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