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e178a5be GH |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Copyright (C) 2019 Google, Inc. | |
4 | * modified from kernel/gcov/gcc_4_7.c | |
5 | * | |
6 | * This software is licensed under the terms of the GNU General Public | |
7 | * License version 2, as published by the Free Software Foundation, and | |
8 | * may be copied, distributed, and modified under those terms. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * | |
16 | * LLVM uses profiling data that's deliberately similar to GCC, but has a | |
17 | * very different way of exporting that data. LLVM calls llvm_gcov_init() once | |
18 | * per module, and provides a couple of callbacks that we can use to ask for | |
19 | * more data. | |
20 | * | |
21 | * We care about the "writeout" callback, which in turn calls back into | |
22 | * compiler-rt/this module to dump all the gathered coverage data to disk: | |
23 | * | |
24 | * llvm_gcda_start_file() | |
25 | * llvm_gcda_emit_function() | |
26 | * llvm_gcda_emit_arcs() | |
27 | * llvm_gcda_emit_function() | |
28 | * llvm_gcda_emit_arcs() | |
29 | * [... repeats for each function ...] | |
30 | * llvm_gcda_summary_info() | |
31 | * llvm_gcda_end_file() | |
32 | * | |
33 | * This design is much more stateless and unstructured than gcc's, and is | |
34 | * intended to run at process exit. This forces us to keep some local state | |
35 | * about which module we're dealing with at the moment. On the other hand, it | |
36 | * also means we don't depend as much on how LLVM represents profiling data | |
37 | * internally. | |
38 | * | |
39 | * See LLVM's lib/Transforms/Instrumentation/GCOVProfiling.cpp for more | |
40 | * details on how this works, particularly GCOVProfiler::emitProfileArcs(), | |
41 | * GCOVProfiler::insertCounterWriteout(), and | |
42 | * GCOVProfiler::insertFlush(). | |
43 | */ | |
44 | ||
45 | #define pr_fmt(fmt) "gcov: " fmt | |
46 | ||
47 | #include <linux/kernel.h> | |
48 | #include <linux/list.h> | |
49 | #include <linux/printk.h> | |
50 | #include <linux/ratelimit.h> | |
e178a5be | 51 | #include <linux/slab.h> |
1391efa9 | 52 | #include <linux/mm.h> |
e178a5be GH |
53 | #include "gcov.h" |
54 | ||
55 | typedef void (*llvm_gcov_callback)(void); | |
56 | ||
57 | struct gcov_info { | |
58 | struct list_head head; | |
59 | ||
60 | const char *filename; | |
61 | unsigned int version; | |
62 | u32 checksum; | |
63 | ||
64 | struct list_head functions; | |
65 | }; | |
66 | ||
67 | struct gcov_fn_info { | |
68 | struct list_head head; | |
69 | ||
70 | u32 ident; | |
71 | u32 checksum; | |
e178a5be GH |
72 | u32 cfg_checksum; |
73 | ||
74 | u32 num_counters; | |
75 | u64 *counters; | |
e178a5be GH |
76 | }; |
77 | ||
78 | static struct gcov_info *current_info; | |
79 | ||
80 | static LIST_HEAD(clang_gcov_list); | |
81 | ||
82 | void llvm_gcov_init(llvm_gcov_callback writeout, llvm_gcov_callback flush) | |
83 | { | |
84 | struct gcov_info *info = kzalloc(sizeof(*info), GFP_KERNEL); | |
85 | ||
86 | if (!info) | |
87 | return; | |
88 | ||
89 | INIT_LIST_HEAD(&info->head); | |
90 | INIT_LIST_HEAD(&info->functions); | |
91 | ||
92 | mutex_lock(&gcov_lock); | |
93 | ||
94 | list_add_tail(&info->head, &clang_gcov_list); | |
95 | current_info = info; | |
96 | writeout(); | |
97 | current_info = NULL; | |
98 | if (gcov_events_enabled) | |
99 | gcov_event(GCOV_ADD, info); | |
100 | ||
101 | mutex_unlock(&gcov_lock); | |
102 | } | |
