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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
2521f2c2 PO |
2 | /* |
3 | * This code exports profiling data as debugfs files to userspace. | |
4 | * | |
5 | * Copyright IBM Corp. 2009 | |
6 | * Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com> | |
7 | * | |
8 | * Uses gcc-internal data definitions. | |
9 | * Based on the gcov-kernel patch by: | |
10 | * Hubertus Franke <frankeh@us.ibm.com> | |
11 | * Nigel Hinds <nhinds@us.ibm.com> | |
12 | * Rajan Ravindran <rajancr@us.ibm.com> | |
13 | * Peter Oberparleiter <oberpar@linux.vnet.ibm.com> | |
14 | * Paul Larson | |
15 | * Yi CDL Yang | |
16 | */ | |
17 | ||
18 | #define pr_fmt(fmt) "gcov: " fmt | |
19 | ||
20 | #include <linux/init.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/debugfs.h> | |
23 | #include <linux/fs.h> | |
24 | #include <linux/list.h> | |
25 | #include <linux/string.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/mutex.h> | |
28 | #include <linux/seq_file.h> | |
29 | #include "gcov.h" | |
30 | ||
31 | /** | |
32 | * struct gcov_node - represents a debugfs entry | |
33 | * @list: list head for child node list | |
34 | * @children: child nodes | |
35 | * @all: list head for list of all nodes | |
36 | * @parent: parent node | |
85a0fdfd PO |
37 | * @loaded_info: array of pointers to profiling data sets for loaded object |
38 | * files. | |
39 | * @num_loaded: number of profiling data sets for loaded object files. | |
40 | * @unloaded_info: accumulated copy of profiling data sets for unloaded | |
41 | * object files. Used only when gcov_persist=1. | |
2521f2c2 PO |
42 | * @dentry: main debugfs entry, either a directory or data file |
43 | * @links: associated symbolic links | |
44 | * @name: data file basename | |
45 | * | |
46 | * struct gcov_node represents an entity within the gcov/ subdirectory | |
47 | * of debugfs. There are directory and data file nodes. The latter represent | |
48 | * the actual synthesized data file plus any associated symbolic links which | |
49 | * are needed by the gcov tool to work correctly. | |
50 | */ | |
51 | struct gcov_node { | |
52 | struct list_head list; | |
53 | struct list_head children; | |
54 | struct list_head all; | |
55 | struct gcov_node *parent; | |
85a0fdfd PO |
56 | struct gcov_info **loaded_info; |
57 | struct gcov_info *unloaded_info; | |
2521f2c2 PO |
58 | struct dentry *dentry; |
59 | struct dentry **links; | |
85a0fdfd | 60 | int num_loaded; |
2521f2c2 PO |
61 | char name[0]; |
62 | }; | |
63 | ||
64 | static const char objtree[] = OBJTREE; | |
65 | static const char srctree[] = SRCTREE; | |
66 | static struct gcov_node root_node; | |
2521f2c2 PO |
67 | static LIST_HEAD(all_head); |
68 | static DEFINE_MUTEX(node_lock); | |
69 | ||
70 | /* If non-zero, keep copies of profiling data for unloaded modules. */ | |
71 | static int gcov_persist = 1; | |
72 | ||
73 | static int __init gcov_persist_setup(char *str) | |
74 | { | |
75 | unsigned long val; | |
76 | ||
6072ddc8 | 77 | if (kstrtoul(str, 0, &val)) { |
a5ebb875 | 78 | pr_warn("invalid gcov_persist parameter '%s'\n", str); |
2521f2c2 PO |
79 | return 0; |
80 | } | |
81 | gcov_persist = val; | |
82 | pr_info("setting gcov_persist to %d\n", gcov_persist); | |
83 | ||
84 | return 1; | |
85 | } | |
86 | __setup("gcov_persist=", gcov_persist_setup); | |
