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_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(string); 152 153 #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type 154 155 /* Declare macro for basic types */ 156 #define DECLARE_FETCH_FUNC(method, type) \ 157 extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \ 158 void *data, void *dest) 159 160 #define DECLARE_BASIC_FETCH_FUNCS(method) \ 161 DECLARE_FETCH_FUNC(method, u8); \ 162 DECLARE_FETCH_FUNC(method, u16); \ 163 DECLARE_FETCH_FUNC(method, u32); \ 164 DECLARE_FETCH_FUNC(method, u64) 165 166 DECLARE_BASIC_FETCH_FUNCS(reg); 167 #define fetch_reg_string NULL 168 #define fetch_reg_string_size NULL 169 170 DECLARE_BASIC_FETCH_FUNCS(retval); 171 #define fetch_retval_string NULL 172 #define fetch_retval_string_size NULL 173 174 DECLARE_BASIC_FETCH_FUNCS(symbol); 175 DECLARE_FETCH_FUNC(symbol, string); 176 DECLARE_FETCH_FUNC(symbol, string_size); 177 178 DECLARE_BASIC_FETCH_FUNCS(deref); 179 DECLARE_FETCH_FUNC(deref, string); 180 DECLARE_FETCH_FUNC(deref, string_size); 181 182 DECLARE_BASIC_FETCH_FUNCS(bitfield); 183 #define fetch_bitfield_string NULL 184 #define fetch_bitfield_string_size NULL 185 186 /* 187 * Define macro for basic types - we don't need to define s* types, because 188 * we have to care only about bitwidth at recording time. 189 */ 190 #define DEFINE_BASIC_FETCH_FUNCS(method) \ 191 DEFINE_FETCH_##method(u8) \ 192 DEFINE_FETCH_##method(u16) \ 193 DEFINE_FETCH_##method(u32) \ 194 DEFINE_FETCH_##method(u64) 195 196 /* Default (unsigned long) fetch type */ 197 #define __DEFAULT_FETCH_TYPE(t) u##t 198 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 199 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 200 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 201 202 #define ASSIGN_FETCH_FUNC(method, type) \ 203 [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) 204 205 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 206 {.name = _name, \ 207 .size = _size, \ 208 .is_signed = sign, \ 209 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 210 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 211 .fmttype = _fmttype, \ 212 .fetch = { \ 213 ASSIGN_FETCH_FUNC(reg, ftype), \ 214 ASSIGN_FETCH_FUNC(stack, ftype), \ 215 ASSIGN_FETCH_FUNC(retval, ftype), \ 216 ASSIGN_FETCH_FUNC(memory, ftype), \ 217 ASSIGN_FETCH_FUNC(symbol, ftype), \ 218 ASSIGN_FETCH_FUNC(deref, ftype), \ 219 ASSIGN_FETCH_FUNC(bitfield, ftype), \ 220 ASSIGN_FETCH_FUNC(file_offset, ftype), \ 221 } \ 222 } 223 224 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 225 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) 226 227 #define ASSIGN_FETCH_TYPE_END {} 228 229 #define FETCH_TYPE_STRING 0 230 #define FETCH_TYPE_STRSIZE 1 231 232 #ifdef CONFIG_KPROBE_EVENT 233 struct symbol_cache; 234 unsigned long update_symbol_cache(struct symbol_cache *sc); 235 void free_symbol_cache(struct symbol_cache *sc); 236 struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); 237 #else 238 /* uprobes do not support symbol fetch methods */ 239 #define fetch_symbol_u8 NULL 240 #define fetch_symbol_u16 NULL 241 #define fetch_symbol_u32 NULL 242 #define fetch_symbol_u64 NULL 243 #define fetch_symbol_string NULL 244 #define fetch_symbol_string_size NULL 245 246 struct symbol_cache { 247 }; 248 static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) 249 { 250 return 0; 251 } 252 253 static inline void __used free_symbol_cache(struct symbol_cache *sc) 254 { 255 } 256 257 static inline struct symbol_cache * __used 258 alloc_symbol_cache(const char *sym, long offset) 259 { 260 return NULL; 261 } 262 #endif /* CONFIG_KPROBE_EVENT */ 263 264 struct probe_arg { 265 struct fetch_param fetch; 266 struct fetch_param fetch_size; 267 unsigned int offset; /* Offset