xref: /linux/lib/alloc_tag.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 DEFINE_STATIC_KEY_FALSE(mem_profiling_compressed);
33 
34 struct alloc_tag_kernel_section kernel_tags = { NULL, 0 };
35 unsigned long alloc_tag_ref_mask;
36 int alloc_tag_ref_offs;
37 
38 struct allocinfo_private {
39 	struct codetag_iterator iter;
40 	bool print_header;
41 };
42 
43 static void *allocinfo_start(struct seq_file *m, loff_t *pos)
44 {
45 	struct allocinfo_private *priv;
46 	struct codetag *ct;
47 	loff_t node = *pos;
48 
49 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
50 	m->private = priv;
51 	if (!priv)
52 		return NULL;
53 
54 	priv->print_header = (node == 0);
55 	codetag_lock_module_list(alloc_tag_cttype, true);
56 	priv->iter = codetag_get_ct_iter(alloc_tag_cttype);
57 	while ((ct = codetag_next_ct(&priv->iter)) != NULL && node)
58 		node--;
59 
60 	return ct ? priv : NULL;
61 }
62 
63 static void *allocinfo_next(struct seq_file *m, void *arg, loff_t *pos)
64 {
65 	struct allocinfo_private *priv = (struct allocinfo_private *)arg;
66 	struct codetag *ct = codetag_next_ct(&priv->iter);
67 
68 	(*pos)++;
69 	if (!ct)
70 		return NULL;
71 
72 	return priv;
73 }
74 
75 static void allocinfo_stop(struct seq_file *m, void *arg)
76 {
77 	struct allocinfo_private *priv = (struct allocinfo_private *)m->private;
78 
79 	if (priv) {
80 		codetag_lock_module_list(alloc_tag_cttype, false);
81 		kfree(priv);
82 	}
83 }
84 
85 static void print_allocinfo_header(struct seq_buf *buf)
86 {
87 	/* Output format version, so we can change it. */
88 	seq_buf_printf(buf, "allocinfo - version: 1.0\n");
89 	seq_buf_printf(buf, "#     <size>  <calls> <tag info>\n");
90 }
91 
92 static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct)
93 {
94 	struct alloc_tag *tag = ct_to_alloc_tag(ct);
95 	struct alloc_tag_counters counter = alloc_tag_read(tag);
96 	s64 bytes = counter.bytes;
97 
98 	seq_buf_printf(out, "%12lli %8llu ", bytes, counter.calls);
99 	codetag_to_text(out, ct);
100 	seq_buf_putc(out, ' ');
101 	seq_buf_putc(out, '\n');
102 }
103 
104 static int allocinfo_show(struct seq_file *m, void *arg)
105 {
106 	struct allocinfo_private *priv = (struct allocinfo_private *)arg;
107 	char *bufp;
108 	size_t n = seq_get_buf(m, &bufp);
109 	struct seq_buf buf;
110 
111 	seq_buf_init(&buf, bufp, n);
112 	if (priv->print_header) {
113 		print_allocinfo_header(&buf);
114 		priv->print_header = false;
115 	}
116 	alloc_tag_to_text(&buf, priv->iter.ct);
117 	seq_commit(m, seq_buf_used(&buf));
118 	return 0;
119 }
120 
121 static const struct seq_operations allocinfo_seq_op = {
122 	.start	= allocinfo_start,
123 	.next	= allocinfo_next,
124 	.stop	= allocinfo_stop,
125 	.show	= allocinfo_show,
126 };
127 
128 size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep)
129 {
130 	struct codetag_iterator iter;
131 	struct codetag *ct;
132 	struct codetag_bytes n;
133 	unsigned int i, nr = 0;
134 
135 	if (can_sleep)
136 		codetag_lock_module_list(alloc_tag_cttype, true);
137 	else if (!codetag_trylock_module_list(alloc_tag_cttype))
138 		return 0;
139 
140 	iter = codetag_get_ct_iter(alloc_tag_cttype);
141 	while ((ct = codetag_next_ct(&iter))) {
142 		struct alloc_tag_counters counter = alloc_tag_read(ct_to_alloc_tag(ct));
143 
144 		n.ct	= ct;
145 		n.bytes = counter.bytes;
146 
147 		for (i = 0; i < nr; i++)
148 			if (n.bytes > tags[i].bytes)
149 				break;
150 
151 		if (i < count) {
152 			nr -= nr == count;
153 			memmove(&tags[i + 1],
154 				&tags[i],
155 				sizeof(tags[0]) * (nr - i));
156 			nr++;
157 			tags[i] = n;
158 		}
159 	}
160 
161 	codetag_lock_module_list(alloc_tag_cttype, false);
162 
163 	return nr;
164 }
165 
166 void pgalloc_tag_split(struct folio *folio, int old_order, int new_order)
167 {
168 	int i;
169 	struct alloc_tag *tag;
170 	unsigned int nr_pages = 1 << new_order;
171 
172 	if (!mem_alloc_profiling_enabled())
173 		return;
174 
175 	tag = pgalloc_tag_get(&folio->page);
176 	if (!tag)
177 		return;