87 | ||
88 | /* | |
89 | * seq_file.start() implementation for gcov data files. Note that the | |
90 | * gcov_iterator interface is designed to be more restrictive than seq_file | |
91 | * (no start from arbitrary position, etc.), to simplify the iterator | |
92 | * implementation. | |
93 | */ | |
94 | static void *gcov_seq_start(struct seq_file *seq, loff_t *pos) | |
95 | { | |
96 | loff_t i; | |
97 | ||
98 | gcov_iter_start(seq->private); | |
99 | for (i = 0; i < *pos; i++) { | |
100 | if (gcov_iter_next(seq->private)) | |
101 | return NULL; | |
102 | } | |
103 | return seq->private; | |
104 | } | |
105 | ||
106 | /* seq_file.next() implementation for gcov data files. */ | |
107 | static void *gcov_seq_next(struct seq_file *seq, void *data, loff_t *pos) | |
108 | { | |
109 | struct gcov_iterator *iter = data; | |
110 | ||
111 | if (gcov_iter_next(iter)) | |
112 | return NULL; | |
113 | (*pos)++; | |
114 | ||
115 | return iter; | |
116 | } | |
117 | ||
118 | /* seq_file.show() implementation for gcov data files. */ | |
119 | static int gcov_seq_show(struct seq_file *seq, void *data) | |
120 | { | |
121 | struct gcov_iterator *iter = data; | |
122 | ||
123 | if (gcov_iter_write(iter, seq)) | |
124 | return -EINVAL; | |
125 | return 0; | |
126 | } | |
127 | ||
128 | static void gcov_seq_stop(struct seq_file *seq, void *data) | |
129 | { | |
130 | /* Unused. */ | |
131 | } | |
132 | ||
133 | static const struct seq_operations gcov_seq_ops = { | |
134 | .start = gcov_seq_start, | |
135 | .next = gcov_seq_next, | |
136 | .show = gcov_seq_show, | |
137 | .stop = gcov_seq_stop, | |
138 | }; | |
139 | ||
140 | /* | |
85a0fdfd PO |
141 | * Return a profiling data set associated with the given node. This is |
142 | * either a data set for a loaded object file or a data set copy in case | |
143 | * all associated object files have been unloaded. | |
2521f2c2 PO |
144 | */ |
145 | static struct gcov_info *get_node_info(struct gcov_node *node) | |
146 | { | |
85a0fdfd PO |
147 | if (node->num_loaded > 0) |
148 | return node->loaded_info[0]; | |
2521f2c2 | 149 | |
85a0fdfd PO |
150 | return node->unloaded_info; |
151 | } | |
152 | ||
153 | /* | |
154 | * Return a newly allocated profiling data set which contains the sum of | |
155 | * all profiling data associated with the given node. | |
156 | */ | |
157 | static struct gcov_info *get_accumulated_info(struct gcov_node *node) | |
158 | { | |
159 | struct gcov_info *info; | |
160 | int i = 0; | |
161 | ||
162 | if (node->unloaded_info) | |
163 | info = gcov_info_dup(node->unloaded_info); | |
164 | else | |
165 | info = gcov_info_dup(node->loaded_info[i++]); | |
166 | if (!info) | |
167 | return NULL; | |
168 | for (; i < node->num_loaded; i++) | |
169 | gcov_info_add(info, node->loaded_info[i]); | |
170 | ||
171 | return info; | |
2521f2c2 PO |
172 | } |
173 | ||
174 | /* | |
175 | * open() implementation for gcov data files. Create a copy of the profiling | |
176 | * data set and initialize the iterator and seq_file interface. | |
177 | */ | |
178 | static int gcov_seq_open(struct inode *inode, struct file *file) | |
179 | { | |
180 | struct gcov_node *node = inode->i_private; | |
181 | struct gcov_iterator *iter; | |
182 | struct seq_file *seq; | |
183 | struct gcov_info *info; | |
184 | int rc = -ENOMEM; | |
185 | ||
186 | mutex_lock(&node_lock); | |
