1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/alloc_tag.h>
3 #include <linux/execmem.h>
4 #include <linux/fs.h>
5 #include <linux/gfp.h>
6 #include <linux/kallsyms.h>
7 #include <linux/module.h>
8 #include <linux/page_ext.h>
9 #include <linux/proc_fs.h>
10 #include <linux/seq_buf.h>
11 #include <linux/seq_file.h>
12 #include <linux/vmalloc.h>
13
14 #define ALLOCINFO_FILE_NAME "allocinfo"
15 #define MODULE_ALLOC_TAG_VMAP_SIZE (100000UL * sizeof(struct alloc_tag))
16 #define SECTION_START(NAME) (CODETAG_SECTION_START_PREFIX NAME)
17 #define SECTION_STOP(NAME) (CODETAG_SECTION_STOP_PREFIX NAME)
18
19 #ifdef CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
20 static bool mem_profiling_support = true;
21 #else
22 static bool mem_profiling_support;
23 #endif
24
25 static struct codetag_type *alloc_tag_cttype;
26
27 DEFINE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
28 EXPORT_SYMBOL(_shared_alloc_tag);
29
30 DEFINE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
31 mem_alloc_profiling_key);
32 EXPORT_SYMBOL(mem_alloc_profiling_key);
33
34 DEFINE_STATIC_KEY_FALSE(mem_profiling_compressed);
35
36 struct alloc_tag_kernel_section kernel_tags = { NULL, 0 };
37 unsigned long alloc_tag_ref_mask;
38 int alloc_tag_ref_offs;
39
40 struct allocinfo_private {
41 struct codetag_iterator iter;
42 bool print_header;
43 };
44
allocinfo_start(struct seq_file * m,loff_t * pos)45 static void *allocinfo_start(struct seq_file *m, loff_t *pos)
46 {
47 struct allocinfo_private *priv;
48 struct codetag *ct;
49 loff_t node = *pos;
50
51 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
52 m->private = priv;
53 if (!priv)
54 return NULL;
55
56 priv->print_header = (node == 0);
57 codetag_lock_module_list(alloc_tag_cttype, true);
58 priv->iter = codetag_get_ct_iter(alloc_tag_cttype);
59 while ((ct = codetag_next_ct(&priv->iter)) != NULL && node)
60 node--;
61
62 return ct ? priv : NULL;
63 }
64
allocinfo_next(struct seq_file * m,void * arg,loff_t * pos)65 static void *allocinfo_next(struct seq_file *m, void *arg, loff_t *pos)
66 {
67 struct allocinfo_private *priv = (struct allocinfo_private *)arg;
68 struct codetag *ct = codetag_next_ct(&priv->iter);
69
70 (*pos)++;
71 if (!ct)
72 return NULL;
73
74 return priv;
75 }
76
allocinfo_stop(struct seq_file * m,void * arg)77 static void allocinfo_stop(struct seq_file *m, void *arg)
78 {
79 struct allocinfo_private *priv = (struct allocinfo_private *)m->private;
80
81 if (priv) {
82 codetag_lock_module_list(alloc_tag_cttype, false);
83 kfree(priv);
84 }
85 }
86
print_allocinfo_header(struct seq_buf * buf)87 static void print_allocinfo_header(struct seq_buf *buf)
88 {
89 /* Output format version, so we can change it. */
90 seq_buf_printf(buf, "allocinfo - version: 1.0\n");
91 seq_buf_printf(buf, "# <size> <calls> <tag info>\n");
92 }
93
alloc_tag_to_text(struct seq_buf * out,struct codetag * ct)94 static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct)
95 {
96 struct alloc_tag *tag = ct_to_alloc_tag(ct);
97 struct alloc_tag_counters counter = alloc_tag_read(tag);
98 s64 bytes = counter.bytes;
99
100 seq_buf_printf(out, "%12lli %8llu ", bytes, counter.calls);
101 codetag_to_text(out, ct);
102 seq_buf_putc(out, ' ');