103 | EXPORT_SYMBOL(llvm_gcov_init); | |
104 | ||
60bcf728 ND |
105 | void llvm_gcda_start_file(const char *orig_filename, u32 version, u32 checksum) |
106 | { | |
107 | current_info->filename = orig_filename; | |
108 | current_info->version = version; | |
109 | current_info->checksum = checksum; | |
110 | } | |
111 | EXPORT_SYMBOL(llvm_gcda_start_file); | |
e178a5be | 112 | |
9562fd13 | 113 | void llvm_gcda_emit_function(u32 ident, u32 func_checksum, u32 cfg_checksum) |
60bcf728 ND |
114 | { |
115 | struct gcov_fn_info *info = kzalloc(sizeof(*info), GFP_KERNEL); | |
116 | ||
117 | if (!info) | |
118 | return; | |
119 | ||
120 | INIT_LIST_HEAD(&info->head); | |
121 | info->ident = ident; | |
122 | info->checksum = func_checksum; | |
60bcf728 ND |
123 | info->cfg_checksum = cfg_checksum; |
124 | list_add_tail(&info->head, ¤t_info->functions); | |
125 | } | |
9562fd13 | 126 | EXPORT_SYMBOL(llvm_gcda_emit_function); |
e178a5be GH |
127 | |
128 | void llvm_gcda_emit_arcs(u32 num_counters, u64 *counters) | |
129 | { | |
130 | struct gcov_fn_info *info = list_last_entry(¤t_info->functions, | |
131 | struct gcov_fn_info, head); | |
132 | ||
133 | info->num_counters = num_counters; | |
134 | info->counters = counters; | |
135 | } | |
136 | EXPORT_SYMBOL(llvm_gcda_emit_arcs); | |
137 | ||
138 | void llvm_gcda_summary_info(void) | |
139 | { | |
140 | } | |
141 | EXPORT_SYMBOL(llvm_gcda_summary_info); | |
142 | ||
143 | void llvm_gcda_end_file(void) | |
144 | { | |
145 | } | |
146 | EXPORT_SYMBOL(llvm_gcda_end_file); | |
147 | ||
148 | /** | |
149 | * gcov_info_filename - return info filename | |
150 | * @info: profiling data set | |
151 | */ | |
152 | const char *gcov_info_filename(struct gcov_info *info) | |
153 | { | |
154 | return info->filename; | |
155 | } | |
156 | ||
157 | /** | |
158 | * gcov_info_version - return info version | |
159 | * @info: profiling data set | |
160 | */ | |
161 | unsigned int gcov_info_version(struct gcov_info *info) | |
162 | { | |
163 | return info->version; | |
164 | } | |
165 | ||
166 | /** | |
167 | * gcov_info_next - return next profiling data set | |
168 | * @info: profiling data set | |
169 | * | |
170 | * Returns next gcov_info following @info or first gcov_info in the chain if | |
171 | * @info is %NULL. | |
172 | */ | |
173 | struct gcov_info *gcov_info_next(struct gcov_info *info) | |
174 | { | |
175 | if (!info) | |
176 | return list_first_entry_or_null(&clang_gcov_list, | |
177 | struct gcov_info, head); | |
178 | if (list_is_last(&info->head, &clang_gcov_list)) | |
179 | return NULL; | |
180 | return list_next_entry(info, head); | |
181 | } | |
182 | ||
183 | /** | |
184 | * gcov_info_link - link/add profiling data set to the list | |
185 | * @info: profiling data set | |
186 | */ | |
187 | void gcov_info_link(struct gcov_info *info) | |
188 | { | |
189 | list_add_tail(&info->head, &clang_gcov_list); | |
190 | } | |
191 | ||
192 | /** | |
193 | * gcov_info_unlink - unlink/remove profiling data set from the list | |
194 | * @prev: previous profiling data set | |
195 | * @info: profiling data set | |
196 | */ | |
197 | void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info) | |
198 | { | |
199 | /* Generic code unlinks while iterating. */ | |
200 | __list_del_entry(&info->head); | |
201 | } | |
202 | ||
203 | /** | |
204 | * gcov_info_within_module - check if a profiling data set belongs to a module | |
205 | * @info: profiling data set | |
206 | * @mod: module | |
207 | * | |