187 | /* | |
188 | * Read from a profiling data copy to minimize reference tracking | |
85a0fdfd PO |
189 | * complexity and concurrent access and to keep accumulating multiple |
190 | * profiling data sets associated with one node simple. | |
2521f2c2 | 191 | */ |
85a0fdfd | 192 | info = get_accumulated_info(node); |
2521f2c2 PO |
193 | if (!info) |
194 | goto out_unlock; | |
195 | iter = gcov_iter_new(info); | |
196 | if (!iter) | |
197 | goto err_free_info; | |
198 | rc = seq_open(file, &gcov_seq_ops); | |
199 | if (rc) | |
200 | goto err_free_iter_info; | |
201 | seq = file->private_data; | |
202 | seq->private = iter; | |
203 | out_unlock: | |
204 | mutex_unlock(&node_lock); | |
205 | return rc; | |
206 | ||
207 | err_free_iter_info: | |
208 | gcov_iter_free(iter); | |
209 | err_free_info: | |
210 | gcov_info_free(info); | |
211 | goto out_unlock; | |
212 | } | |
213 | ||
214 | /* | |
215 | * release() implementation for gcov data files. Release resources allocated | |
216 | * by open(). | |
217 | */ | |
218 | static int gcov_seq_release(struct inode *inode, struct file *file) | |
219 | { | |
220 | struct gcov_iterator *iter; | |
221 | struct gcov_info *info; | |
222 | struct seq_file *seq; | |
223 | ||
224 | seq = file->private_data; | |
225 | iter = seq->private; | |
226 | info = gcov_iter_get_info(iter); | |
227 | gcov_iter_free(iter); | |
228 | gcov_info_free(info); | |
229 | seq_release(inode, file); | |
230 | ||
231 | return 0; | |
232 | } | |
233 | ||
234 | /* | |
235 | * Find a node by the associated data file name. Needs to be called with | |
236 | * node_lock held. | |
237 | */ | |
238 | static struct gcov_node *get_node_by_name(const char *name) | |
239 | { | |
240 | struct gcov_node *node; | |
241 | struct gcov_info *info; | |
242 | ||
243 | list_for_each_entry(node, &all_head, all) { | |
244 | info = get_node_info(node); | |
8cbce376 | 245 | if (info && (strcmp(gcov_info_filename(info), name) == 0)) |
2521f2c2 PO |
246 | return node; |
247 | } | |
248 | ||
249 | return NULL; | |
250 | } | |
251 | ||
85a0fdfd PO |
252 | /* |
253 | * Reset all profiling data associated with the specified node. | |
254 | */ | |
255 | static void reset_node(struct gcov_node *node) | |
256 | { | |
257 | int i; | |
258 | ||
259 | if (node->unloaded_info) | |
260 | gcov_info_reset(node->unloaded_info); | |
261 | for (i = 0; i < node->num_loaded; i++) | |
262 | gcov_info_reset(node->loaded_info[i]); | |
263 | } | |
264 | ||
2521f2c2 PO |
265 | static void remove_node(struct gcov_node *node); |
266 | ||
267 | /* | |
268 | * write() implementation for gcov data files. Reset profiling data for the | |
85a0fdfd PO |
269 | * corresponding file. If all associated object files have been unloaded, |
270 | * remove the debug fs node as well. | |
2521f2c2 PO |
271 | */ |
272 | static ssize_t gcov_seq_write(struct file *file, const char __user *addr, | |
273 | size_t len, loff_t *pos) | |
274 | { | |
275 | struct seq_file *seq; | |
276 | struct gcov_info *info; | |
277 | struct gcov_node *node; | |
278 | ||
279 | seq = file->private_data; | |
280 | info = gcov_iter_get_info(seq->private); | |
281 | mutex_lock(&node_lock); | |
8cbce376 | 282 | node = get_node_by_name(gcov_info_filename(info)); |
2521f2c2 PO |
283 | if (node) { |
284 | /* Reset counts or remove node for unloaded modules. */ | |
