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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
2521f2c2 PO |
2 | /* |
3 | * This code provides functions to handle gcc's profiling data format | |
4 | * introduced with gcc 3.4. Future versions of gcc may change the gcov | |
5 | * format (as happened before), so all format-specific information needs | |
6 | * to be kept modular and easily exchangeable. | |
7 | * | |
8 | * This file is based on gcc-internal definitions. Functions and data | |
9 | * structures are defined to be compatible with gcc counterparts. | |
10 | * For a better understanding, refer to gcc source: gcc/gcov-io.h. | |
11 | * | |
12 | * Copyright IBM Corp. 2009 | |
13 | * Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com> | |
14 | * | |
15 | * Uses gcc-internal data definitions. | |
16 | */ | |
17 | ||
18 | #include <linux/errno.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/string.h> | |
21 | #include <linux/seq_file.h> | |
22 | #include <linux/vmalloc.h> | |
23 | #include "gcov.h" | |
24 | ||
8cbce376 FH |
25 | #define GCOV_COUNTERS 5 |
26 | ||
27 | static struct gcov_info *gcov_info_head; | |
28 | ||
29 | /** | |
30 | * struct gcov_fn_info - profiling meta data per function | |
31 | * @ident: object file-unique function identifier | |
32 | * @checksum: function checksum | |
33 | * @n_ctrs: number of values per counter type belonging to this function | |
34 | * | |
35 | * This data is generated by gcc during compilation and doesn't change | |
36 | * at run-time. | |
37 | */ | |
38 | struct gcov_fn_info { | |
39 | unsigned int ident; | |
40 | unsigned int checksum; | |
41 | unsigned int n_ctrs[0]; | |
42 | }; | |
43 | ||
44 | /** | |
45 | * struct gcov_ctr_info - profiling data per counter type | |
46 | * @num: number of counter values for this type | |
47 | * @values: array of counter values for this type | |
48 | * @merge: merge function for counter values of this type (unused) | |
49 | * | |
50 | * This data is generated by gcc during compilation and doesn't change | |
51 | * at run-time with the exception of the values array. | |
52 | */ | |
53 | struct gcov_ctr_info { | |
54 | unsigned int num; | |
55 | gcov_type *values; | |
56 | void (*merge)(gcov_type *, unsigned int); | |
57 | }; | |
58 | ||
59 | /** | |
60 | * struct gcov_info - profiling data per object file | |
61 | * @version: gcov version magic indicating the gcc version used for compilation | |
62 | * @next: list head for a singly-linked list | |
63 | * @stamp: time stamp | |
64 | * @filename: name of the associated gcov data file | |
65 | * @n_functions: number of instrumented functions | |
66 | * @functions: function data | |
67 | * @ctr_mask: mask specifying which counter types are active | |
68 | * @counts: counter data per counter type | |
69 | * | |
70 | * This data is generated by gcc during compilation and doesn't change | |
71 | * at run-time with the exception of the next pointer. | |
72 | */ | |
73 | struct gcov_info { | |
74 | unsigned int version; | |
75 | struct gcov_info *next; | |
76 | unsigned int stamp; | |
77 | const char *filename; | |
78 | unsigned int n_functions; | |
79 | const struct gcov_fn_info *functions; | |
80 | unsigned int ctr_mask; | |
81 | struct gcov_ctr_info counts[0]; | |
82 | }; | |
83 | ||
84 | /** | |
85 | * gcov_info_filename - return info filename | |
86 | * @info: profiling data set | |
87 | */ | |
88 | const char *gcov_info_filename(struct gcov_info *info) | |
89 | { | |
90 | return info->filename; | |
91 | } | |
92 | ||
93 | /** | |
94 | * gcov_info_version - return info version | |
95 | * @info: profiling data set | |
96 | */ | |
97 | unsigned int gcov_info_version(struct gcov_info *info) | |
98 | { | |
99 | return info->version; | |
100 | } | |
101 | ||
102 | /** | |