103 seq_buf_putc(out, '\n');
104 }
105
allocinfo_show(struct seq_file * m,void * arg)106 static int allocinfo_show(struct seq_file *m, void *arg)
107 {
108 struct allocinfo_private *priv = (struct allocinfo_private *)arg;
109 char *bufp;
110 size_t n = seq_get_buf(m, &bufp);
111 struct seq_buf buf;
112
113 seq_buf_init(&buf, bufp, n);
114 if (priv->print_header) {
115 print_allocinfo_header(&buf);
116 priv->print_header = false;
117 }
118 alloc_tag_to_text(&buf, priv->iter.ct);
119 seq_commit(m, seq_buf_used(&buf));
120 return 0;
121 }
122
123 static const struct seq_operations allocinfo_seq_op = {
124 .start = allocinfo_start,
125 .next = allocinfo_next,
126 .stop = allocinfo_stop,
127 .show = allocinfo_show,
128 };
129
alloc_tag_top_users(struct codetag_bytes * tags,size_t count,bool can_sleep)130 size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep)
131 {
132 struct codetag_iterator iter;
133 struct codetag *ct;
134 struct codetag_bytes n;
135 unsigned int i, nr = 0;
136
137 if (can_sleep)
138 codetag_lock_module_list(alloc_tag_cttype, true);
139 else if (!codetag_trylock_module_list(alloc_tag_cttype))
140 return 0;
141
142 iter = codetag_get_ct_iter(alloc_tag_cttype);
143 while ((ct = codetag_next_ct(&iter))) {
144 struct alloc_tag_counters counter = alloc_tag_read(ct_to_alloc_tag(ct));
145
146 n.ct = ct;
147 n.bytes = counter.bytes;
148
149 for (i = 0; i < nr; i++)
150 if (n.bytes > tags[i].bytes)
151 break;
152
153 if (i < count) {
154 nr -= nr == count;
155 memmove(&tags[i + 1],
156 &tags[i],
157 sizeof(tags[0]) * (nr - i));
158 nr++;
159 tags[i] = n;
160 }
161 }
162
163 codetag_lock_module_list(alloc_tag_cttype, false);
164
165 return nr;
166 }
167
pgalloc_tag_split(struct folio * folio,int old_order,int new_order)168 void pgalloc_tag_split(struct folio *folio, int old_order, int new_order)
169 {
170 int i;
171 struct alloc_tag *tag;
172 unsigned int nr_pages = 1 << new_order;
173
174 if (!mem_alloc_profiling_enabled())
175 return;
176
177 tag = __pgalloc_tag_get(&folio->page);
178 if (!tag)
179 return;
180
181 for (i = nr_pages; i < (1 << old_order); i += nr_pages) {
182 union pgtag_ref_handle handle;
183 union codetag_ref ref;
184
185 if (get_page_tag_ref(folio_page(folio, i), &ref, &handle)) {
186 /* Set new reference to point to the original tag */
187 alloc_tag_ref_set(&ref, tag);
188 update_page_tag_ref(handle, &ref);
189 put_page_tag_ref(handle);
190 }
191 }
192 }
193
pgalloc_tag_swap(struct folio * new,struct folio * old)194 void pgalloc_tag_swap(struct folio *new, struct folio *old)
195 {
196 union pgtag_ref_handle handle_old, handle_new;
197 union codetag_ref ref_old, ref_new;
198 struct alloc_tag *tag_old, *tag_new;
199
200 if (!mem_alloc_profiling_enabled())
201 return;
202
203 tag_old = __pgalloc_tag_get(&old->page);
204 if (!tag_old)
205 return;
206 tag_new = __pgalloc_tag_get(&new->page);
207 if (!tag_new)
208 return;
209
210 if (!get_page_tag_ref(&old->page, &ref_old, &handle_old))
211 return;
212 if (!get_page_tag_ref(&new->page, &ref_new, &handle_new)) {
213 put_page_tag_ref(handle_old);
214 return;
215 }
216
217 /*
218 * Clear tag references to avoid debug warning when using
219 * __alloc_tag_ref_set() with non-empty reference.