85a0fdfd | 285 | if (node->num_loaded == 0) |
2521f2c2 PO |
286 | remove_node(node); |
287 | else | |
85a0fdfd | 288 | reset_node(node); |
2521f2c2 PO |
289 | } |
290 | /* Reset counts for open file. */ | |
291 | gcov_info_reset(info); | |
292 | mutex_unlock(&node_lock); | |
293 | ||
294 | return len; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Given a string <path> representing a file path of format: | |
299 | * path/to/file.gcda | |
300 | * construct and return a new string: | |
301 | * <dir/>path/to/file.<ext> | |
302 | */ | |
303 | static char *link_target(const char *dir, const char *path, const char *ext) | |
304 | { | |
305 | char *target; | |
306 | char *old_ext; | |
307 | char *copy; | |
308 | ||
309 | copy = kstrdup(path, GFP_KERNEL); | |
310 | if (!copy) | |
311 | return NULL; | |
312 | old_ext = strrchr(copy, '.'); | |
313 | if (old_ext) | |
314 | *old_ext = '\0'; | |
315 | if (dir) | |
316 | target = kasprintf(GFP_KERNEL, "%s/%s.%s", dir, copy, ext); | |
317 | else | |
318 | target = kasprintf(GFP_KERNEL, "%s.%s", copy, ext); | |
319 | kfree(copy); | |
320 | ||
321 | return target; | |
322 | } | |
323 | ||
324 | /* | |
325 | * Construct a string representing the symbolic link target for the given | |
326 | * gcov data file name and link type. Depending on the link type and the | |
327 | * location of the data file, the link target can either point to a | |
328 | * subdirectory of srctree, objtree or in an external location. | |
329 | */ | |
330 | static char *get_link_target(const char *filename, const struct gcov_link *ext) | |
331 | { | |
332 | const char *rel; | |
333 | char *result; | |
334 | ||
335 | if (strncmp(filename, objtree, strlen(objtree)) == 0) { | |
336 | rel = filename + strlen(objtree) + 1; | |
337 | if (ext->dir == SRC_TREE) | |
338 | result = link_target(srctree, rel, ext->ext); | |
339 | else | |
340 | result = link_target(objtree, rel, ext->ext); | |
341 | } else { | |
342 | /* External compilation. */ | |
343 | result = link_target(NULL, filename, ext->ext); | |
344 | } | |
345 | ||
346 | return result; | |
347 | } | |
348 | ||
349 | #define SKEW_PREFIX ".tmp_" | |
350 | ||
351 | /* | |
352 | * For a filename .tmp_filename.ext return filename.ext. Needed to compensate | |
353 | * for filename skewing caused by the mod-versioning mechanism. | |
354 | */ | |
355 | static const char *deskew(const char *basename) | |
356 | { | |
357 | if (strncmp(basename, SKEW_PREFIX, sizeof(SKEW_PREFIX) - 1) == 0) | |
358 | return basename + sizeof(SKEW_PREFIX) - 1; | |
359 | return basename; | |
360 | } | |
361 | ||
362 | /* | |
363 | * Create links to additional files (usually .c and .gcno files) which the | |
364 | * gcov tool expects to find in the same directory as the gcov data file. | |
365 | */ | |
366 | static void add_links(struct gcov_node *node, struct dentry *parent) | |
367 | { | |
1931d433 | 368 | const char *basename; |
2521f2c2 PO |
369 | char *target; |
370 | int num; | |
371 | int i; | |
372 | ||
373 | for (num = 0; gcov_link[num].ext; num++) | |
374 | /* Nothing. */; | |
375 | node->links = kcalloc(num, sizeof(struct dentry *), GFP_KERNEL); | |
376 | if (!node->links) | |
377 | return; | |
378 | for (i = 0; i < num; i++) { | |
8cbce376 FH |
379 | target = get_link_target( |
380 | gcov_info_filename(get_node_info(node)), | |
381 | &gcov_link[i]); | |
2521f2c2 PO |
