Peter Oberparleiter | 2521f2c | 2009-06-17 16:28:08 -0700 | [diff] [blame] | 1 | /* |
| 2 | * This code provides functions to handle gcc's profiling data format |
| 3 | * introduced with gcc 3.4. Future versions of gcc may change the gcov |
| 4 | * format (as happened before), so all format-specific information needs |
| 5 | * to be kept modular and easily exchangeable. |
| 6 | * |
| 7 | * This file is based on gcc-internal definitions. Functions and data |
| 8 | * structures are defined to be compatible with gcc counterparts. |
| 9 | * For a better understanding, refer to gcc source: gcc/gcov-io.h. |
| 10 | * |
| 11 | * Copyright IBM Corp. 2009 |
| 12 | * Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com> |
| 13 | * |
| 14 | * Uses gcc-internal data definitions. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/errno.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/string.h> |
| 20 | #include <linux/seq_file.h> |
| 21 | #include <linux/vmalloc.h> |
| 22 | #include "gcov.h" |
| 23 | |
Frantisek Hrbata | 8cbce37 | 2013-11-12 15:11:24 -0800 | [diff] [blame] | 24 | #define GCOV_COUNTERS 5 |
| 25 | |
| 26 | static struct gcov_info *gcov_info_head; |
| 27 | |
| 28 | /** |
| 29 | * struct gcov_fn_info - profiling meta data per function |
| 30 | * @ident: object file-unique function identifier |
| 31 | * @checksum: function checksum |
| 32 | * @n_ctrs: number of values per counter type belonging to this function |
| 33 | * |
| 34 | * This data is generated by gcc during compilation and doesn't change |
| 35 | * at run-time. |
| 36 | */ |
| 37 | struct gcov_fn_info { |
| 38 | unsigned int ident; |
| 39 | unsigned int checksum; |
| 40 | unsigned int n_ctrs[0]; |
| 41 | }; |
| 42 | |
| 43 | /** |
| 44 | * struct gcov_ctr_info - profiling data per counter type |
| 45 | * @num: number of counter values for this type |
| 46 | * @values: array of counter values for this type |
| 47 | * @merge: merge function for counter values of this type (unused) |
| 48 | * |
| 49 | * This data is generated by gcc during compilation and doesn't change |
| 50 | * at run-time with the exception of the values array. |
| 51 | */ |
| 52 | struct gcov_ctr_info { |
| 53 | unsigned int num; |
| 54 | gcov_type *values; |
| 55 | void (*merge)(gcov_type *, unsigned int); |
| 56 | }; |
| 57 | |
| 58 | /** |
| 59 | * struct gcov_info - profiling data per object file |
| 60 | * @version: gcov version magic indicating the gcc version used for compilation |
| 61 | * @next: list head for a singly-linked list |
| 62 | * @stamp: time stamp |
| 63 | * @filename: name of the associated gcov data file |
| 64 | * @n_functions: number of instrumented functions |
| 65 | * @functions: function data |
| 66 | * @ctr_mask: mask specifying which counter types are active |
| 67 | * @counts: counter data per counter type |
| 68 | * |
| 69 | * This data is generated by gcc during compilation and doesn't change |
| 70 | * at run-time with the exception of the next pointer. |
| 71 | */ |
| 72 | struct gcov_info { |
| 73 | unsigned int version; |
| 74 | struct gcov_info *next; |
| 75 | unsigned int stamp; |
| 76 | const char *filename; |
| 77 | unsigned int n_functions; |
| 78 | const struct gcov_fn_info *functions; |