178 
179 	for (i = nr_pages; i < (1 << old_order); i += nr_pages) {
180 		union pgtag_ref_handle handle;
181 		union codetag_ref ref;
182 
183 		if (get_page_tag_ref(folio_page(folio, i), &ref, &handle)) {
184 			/* Set new reference to point to the original tag */
185 			alloc_tag_ref_set(&ref, tag);
186 			update_page_tag_ref(handle, &ref);
187 			put_page_tag_ref(handle);
188 		}
189 	}
190 }
191 
192 void pgalloc_tag_copy(struct folio *new, struct folio *old)
193 {
194 	union pgtag_ref_handle handle;
195 	union codetag_ref ref;
196 	struct alloc_tag *tag;
197 
198 	tag = pgalloc_tag_get(&old->page);
199 	if (!tag)
200 		return;
201 
202 	if (!get_page_tag_ref(&new->page, &ref, &handle))
203 		return;
204 
205 	/* Clear the old ref to the original allocation tag. */
206 	clear_page_tag_ref(&old->page);
207 	/* Decrement the counters of the tag on get_new_folio. */
208 	alloc_tag_sub(&ref, folio_size(new));
209 	__alloc_tag_ref_set(&ref, tag);
210 	update_page_tag_ref(handle, &ref);
211 	put_page_tag_ref(handle);
212 }
213 
214 static void shutdown_mem_profiling(bool remove_file)
215 {
216 	if (mem_alloc_profiling_enabled())
217 		static_branch_disable(&mem_alloc_profiling_key);
218 
219 	if (!mem_profiling_support)
220 		return;
221 
222 	if (remove_file)
223 		remove_proc_entry(ALLOCINFO_FILE_NAME, NULL);
224 	mem_profiling_support = false;
225 }
226 
227 static void __init procfs_init(void)
228 {
229 	if (!mem_profiling_support)
230 		return;
231 
232 	if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
233 		pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
234 		shutdown_mem_profiling(false);
235 	}
236 }
237 
238 void __init alloc_tag_sec_init(void)
239 {
240 	struct alloc_tag *last_codetag;
241 
242 	if (!mem_profiling_support)
243 		return;
244 
245 	if (!static_key_enabled(&mem_profiling_compressed))
246 		return;
247 
248 	kernel_tags.first_tag = (struct alloc_tag *)kallsyms_lookup_name(
249 					SECTION_START(ALLOC_TAG_SECTION_NAME));
250 	last_codetag = (struct alloc_tag *)kallsyms_lookup_name(
251 					SECTION_STOP(ALLOC_TAG_SECTION_NAME));
252 	kernel_tags.count = last_codetag - kernel_tags.first_tag;
253 
254 	/* Check if kernel tags fit into page flags */
255 	if (kernel_tags.count > (1UL << NR_UNUSED_PAGEFLAG_BITS)) {
256 		shutdown_mem_profiling(false); /* allocinfo file does not exist yet */
257 		pr_err("%lu allocation tags cannot be references using %d available page flag bits. Memory allocation profiling is disabled!\n",
258 			kernel_tags.count, NR_UNUSED_PAGEFLAG_BITS);
259 		return;
260 	}
261 
262 	alloc_tag_ref_offs = (LRU_REFS_PGOFF - NR_UNUSED_PAGEFLAG_BITS);
263 	alloc_tag_ref_mask = ((1UL << NR_UNUSED_PAGEFLAG_BITS) - 1);
264 	pr_debug("Memory allocation profiling compression is using %d page flag bits!\n",
265 		 NR_UNUSED_PAGEFLAG_BITS);
266 }
267 
268 #ifdef CONFIG_MODULES
269 
270 static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
271 static struct vm_struct *vm_module_tags;
272 /* A dummy object used to indicate an unloaded module */
273 static struct module unloaded_mod;
274 /* A dummy object used to indicate a module prepended area */
275 static struct module prepend_mod;
276 
277 struct alloc_tag_module_section module_tags;
278 
279 static inline unsigned long alloc_tag_align(unsigned long val)
280 {
281 	if (!static_key_enabled(&mem_profiling_compressed)) {
282 		/* No alignment requirements when we are not indexing the tags */
283 		return val;
284 	}
285 
286 	if (val % sizeof(struct alloc_tag) == 0)
287 		return val;
288 	return ((val / sizeof(struct alloc_tag)) + 1) * sizeof(struct alloc_tag);
289 }
290 
291 static bool ensure_alignment(unsigned long align, unsigned int *prepend)
292 {
293 	if (!static_key_enabled(&mem_profiling_compressed)) {
294 		/* No alignment requirements when we are not indexing the tags */
295 		return true;
296 	}
297 
298 	/*
299 	 * If alloc_tag size is not a multiple of required alignment, tag
300 	 * indexing does not work.