103 | * gcov_info_next - return next profiling data set | |
104 | * @info: profiling data set | |
105 | * | |
106 | * Returns next gcov_info following @info or first gcov_info in the chain if | |
107 | * @info is %NULL. | |
108 | */ | |
109 | struct gcov_info *gcov_info_next(struct gcov_info *info) | |
110 | { | |
111 | if (!info) | |
112 | return gcov_info_head; | |
113 | ||
114 | return info->next; | |
115 | } | |
116 | ||
117 | /** | |
118 | * gcov_info_link - link/add profiling data set to the list | |
119 | * @info: profiling data set | |
120 | */ | |
121 | void gcov_info_link(struct gcov_info *info) | |
122 | { | |
123 | info->next = gcov_info_head; | |
124 | gcov_info_head = info; | |
125 | } | |
126 | ||
127 | /** | |
128 | * gcov_info_unlink - unlink/remove profiling data set from the list | |
129 | * @prev: previous profiling data set | |
130 | * @info: profiling data set | |
131 | */ | |
132 | void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info) | |
133 | { | |
134 | if (prev) | |
135 | prev->next = info->next; | |
136 | else | |
137 | gcov_info_head = info->next; | |
138 | } | |
139 | ||
2521f2c2 PO |
140 | /* Symbolic links to be created for each profiling data file. */ |
141 | const struct gcov_link gcov_link[] = { | |
142 | { OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */ | |
143 | { 0, NULL}, | |
144 | }; | |
145 | ||
146 | /* | |
147 | * Determine whether a counter is active. Based on gcc magic. Doesn't change | |
148 | * at run-time. | |
149 | */ | |
150 | static int counter_active(struct gcov_info *info, unsigned int type) | |
151 | { | |
152 | return (1 << type) & info->ctr_mask; | |
153 | } | |
154 | ||
155 | /* Determine number of active counters. Based on gcc magic. */ | |
156 | static unsigned int num_counter_active(struct gcov_info *info) | |
157 | { | |
158 | unsigned int i; | |
159 | unsigned int result = 0; | |
160 | ||
161 | for (i = 0; i < GCOV_COUNTERS; i++) { | |
162 | if (counter_active(info, i)) | |
163 | result++; | |
164 | } | |
165 | return result; | |
166 | } | |
167 | ||
168 | /** | |
169 | * gcov_info_reset - reset profiling data to zero | |
170 | * @info: profiling data set | |
171 | */ | |
172 | void gcov_info_reset(struct gcov_info *info) | |
173 | { | |
174 | unsigned int active = num_counter_active(info); | |
175 | unsigned int i; | |
176 | ||
177 | for (i = 0; i < active; i++) { | |
178 | memset(info->counts[i].values, 0, | |
179 | info->counts[i].num * sizeof(gcov_type)); | |
180 | } | |
181 | } | |
182 | ||
183 | /** | |
184 | * gcov_info_is_compatible - check if profiling data can be added | |
185 | * @info1: first profiling data set | |
186 | * @info2: second profiling data set | |
187 | * | |
188 | * Returns non-zero if profiling data can be added, zero otherwise. | |
189 | */ | |
190 | int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2) | |
191 | { | |
192 | return (info1->stamp == info2->stamp); | |
193 | } | |
194 | ||
195 | /** | |
196 | * gcov_info_add - add up profiling data | |
197 | * @dest: profiling data set to which data is added | |
198 | * @source: profiling data set which is added | |
199 | * | |
200 | * Adds profiling counts of @source to @dest. | |
201 | */ | |
202 | void gcov_info_add(struct gcov_info *dest, struct gcov_info *source) | |
203 | { | |
204 | unsigned int i; | |
205 | unsigned int j; | |
206 | ||
207 | for (i = 0; i < num_counter_active(dest); i++) { | |
208 | for (j = 0; j < dest->counts[i].num; j++) { | |
209 | dest->counts[i].values[j] += | |
210 | source->counts[i].values[j]; | |
211 | } | |
212 | } | |
213 | } | |
214 | ||
215 | /* Get size of function info entry. Based on gcc magic. */ | |
216 | static size_t get_fn_size(struct gcov_info *info) | |
217 | { | |
218 | size_t size; | |
219 | ||
220 | size = sizeof(struct gcov_fn_info) + num_counter_active(info) * | |
