNC(file_offset, ftype), \ 223 } \ 224 } 225 226 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 227 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) 228 229 /* If ptype is an alias of atype, use this macro (show atype in format) */ 230 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ 231 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #atype) 232 233 #define ASSIGN_FETCH_TYPE_END {} 234 235 #define FETCH_TYPE_STRING 0 236 #define FETCH_TYPE_STRSIZE 1 237 238 #ifdef CONFIG_KPROBE_EVENTS 239 struct symbol_cache; 240 unsigned long update_symbol_cache(struct symbol_cache *sc); 241 void free_symbol_cache(struct symbol_cache *sc); 242 struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); 243 bool trace_kprobe_on_func_entry(struct trace_event_call *call); 244 bool trace_kprobe_error_injectable(struct trace_event_call *call); 245 #else 246 /* uprobes do not support symbol fetch methods */ 247 #define fetch_symbol_u8 NULL 248 #define fetch_symbol_u16 NULL 249 #define fetch_symbol_u32 NULL 250 #define fetch_symbol_u64 NULL 251 #define fetch_symbol_string NULL 252 #define fetch_symbol_string_size NULL 253 254 struct symbol_cache { 255 }; 256 static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) 257 { 258 return 0; 259 } 260 261 static inline void __used free_symbol_cache(struct symbol_cache *sc) 262 { 263 } 264 265 static inline struct symbol_cache * __used 266 alloc_symbol_cache(const char *sym, long offset) 267 { 268 return NULL; 269 } 270 271 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) 272 { 273 return false; 274 } 275 276 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) 277 { 278 return false; 279 } 280 #endif /* CONFIG_KPROBE_EVENTS */ 281 282 struct probe_arg { 283 struct fetch_param fetch; 284 struct fetch_param fetch_size; 285 unsigned int offset; /* Offset from argument entry */ 286 const char *name; /* Name of this argument */ 287 const char *comm; /* Command of this argument */ 288 const struct fetch_type *type; /* Type of this argument */ 289 }; 290 291 struct trace_probe { 292 unsigned int flags; /* For TP_FLAG_* */ 293 struct trace_event_class class; 294 struct trace_event_call call; 295 struct list_head files; 296 ssize_t size; /* trace entry size */ 297 unsigned int nr_args; 298 struct probe_arg args[]; 299 }; 300 301 struct event_file_link { 302 struct trace_event_file *file; 303 struct list_head list; 304 }; 305 306 static inline bool trace_probe_is_enabled(struct trace_probe *tp) 307 { 308 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); 309 } 310 311 static inline bool trace_probe_is_registered(struct trace_probe *tp) 312 { 313 return !!(tp->flags & TP_FLAG_REGISTERED); 314 } 315 316 static nokprobe_inline void call_fetch(struct fetch_param *fprm, 317 struct pt_regs *regs, void *dest) 318 { 319 return fprm->fn(regs, fprm->data, dest); 320 } 321 322 /* Check the name is good for event/group/fields */ 323 static inline bool is_good_name(const char *name) 324 { 325 if (!isalpha(*name) && *name != '_') 326 return false; 327 while (*++name != '\0') { 328 if (!isalpha(*name) && !isdigit(*name) && *name != '_') 329 return false; 330 } 331 return true; 332 } 333 334 static inline struct event_file_link * 335 find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) 336 { 337 struct event_file_link *link; 338 339 list_for_each_entry(link, &tp->files, list) 340 if (link->file == file) 341 return link; 342 343 return NULL; 344 } 345 346 extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, 347 struct probe_arg *parg, bool is_return, bool is_kprobe, 348 const struct fetch_type *ftbl); 349 350 extern int traceprobe_conflict_field_name(const char *name, 351 struct probe_arg *args, int narg); 352 353 extern void traceprobe_update_arg(struct probe_arg *arg); 354 extern void traceprobe_free_probe_arg(struct probe_arg *arg); 355 356 extern int traceprobe_split_symbol_offset(char *symbol, long *offset); 357 358 /* Sum up total data length for dynamic arraies (strings) */ 359 static nokprobe_inline int 360 __get_data_size(struct trace_probe *tp, struct pt_regs *regs) 361 { 362 int i, ret = 0; 363 u32 len; 364 365 for (i = 0; i < tp->nr_args; i++) 366 if (unlikely(tp->args[i].fetch_size.fn)) { 367 call_fetch(&tp->args[i].fetch_size, regs, &len); 368 ret += len; 369 } 370 371 return ret; 372 } 373 374 /* Store the value of each argument */ 375 static nokprobe_inline void 376 store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, 377 u8 *data, int maxlen) 378 { 379 int i; 380 u32 end = tp->size; 381 u32 *dl; /* Data (relative) location */ 382 383 for (i = 0; i < tp->nr_args; i++) { 384 if (unlikely(tp->args[i].fetch_size.fn)) { 385 /* 386 * First, we set the relative location and 387 * maximum data length to *dl 388 */ 389 dl = (u32 *)(data + tp->args[i].offset); 390 *dl = make_data_rloc(maxlen, end - tp->args[i].offset); 391 /* Then try to fetch string or dynamic array data */ 392 call_fetch(&tp->args[i].fetch, regs, dl); 393 /* Reduce maximum length */ 394 end += get_rloc_len(*dl); 395 maxlen -= get_rloc_len(*dl); 396 /* Trick here, convert data_rloc to data_loc */ 397 *dl = convert_rloc_to_loc(*dl, 398 ent_size + tp->args[i].offset); 399 } else 400 /* Just fetching data normally */ 401 call_fetch(&tp->args[i].fetch, regs, 402 data + tp->args[i].offset); 403 } 404 } 405 406 extern int set_print_fmt(struct trace_probe *tp, bool is_return); 407 408 #ifdef CONFIG_PERF_EVENTS 409 extern struct trace_event_call * 410 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 411 bool is_return); 412 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); 413 414 extern struct trace_event_call * 415 create_local_trace_uprobe(char *name, unsigned long offs, bool is_return); 416 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); 417 #endif 418