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