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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
5f41ea03 FH |
2 | /* |
3 | * This code provides functions to handle gcc's profiling data format | |
4 | * introduced with gcc 4.7. | |
5 | * | |
6 | * This file is based heavily on gcc_3_4.c file. | |
7 | * | |
8 | * For a better understanding, refer to gcc source: | |
9 | * gcc/gcov-io.h | |
10 | * libgcc/libgcov.c | |
11 | * | |
12 | * Uses gcc-internal data definitions. | |
13 | */ | |
14 | ||
15 | #include <linux/errno.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/string.h> | |
18 | #include <linux/seq_file.h> | |
19 | #include <linux/vmalloc.h> | |
20 | #include "gcov.h" | |
21 | ||
05384213 ML |
22 | #if (__GNUC__ >= 7) |
23 | #define GCOV_COUNTERS 9 | |
24 | #elif (__GNUC__ > 5) || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1) | |
3e44c471 LS |
25 | #define GCOV_COUNTERS 10 |
26 | #elif __GNUC__ == 4 && __GNUC_MINOR__ >= 9 | |
a992bf83 YP |
27 | #define GCOV_COUNTERS 9 |
28 | #else | |
5f41ea03 | 29 | #define GCOV_COUNTERS 8 |
a992bf83 YP |
30 | #endif |
31 | ||
5f41ea03 FH |
32 | #define GCOV_TAG_FUNCTION_LENGTH 3 |
33 | ||
34 | static struct gcov_info *gcov_info_head; | |
35 | ||
36 | /** | |
37 | * struct gcov_ctr_info - information about counters for a single function | |
38 | * @num: number of counter values for this type | |
39 | * @values: array of counter values for this type | |
40 | * | |
41 | * This data is generated by gcc during compilation and doesn't change | |
42 | * at run-time with the exception of the values array. | |
43 | */ | |
44 | struct gcov_ctr_info { | |
45 | unsigned int num; | |
46 | gcov_type *values; | |
47 | }; | |
48 | ||
49 | /** | |
50 | * struct gcov_fn_info - profiling meta data per function | |
51 | * @key: comdat key | |
52 | * @ident: unique ident of function | |
53 | * @lineno_checksum: function lineo_checksum | |
54 | * @cfg_checksum: function cfg checksum | |
55 | * @ctrs: instrumented counters | |
56 | * | |
57 | * This data is generated by gcc during compilation and doesn't change | |
58 | * at run-time. | |
59 | * | |
60 | * Information about a single function. This uses the trailing array | |
61 | * idiom. The number of counters is determined from the merge pointer | |
62 | * array in gcov_info. The key is used to detect which of a set of | |
63 | * comdat functions was selected -- it points to the gcov_info object | |
64 | * of the object file containing the selected comdat function. | |
65 | */ | |
66 | struct gcov_fn_info { | |
67 | const struct gcov_info *key; | |
68 | unsigned int ident; | |
69 | unsigned int lineno_checksum; | |
70 | unsigned int cfg_checksum; | |
71 | struct gcov_ctr_info ctrs[0]; | |
72 | }; | |
73 | ||
74 | /** | |
75 | * struct gcov_info - profiling data per object file | |
76 | * @version: gcov version magic indicating the gcc version used for compilation | |
77 | * @next: list head for a singly-linked list | |
78 | * @stamp: uniquifying time stamp | |
79 | * @filename: name of the associated gcov data file | |
80 | * @merge: merge functions (null for unused counter type) | |
81 | * @n_functions: number of instrumented functions | |
82 | * @functions: pointer to pointers to function information | |
83 | * | |
84 | * This data is generated by gcc during compilation and doesn't change | |
85 | * at run-time with the exception of the next pointer. | |
86 | */ | |
87 | struct gcov_info { | |
88 | unsigned int version; | |
89 | struct gcov_info *next; | |
90 | unsigned int stamp; | |
91 | const char *filename; | |
92 | void (*merge[GCOV_COUNTERS])(gcov_type *, unsigned int); | |
93 | unsigned int n_functions; | |
94 | struct gcov_fn_info **functions; | |
95 | }; | |
96 | ||
97 | /** | |