220 */
221 set_codetag_empty(&ref_old);
222 set_codetag_empty(&ref_new);
223
224 /* swap tags */
225 __alloc_tag_ref_set(&ref_old, tag_new);
226 update_page_tag_ref(handle_old, &ref_old);
227 __alloc_tag_ref_set(&ref_new, tag_old);
228 update_page_tag_ref(handle_new, &ref_new);
229
230 put_page_tag_ref(handle_old);
231 put_page_tag_ref(handle_new);
232 }
233
shutdown_mem_profiling(bool remove_file)234 static void shutdown_mem_profiling(bool remove_file)
235 {
236 if (mem_alloc_profiling_enabled())
237 static_branch_disable(&mem_alloc_profiling_key);
238
239 if (!mem_profiling_support)
240 return;
241
242 if (remove_file)
243 remove_proc_entry(ALLOCINFO_FILE_NAME, NULL);
244 mem_profiling_support = false;
245 }
246
procfs_init(void)247 static void __init procfs_init(void)
248 {
249 if (!mem_profiling_support)
250 return;
251
252 if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
253 pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
254 shutdown_mem_profiling(false);
255 }
256 }
257
alloc_tag_sec_init(void)258 void __init alloc_tag_sec_init(void)
259 {
260 struct alloc_tag *last_codetag;
261
262 if (!mem_profiling_support)
263 return;
264
265 if (!static_key_enabled(&mem_profiling_compressed))
266 return;
267
268 kernel_tags.first_tag = (struct alloc_tag *)kallsyms_lookup_name(
269 SECTION_START(ALLOC_TAG_SECTION_NAME));
270 last_codetag = (struct alloc_tag *)kallsyms_lookup_name(
271 SECTION_STOP(ALLOC_TAG_SECTION_NAME));
272 kernel_tags.count = last_codetag - kernel_tags.first_tag;
273
274 /* Check if kernel tags fit into page flags */
275 if (kernel_tags.count > (1UL << NR_UNUSED_PAGEFLAG_BITS)) {
276 shutdown_mem_profiling(false); /* allocinfo file does not exist yet */
277 pr_err("%lu allocation tags cannot be references using %d available page flag bits. Memory allocation profiling is disabled!\n",
278 kernel_tags.count, NR_UNUSED_PAGEFLAG_BITS);
279 return;
280 }
281
282 alloc_tag_ref_offs = (LRU_REFS_PGOFF - NR_UNUSED_PAGEFLAG_BITS);
283 alloc_tag_ref_mask = ((1UL << NR_UNUSED_PAGEFLAG_BITS) - 1);
284 pr_debug("Memory allocation profiling compression is using %d page flag bits!\n",
285 NR_UNUSED_PAGEFLAG_BITS);
286 }
287
288 #ifdef CONFIG_MODULES
289
290 static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
291 static struct vm_struct *vm_module_tags;
292 /* A dummy object used to indicate an unloaded module */
293 static struct module unloaded_mod;
294 /* A dummy object used to indicate a module prepended area */
295 static struct module prepend_mod;
296
297 struct alloc_tag_module_section module_tags;
298
alloc_tag_align(unsigned long val)299 static inline unsigned long alloc_tag_align(unsigned long val)
300 {
301 if (!static_key_enabled(&mem_profiling_compressed)) {
302 /* No alignment requirements when we are not indexing the tags */
303 return val;
304 }
305
306 if (val % sizeof(struct alloc_tag) == 0)
307 return val;
308 return ((val / sizeof(struct alloc_tag)) + 1) * sizeof(struct alloc_tag);
309 }
310
ensure_alignment(unsigned long align,unsigned int * prepend)311 static bool ensure_alignment(unsigned long align, unsigned int *prepend)
312 {
313 if (!static_key_enabled(&mem_profiling_compressed)) {
314 /* No alignment requirements when we are not indexing the tags */
315 return true;
316 }
317
318 /*
319 * If alloc_tag size is not a multiple of required alignment, tag
320 * indexing does not work.
