1 /* 2 * Common header file for probe-based Dynamic events. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 16 * 17 * This code was copied from kernel/trace/trace_kprobe.h written by 18 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> 19 * 20 * Updates to make this generic: 21 * Copyright (C) IBM Corporation, 2010-2011 22 * Author: Srikar Dronamraju 23 */ 24 25 #include <linux/seq_file.h> 26 #include <linux/slab.h> 27 #include <linux/smp.h> 28 #include <linux/tracefs.h> 29 #include <linux/types.h> 30 #include <linux/string.h> 31 #include <linux/ctype.h> 32 #include <linux/ptrace.h> 33 #include <linux/perf_event.h> 34 #include <linux/kprobes.h> 35 #include <linux/stringify.h> 36 #include <linux/limits.h> 37 #include <linux/uaccess.h> 38 #include <asm/bitsperlong.h> 39 40 #include "trace.h" 41 #include "trace_output.h" 42 43 #define MAX_TRACE_ARGS 128 44 #define MAX_ARGSTR_LEN 63 45 #define MAX_STRING_SIZE PATH_MAX 46 47 /* Reserved field names */ 48 #define FIELD_STRING_IP "__probe_ip" 49 #define FIELD_STRING_RETIP "__probe_ret_ip" 50 #define FIELD_STRING_FUNC "__probe_func" 51 52 #undef DEFINE_FIELD 53 #define DEFINE_FIELD(type, item, name, is_signed) \ 54 do { \ 55 ret = trace_define_field(event_call, #type, name, \ 56 offsetof(typeof(field), item), \ 57 sizeof(field.item), is_signed, \ 58 FILTER_OTHER); \ 59 if (ret) \ 60 return ret; \ 61 } while (0) 62 63 64 /* Flags for trace_probe */ 65 #define TP_FLAG_TRACE 1 66 #define TP_FLAG_PROFILE 2 67 #define TP_FLAG_REGISTERED 4 68 69 70 /* data_rloc: data relative location, compatible with u32 */ 71 #define make_data_rloc(len, roffs) \ 72 (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) 73 #define get_rloc_len(dl) ((u32)(dl) >> 16) 74 #define get_rloc_offs(dl) ((u32)(dl) & 0xffff) 75 76 /* 77 * Convert data_rloc to data_loc: 78 * data_rloc stores the offset from data_rloc itself, but data_loc 79 * stores the offset from event entry. 80 */ 81 #define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) 82 83 static nokprobe_inline void *get_rloc_data(u32 *dl) 84 { 85 return (u8 *)dl + get_rloc_offs(*dl); 86 } 87 88 /* For data_loc conversion */ 89 static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) 90 { 91 return (u8 *)ent + get_rloc_offs(*dl); 92 } 93 94 /* Data fetch function type */ 95 typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); 96 /* Printing function type */ 97 typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); 98 99 /* Fetch types */ 100 enum { 101 FETCH_MTD_reg = 0, 102 FETCH_MTD_stack, 103 FETCH_MTD_retval, 104 FETCH_MTD_comm, 105 FETCH_MTD_memory, 106 FETCH_MTD_symbol, 107 FETCH_MTD_deref, 108 FETCH_MTD_bitfield, 109 FETCH_MTD_file_offset, 110 FETCH_MTD_END, 111 }; 112 113 /* Fetch type information table */ 114 struct fetch_type { 115 const char *name; /* Name of type */ 116 size_t size; /* Byte size of type */ 117 int is_signed; /* Signed flag */ 118 print_type_func_t print; /* Print functions */ 119 const char *fmt; /* Fromat string */ 120 const char *fmttype; /* Name in format file */ 121 /* Fetch functions */ 122 fetch_func_t fetch[FETCH_MTD_END]; 123 }; 124 125 struct fetch_param { 126 fetch_func_t fn; 127 void *data; 128 }; 129 130 /* For defining macros, define string/string_size types */ 131 typedef u32 string; 132 typedef u32 string_size; 133 134 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type 135 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type 136 137 /* Printing in basic type function template */ 138 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ 139 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ 140 void *data, void *ent); \ 141 extern const char PRINT_TYPE_FMT_NAME(type)[] 142 143 DECLARE_BASIC_PRINT_TYPE_FUNC(u8); 144 DECLARE_BASIC_PRINT_TYPE_FUNC(u16); 145 DECLARE_BASIC_PRINT_TYPE_FUNC(u32); 146 DECLARE_BASIC_PRINT_TYPE_FUNC(u64); 147 DECLARE_BASIC_PRINT_TYPE_FUNC(s8); 148 DECLARE_BASIC_PRINT_TYPE_FUNC(s16); 149 DECLARE_BASIC_PRINT_TYPE_FUNC(s32); 150 DECLARE_BASIC_PRINT_TYPE_FUNC(s64); 151 DECLARE_BASIC_PRINT_TYPE_FUNC(x8); 152 DECLARE_BASIC_PRINT_TYPE_FUNC(x16); 153 DECLARE_BASIC_PRINT_TYPE_FUNC(x32); 154 DECLARE_BASIC_PRINT_TYPE_FUNC(x64); 155 156 DECLARE_BASIC_PRINT_TYPE_FUNC(string); 157 