382 | if (!target) |
383 | goto out_err; | |
1931d433 AS |
384 | basename = kbasename(target); |
385 | if (basename == target) | |
2521f2c2 | 386 | goto out_err; |
2521f2c2 PO |
387 | node->links[i] = debugfs_create_symlink(deskew(basename), |
388 | parent, target); | |
2521f2c2 PO |
389 | kfree(target); |
390 | } | |
391 | ||
392 | return; | |
393 | out_err: | |
394 | kfree(target); | |
395 | while (i-- > 0) | |
396 | debugfs_remove(node->links[i]); | |
397 | kfree(node->links); | |
398 | node->links = NULL; | |
399 | } | |
400 | ||
401 | static const struct file_operations gcov_data_fops = { | |
402 | .open = gcov_seq_open, | |
403 | .release = gcov_seq_release, | |
404 | .read = seq_read, | |
405 | .llseek = seq_lseek, | |
406 | .write = gcov_seq_write, | |
407 | }; | |
408 | ||
409 | /* Basic initialization of a new node. */ | |
410 | static void init_node(struct gcov_node *node, struct gcov_info *info, | |
411 | const char *name, struct gcov_node *parent) | |
412 | { | |
413 | INIT_LIST_HEAD(&node->list); | |
414 | INIT_LIST_HEAD(&node->children); | |
415 | INIT_LIST_HEAD(&node->all); | |
85a0fdfd PO |
416 | if (node->loaded_info) { |
417 | node->loaded_info[0] = info; | |
418 | node->num_loaded = 1; | |
419 | } | |
2521f2c2 PO |
420 | node->parent = parent; |
421 | if (name) | |
422 | strcpy(node->name, name); | |
423 | } | |
424 | ||
425 | /* | |
426 | * Create a new node and associated debugfs entry. Needs to be called with | |
427 | * node_lock held. | |
428 | */ | |
429 | static struct gcov_node *new_node(struct gcov_node *parent, | |
430 | struct gcov_info *info, const char *name) | |
431 | { | |
432 | struct gcov_node *node; | |
433 | ||
434 | node = kzalloc(sizeof(struct gcov_node) + strlen(name) + 1, GFP_KERNEL); | |
85a0fdfd PO |
435 | if (!node) |
436 | goto err_nomem; | |
437 | if (info) { | |
438 | node->loaded_info = kcalloc(1, sizeof(struct gcov_info *), | |
439 | GFP_KERNEL); | |
440 | if (!node->loaded_info) | |
441 | goto err_nomem; | |
2521f2c2 PO |
442 | } |
443 | init_node(node, info, name, parent); | |
444 | /* Differentiate between gcov data file nodes and directory nodes. */ | |
445 | if (info) { | |
446 | node->dentry = debugfs_create_file(deskew(node->name), 0600, | |
447 | parent->dentry, node, &gcov_data_fops); | |
448 | } else | |
449 | node->dentry = debugfs_create_dir(node->name, parent->dentry); | |
2521f2c2 PO |
450 | if (info) |
451 | add_links(node, parent->dentry); | |
452 | list_add(&node->list, &parent->children); | |
453 | list_add(&node->all, &all_head); | |
454 | ||
455 | return node; | |
85a0fdfd PO |
456 | |
457 | err_nomem: | |
458 | kfree(node); | |
a5ebb875 | 459 | pr_warn("out of memory\n"); |
85a0fdfd | 460 | return NULL; |
2521f2c2 PO |
461 | } |
462 | ||
463 | /* Remove symbolic links associated with node. */ | |
464 | static void remove_links(struct gcov_node *node) | |
465 | { | |
466 | int i; | |
467 | ||
468 | if (!node->links) | |
469 | return; | |
470 | for (i = 0; gcov_link[i].ext; i++) | |
471 | debugfs_remove(node->links[i]); | |
472 | kfree(node->links); | |
473 | node->links = NULL; | |
474 | } | |
475 | ||
476 | /* | |
477 | * Remove node from all lists and debugfs and release associated resources. | |
478 | * Needs to be called with node_lock held. | |
479 | */ | |
480 | static void release_node(struct gcov_node *node) | |