| 79 | unsigned int ctr_mask; |
| 80 | struct gcov_ctr_info counts[0]; |
| 81 | }; |
| 82 | |
| 83 | /** |
| 84 | * gcov_info_filename - return info filename |
| 85 | * @info: profiling data set |
| 86 | */ |
| 87 | const char *gcov_info_filename(struct gcov_info *info) |
| 88 | { |
| 89 | return info->filename; |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * gcov_info_version - return info version |
| 94 | * @info: profiling data set |
| 95 | */ |
| 96 | unsigned int gcov_info_version(struct gcov_info *info) |
| 97 | { |
| 98 | return info->version; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * gcov_info_next - return next profiling data set |
| 103 | * @info: profiling data set |
| 104 | * |
| 105 | * Returns next gcov_info following @info or first gcov_info in the chain if |
| 106 | * @info is %NULL. |
| 107 | */ |
| 108 | struct gcov_info *gcov_info_next(struct gcov_info *info) |
| 109 | { |
| 110 | if (!info) |
| 111 | return gcov_info_head; |
| 112 | |
| 113 | return info->next; |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * gcov_info_link - link/add profiling data set to the list |
| 118 | * @info: profiling data set |
| 119 | */ |
| 120 | void gcov_info_link(struct gcov_info *info) |
| 121 | { |
| 122 | info->next = gcov_info_head; |
| 123 | gcov_info_head = info; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * gcov_info_unlink - unlink/remove profiling data set from the list |
| 128 | * @prev: previous profiling data set |
| 129 | * @info: profiling data set |
| 130 | */ |
| 131 | void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info) |
| 132 | { |
| 133 | if (prev) |
| 134 | prev->next = info->next; |
| 135 | else |
| 136 | gcov_info_head = info->next; |
| 137 | } |
| 138 | |
Peter Oberparleiter | 2521f2c | 2009-06-17 16:28:08 -0700 | [diff] [blame] | 139 | /* Symbolic links to be created for each profiling data file. */ |
| 140 | const struct gcov_link gcov_link[] = { |
| 141 | { OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */ |
| 142 | { 0, NULL}, |
| 143 | }; |
| 144 | |
| 145 | /* |
| 146 | * Determine whether a counter is active. Based on gcc magic. Doesn't change |
| 147 | * at run-time. |
| 148 | */ |
| 149 | static int counter_active(struct gcov_info *info, unsigned int type) |
| 150 | { |
| 151 | return (1 << type) & info->ctr_mask; |
| 152 | } |
| 153 | |
| 154 | /* Determine number of active counters. Based on gcc magic. */ |
| 155 | static unsigned int num_counter_active(struct gcov_info *info) |
| 156 | { |
| 157 | unsigned int i; |
| 158 | unsigned int result = 0; |
| 159 | |
| 160 | for (i = 0; i < GCOV_COUNTERS; i++) { |
| 161 | if (counter_active(info, i)) |
| 162 | result++; |
| 163 | } |
| 164 | return result; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * gcov_info_reset - reset profiling data to zero |
| 169 | * @info: profiling data set |
| 170 | */ |
| 171 | void gcov_info_reset(struct gcov_info *info) |
| 172 | { |
| 173 | unsigned int active = num_counter_active(info); |
| 174 | unsigned int i; |
| 175 | |
| 176 | for (i = 0; i < active; i++) { |
| 177 | memset(info->counts[i].values, 0, |
| 178 | info->counts[i].num * sizeof(gcov_type)); |