221 | sizeof(unsigned int); | |
222 | if (__alignof__(struct gcov_fn_info) > sizeof(unsigned int)) | |
223 | size = ALIGN(size, __alignof__(struct gcov_fn_info)); | |
224 | return size; | |
225 | } | |
226 | ||
227 | /* Get address of function info entry. Based on gcc magic. */ | |
228 | static struct gcov_fn_info *get_fn_info(struct gcov_info *info, unsigned int fn) | |
229 | { | |
230 | return (struct gcov_fn_info *) | |
231 | ((char *) info->functions + fn * get_fn_size(info)); | |
232 | } | |
233 | ||
234 | /** | |
235 | * gcov_info_dup - duplicate profiling data set | |
236 | * @info: profiling data set to duplicate | |
237 | * | |
238 | * Return newly allocated duplicate on success, %NULL on error. | |
239 | */ | |
240 | struct gcov_info *gcov_info_dup(struct gcov_info *info) | |
241 | { | |
242 | struct gcov_info *dup; | |
243 | unsigned int i; | |
244 | unsigned int active; | |
245 | ||
246 | /* Duplicate gcov_info. */ | |
247 | active = num_counter_active(info); | |
248 | dup = kzalloc(sizeof(struct gcov_info) + | |
249 | sizeof(struct gcov_ctr_info) * active, GFP_KERNEL); | |
250 | if (!dup) | |
251 | return NULL; | |
252 | dup->version = info->version; | |
253 | dup->stamp = info->stamp; | |
254 | dup->n_functions = info->n_functions; | |
255 | dup->ctr_mask = info->ctr_mask; | |
256 | /* Duplicate filename. */ | |
257 | dup->filename = kstrdup(info->filename, GFP_KERNEL); | |
258 | if (!dup->filename) | |
259 | goto err_free; | |
260 | /* Duplicate table of functions. */ | |
261 | dup->functions = kmemdup(info->functions, info->n_functions * | |
262 | get_fn_size(info), GFP_KERNEL); | |
263 | if (!dup->functions) | |
264 | goto err_free; | |
265 | /* Duplicate counter arrays. */ | |
266 | for (i = 0; i < active ; i++) { | |
267 | struct gcov_ctr_info *ctr = &info->counts[i]; | |
268 | size_t size = ctr->num * sizeof(gcov_type); | |
269 | ||
270 | dup->counts[i].num = ctr->num; | |
271 | dup->counts[i].merge = ctr->merge; | |
272 | dup->counts[i].values = vmalloc(size); | |
273 | if (!dup->counts[i].values) | |
274 | goto err_free; | |
275 | memcpy(dup->counts[i].values, ctr->values, size); | |
276 | } | |
277 | return dup; | |
278 | ||
279 | err_free: | |
280 | gcov_info_free(dup); | |
281 | return NULL; | |
282 | } | |
283 | ||
284 | /** | |
285 | * gcov_info_free - release memory for profiling data set duplicate | |
286 | * @info: profiling data set duplicate to free | |
287 | */ | |
288 | void gcov_info_free(struct gcov_info *info) | |
289 | { | |
290 | unsigned int active = num_counter_active(info); | |
291 | unsigned int i; | |
292 | ||
293 | for (i = 0; i < active ; i++) | |
294 | vfree(info->counts[i].values); | |
295 | kfree(info->functions); | |
296 | kfree(info->filename); | |
297 | kfree(info); | |
298 | } | |
299 | ||
300 | /** | |
301 | * struct type_info - iterator helper array | |
302 | * @ctr_type: counter type | |
303 | * @offset: index of the first value of the current function for this type | |
304 | * | |
305 | * This array is needed to convert the in-memory data format into the in-file | |
306 | * data format: | |
307 | * | |
308 | * In-memory: | |
309 | * for each counter type | |
310 | * for each function | |
311 | * values | |
312 | * | |
313 | * In-file: | |
314 | * for each function | |
315 | * for each counter type | |
316 | * values | |
317 | * | |
318 | * See gcc source gcc/gcov-io.h for more information on data organization. | |
319 | */ | |
320 | struct type_info { | |
321 | int ctr_type; | |
322 | unsigned int offset; | |
323 | }; | |
324 | ||
325 | /** | |
326 | * struct gcov_iterator - specifies current file position in logical records | |
327 | * @info: associated profiling data | |
328 | * @record: record type | |
329 | * @function: function number | |
330 | * @type: counter type | |