98 | * gcov_info_filename - return info filename | |
99 | * @info: profiling data set | |
100 | */ | |
101 | const char *gcov_info_filename(struct gcov_info *info) | |
102 | { | |
103 | return info->filename; | |
104 | } | |
105 | ||
106 | /** | |
107 | * gcov_info_version - return info version | |
108 | * @info: profiling data set | |
109 | */ | |
110 | unsigned int gcov_info_version(struct gcov_info *info) | |
111 | { | |
112 | return info->version; | |
113 | } | |
114 | ||
115 | /** | |
116 | * gcov_info_next - return next profiling data set | |
117 | * @info: profiling data set | |
118 | * | |
119 | * Returns next gcov_info following @info or first gcov_info in the chain if | |
120 | * @info is %NULL. | |
121 | */ | |
122 | struct gcov_info *gcov_info_next(struct gcov_info *info) | |
123 | { | |
124 | if (!info) | |
125 | return gcov_info_head; | |
126 | ||
127 | return info->next; | |
128 | } | |
129 | ||
130 | /** | |
131 | * gcov_info_link - link/add profiling data set to the list | |
132 | * @info: profiling data set | |
133 | */ | |
134 | void gcov_info_link(struct gcov_info *info) | |
135 | { | |
136 | info->next = gcov_info_head; | |
137 | gcov_info_head = info; | |
138 | } | |
139 | ||
140 | /** | |
141 | * gcov_info_unlink - unlink/remove profiling data set from the list | |
142 | * @prev: previous profiling data set | |
143 | * @info: profiling data set | |
144 | */ | |
145 | void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info) | |
146 | { | |
147 | if (prev) | |
148 | prev->next = info->next; | |
149 | else | |
150 | gcov_info_head = info->next; | |
151 | } | |
152 | ||
153 | /* Symbolic links to be created for each profiling data file. */ | |
154 | const struct gcov_link gcov_link[] = { | |
155 | { OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */ | |
156 | { 0, NULL}, | |
157 | }; | |
158 | ||
159 | /* | |
160 | * Determine whether a counter is active. Doesn't change at run-time. | |
161 | */ | |
162 | static int counter_active(struct gcov_info *info, unsigned int type) | |
163 | { | |
164 | return info->merge[type] ? 1 : 0; | |
165 | } | |
166 | ||
167 | /* Determine number of active counters. Based on gcc magic. */ | |
168 | static unsigned int num_counter_active(struct gcov_info *info) | |
169 | { | |
170 | unsigned int i; | |
171 | unsigned int result = 0; | |
172 | ||
173 | for (i = 0; i < GCOV_COUNTERS; i++) { | |
174 | if (counter_active(info, i)) | |
175 | result++; | |
176 | } | |
177 | return result; | |
178 | } | |
179 | ||
180 | /** | |
181 | * gcov_info_reset - reset profiling data to zero | |
182 | * @info: profiling data set | |
183 | */ | |
184 | void gcov_info_reset(struct gcov_info *info) | |
185 | { | |
186 | struct gcov_ctr_info *ci_ptr; | |
187 | unsigned int fi_idx; | |
188 | unsigned int ct_idx; | |
189 | ||
190 | for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) { | |
191 | ci_ptr = info->functions[fi_idx]->ctrs; | |
192 | ||
193 | for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) { | |
194 | if (!counter_active(info, ct_idx)) | |
195 | continue; | |
196 | ||
197 | memset(ci_ptr->values, 0, | |
198 | sizeof(gcov_type) * ci_ptr->num); | |
199 | ci_ptr++; | |
200 | } | |
201 | } | |
202 | } | |
203 | ||
204 | /** | |
205 | * gcov_info_is_compatible - check if profiling data can be added | |
206 | * @info1: first profiling data set | |
207 | * @info2: second profiling data set | |
208 | * | |
209 | * Returns non-zero if profiling data can be added, zero otherwise. | |
210 | */ | |
211 | int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2) | |
212 | { | |
213 | return (info1->stamp == info2->stamp); | |
214 | } | |
215 | ||
216 | /** | |
217 | * gcov_info_add - add up profiling data | |
218 | * @dest: profiling data set to which data is added | |