481 | { | |
482 | list_del(&node->list); | |
483 | list_del(&node->all); | |
484 | debugfs_remove(node->dentry); | |
485 | remove_links(node); | |
85a0fdfd PO |
486 | kfree(node->loaded_info); |
487 | if (node->unloaded_info) | |
488 | gcov_info_free(node->unloaded_info); | |
2521f2c2 PO |
489 | kfree(node); |
490 | } | |
491 | ||
492 | /* Release node and empty parents. Needs to be called with node_lock held. */ | |
493 | static void remove_node(struct gcov_node *node) | |
494 | { | |
495 | struct gcov_node *parent; | |
496 | ||
497 | while ((node != &root_node) && list_empty(&node->children)) { | |
498 | parent = node->parent; | |
499 | release_node(node); | |
500 | node = parent; | |
501 | } | |
502 | } | |
503 | ||
504 | /* | |
505 | * Find child node with given basename. Needs to be called with node_lock | |
506 | * held. | |
507 | */ | |
508 | static struct gcov_node *get_child_by_name(struct gcov_node *parent, | |
509 | const char *name) | |
510 | { | |
511 | struct gcov_node *node; | |
512 | ||
513 | list_for_each_entry(node, &parent->children, list) { | |
514 | if (strcmp(node->name, name) == 0) | |
515 | return node; | |
516 | } | |
517 | ||
518 | return NULL; | |
519 | } | |
520 | ||
521 | /* | |
522 | * write() implementation for reset file. Reset all profiling data to zero | |
85a0fdfd | 523 | * and remove nodes for which all associated object files are unloaded. |
2521f2c2 PO |
524 | */ |
525 | static ssize_t reset_write(struct file *file, const char __user *addr, | |
526 | size_t len, loff_t *pos) | |
527 | { | |
528 | struct gcov_node *node; | |
529 | ||
530 | mutex_lock(&node_lock); | |
531 | restart: | |
532 | list_for_each_entry(node, &all_head, all) { | |
85a0fdfd PO |
533 | if (node->num_loaded > 0) |
534 | reset_node(node); | |
2521f2c2 PO |
535 | else if (list_empty(&node->children)) { |
536 | remove_node(node); | |
537 | /* Several nodes may have gone - restart loop. */ | |
538 | goto restart; | |
539 | } | |
540 | } | |
541 | mutex_unlock(&node_lock); | |
542 | ||
543 | return len; | |
544 | } | |
545 | ||
546 | /* read() implementation for reset file. Unused. */ | |
547 | static ssize_t reset_read(struct file *file, char __user *addr, size_t len, | |
548 | loff_t *pos) | |
549 | { | |
550 | /* Allow read operation so that a recursive copy won't fail. */ | |
551 | return 0; | |
552 | } | |
553 | ||
554 | static const struct file_operations gcov_reset_fops = { | |
555 | .write = reset_write, | |
556 | .read = reset_read, | |
6038f373 | 557 | .llseek = noop_llseek, |
2521f2c2 PO |
558 | }; |
559 | ||
560 | /* | |
561 | * Create a node for a given profiling data set and add it to all lists and | |
562 | * debugfs. Needs to be called with node_lock held. | |
563 | */ | |
564 | static void add_node(struct gcov_info *info) | |
565 | { | |
566 | char *filename; | |
567 | char *curr; | |
568 | char *next; | |
569 | struct gcov_node *parent; | |
570 | struct gcov_node *node; | |
571 | ||
8cbce376 | 572 | filename = kstrdup(gcov_info_filename(info), GFP_KERNEL); |
2521f2c2 PO |
573 | if (!filename) |
574 | return; | |
575 | parent = &root_node; | |
576 | /* Create directory nodes along the path. */ | |
577 | for (curr = filename; (next = strchr(curr, '/')); curr = next + 1) { | |
578 | if (curr == next) | |
579 | continue; | |
580 | *next = 0; | |
581 | if (strcmp(curr, ".") == 0) | |