321 */
322 if (!IS_ALIGNED(sizeof(struct alloc_tag), align))
323 return false;
324
325 /* Ensure prepend consumes multiple of alloc_tag-sized blocks */
326 if (*prepend)
327 *prepend = alloc_tag_align(*prepend);
328
329 return true;
330 }
331
tags_addressable(void)332 static inline bool tags_addressable(void)
333 {
334 unsigned long tag_idx_count;
335
336 if (!static_key_enabled(&mem_profiling_compressed))
337 return true; /* with page_ext tags are always addressable */
338
339 tag_idx_count = CODETAG_ID_FIRST + kernel_tags.count +
340 module_tags.size / sizeof(struct alloc_tag);
341
342 return tag_idx_count < (1UL << NR_UNUSED_PAGEFLAG_BITS);
343 }
344
needs_section_mem(struct module * mod,unsigned long size)345 static bool needs_section_mem(struct module *mod, unsigned long size)
346 {
347 if (!mem_profiling_support)
348 return false;
349
350 return size >= sizeof(struct alloc_tag);
351 }
352
clean_unused_counters(struct alloc_tag * start_tag,struct alloc_tag * end_tag)353 static bool clean_unused_counters(struct alloc_tag *start_tag,
354 struct alloc_tag *end_tag)
355 {
356 struct alloc_tag *tag;
357 bool ret = true;
358
359 for (tag = start_tag; tag <= end_tag; tag++) {
360 struct alloc_tag_counters counter;
361
362 if (!tag->counters)
363 continue;
364
365 counter = alloc_tag_read(tag);
366 if (!counter.bytes) {
367 free_percpu(tag->counters);
368 tag->counters = NULL;
369 } else {
370 ret = false;
371 }
372 }
373
374 return ret;
375 }
376
377 /* Called with mod_area_mt locked */
clean_unused_module_areas_locked(void)378 static void clean_unused_module_areas_locked(void)
379 {
380 MA_STATE(mas, &mod_area_mt, 0, module_tags.size);
381 struct module *val;
382
383 mas_for_each(&mas, val, module_tags.size) {
384 struct alloc_tag *start_tag;
385 struct alloc_tag *end_tag;
386
387 if (val != &unloaded_mod)
388 continue;
389
390 /* Release area if all tags are unused */
391 start_tag = (struct alloc_tag *)(module_tags.start_addr + mas.index);
392 end_tag = (struct alloc_tag *)(module_tags.start_addr + mas.last);
393 if (clean_unused_counters(start_tag, end_tag))
394 mas_erase(&mas);
395 }
396 }
397
398 /* Called with mod_area_mt locked */
find_aligned_area(struct ma_state * mas,unsigned long section_size,unsigned long size,unsigned int prepend,unsigned long align)399 static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
400 unsigned long size, unsigned int prepend, unsigned long align)
401 {
402 bool cleanup_done = false;
403
404 repeat:
405 /* Try finding exact size and hope the start is aligned */
406 if (!mas_empty_area(mas, 0, section_size - 1, prepend + size)) {
407 if (IS_ALIGNED(mas->index + prepend, align))
408 return true;
409
410 /* Try finding larger area to align later */
411 mas_reset(mas);
412 if (!mas_empty_area(mas, 0, section_size - 1,
413 size + prepend + align - 1))
414 return true;
415 }
416
417 /* No free area, try cleanup stale data and repeat the search once */
418 if (!cleanup_done) {
419 clean_unused_module_areas_locked();
420 cleanup_done = true;
421 mas_reset(mas);
422 goto repeat;
423 }
424
425 return false;
426 }
427
vm_module_tags_populate(void)428 static int vm_module_tags_populate(void)
429 {
430 unsigned long phys_end = ALIGN_DOWN(module_tags.start_addr, PAGE_SIZE) +
431 (vm_module_tags->nr_pages << PAGE_SHIFT);
432 unsigned long new_end = module_tags.start_addr + module_tags.size;
433
434 if (phys_end < new_end) {
435 struct page **next_page = vm_module_tags->pages + vm_module_tags->nr_pages;
436 unsigned long old_shadow_end = ALIGN(phys_end, MODULE_ALIGN);
437 unsigned long new_shadow_end = ALIGN(new_end, MODULE_ALIGN);
438 unsigned long more_pages;
439 unsigned long nr = 0;
440
441 more_pages = ALIGN(new_end - phys_end, PAGE_SIZE) >> PAGE_SHIFT;
442 while (nr < more_pages) {
443 unsigned long allocated;
444
445 allocated = alloc_pages_bulk_node(GFP_KERNEL | __GFP_NOWARN,
446 NUMA_NO_NODE, more_pages - nr, next_page + nr);
447
448 if (!allocated)
449 break;
450 nr += allocated;
451 }
452
453 if (nr < more_pages ||
454 vmap_pages_range(phys_end, phys_end + (nr << PAGE_SHIFT), PAGE_KERNEL,
455 next_page, PAGE_SHIFT) < 0) {
456 /* Clean up and error out */
457 for (int i = 0; i < nr; i++)
458 __free_page(next_page[i]);
459 return -ENOMEM;
460 }
461
462 vm_module_tags->nr_pages += nr;
463
464 /*
465 * Kasan allocates 1 byte of shadow for every 8 bytes of data.