219 | * @source: profiling data set which is added | |
220 | * | |
221 | * Adds profiling counts of @source to @dest. | |
222 | */ | |
223 | void gcov_info_add(struct gcov_info *dst, struct gcov_info *src) | |
224 | { | |
225 | struct gcov_ctr_info *dci_ptr; | |
226 | struct gcov_ctr_info *sci_ptr; | |
227 | unsigned int fi_idx; | |
228 | unsigned int ct_idx; | |
229 | unsigned int val_idx; | |
230 | ||
231 | for (fi_idx = 0; fi_idx < src->n_functions; fi_idx++) { | |
232 | dci_ptr = dst->functions[fi_idx]->ctrs; | |
233 | sci_ptr = src->functions[fi_idx]->ctrs; | |
234 | ||
235 | for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) { | |
236 | if (!counter_active(src, ct_idx)) | |
237 | continue; | |
238 | ||
239 | for (val_idx = 0; val_idx < sci_ptr->num; val_idx++) | |
240 | dci_ptr->values[val_idx] += | |
241 | sci_ptr->values[val_idx]; | |
242 | ||
243 | dci_ptr++; | |
244 | sci_ptr++; | |
245 | } | |
246 | } | |
247 | } | |
248 | ||
249 | /** | |
250 | * gcov_info_dup - duplicate profiling data set | |
251 | * @info: profiling data set to duplicate | |
252 | * | |
253 | * Return newly allocated duplicate on success, %NULL on error. | |
254 | */ | |
255 | struct gcov_info *gcov_info_dup(struct gcov_info *info) | |
256 | { | |
257 | struct gcov_info *dup; | |
258 | struct gcov_ctr_info *dci_ptr; /* dst counter info */ | |
259 | struct gcov_ctr_info *sci_ptr; /* src counter info */ | |
260 | unsigned int active; | |
261 | unsigned int fi_idx; /* function info idx */ | |
262 | unsigned int ct_idx; /* counter type idx */ | |
263 | size_t fi_size; /* function info size */ | |
264 | size_t cv_size; /* counter values size */ | |
265 | ||
266 | dup = kmemdup(info, sizeof(*dup), GFP_KERNEL); | |
267 | if (!dup) | |
268 | return NULL; | |
269 | ||
270 | dup->next = NULL; | |
271 | dup->filename = NULL; | |
272 | dup->functions = NULL; | |
273 | ||
274 | dup->filename = kstrdup(info->filename, GFP_KERNEL); | |
275 | if (!dup->filename) | |
276 | goto err_free; | |
277 | ||
278 | dup->functions = kcalloc(info->n_functions, | |
279 | sizeof(struct gcov_fn_info *), GFP_KERNEL); | |
280 | if (!dup->functions) | |
281 | goto err_free; | |
282 | ||
283 | active = num_counter_active(info); | |
284 | fi_size = sizeof(struct gcov_fn_info); | |
285 | fi_size += sizeof(struct gcov_ctr_info) * active; | |
286 | ||
287 | for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) { | |
288 | dup->functions[fi_idx] = kzalloc(fi_size, GFP_KERNEL); | |
289 | if (!dup->functions[fi_idx]) | |
290 | goto err_free; | |
291 | ||
292 | *(dup->functions[fi_idx]) = *(info->functions[fi_idx]); | |
293 | ||
294 | sci_ptr = info->functions[fi_idx]->ctrs; | |
295 | dci_ptr = dup->functions[fi_idx]->ctrs; | |
296 | ||
297 | for (ct_idx = 0; ct_idx < active; ct_idx++) { | |
298 | ||
299 | cv_size = sizeof(gcov_type) * sci_ptr->num; | |
300 | ||
301 | dci_ptr->values = vmalloc(cv_size); | |
302 | ||
303 | if (!dci_ptr->values) | |
304 | goto err_free; | |
305 | ||
306 | dci_ptr->num = sci_ptr->num; | |
307 | memcpy(dci_ptr->values, sci_ptr->values, cv_size); | |
308 | ||
309 | sci_ptr++; | |
310 | dci_ptr++; | |
311 | } | |
312 | } | |
313 | ||
314 | return dup; | |
315 | err_free: | |
316 | gcov_info_free(dup); | |
317 | return NULL; | |
318 | } | |
319 | ||
320 | /** | |
321 | * gcov_info_free - release memory for profiling data set duplicate | |
322 | * @info: profiling data set duplicate to free | |
323 | */ | |
324 | void gcov_info_free(struct gcov_info *info) | |
325 | { | |
326 | unsigned int active; | |
327 | unsigned int fi_idx; | |
328 | unsigned int ct_idx; | |
329 | struct gcov_ctr_info *ci_ptr; | |
330 | ||
331 | if (!info->functions) | |
332 | goto free_info; | |
333 | ||
334 | active = num_counter_active(info); | |
335 | ||