582 | continue; | |
583 | if (strcmp(curr, "..") == 0) { | |
584 | if (!parent->parent) | |
585 | goto err_remove; | |
586 | parent = parent->parent; | |
587 | continue; | |
588 | } | |
589 | node = get_child_by_name(parent, curr); | |
590 | if (!node) { | |
591 | node = new_node(parent, NULL, curr); | |
592 | if (!node) | |
593 | goto err_remove; | |
594 | } | |
595 | parent = node; | |
596 | } | |
597 | /* Create file node. */ | |
598 | node = new_node(parent, info, curr); | |
599 | if (!node) | |
600 | goto err_remove; | |
601 | out: | |
602 | kfree(filename); | |
603 | return; | |
604 | ||
605 | err_remove: | |
606 | remove_node(parent); | |
607 | goto out; | |
608 | } | |
609 | ||
610 | /* | |
85a0fdfd PO |
611 | * Associate a profiling data set with an existing node. Needs to be called |
612 | * with node_lock held. | |
2521f2c2 | 613 | */ |
85a0fdfd | 614 | static void add_info(struct gcov_node *node, struct gcov_info *info) |
2521f2c2 | 615 | { |
85a0fdfd PO |
616 | struct gcov_info **loaded_info; |
617 | int num = node->num_loaded; | |
618 | ||
619 | /* | |
620 | * Prepare new array. This is done first to simplify cleanup in | |
621 | * case the new data set is incompatible, the node only contains | |
622 | * unloaded data sets and there's not enough memory for the array. | |
623 | */ | |
624 | loaded_info = kcalloc(num + 1, sizeof(struct gcov_info *), GFP_KERNEL); | |
625 | if (!loaded_info) { | |
a5ebb875 AM |
626 | pr_warn("could not add '%s' (out of memory)\n", |
627 | gcov_info_filename(info)); | |
85a0fdfd PO |
628 | return; |
629 | } | |
630 | memcpy(loaded_info, node->loaded_info, | |
631 | num * sizeof(struct gcov_info *)); | |
632 | loaded_info[num] = info; | |
633 | /* Check if the new data set is compatible. */ | |
634 | if (num == 0) { | |
635 | /* | |
636 | * A module was unloaded, modified and reloaded. The new | |
637 | * data set replaces the copy of the last one. | |
638 | */ | |
639 | if (!gcov_info_is_compatible(node->unloaded_info, info)) { | |
a5ebb875 AM |
640 | pr_warn("discarding saved data for %s " |
641 | "(incompatible version)\n", | |
642 | gcov_info_filename(info)); | |
85a0fdfd PO |
643 | gcov_info_free(node->unloaded_info); |
644 | node->unloaded_info = NULL; | |
645 | } | |
646 | } else { | |
647 | /* | |
648 | * Two different versions of the same object file are loaded. | |
649 | * The initial one takes precedence. | |
650 | */ | |
651 | if (!gcov_info_is_compatible(node->loaded_info[0], info)) { | |
a5ebb875 AM |
652 | pr_warn("could not add '%s' (incompatible " |
653 | "version)\n", gcov_info_filename(info)); | |
85a0fdfd PO |
654 | kfree(loaded_info); |
655 | return; | |
656 | } | |
2521f2c2 | 657 | } |
85a0fdfd PO |
658 | /* Overwrite previous array. */ |
659 | kfree(node->loaded_info); | |
660 | node->loaded_info = loaded_info; | |
661 | node->num_loaded = num + 1; | |
662 | } | |
2521f2c2 | 663 | |
85a0fdfd PO |
664 | /* |
665 | * Return the index of a profiling data set associated with a node. | |
666 | */ | |
667 | static int get_info_index(struct gcov_node *node, struct gcov_info *info) | |
668 | { | |
669 | int i; | |
670 | ||
671 | for (i = 0; i < node->num_loaded; i++) { | |
672 | if (node->loaded_info[i] == info) | |
673 | return i; | |
674 | } | |
675 | return -ENOENT; | |
2521f2c2 PO |
676 | } |
677 | ||
678 | /* | |