| 179 | } |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * gcov_info_is_compatible - check if profiling data can be added |
| 184 | * @info1: first profiling data set |
| 185 | * @info2: second profiling data set |
| 186 | * |
| 187 | * Returns non-zero if profiling data can be added, zero otherwise. |
| 188 | */ |
| 189 | int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2) |
| 190 | { |
| 191 | return (info1->stamp == info2->stamp); |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * gcov_info_add - add up profiling data |
| 196 | * @dest: profiling data set to which data is added |
| 197 | * @source: profiling data set which is added |
| 198 | * |
| 199 | * Adds profiling counts of @source to @dest. |
| 200 | */ |
| 201 | void gcov_info_add(struct gcov_info *dest, struct gcov_info *source) |
| 202 | { |
| 203 | unsigned int i; |
| 204 | unsigned int j; |
| 205 | |
| 206 | for (i = 0; i < num_counter_active(dest); i++) { |
| 207 | for (j = 0; j < dest->counts[i].num; j++) { |
| 208 | dest->counts[i].values[j] += |
| 209 | source->counts[i].values[j]; |
| 210 | } |
| 211 | } |
| 212 | } |
| 213 | |
| 214 | /* Get size of function info entry. Based on gcc magic. */ |
| 215 | static size_t get_fn_size(struct gcov_info *info) |
| 216 | { |
| 217 | size_t size; |
| 218 | |
| 219 | size = sizeof(struct gcov_fn_info) + num_counter_active(info) * |
| 220 | sizeof(unsigned int); |
| 221 | if (__alignof__(struct gcov_fn_info) > sizeof(unsigned int)) |
| 222 | size = ALIGN(size, __alignof__(struct gcov_fn_info)); |
| 223 | return size; |
| 224 | } |
| 225 | |
| 226 | /* Get address of function info entry. Based on gcc magic. */ |
| 227 | static struct gcov_fn_info *get_fn_info(struct gcov_info *info, unsigned int fn) |
| 228 | { |
| 229 | return (struct gcov_fn_info *) |
| 230 | ((char *) info->functions + fn * get_fn_size(info)); |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | * gcov_info_dup - duplicate profiling data set |
| 235 | * @info: profiling data set to duplicate |
| 236 | * |
| 237 | * Return newly allocated duplicate on success, %NULL on error. |
| 238 | */ |
| 239 | struct gcov_info *gcov_info_dup(struct gcov_info *info) |
| 240 | { |
| 241 | struct gcov_info *dup; |
| 242 | unsigned int i; |
| 243 | unsigned int active; |
| 244 | |
| 245 | /* Duplicate gcov_info. */ |
| 246 | active = num_counter_active(info); |
| 247 | dup = kzalloc(sizeof(struct gcov_info) + |
| 248 | sizeof(struct gcov_ctr_info) * active, GFP_KERNEL); |
| 249 | if (!dup) |
| 250 | return NULL; |
| 251 | dup->version = info->version; |
| 252 | dup->stamp = info->stamp; |
| 253 | dup->n_functions = info->n_functions; |
| 254 | dup->ctr_mask = info->ctr_mask; |
| 255 | /* Duplicate filename. */ |
| 256 | dup->filename = kstrdup(info->filename, GFP_KERNEL); |
| 257 | if (!dup->filename) |
| 258 | goto err_free; |
| 259 | /* Duplicate table of functions. */ |
| 260 | dup->functions = kmemdup(info->functions, info->n_functions * |
| 261 | get_fn_size(info), GFP_KERNEL); |
| 262 | if (!dup->functions) |
| 263 | goto err_free; |
| 264 | /* Duplicate counter arrays. */ |
| 265 | for (i = 0; i < active ; i++) { |
| 266 | struct gcov_ctr_info *ctr = &info->counts[i]; |