336 | for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) { | |
337 | if (!info->functions[fi_idx]) | |
338 | continue; | |
339 | ||
340 | ci_ptr = info->functions[fi_idx]->ctrs; | |
341 | ||
342 | for (ct_idx = 0; ct_idx < active; ct_idx++, ci_ptr++) | |
343 | vfree(ci_ptr->values); | |
344 | ||
345 | kfree(info->functions[fi_idx]); | |
346 | } | |
347 | ||
348 | free_info: | |
349 | kfree(info->functions); | |
350 | kfree(info->filename); | |
351 | kfree(info); | |
352 | } | |
353 | ||
354 | #define ITER_STRIDE PAGE_SIZE | |
355 | ||
356 | /** | |
357 | * struct gcov_iterator - specifies current file position in logical records | |
358 | * @info: associated profiling data | |
359 | * @buffer: buffer containing file data | |
360 | * @size: size of buffer | |
361 | * @pos: current position in file | |
362 | */ | |
363 | struct gcov_iterator { | |
364 | struct gcov_info *info; | |
365 | void *buffer; | |
366 | size_t size; | |
367 | loff_t pos; | |
368 | }; | |
369 | ||
370 | /** | |
371 | * store_gcov_u32 - store 32 bit number in gcov format to buffer | |
372 | * @buffer: target buffer or NULL | |
373 | * @off: offset into the buffer | |
374 | * @v: value to be stored | |
375 | * | |
376 | * Number format defined by gcc: numbers are recorded in the 32 bit | |
377 | * unsigned binary form of the endianness of the machine generating the | |
378 | * file. Returns the number of bytes stored. If @buffer is %NULL, doesn't | |
379 | * store anything. | |
380 | */ | |
381 | static size_t store_gcov_u32(void *buffer, size_t off, u32 v) | |
382 | { | |
383 | u32 *data; | |
384 | ||
385 | if (buffer) { | |
386 | data = buffer + off; | |
387 | *data = v; | |
388 | } | |
389 | ||
390 | return sizeof(*data); | |
391 | } | |
392 | ||
393 | /** | |
394 | * store_gcov_u64 - store 64 bit number in gcov format to buffer | |
395 | * @buffer: target buffer or NULL | |
396 | * @off: offset into the buffer | |
397 | * @v: value to be stored | |
398 | * | |
399 | * Number format defined by gcc: numbers are recorded in the 32 bit | |
400 | * unsigned binary form of the endianness of the machine generating the | |
401 | * file. 64 bit numbers are stored as two 32 bit numbers, the low part | |
402 | * first. Returns the number of bytes stored. If @buffer is %NULL, doesn't store | |
403 | * anything. | |
404 | */ | |
405 | static size_t store_gcov_u64(void *buffer, size_t off, u64 v) | |
406 | { | |
407 | u32 *data; | |
408 | ||
409 | if (buffer) { | |
410 | data = buffer + off; | |
411 | ||
412 | data[0] = (v & 0xffffffffUL); | |
413 | data[1] = (v >> 32); | |
414 | } | |
415 | ||
416 | return sizeof(*data) * 2; | |
417 | } | |
418 | ||
419 | /** | |
420 | * convert_to_gcda - convert profiling data set to gcda file format | |
421 | * @buffer: the buffer to store file data or %NULL if no data should be stored | |
422 | * @info: profiling data set to be converted | |
423 | * | |
424 | * Returns the number of bytes that were/would have been stored into the buffer. | |
425 | */ | |
426 | static size_t convert_to_gcda(char *buffer, struct gcov_info *info) | |
427 | { | |
428 | struct gcov_fn_info *fi_ptr; | |
429 | struct gcov_ctr_info *ci_ptr; | |
430 | unsigned int fi_idx; | |
431 | unsigned int ct_idx; | |
432 | unsigned int cv_idx; | |
433 | size_t pos = 0; | |
434 | ||
435 | /* File header. */ | |
436 | pos += store_gcov_u32(buffer, pos, GCOV_DATA_MAGIC); | |
437 | pos += store_gcov_u32(buffer, pos, info->version); | |
438 | pos += store_gcov_u32(buffer, pos, info->stamp); | |
439 | ||
440 | for (fi_idx = 0; fi_idx < info->n_functions; fi_idx++) { | |
441 | fi_ptr = info->functions[fi_idx]; | |
442 | ||
443 | /* Function record. */ | |
444 | pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION); | |