208 | * Returns true if profiling data belongs module, false otherwise. | |
209 | */ | |
210 | bool gcov_info_within_module(struct gcov_info *info, struct module *mod) | |
211 | { | |
212 | return within_module((unsigned long)info->filename, mod); | |
213 | } | |
214 | ||
215 | /* Symbolic links to be created for each profiling data file. */ | |
216 | const struct gcov_link gcov_link[] = { | |
217 | { OBJ_TREE, "gcno" }, /* Link to .gcno file in $(objtree). */ | |
218 | { 0, NULL}, | |
219 | }; | |
220 | ||
221 | /** | |
222 | * gcov_info_reset - reset profiling data to zero | |
223 | * @info: profiling data set | |
224 | */ | |
225 | void gcov_info_reset(struct gcov_info *info) | |
226 | { | |
227 | struct gcov_fn_info *fn; | |
228 | ||
229 | list_for_each_entry(fn, &info->functions, head) | |
230 | memset(fn->counters, 0, | |
231 | sizeof(fn->counters[0]) * fn->num_counters); | |
232 | } | |
233 | ||
234 | /** | |
235 | * gcov_info_is_compatible - check if profiling data can be added | |
236 | * @info1: first profiling data set | |
237 | * @info2: second profiling data set | |
238 | * | |
239 | * Returns non-zero if profiling data can be added, zero otherwise. | |
240 | */ | |
241 | int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2) | |
242 | { | |
243 | struct gcov_fn_info *fn_ptr1 = list_first_entry_or_null( | |
244 | &info1->functions, struct gcov_fn_info, head); | |
245 | struct gcov_fn_info *fn_ptr2 = list_first_entry_or_null( | |
246 | &info2->functions, struct gcov_fn_info, head); | |
247 | ||
248 | if (info1->checksum != info2->checksum) | |
249 | return false; | |
250 | if (!fn_ptr1) | |
251 | return fn_ptr1 == fn_ptr2; | |
252 | while (!list_is_last(&fn_ptr1->head, &info1->functions) && | |
253 | !list_is_last(&fn_ptr2->head, &info2->functions)) { | |
254 | if (fn_ptr1->checksum != fn_ptr2->checksum) | |
255 | return false; | |
9562fd13 ND |
256 | if (fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum) |
257 | return false; | |
e178a5be GH |
258 | fn_ptr1 = list_next_entry(fn_ptr1, head); |
259 | fn_ptr2 = list_next_entry(fn_ptr2, head); | |
260 | } | |
261 | return list_is_last(&fn_ptr1->head, &info1->functions) && | |
262 | list_is_last(&fn_ptr2->head, &info2->functions); | |
263 | } | |
264 | ||
265 | /** | |
266 | * gcov_info_add - add up profiling data | |
267 | * @dest: profiling data set to which data is added | |
268 | * @source: profiling data set which is added | |
269 | * | |
270 | * Adds profiling counts of @source to @dest. | |
271 | */ | |
272 | void gcov_info_add(struct gcov_info *dst, struct gcov_info *src) | |
273 | { | |
274 | struct gcov_fn_info *dfn_ptr; | |
275 | struct gcov_fn_info *sfn_ptr = list_first_entry_or_null(&src->functions, | |
276 | struct gcov_fn_info, head); | |
277 | ||
278 | list_for_each_entry(dfn_ptr, &dst->functions, head) { | |
279 | u32 i; | |
280 | ||
281 | for (i = 0; i < sfn_ptr->num_counters; i++) | |
282 | dfn_ptr->counters[i] += sfn_ptr->counters[i]; | |
a6f810ef MO |
283 | |
284 | sfn_ptr = list_next_entry(sfn_ptr, head); | |
e178a5be GH |
285 | } |
286 | } | |
287 | ||
60bcf728 ND |
288 | static struct gcov_fn_info *gcov_fn_info_dup(struct gcov_fn_info *fn) |
289 | { | |
290 | size_t cv_size; /* counter values size */ | |
291 | struct gcov_fn_info *fn_dup = kmemdup(fn, sizeof(*fn), | |
292 | GFP_KERNEL); | |
293 | if (!fn_dup) | |
294 | return NULL; | |
295 | INIT_LIST_HEAD(&fn_dup->head); | |
296 | ||
297 | cv_size = fn->num_counters * sizeof(fn->counters[0]); | |