85a0fdfd | 679 | * Save the data of a profiling data set which is being unloaded. |
2521f2c2 | 680 | */ |
85a0fdfd | 681 | static void save_info(struct gcov_node *node, struct gcov_info *info) |
2521f2c2 | 682 | { |
85a0fdfd PO |
683 | if (node->unloaded_info) |
684 | gcov_info_add(node->unloaded_info, info); | |
2521f2c2 | 685 | else { |
85a0fdfd PO |
686 | node->unloaded_info = gcov_info_dup(info); |
687 | if (!node->unloaded_info) { | |
a5ebb875 AM |
688 | pr_warn("could not save data for '%s' " |
689 | "(out of memory)\n", | |
690 | gcov_info_filename(info)); | |
85a0fdfd PO |
691 | } |
692 | } | |
693 | } | |
694 | ||
695 | /* | |
696 | * Disassociate a profiling data set from a node. Needs to be called with | |
697 | * node_lock held. | |
698 | */ | |
699 | static void remove_info(struct gcov_node *node, struct gcov_info *info) | |
700 | { | |
701 | int i; | |
702 | ||
703 | i = get_info_index(node, info); | |
704 | if (i < 0) { | |
a5ebb875 AM |
705 | pr_warn("could not remove '%s' (not found)\n", |
706 | gcov_info_filename(info)); | |
85a0fdfd | 707 | return; |
2521f2c2 | 708 | } |
85a0fdfd PO |
709 | if (gcov_persist) |
710 | save_info(node, info); | |
711 | /* Shrink array. */ | |
712 | node->loaded_info[i] = node->loaded_info[node->num_loaded - 1]; | |
713 | node->num_loaded--; | |
714 | if (node->num_loaded > 0) | |
715 | return; | |
716 | /* Last loaded data set was removed. */ | |
717 | kfree(node->loaded_info); | |
718 | node->loaded_info = NULL; | |
719 | node->num_loaded = 0; | |
720 | if (!node->unloaded_info) | |
721 | remove_node(node); | |
2521f2c2 PO |
722 | } |
723 | ||
724 | /* | |
725 | * Callback to create/remove profiling files when code compiled with | |
726 | * -fprofile-arcs is loaded/unloaded. | |
727 | */ | |
728 | void gcov_event(enum gcov_action action, struct gcov_info *info) | |
729 | { | |
730 | struct gcov_node *node; | |
731 | ||
732 | mutex_lock(&node_lock); | |
8cbce376 | 733 | node = get_node_by_name(gcov_info_filename(info)); |
2521f2c2 PO |
734 | switch (action) { |
735 | case GCOV_ADD: | |
85a0fdfd PO |
736 | if (node) |
737 | add_info(node, info); | |
738 | else | |
2521f2c2 | 739 | add_node(info); |
2521f2c2 PO |
740 | break; |
741 | case GCOV_REMOVE: | |
85a0fdfd PO |
742 | if (node) |
743 | remove_info(node, info); | |
744 | else { | |
a5ebb875 AM |
745 | pr_warn("could not remove '%s' (not found)\n", |
746 | gcov_info_filename(info)); | |
2521f2c2 | 747 | } |
2521f2c2 PO |
748 | break; |
749 | } | |
750 | mutex_unlock(&node_lock); | |
751 | } | |
752 | ||
753 | /* Create debugfs entries. */ | |
754 | static __init int gcov_fs_init(void) | |
755 | { | |
2521f2c2 PO |
756 | init_node(&root_node, NULL, NULL, NULL); |
757 | /* | |
758 | * /sys/kernel/debug/gcov will be parent for the reset control file | |
759 | * and all profiling files. | |
760 | */ | |
761 | root_node.dentry = debugfs_create_dir("gcov", NULL); | |
2521f2c2 PO |
762 | /* |
763 | * Create reset file which resets all profiling counts when written | |
764 | * to. | |
765 | */ | |
1c769fc4 GKH |
766 | debugfs_create_file("reset", 0600, root_node.dentry, NULL, |
767 | &gcov_reset_fops); | |
2521f2c2 PO |
768 | /* Replay previous events to get our fs hierarchy up-to-date. */ |
769 | gcov_enable_events(); | |
770 | return 0; | |
2521f2c2 PO |
771 | } |
772 | device_initcall(gcov_fs_init); |