| 267 | size_t size = ctr->num * sizeof(gcov_type); |
| 268 | |
| 269 | dup->counts[i].num = ctr->num; |
| 270 | dup->counts[i].merge = ctr->merge; |
| 271 | dup->counts[i].values = vmalloc(size); |
| 272 | if (!dup->counts[i].values) |
| 273 | goto err_free; |
| 274 | memcpy(dup->counts[i].values, ctr->values, size); |
| 275 | } |
| 276 | return dup; |
| 277 | |
| 278 | err_free: |
| 279 | gcov_info_free(dup); |
| 280 | return NULL; |
| 281 | } |
| 282 | |
| 283 | /** |
| 284 | * gcov_info_free - release memory for profiling data set duplicate |
| 285 | * @info: profiling data set duplicate to free |
| 286 | */ |
| 287 | void gcov_info_free(struct gcov_info *info) |
| 288 | { |
| 289 | unsigned int active = num_counter_active(info); |
| 290 | unsigned int i; |
| 291 | |
| 292 | for (i = 0; i < active ; i++) |
| 293 | vfree(info->counts[i].values); |
| 294 | kfree(info->functions); |
| 295 | kfree(info->filename); |
| 296 | kfree(info); |
| 297 | } |
| 298 | |
| 299 | /** |
| 300 | * struct type_info - iterator helper array |
| 301 | * @ctr_type: counter type |
| 302 | * @offset: index of the first value of the current function for this type |
| 303 | * |
| 304 | * This array is needed to convert the in-memory data format into the in-file |
| 305 | * data format: |
| 306 | * |
| 307 | * In-memory: |
| 308 | * for each counter type |
| 309 | * for each function |
| 310 | * values |
| 311 | * |
| 312 | * In-file: |
| 313 | * for each function |
| 314 | * for each counter type |
| 315 | * values |
| 316 | * |
| 317 | * See gcc source gcc/gcov-io.h for more information on data organization. |
| 318 | */ |
| 319 | struct type_info { |
| 320 | int ctr_type; |
| 321 | unsigned int offset; |
| 322 | }; |
| 323 | |
| 324 | /** |
| 325 | * struct gcov_iterator - specifies current file position in logical records |
| 326 | * @info: associated profiling data |
| 327 | * @record: record type |
| 328 | * @function: function number |
| 329 | * @type: counter type |
| 330 | * @count: index into values array |
| 331 | * @num_types: number of counter types |
| 332 | * @type_info: helper array to get values-array offset for current function |
| 333 | */ |
| 334 | struct gcov_iterator { |
| 335 | struct gcov_info *info; |
| 336 | |
| 337 | int record; |
| 338 | unsigned int function; |
| 339 | unsigned int type; |
| 340 | unsigned int count; |
| 341 | |
| 342 | int num_types; |
| 343 | struct type_info type_info[0]; |
| 344 | }; |
| 345 | |
| 346 | static struct gcov_fn_info *get_func(struct gcov_iterator *iter) |
| 347 | { |
| 348 | return get_fn_info(iter->info, iter->function); |
| 349 | } |
| 350 | |
| 351 | static struct type_info *get_type(struct gcov_iterator *iter) |
| 352 | { |
| 353 | return &iter->type_info[iter->type]; |
| 354 | } |
| 355 | |
| 356 | /** |
| 357 | * gcov_iter_new - allocate and initialize profiling data iterator |
| 358 | * @info: profiling data set to be iterated |
| 359 | * |
| 360 | * Return file iterator on success, %NULL otherwise. |
| 361 | */ |
| 362 | struct gcov_iterator *gcov_iter_new(struct gcov_info *info) |
| 363 | { |
| 364 | struct gcov_iterator *iter; |
| 365 | |
| 366 | iter = kzalloc(sizeof(struct gcov_iterator) + |
