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