158 #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type 159 160 /* Declare macro for basic types */ 161 #define DECLARE_FETCH_FUNC(method, type) \ 162 extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \ 163 void *data, void *dest) 164 165 #define DECLARE_BASIC_FETCH_FUNCS(method) \ 166 DECLARE_FETCH_FUNC(method, u8); \ 167 DECLARE_FETCH_FUNC(method, u16); \ 168 DECLARE_FETCH_FUNC(method, u32); \ 169 DECLARE_FETCH_FUNC(method, u64) 170 171 DECLARE_BASIC_FETCH_FUNCS(reg); 172 #define fetch_reg_string NULL 173 #define fetch_reg_string_size NULL 174 175 DECLARE_BASIC_FETCH_FUNCS(retval); 176 #define fetch_retval_string NULL 177 #define fetch_retval_string_size NULL 178 179 DECLARE_BASIC_FETCH_FUNCS(symbol); 180 DECLARE_FETCH_FUNC(symbol, string); 181 DECLARE_FETCH_FUNC(symbol, string_size); 182 183 DECLARE_BASIC_FETCH_FUNCS(deref); 184 DECLARE_FETCH_FUNC(deref, string); 185 DECLARE_FETCH_FUNC(deref, string_size); 186 187 DECLARE_BASIC_FETCH_FUNCS(bitfield); 188 #define fetch_bitfield_string NULL 189 #define fetch_bitfield_string_size NULL 190 191 /* comm only makes sense as a string */ 192 #define fetch_comm_u8 NULL 193 #define fetch_comm_u16 NULL 194 #define fetch_comm_u32 NULL 195 #define fetch_comm_u64 NULL 196 DECLARE_FETCH_FUNC(comm, string); 197 DECLARE_FETCH_FUNC(comm, string_size); 198 199 /* 200 * Define macro for basic types - we don't need to define s* types, because 201 * we have to care only about bitwidth at recording time. 202 */ 203 #define DEFINE_BASIC_FETCH_FUNCS(method) \ 204 DEFINE_FETCH_##method(u8) \ 205 DEFINE_FETCH_##method(u16) \ 206 DEFINE_FETCH_##method(u32) \ 207 DEFINE_FETCH_##method(u64) 208 209 /* Default (unsigned long) fetch type */ 210 #define __DEFAULT_FETCH_TYPE(t) x##t 211 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 212 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 213 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 214 215 #define ASSIGN_FETCH_FUNC(method, type) \ 216 [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) 217 218 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 219 {.name = _name, \ 220 .size = _size, \ 221 .is_signed = sign, \ 222 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 223 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 224 .fmttype = _fmttype, \ 225 .fetch = { \ 226 ASSIGN_FETCH_FUNC(reg, ftype), \ 227 ASSIGN_FETCH_FUNC(stack, ftype), \ 228 ASSIGN_FETCH_FUNC(retval, ftype), \ 229 ASSIGN_FETCH_FUNC(comm, ftype), \ 230 ASSIGN_FETCH_FUNC(memory, ftype), \ 231 ASSIGN_FETCH_FUNC(symbol, ftype), \ 232 ASSIGN_FETCH_FUNC(deref, ftype), \ 233 ASSIGN_FETCH_FUNC(bitfield, ftype), \ 234 ASSIGN_FETCH_FUNC(file_offset, ftype), \ 235 } \ 236 } 237 238 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 239 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) 240 241 /* If ptype is an alias of atype, use this macro (show atype in format) */ 242 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ 243 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #atype) 244 245 #define ASSIGN_FETCH_TYPE_END {} 246 247 #define FETCH_TYPE_STRING 0 248 #define FETCH_TYPE_STRSIZE 1 249 250 #ifdef CONFIG_KPROBE_EVENTS 251 struct symbol_cache; 252 unsigned long update_symbol_cache(struct symbol_cache *sc); 253 void free_symbol_cache(struct symbol_cache *sc); 254 struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); 255 bool trace_kprobe_on_func_entry(struct trace_event_call *call); 256 bool trace_kprobe_error_injectable(struct trace_event_call *call); 257 #else 258 /* uprobes do not support symbol fetch methods */ 259 #define fetch_symbol_u8 NULL 260 #define fetch_symbol_u16 NULL 261 #define fetch_symbol_u32 NULL 262 #define fetch_symbol_u64 NULL 263 #define fetch_symbol_string NULL 264 #define fetch_symbol_string_size NULL 265 266 struct symbol_cache { 267 }; 268 static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) 269 { 270 return 0; 271 } 272 273 static inline void __used free_symbol_cache(struct symbol_cache *sc) 274 { 275 } 276 277 static inline struct symbol_cache * __used 278 alloc_symbol_cache(const char *sym, long offset) 279 { 280 return NULL; 281 } 282 283 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) 284 { 285 return false; 