445 | pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION_LENGTH); | |
446 | pos += store_gcov_u32(buffer, pos, fi_ptr->ident); | |
447 | pos += store_gcov_u32(buffer, pos, fi_ptr->lineno_checksum); | |
448 | pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum); | |
449 | ||
450 | ci_ptr = fi_ptr->ctrs; | |
451 | ||
452 | for (ct_idx = 0; ct_idx < GCOV_COUNTERS; ct_idx++) { | |
453 | if (!counter_active(info, ct_idx)) | |
454 | continue; | |
455 | ||
456 | /* Counter record. */ | |
457 | pos += store_gcov_u32(buffer, pos, | |
458 | GCOV_TAG_FOR_COUNTER(ct_idx)); | |
459 | pos += store_gcov_u32(buffer, pos, ci_ptr->num * 2); | |
460 | ||
461 | for (cv_idx = 0; cv_idx < ci_ptr->num; cv_idx++) { | |
462 | pos += store_gcov_u64(buffer, pos, | |
463 | ci_ptr->values[cv_idx]); | |
464 | } | |
465 | ||
466 | ci_ptr++; | |
467 | } | |
468 | } | |
469 | ||
470 | return pos; | |
471 | } | |
472 | ||
473 | /** | |
474 | * gcov_iter_new - allocate and initialize profiling data iterator | |
475 | * @info: profiling data set to be iterated | |
476 | * | |
477 | * Return file iterator on success, %NULL otherwise. | |
478 | */ | |
479 | struct gcov_iterator *gcov_iter_new(struct gcov_info *info) | |
480 | { | |
481 | struct gcov_iterator *iter; | |
482 | ||
483 | iter = kzalloc(sizeof(struct gcov_iterator), GFP_KERNEL); | |
484 | if (!iter) | |
485 | goto err_free; | |
486 | ||
487 | iter->info = info; | |
488 | /* Dry-run to get the actual buffer size. */ | |
489 | iter->size = convert_to_gcda(NULL, info); | |
490 | iter->buffer = vmalloc(iter->size); | |
491 | if (!iter->buffer) | |
492 | goto err_free; | |
493 | ||
494 | convert_to_gcda(iter->buffer, info); | |
495 | ||
496 | return iter; | |
497 | ||
498 | err_free: | |
499 | kfree(iter); | |
500 | return NULL; | |
501 | } | |
502 | ||
503 | ||
504 | /** | |
505 | * gcov_iter_get_info - return profiling data set for given file iterator | |
506 | * @iter: file iterator | |
507 | */ | |
508 | void gcov_iter_free(struct gcov_iterator *iter) | |
509 | { | |
510 | vfree(iter->buffer); | |
511 | kfree(iter); | |
512 | } | |
513 | ||
514 | /** | |
515 | * gcov_iter_get_info - return profiling data set for given file iterator | |
516 | * @iter: file iterator | |
517 | */ | |
518 | struct gcov_info *gcov_iter_get_info(struct gcov_iterator *iter) | |
519 | { | |
520 | return iter->info; | |
521 | } | |
522 | ||
523 | /** | |
524 | * gcov_iter_start - reset file iterator to starting position | |
525 | * @iter: file iterator | |
526 | */ | |
527 | void gcov_iter_start(struct gcov_iterator *iter) | |
528 | { | |
529 | iter->pos = 0; | |
530 | } | |
531 | ||
532 | /** | |
533 | * gcov_iter_next - advance file iterator to next logical record | |
534 | * @iter: file iterator | |
535 | * | |
536 | * Return zero if new position is valid, non-zero if iterator has reached end. | |
537 | */ | |
538 | int gcov_iter_next(struct gcov_iterator *iter) | |
539 | { | |
540 | if (iter->pos < iter->size) | |
541 | iter->pos += ITER_STRIDE; | |
542 | ||
543 | if (iter->pos >= iter->size) | |
544 | return -EINVAL; | |
545 | ||
546 | return 0; | |
547 | } | |
548 | ||
549 | /** | |
550 | * gcov_iter_write - write data for current pos to seq_file | |
551 | * @iter: file iterator | |
552 | * @seq: seq_file handle | |
553 | * | |
554 | * Return zero on success, non-zero otherwise. | |
555 | */ | |
556 | int gcov_iter_write(struct gcov_iterator *iter, struct seq_file *seq) | |
557 | { | |
558 | size_t len; | |
559 | ||
560 | if (iter->pos >= iter->size) | |
561 | return -EINVAL; | |
562 | ||
563 | len = ITER_STRIDE; | |
564 | if (iter->pos + len > iter->size) | |
565 | len = iter->size - iter->pos; | |
566 | ||
567 | seq_write(seq, iter->buffer + iter->pos, len); | |
568 | ||
569 | return 0; | |
570 | } |