466 * When kasan_alloc_module_shadow allocates shadow memory,
467 * its unit of allocation is a page.
468 * Therefore, here we need to align to MODULE_ALIGN.
469 */
470 if (old_shadow_end < new_shadow_end)
471 kasan_alloc_module_shadow((void *)old_shadow_end,
472 new_shadow_end - old_shadow_end,
473 GFP_KERNEL);
474 }
475
476 /*
477 * Mark the pages as accessible, now that they are mapped.
478 * With hardware tag-based KASAN, marking is skipped for
479 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
480 */
481 kasan_unpoison_vmalloc((void *)module_tags.start_addr,
482 new_end - module_tags.start_addr,
483 KASAN_VMALLOC_PROT_NORMAL);
484
485 return 0;
486 }
487
reserve_module_tags(struct module * mod,unsigned long size,unsigned int prepend,unsigned long align)488 static void *reserve_module_tags(struct module *mod, unsigned long size,
489 unsigned int prepend, unsigned long align)
490 {
491 unsigned long section_size = module_tags.end_addr - module_tags.start_addr;
492 MA_STATE(mas, &mod_area_mt, 0, section_size - 1);
493 unsigned long offset;
494 void *ret = NULL;
495
496 /* If no tags return error */
497 if (size < sizeof(struct alloc_tag))
498 return ERR_PTR(-EINVAL);
499
500 /*
501 * align is always power of 2, so we can use IS_ALIGNED and ALIGN.
502 * align 0 or 1 means no alignment, to simplify set to 1.
503 */
504 if (!align)
505 align = 1;
506
507 if (!ensure_alignment(align, &prepend)) {
508 shutdown_mem_profiling(true);
509 pr_err("%s: alignment %lu is incompatible with allocation tag indexing. Memory allocation profiling is disabled!\n",
510 mod->name, align);
511 return ERR_PTR(-EINVAL);
512 }
513
514 mas_lock(&mas);
515 if (!find_aligned_area(&mas, section_size, size, prepend, align)) {
516 ret = ERR_PTR(-ENOMEM);
517 goto unlock;
518 }
519
520 /* Mark found area as reserved */
521 offset = mas.index;
522 offset += prepend;
523 offset = ALIGN(offset, align);
524 if (offset != mas.index) {
525 unsigned long pad_start = mas.index;
526
527 mas.last = offset - 1;
528 mas_store(&mas, &prepend_mod);
529 if (mas_is_err(&mas)) {
530 ret = ERR_PTR(xa_err(mas.node));
531 goto unlock;
532 }
533 mas.index = offset;
534 mas.last = offset + size - 1;
535 mas_store(&mas, mod);
536 if (mas_is_err(&mas)) {
537 mas.index = pad_start;
538 mas_erase(&mas);
539 ret = ERR_PTR(xa_err(mas.node));
540 }
541 } else {
542 mas.last = offset + size - 1;
543 mas_store(&mas, mod);
544 if (mas_is_err(&mas))
545 ret = ERR_PTR(xa_err(mas.node));
546 }
547 unlock:
548 mas_unlock(&mas);
549
550 if (IS_ERR(ret))
551 return ret;
552
553 if (module_tags.size < offset + size) {
554 int grow_res;
555
556 module_tags.size = offset + size;
557 if (mem_alloc_profiling_enabled() && !tags_addressable()) {
558 shutdown_mem_profiling(true);
559 pr_warn("With module %s there are too many tags to fit in %d page flag bits. Memory allocation profiling is disabled!\n",
560 mod->name, NR_UNUSED_PAGEFLAG_BITS);
561 }
562
563 grow_res = vm_module_tags_populate();
564 if (grow_res) {
565 shutdown_mem_profiling(true);
566 pr_err("Failed to allocate memory for allocation tags in the module %s. Memory allocation profiling is disabled!\n",
567 mod->name);
568 return ERR_PTR(grow_res);
569 }
570 }
571
572 return (struct alloc_tag *)(module_tags.start_addr + offset);
573 }
574
release_module_tags(struct module * mod,bool used)575 static void release_module_tags(struct module *mod, bool used)
576 {
577 MA_STATE(mas, &mod_area_mt, module_tags.size, module_tags.size);
578 struct alloc_tag *start_tag;
579 struct alloc_tag *end_tag;
580 struct module *val;