| 367 | num_counter_active(info) * sizeof(struct type_info), |
| 368 | GFP_KERNEL); |
| 369 | if (iter) |
| 370 | iter->info = info; |
| 371 | |
| 372 | return iter; |
| 373 | } |
| 374 | |
| 375 | /** |
| 376 | * gcov_iter_free - release memory for iterator |
| 377 | * @iter: file iterator to free |
| 378 | */ |
| 379 | void gcov_iter_free(struct gcov_iterator *iter) |
| 380 | { |
| 381 | kfree(iter); |
| 382 | } |
| 383 | |
| 384 | /** |
| 385 | * gcov_iter_get_info - return profiling data set for given file iterator |
| 386 | * @iter: file iterator |
| 387 | */ |
| 388 | struct gcov_info *gcov_iter_get_info(struct gcov_iterator *iter) |
| 389 | { |
| 390 | return iter->info; |
| 391 | } |
| 392 | |
| 393 | /** |
| 394 | * gcov_iter_start - reset file iterator to starting position |
| 395 | * @iter: file iterator |
| 396 | */ |
| 397 | void gcov_iter_start(struct gcov_iterator *iter) |
| 398 | { |
| 399 | int i; |
| 400 | |
| 401 | iter->record = 0; |
| 402 | iter->function = 0; |
| 403 | iter->type = 0; |
| 404 | iter->count = 0; |
| 405 | iter->num_types = 0; |
| 406 | for (i = 0; i < GCOV_COUNTERS; i++) { |
| 407 | if (counter_active(iter->info, i)) { |
| 408 | iter->type_info[iter->num_types].ctr_type = i; |
| 409 | iter->type_info[iter->num_types++].offset = 0; |
| 410 | } |
| 411 | } |
| 412 | } |
| 413 | |
| 414 | /* Mapping of logical record number to actual file content. */ |
| 415 | #define RECORD_FILE_MAGIC 0 |
| 416 | #define RECORD_GCOV_VERSION 1 |
| 417 | #define RECORD_TIME_STAMP 2 |
| 418 | #define RECORD_FUNCTION_TAG 3 |
| 419 | #define RECORD_FUNCTON_TAG_LEN 4 |
| 420 | #define RECORD_FUNCTION_IDENT 5 |
| 421 | #define RECORD_FUNCTION_CHECK 6 |
| 422 | #define RECORD_COUNT_TAG 7 |
| 423 | #define RECORD_COUNT_LEN 8 |
| 424 | #define RECORD_COUNT 9 |
| 425 | |
| 426 | /** |
| 427 | * gcov_iter_next - advance file iterator to next logical record |
| 428 | * @iter: file iterator |
| 429 | * |
| 430 | * Return zero if new position is valid, non-zero if iterator has reached end. |
| 431 | */ |
| 432 | int gcov_iter_next(struct gcov_iterator *iter) |
| 433 | { |
| 434 | switch (iter->record) { |
| 435 | case RECORD_FILE_MAGIC: |
| 436 | case RECORD_GCOV_VERSION: |
| 437 | case RECORD_FUNCTION_TAG: |
| 438 | case RECORD_FUNCTON_TAG_LEN: |
| 439 | case RECORD_FUNCTION_IDENT: |
| 440 | case RECORD_COUNT_TAG: |
| 441 | /* Advance to next record */ |
| 442 | iter->record++; |
| 443 | break; |
| 444 | case RECORD_COUNT: |
| 445 | /* Advance to next count */ |
| 446 | iter->count++; |
| 447 | /* fall through */ |
| 448 | case RECORD_COUNT_LEN: |
| 449 | if (iter->count < get_func(iter)->n_ctrs[iter->type]) { |
| 450 | iter->record = 9; |
| 451 | break; |
| 452 | } |
| 453 | /* Advance to next counter type */ |
| 454 | get_type(iter)->offset += iter->count; |
| 455 | iter->count = 0; |
| 456 | iter->type++; |
| 457 | /* fall through */ |
| 458 | case RECORD_FUNCTION_CHECK: |
| 459 | if (iter->type < iter->num_types) { |
| 460 | iter->record = 7; |
| 461 | break; |
| 462 | } |
| 463 | /* Advance to next function */ |
| 464 | iter->type = 0; |
| 465 | iter->function++; |
| 466 | /* fall through */ |
| 467 | case RECORD_TIME_STAMP: |