286 } 287 288 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) 289 { 290 return false; 291 } 292 #endif /* CONFIG_KPROBE_EVENTS */ 293 294 struct probe_arg { 295 struct fetch_param fetch; 296 struct fetch_param fetch_size; 297 unsigned int offset; /* Offset from argument entry */ 298 const char *name; /* Name of this argument */ 299 const char *comm; /* Command of this argument */ 300 const struct fetch_type *type; /* Type of this argument */ 301 }; 302 303 struct trace_probe { 304 unsigned int flags; /* For TP_FLAG_* */ 305 struct trace_event_class class; 306 struct trace_event_call call; 307 struct list_head files; 308 ssize_t size; /* trace entry size */ 309 unsigned int nr_args; 310 struct probe_arg args[]; 311 }; 312 313 struct event_file_link { 314 struct trace_event_file *file; 315 struct list_head list; 316 }; 317 318 static inline bool trace_probe_is_enabled(struct trace_probe *tp) 319 { 320 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); 321 } 322 323 static inline bool trace_probe_is_registered(struct trace_probe *tp) 324 { 325 return !!(tp->flags & TP_FLAG_REGISTERED); 326 } 327 328 static nokprobe_inline void call_fetch(struct fetch_param *fprm, 329 struct pt_regs *regs, void *dest) 330 { 331 return fprm->fn(regs, fprm->data, dest); 332 } 333 334 /* Check the name is good for event/group/fields */ 335 static inline bool is_good_name(const char *name) 336 { 337 if (!isalpha(*name) && *name != '_') 338 return false; 339 while (*++name != '\0') { 340 if (!isalpha(*name) && !isdigit(*name) && *name != '_') 341 return false; 342 } 343 return true; 344 } 345 346 static inline struct event_file_link * 347 find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) 348 { 349 struct event_file_link *link; 350 351 list_for_each_entry(link, &tp->files, list) 352 if (link->file == file) 353 return link; 354 355 return NULL; 356 } 357 358 extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, 359 struct probe_arg *parg, bool is_return, bool is_kprobe, 360 const struct fetch_type *ftbl); 361 362 extern int traceprobe_conflict_field_name(const char *name, 363 struct probe_arg *args, int narg); 364 365 extern void traceprobe_update_arg(struct probe_arg *arg); 366 extern void traceprobe_free_probe_arg(struct probe_arg *arg); 367 368 extern int traceprobe_split_symbol_offset(char *symbol, long *offset); 369 370 /* Sum up total data length for dynamic arraies (strings) */ 371 static nokprobe_inline int 372 __get_data_size(struct trace_probe *tp, struct pt_regs *regs) 373 { 374 int i, ret = 0; 375 u32 len; 376 377 for (i = 0; i < tp->nr_args; i++) 378 if (unlikely(tp->args[i].fetch_size.fn)) { 379 call_fetch(&tp->args[i].fetch_size, regs, &len); 380 ret += len; 381 } 382 383 return ret; 384 } 385 386 /* Store the value of each argument */ 387 static nokprobe_inline void 388 store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, 389 u8 *data, int maxlen) 390 { 391 int i; 392 u32 end = tp->size; 393 u32 *dl; /* Data (relative) location */ 394 395 for (i = 0; i < tp->nr_args; i++) { 396 if (unlikely(tp->args[i].fetch_size.fn)) { 397 /* 398 * First, we set the relative location and 399 * maximum data length to *dl 400 */ 401 dl = (u32 *)(data + tp->args[i].offset); 402 *dl = make_data_rloc(maxlen, end - tp->args[i].offset); 403 /* Then try to fetch string or dynamic array data */ 404 call_fetch(&tp->args[i].fetch, regs, dl); 405 /* Reduce maximum length */ 406 end += get_rloc_len(*dl); 407 maxlen -= get_rloc_len(*dl); 408 /* Trick here, convert data_rloc to data_loc */ 409 *dl = convert_rloc_to_loc(*dl, 410 ent_size + tp->args[i].offset); 411 } else 412 /* Just fetching data normally */ 413 call_fetch(&tp->args[i].fetch, regs, 414 data + tp->args[i].offset); 415 } 416 } 417 418 extern int set_print_fmt(struct trace_probe *tp, bool is_return); 419 420 #ifdef CONFIG_PERF_EVENTS 421 extern struct trace_event_call * 422 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 423 bool is_return); 424 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); 425 426 extern struct trace_event_call * 427 create_local_trace_uprobe(char *name, unsigned long offs, bool is_return); 428 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); 429 #endif 430