331 | * @count: index into values array | |
332 | * @num_types: number of counter types | |
333 | * @type_info: helper array to get values-array offset for current function | |
334 | */ | |
335 | struct gcov_iterator { | |
336 | struct gcov_info *info; | |
337 | ||
338 | int record; | |
339 | unsigned int function; | |
340 | unsigned int type; | |
341 | unsigned int count; | |
342 | ||
343 | int num_types; | |
344 | struct type_info type_info[0]; | |
345 | }; | |
346 | ||
347 | static struct gcov_fn_info *get_func(struct gcov_iterator *iter) | |
348 | { | |
349 | return get_fn_info(iter->info, iter->function); | |
350 | } | |
351 | ||
352 | static struct type_info *get_type(struct gcov_iterator *iter) | |
353 | { | |
354 | return &iter->type_info[iter->type]; | |
355 | } | |
356 | ||
357 | /** | |
358 | * gcov_iter_new - allocate and initialize profiling data iterator | |
359 | * @info: profiling data set to be iterated | |
360 | * | |
361 | * Return file iterator on success, %NULL otherwise. | |
362 | */ | |
363 | struct gcov_iterator *gcov_iter_new(struct gcov_info *info) | |
364 | { | |
365 | struct gcov_iterator *iter; | |
366 | ||
367 | iter = kzalloc(sizeof(struct gcov_iterator) + | |
368 | num_counter_active(info) * sizeof(struct type_info), | |
369 | GFP_KERNEL); | |
370 | if (iter) | |
371 | iter->info = info; | |
372 | ||
373 | return iter; | |
374 | } | |
375 | ||
376 | /** | |
377 | * gcov_iter_free - release memory for iterator | |
378 | * @iter: file iterator to free | |
379 | */ | |
380 | void gcov_iter_free(struct gcov_iterator *iter) | |
381 | { | |
382 | kfree(iter); | |
383 | } | |
384 | ||
385 | /** | |
386 | * gcov_iter_get_info - return profiling data set for given file iterator | |
387 | * @iter: file iterator | |
388 | */ | |
389 | struct gcov_info *gcov_iter_get_info(struct gcov_iterator *iter) | |
390 | { | |
391 | return iter->info; | |
392 | } | |
393 | ||
394 | /** | |
395 | * gcov_iter_start - reset file iterator to starting position | |
396 | * @iter: file iterator | |
397 | */ | |
398 | void gcov_iter_start(struct gcov_iterator *iter) | |
399 | { | |
400 | int i; | |
401 | ||
402 | iter->record = 0; | |
403 | iter->function = 0; | |
404 | iter->type = 0; | |
405 | iter->count = 0; | |
406 | iter->num_types = 0; | |
407 | for (i = 0; i < GCOV_COUNTERS; i++) { | |
408 | if (counter_active(iter->info, i)) { | |
409 | iter->type_info[iter->num_types].ctr_type = i; | |
410 | iter->type_info[iter->num_types++].offset = 0; | |
411 | } | |
412 | } | |
413 | } | |
414 | ||
415 | /* Mapping of logical record number to actual file content. */ | |
416 | #define RECORD_FILE_MAGIC 0 | |
417 | #define RECORD_GCOV_VERSION 1 | |
418 | #define RECORD_TIME_STAMP 2 | |
419 | #define RECORD_FUNCTION_TAG 3 | |
420 | #define RECORD_FUNCTON_TAG_LEN 4 | |
421 | #define RECORD_FUNCTION_IDENT 5 | |
422 | #define RECORD_FUNCTION_CHECK 6 | |
423 | #define RECORD_COUNT_TAG 7 | |
424 | #define RECORD_COUNT_LEN 8 | |
425 | #define RECORD_COUNT 9 | |
426 | ||
427 | /** | |
428 | * gcov_iter_next - advance file iterator to next logical record | |
429 | * @iter: file iterator | |
430 | * | |
431 | * Return zero if new position is valid, non-zero if iterator has reached end. | |
432 | */ | |
433 | int gcov_iter_next(struct gcov_iterator *iter) | |
434 | { | |
435 | switch (iter->record) { | |
436 | case RECORD_FILE_MAGIC: | |
437 | case RECORD_GCOV_VERSION: | |
438 | case RECORD_FUNCTION_TAG: | |
439 | case RECORD_FUNCTON_TAG_LEN: | |
440 | case RECORD_FUNCTION_IDENT: | |
441 | case RECORD_COUNT_TAG: | |
442 | /* Advance to next record */ | |
443 | iter->record++; | |
444 | break; | |
445 | case RECORD_COUNT: | |
446 | /* Advance to next count */ | |
447 | iter->count++; | |
448 | /* fall through */ | |
449 | case RECORD_COUNT_LEN: | |