| 468 | if (iter->function < iter->info->n_functions) |
| 469 | iter->record = 3; |
| 470 | else |
| 471 | iter->record = -1; |
| 472 | break; |
| 473 | } |
| 474 | /* Check for EOF. */ |
| 475 | if (iter->record == -1) |
| 476 | return -EINVAL; |
| 477 | else |
| 478 | return 0; |
| 479 | } |
| 480 | |
| 481 | /** |
| 482 | * seq_write_gcov_u32 - write 32 bit number in gcov format to seq_file |
| 483 | * @seq: seq_file handle |
| 484 | * @v: value to be stored |
| 485 | * |
| 486 | * Number format defined by gcc: numbers are recorded in the 32 bit |
| 487 | * unsigned binary form of the endianness of the machine generating the |
| 488 | * file. |
| 489 | */ |
| 490 | static int seq_write_gcov_u32(struct seq_file *seq, u32 v) |
| 491 | { |
| 492 | return seq_write(seq, &v, sizeof(v)); |
| 493 | } |
| 494 | |
| 495 | /** |
| 496 | * seq_write_gcov_u64 - write 64 bit number in gcov format to seq_file |
| 497 | * @seq: seq_file handle |
| 498 | * @v: value to be stored |
| 499 | * |
| 500 | * Number format defined by gcc: numbers are recorded in the 32 bit |
| 501 | * unsigned binary form of the endianness of the machine generating the |
| 502 | * file. 64 bit numbers are stored as two 32 bit numbers, the low part |
| 503 | * first. |
| 504 | */ |
| 505 | static int seq_write_gcov_u64(struct seq_file *seq, u64 v) |
| 506 | { |
| 507 | u32 data[2]; |
| 508 | |
| 509 | data[0] = (v & 0xffffffffUL); |
| 510 | data[1] = (v >> 32); |
| 511 | return seq_write(seq, data, sizeof(data)); |
| 512 | } |
| 513 | |
| 514 | /** |
| 515 | * gcov_iter_write - write data for current pos to seq_file |
| 516 | * @iter: file iterator |
| 517 | * @seq: seq_file handle |
| 518 | * |
| 519 | * Return zero on success, non-zero otherwise. |
| 520 | */ |
| 521 | int gcov_iter_write(struct gcov_iterator *iter, struct seq_file *seq) |
| 522 | { |
| 523 | int rc = -EINVAL; |
| 524 | |
| 525 | switch (iter->record) { |
| 526 | case RECORD_FILE_MAGIC: |
| 527 | rc = seq_write_gcov_u32(seq, GCOV_DATA_MAGIC); |
| 528 | break; |
| 529 | case RECORD_GCOV_VERSION: |
| 530 | rc = seq_write_gcov_u32(seq, iter->info->version); |
| 531 | break; |
| 532 | case RECORD_TIME_STAMP: |
| 533 | rc = seq_write_gcov_u32(seq, iter->info->stamp); |
| 534 | break; |
| 535 | case RECORD_FUNCTION_TAG: |
| 536 | rc = seq_write_gcov_u32(seq, GCOV_TAG_FUNCTION); |
| 537 | break; |
| 538 | case RECORD_FUNCTON_TAG_LEN: |
| 539 | rc = seq_write_gcov_u32(seq, 2); |
| 540 | break; |
| 541 | case RECORD_FUNCTION_IDENT: |
| 542 | rc = seq_write_gcov_u32(seq, get_func(iter)->ident); |
| 543 | break; |
| 544 | case RECORD_FUNCTION_CHECK: |
| 545 | rc = seq_write_gcov_u32(seq, get_func(iter)->checksum); |
| 546 | break; |
| 547 | case RECORD_COUNT_TAG: |
| 548 | rc = seq_write_gcov_u32(seq, |
| 549 | GCOV_TAG_FOR_COUNTER(get_type(iter)->ctr_type)); |
| 550 | break; |
| 551 | case RECORD_COUNT_LEN: |
| 552 | rc = seq_write_gcov_u32(seq, |
| 553 | get_func(iter)->n_ctrs[iter->type] * 2); |
| 554 | break; |
| 555 | case RECORD_COUNT: |
| 556 | rc = seq_write_gcov_u64(seq, |
| 557 | iter->info->counts[iter->type]. |
| 558 | values[iter->count + get_type(iter)->offset]); |
| 559 | break; |
| 560 | } |
| 561 | return rc; |
| 562 | } |