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