581
582 mas_lock(&mas);
583 mas_for_each_rev(&mas, val, 0)
584 if (val == mod)
585 break;
586
587 if (!val) /* module not found */
588 goto out;
589
590 if (!used)
591 goto release_area;
592
593 start_tag = (struct alloc_tag *)(module_tags.start_addr + mas.index);
594 end_tag = (struct alloc_tag *)(module_tags.start_addr + mas.last);
595 if (!clean_unused_counters(start_tag, end_tag)) {
596 struct alloc_tag *tag;
597
598 for (tag = start_tag; tag <= end_tag; tag++) {
599 struct alloc_tag_counters counter;
600
601 if (!tag->counters)
602 continue;
603
604 counter = alloc_tag_read(tag);
605 pr_info("%s:%u module %s func:%s has %llu allocated at module unload\n",
606 tag->ct.filename, tag->ct.lineno, tag->ct.modname,
607 tag->ct.function, counter.bytes);
608 }
609 } else {
610 used = false;
611 }
612 release_area:
613 mas_store(&mas, used ? &unloaded_mod : NULL);
614 val = mas_prev_range(&mas, 0);
615 if (val == &prepend_mod)
616 mas_store(&mas, NULL);
617 out:
618 mas_unlock(&mas);
619 }
620
load_module(struct module * mod,struct codetag * start,struct codetag * stop)621 static void load_module(struct module *mod, struct codetag *start, struct codetag *stop)
622 {
623 /* Allocate module alloc_tag percpu counters */
624 struct alloc_tag *start_tag;
625 struct alloc_tag *stop_tag;
626 struct alloc_tag *tag;
627
628 if (!mod)
629 return;
630
631 start_tag = ct_to_alloc_tag(start);
632 stop_tag = ct_to_alloc_tag(stop);
633 for (tag = start_tag; tag < stop_tag; tag++) {
634 WARN_ON(tag->counters);
635 tag->counters = alloc_percpu(struct alloc_tag_counters);
636 if (!tag->counters) {
637 while (--tag >= start_tag) {
638 free_percpu(tag->counters);
639 tag->counters = NULL;
640 }
641 shutdown_mem_profiling(true);
642 pr_err("Failed to allocate memory for allocation tag percpu counters in the module %s. Memory allocation profiling is disabled!\n",
643 mod->name);
644 break;
645 }
646 }
647 }
648
replace_module(struct module * mod,struct module * new_mod)649 static void replace_module(struct module *mod, struct module *new_mod)
650 {
651 MA_STATE(mas, &mod_area_mt, 0, module_tags.size);
652 struct module *val;
653
654 mas_lock(&mas);
655 mas_for_each(&mas, val, module_tags.size) {
656 if (val != mod)
657 continue;
658
659 mas_store_gfp(&mas, new_mod, GFP_KERNEL);
660 break;
661 }
662 mas_unlock(&mas);
663 }
664
alloc_mod_tags_mem(void)665 static int __init alloc_mod_tags_mem(void)
666 {
667 /* Map space to copy allocation tags */
668 vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
669 if (!vm_module_tags) {
670 pr_err("Failed to map %lu bytes for module allocation tags\n",
671 MODULE_ALLOC_TAG_VMAP_SIZE);
672 module_tags.start_addr = 0;
673 return -ENOMEM;
674 }
675
676 vm_module_tags->pages = kmalloc_array(get_vm_area_size(vm_module_tags) >> PAGE_SHIFT,
677 sizeof(struct page *), GFP_KERNEL | __GFP_ZERO);
678 if (!vm_module_tags->pages) {
679 free_vm_area(vm_module_tags);
680 return -ENOMEM;
681 }
682
683 module_tags.start_addr = (unsigned long)vm_module_tags->addr;
684 module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
685 /* Ensure the base is alloc_tag aligned when required for indexing */
686 module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
687
688 return 0;
689 }
690
free_mod_tags_mem(void)691 static void __init free_mod_tags_mem(void)
692 {
693 int i;
694
695 module_tags.start_addr = 0;
696 for (i = 0; i < vm_module_tags->nr_pages; i++)
697 __free_page(vm_module_tags->pages[i]);
698 kfree(vm_module_tags->pages);
699 free_vm_area(vm_module_tags);
700 }
701