from argument entry */ 268 const char *name; /* Name of this argument */ 269 const char *comm; /* Command of this argument */ 270 const struct fetch_type *type; /* Type of this argument */ 271 }; 272 273 struct trace_probe { 274 unsigned int flags; /* For TP_FLAG_* */ 275 struct ftrace_event_class class; 276 struct ftrace_event_call call; 277 struct list_head files; 278 ssize_t size; /* trace entry size */ 279 unsigned int nr_args; 280 struct probe_arg args[]; 281 }; 282 283 struct event_file_link { 284 struct ftrace_event_file *file; 285 struct list_head list; 286 }; 287 288 static inline bool trace_probe_is_enabled(struct trace_probe *tp) 289 { 290 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); 291 } 292 293 static inline bool trace_probe_is_registered(struct trace_probe *tp) 294 { 295 return !!(tp->flags & TP_FLAG_REGISTERED); 296 } 297 298 static nokprobe_inline void call_fetch(struct fetch_param *fprm, 299 struct pt_regs *regs, void *dest) 300 { 301 return fprm->fn(regs, fprm->data, dest); 302 } 303 304 /* Check the name is good for event/group/fields */ 305 static inline int is_good_name(const char *name) 306 { 307 if (!isalpha(*name) && *name != '_') 308 return 0; 309 while (*++name != '\0') { 310 if (!isalpha(*name) && !isdigit(*name) && *name != '_') 311 return 0; 312 } 313 return 1; 314 } 315 316 static inline struct event_file_link * 317 find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file) 318 { 319 struct event_file_link *link; 320 321 list_for_each_entry(link, &tp->files, list) 322 if (link->file == file) 323 return link; 324 325 return NULL; 326 } 327 328 extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, 329 struct probe_arg *parg, bool is_return, bool is_kprobe, 330 const struct fetch_type *ftbl); 331 332 extern int traceprobe_conflict_field_name(const char *name, 333 struct probe_arg *args, int narg); 334 335 extern void traceprobe_update_arg(struct probe_arg *arg); 336 extern void traceprobe_free_probe_arg(struct probe_arg *arg); 337 338 extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); 339 340 extern ssize_t traceprobe_probes_write(struct file *file, 341 const char __user *buffer, size_t count, loff_t *ppos, 342 int (*createfn)(int, char**)); 343 344 extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); 345 346 /* Sum up total data length for dynamic arraies (strings) */ 347 static nokprobe_inline int 348 __get_data_size(struct trace_probe *tp, struct pt_regs *regs) 349 { 350 int i, ret = 0; 351 u32 len; 352 353 for (i = 0; i < tp->nr_args; i++) 354 if (unlikely(tp->args[i].fetch_size.fn)) { 355 call_fetch(&tp->args[i].fetch_size, regs, &len); 356 ret += len; 357 } 358 359 return ret; 360 } 361 362 /* Store the value of each argument */ 363 static nokprobe_inline void 364 store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, 365 u8 *data, int maxlen) 366 { 367 int i; 368 u32 end = tp->size; 369 u32 *dl; /* Data (relative) location */ 370 371 for (i = 0; i < tp->nr_args; i++) { 372 if (unlikely(tp->args[i].fetch_size.fn)) { 373 /* 374 * First, we set the relative location and 375 * maximum data length to *dl 376 */ 377 dl = (u32 *)(data + tp->args[i].offset); 378 *dl = make_data_rloc(maxlen, end - tp->args[i].offset); 379 /* Then try to fetch string or dynamic array data */ 380 call_fetch(&tp->args[i].fetch, regs, dl); 381 /* Reduce maximum length */ 382 end += get_rloc_len(*dl); 383 maxlen -= get_rloc_len(*dl); 384 /* Trick here, convert data_rloc to data_loc */ 385 *dl = convert_rloc_to_loc(*dl, 386 ent_size + tp->args[i].offset); 387 } else 388 /* Just fetching data normally */ 389 call_fetch(&tp->args[i].fetch, regs, 390 data + tp->args[i].offset); 391 } 392 } 393 394 extern int set_print_fmt(struct trace_probe *tp, bool is_return); 395