450 | if (iter->count < get_func(iter)->n_ctrs[iter->type]) { | |
451 | iter->record = 9; | |
452 | break; | |
453 | } | |
454 | /* Advance to next counter type */ | |
455 | get_type(iter)->offset += iter->count; | |
456 | iter->count = 0; | |
457 | iter->type++; | |
458 | /* fall through */ | |
459 | case RECORD_FUNCTION_CHECK: | |
460 | if (iter->type < iter->num_types) { | |
461 | iter->record = 7; | |
462 | break; | |
463 | } | |
464 | /* Advance to next function */ | |
465 | iter->type = 0; | |
466 | iter->function++; | |
467 | /* fall through */ | |
468 | case RECORD_TIME_STAMP: | |
469 | if (iter->function < iter->info->n_functions) | |
470 | iter->record = 3; | |
471 | else | |
472 | iter->record = -1; | |
473 | break; | |
474 | } | |
475 | /* Check for EOF. */ | |
476 | if (iter->record == -1) | |
477 | return -EINVAL; | |
478 | else | |
479 | return 0; | |
480 | } | |
481 | ||
482 | /** | |
483 | * seq_write_gcov_u32 - write 32 bit number in gcov format to seq_file | |
484 | * @seq: seq_file handle | |
485 | * @v: value to be stored | |
486 | * | |
487 | * Number format defined by gcc: numbers are recorded in the 32 bit | |
488 | * unsigned binary form of the endianness of the machine generating the | |
489 | * file. | |
490 | */ | |
491 | static int seq_write_gcov_u32(struct seq_file *seq, u32 v) | |
492 | { | |
493 | return seq_write(seq, &v, sizeof(v)); | |
494 | } | |
495 | ||
496 | /** | |
497 | * seq_write_gcov_u64 - write 64 bit number in gcov format to seq_file | |
498 | * @seq: seq_file handle | |
499 | * @v: value to be stored | |
500 | * | |
501 | * Number format defined by gcc: numbers are recorded in the 32 bit | |
502 | * unsigned binary form of the endianness of the machine generating the | |
503 | * file. 64 bit numbers are stored as two 32 bit numbers, the low part | |
504 | * first. | |
505 | */ | |
506 | static int seq_write_gcov_u64(struct seq_file *seq, u64 v) | |
507 | { | |
508 | u32 data[2]; | |
509 | ||
510 | data[0] = (v & 0xffffffffUL); | |
511 | data[1] = (v >> 32); | |
512 | return seq_write(seq, data, sizeof(data)); | |
513 | } | |
514 | ||
515 | /** | |
516 | * gcov_iter_write - write data for current pos to seq_file | |
517 | * @iter: file iterator | |
518 | * @seq: seq_file handle | |
519 | * | |
520 | * Return zero on success, non-zero otherwise. | |
521 | */ | |
522 | int gcov_iter_write(struct gcov_iterator *iter, struct seq_file *seq) | |
523 | { | |
524 | int rc = -EINVAL; | |
525 | ||
526 | switch (iter->record) { | |
527 | case RECORD_FILE_MAGIC: | |
528 | rc = seq_write_gcov_u32(seq, GCOV_DATA_MAGIC); | |
529 | break; | |
530 | case RECORD_GCOV_VERSION: | |
531 | rc = seq_write_gcov_u32(seq, iter->info->version); | |
532 | break; | |
533 | case RECORD_TIME_STAMP: | |
534 | rc = seq_write_gcov_u32(seq, iter->info->stamp); | |
535 | break; | |
536 | case RECORD_FUNCTION_TAG: | |
537 | rc = seq_write_gcov_u32(seq, GCOV_TAG_FUNCTION); | |
538 | break; | |
539 | case RECORD_FUNCTON_TAG_LEN: | |
540 | rc = seq_write_gcov_u32(seq, 2); | |
541 | break; | |
542 | case RECORD_FUNCTION_IDENT: | |
543 | rc = seq_write_gcov_u32(seq, get_func(iter)->ident); | |
544 | break; | |
545 | case RECORD_FUNCTION_CHECK: | |
546 | rc = seq_write_gcov_u32(seq, get_func(iter)->checksum); | |
547 | break; | |
548 | case RECORD_COUNT_TAG: | |
549 | rc = seq_write_gcov_u32(seq, | |
550 | GCOV_TAG_FOR_COUNTER(get_type(iter)->ctr_type)); | |
551 | break; | |
552 | case RECORD_COUNT_LEN: | |
553 | rc = seq_write_gcov_u32(seq, | |
554 | get_func(iter)->n_ctrs[iter->type] * 2); | |
555 | break; | |
556 | case RECORD_COUNT: | |
557 | rc = seq_write_gcov_u64(seq, | |
558 | iter->info->counts[iter->type]. | |
559 | values[iter->count + get_type(iter)->offset]); | |
560 | break; | |
561 | } | |
562 | return rc; | |
563 | } |