702 #else /* CONFIG_MODULES */
703
alloc_mod_tags_mem(void)704 static inline int alloc_mod_tags_mem(void) { return 0; }
free_mod_tags_mem(void)705 static inline void free_mod_tags_mem(void) {}
706
707 #endif /* CONFIG_MODULES */
708
709 /* See: Documentation/mm/allocation-profiling.rst */
setup_early_mem_profiling(char * str)710 static int __init setup_early_mem_profiling(char *str)
711 {
712 bool compressed = false;
713 bool enable;
714
715 if (!str || !str[0])
716 return -EINVAL;
717
718 if (!strncmp(str, "never", 5)) {
719 enable = false;
720 mem_profiling_support = false;
721 pr_info("Memory allocation profiling is disabled!\n");
722 } else {
723 char *token = strsep(&str, ",");
724
725 if (kstrtobool(token, &enable))
726 return -EINVAL;
727
728 if (str) {
729
730 if (strcmp(str, "compressed"))
731 return -EINVAL;
732
733 compressed = true;
734 }
735 mem_profiling_support = true;
736 pr_info("Memory allocation profiling is enabled %s compression and is turned %s!\n",
737 compressed ? "with" : "without", enable ? "on" : "off");
738 }
739
740 if (enable != mem_alloc_profiling_enabled()) {
741 if (enable)
742 static_branch_enable(&mem_alloc_profiling_key);
743 else
744 static_branch_disable(&mem_alloc_profiling_key);
745 }
746 if (compressed != static_key_enabled(&mem_profiling_compressed)) {
747 if (compressed)
748 static_branch_enable(&mem_profiling_compressed);
749 else
750 static_branch_disable(&mem_profiling_compressed);
751 }
752
753 return 0;
754 }
755 early_param("sysctl.vm.mem_profiling", setup_early_mem_profiling);
756
need_page_alloc_tagging(void)757 static __init bool need_page_alloc_tagging(void)
758 {
759 if (static_key_enabled(&mem_profiling_compressed))
760 return false;
761
762 return mem_profiling_support;
763 }
764
init_page_alloc_tagging(void)765 static __init void init_page_alloc_tagging(void)
766 {
767 }
768
769 struct page_ext_operations page_alloc_tagging_ops = {
770 .size = sizeof(union codetag_ref),
771 .need = need_page_alloc_tagging,
772 .init = init_page_alloc_tagging,
773 };
774 EXPORT_SYMBOL(page_alloc_tagging_ops);
775
776 #ifdef CONFIG_SYSCTL
777 static struct ctl_table memory_allocation_profiling_sysctls[] = {
778 {
779 .procname = "mem_profiling",
780 .data = &mem_alloc_profiling_key,
781 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
782 .mode = 0444,
783 #else
784 .mode = 0644,
785 #endif
786 .proc_handler = proc_do_static_key,
787 },
788 };
789
sysctl_init(void)790 static void __init sysctl_init(void)
791 {
792 if (!mem_profiling_support)
793 memory_allocation_profiling_sysctls[0].mode = 0444;
794
795 register_sysctl_init("vm", memory_allocation_profiling_sysctls);
796 }
797 #else /* CONFIG_SYSCTL */
sysctl_init(void)798 static inline void sysctl_init(void) {}
799 #endif /* CONFIG_SYSCTL */
800
alloc_tag_init(void)801 static int __init alloc_tag_init(void)
802 {
803 const struct codetag_type_desc desc = {
804 .section = ALLOC_TAG_SECTION_NAME,
805 .tag_size = sizeof(struct alloc_tag),
806 #ifdef CONFIG_MODULES
807 .needs_section_mem = needs_section_mem,
808 .alloc_section_mem = reserve_module_tags,
809 .free_section_mem = release_module_tags,
810 .module_load = load_module,
811 .module_replaced = replace_module,
812 #endif
813 };
814 int res;
815
816 res = alloc_mod_tags_mem();
817 if (res)
818 return res;
819
820 alloc_tag_cttype = codetag_register_type(&desc);
821 if (IS_ERR(alloc_tag_cttype)) {
822 free_mod_tags_mem();
823 return PTR_ERR(alloc_tag_cttype);
824 }
825
826 sysctl_init();
827 procfs_init();
828
829 return 0;
830 }
831 module_init(alloc_tag_init);
832