1391efa9 | 298 | fn_dup->counters = kvmalloc(cv_size, GFP_KERNEL); |
60bcf728 ND |
299 | if (!fn_dup->counters) { |
300 | kfree(fn_dup); | |
301 | return NULL; | |
302 | } | |
303 | ||
304 | memcpy(fn_dup->counters, fn->counters, cv_size); | |
305 | ||
306 | return fn_dup; | |
307 | } | |
e178a5be GH |
308 | |
309 | /** | |
310 | * gcov_info_dup - duplicate profiling data set | |
311 | * @info: profiling data set to duplicate | |
312 | * | |
313 | * Return newly allocated duplicate on success, %NULL on error. | |
314 | */ | |
315 | struct gcov_info *gcov_info_dup(struct gcov_info *info) | |
316 | { | |
317 | struct gcov_info *dup; | |
318 | struct gcov_fn_info *fn; | |
319 | ||
320 | dup = kmemdup(info, sizeof(*dup), GFP_KERNEL); | |
321 | if (!dup) | |
322 | return NULL; | |
323 | INIT_LIST_HEAD(&dup->head); | |
324 | INIT_LIST_HEAD(&dup->functions); | |
325 | dup->filename = kstrdup(info->filename, GFP_KERNEL); | |
326 | if (!dup->filename) | |
327 | goto err; | |
328 | ||
329 | list_for_each_entry(fn, &info->functions, head) { | |
330 | struct gcov_fn_info *fn_dup = gcov_fn_info_dup(fn); | |
331 | ||
332 | if (!fn_dup) | |
333 | goto err; | |
334 | list_add_tail(&fn_dup->head, &dup->functions); | |
335 | } | |
336 | ||
337 | return dup; | |
338 | ||
339 | err: | |
340 | gcov_info_free(dup); | |
341 | return NULL; | |
342 | } | |
343 | ||
344 | /** | |
345 | * gcov_info_free - release memory for profiling data set duplicate | |
346 | * @info: profiling data set duplicate to free | |
347 | */ | |
60bcf728 ND |
348 | void gcov_info_free(struct gcov_info *info) |
349 | { | |
350 | struct gcov_fn_info *fn, *tmp; | |
351 | ||
352 | list_for_each_entry_safe(fn, tmp, &info->functions, head) { | |
1391efa9 | 353 | kvfree(fn->counters); |
60bcf728 ND |
354 | list_del(&fn->head); |
355 | kfree(fn); | |
356 | } | |
357 | kfree(info->filename); | |
358 | kfree(info); | |
359 | } | |
e178a5be | 360 | |
e178a5be GH |
361 | /** |
362 | * convert_to_gcda - convert profiling data set to gcda file format | |
363 | * @buffer: the buffer to store file data or %NULL if no data should be stored | |
364 | * @info: profiling data set to be converted | |
365 | * | |
366 | * Returns the number of bytes that were/would have been stored into the buffer. | |
367 | */ | |
7a1d55b9 | 368 | size_t convert_to_gcda(char *buffer, struct gcov_info *info) |
e178a5be GH |
369 | { |
370 | struct gcov_fn_info *fi_ptr; | |
371 | size_t pos = 0; | |
372 | ||
373 | /* File header. */ | |
374 | pos += store_gcov_u32(buffer, pos, GCOV_DATA_MAGIC); | |
375 | pos += store_gcov_u32(buffer, pos, info->version); | |
376 | pos += store_gcov_u32(buffer, pos, info->checksum); | |
377 | ||
378 | list_for_each_entry(fi_ptr, &info->functions, head) { | |
379 | u32 i; | |
e178a5be GH |
380 | |
381 | pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION); | |
9562fd13 | 382 | pos += store_gcov_u32(buffer, pos, 3); |
e178a5be GH |
383 | pos += store_gcov_u32(buffer, pos, fi_ptr->ident); |
384 | pos += store_gcov_u32(buffer, pos, fi_ptr->checksum); | |
9562fd13 | 385 | pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum); |
e178a5be GH |
386 | pos += store_gcov_u32(buffer, pos, GCOV_TAG_COUNTER_BASE); |
387 | pos += store_gcov_u32(buffer, pos, fi_ptr->num_counters * 2); | |
388 | for (i = 0; i < fi_ptr->num_counters; i++) | |
389 | pos += store_gcov_u64(buffer, pos, fi_ptr->counters[i]); | |
390 | } | |
391 | ||
392 | return pos; | |
393 | } |