301 	 */
302 	if (!IS_ALIGNED(sizeof(struct alloc_tag), align))
303 		return false;
304 
305 	/* Ensure prepend consumes multiple of alloc_tag-sized blocks */
306 	if (*prepend)
307 		*prepend = alloc_tag_align(*prepend);
308 
309 	return true;
310 }
311 
312 static inline bool tags_addressable(void)
313 {
314 	unsigned long tag_idx_count;
315 
316 	if (!static_key_enabled(&mem_profiling_compressed))
317 		return true; /* with page_ext tags are always addressable */
318 
319 	tag_idx_count = CODETAG_ID_FIRST + kernel_tags.count +
320 			module_tags.size / sizeof(struct alloc_tag);
321 
322 	return tag_idx_count < (1UL << NR_UNUSED_PAGEFLAG_BITS);
323 }
324 
325 static bool needs_section_mem(struct module *mod, unsigned long size)
326 {
327 	if (!mem_profiling_support)
328 		return false;
329 
330 	return size >= sizeof(struct alloc_tag);
331 }
332 
333 static struct alloc_tag *find_used_tag(struct alloc_tag *from, struct alloc_tag *to)
334 {
335 	while (from <= to) {
336 		struct alloc_tag_counters counter;
337 
338 		counter = alloc_tag_read(from);
339 		if (counter.bytes)
340 			return from;
341 		from++;
342 	}
343 
344 	return NULL;
345 }
346 
347 /* Called with mod_area_mt locked */
348 static void clean_unused_module_areas_locked(void)
349 {
350 	MA_STATE(mas, &mod_area_mt, 0, module_tags.size);
351 	struct module *val;
352 
353 	mas_for_each(&mas, val, module_tags.size) {
354 		if (val != &unloaded_mod)
355 			continue;
356 
357 		/* Release area if all tags are unused */
358 		if (!find_used_tag((struct alloc_tag *)(module_tags.start_addr + mas.index),
359 				   (struct alloc_tag *)(module_tags.start_addr + mas.last)))
360 			mas_erase(&mas);
361 	}
362 }
363 
364 /* Called with mod_area_mt locked */
365 static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
366 			      unsigned long size, unsigned int prepend, unsigned long align)
367 {
368 	bool cleanup_done = false;
369 
370 repeat:
371 	/* Try finding exact size and hope the start is aligned */
372 	if (!mas_empty_area(mas, 0, section_size - 1, prepend + size)) {
373 		if (IS_ALIGNED(mas->index + prepend, align))
374 			return true;
375 
376 		/* Try finding larger area to align later */
377 		mas_reset(mas);
378 		if (!mas_empty_area(mas, 0, section_size - 1,
379 				    size + prepend + align - 1))
380 			return true;
381 	}
382 
383 	/* No free area, try cleanup stale data and repeat the search once */
384 	if (!cleanup_done) {
385 		clean_unused_module_areas_locked();
386 		cleanup_done = true;
387 		mas_reset(mas);
388 		goto repeat;
389 	}
390 
391 	return false;
392 }
393 
394 static int vm_module_tags_populate(void)
395 {
396 	unsigned long phys_size = vm_module_tags->nr_pages << PAGE_SHIFT;
397 
398 	if (phys_size < module_tags.size) {
399 		struct page **next_page = vm_module_tags->pages + vm_module_tags->nr_pages;
400 		unsigned long addr = module_tags.start_addr + phys_size;
401 		unsigned long more_pages;
402 		unsigned long nr;
403 
404 		more_pages = ALIGN(module_tags.size - phys_size, PAGE_SIZE) >> PAGE_SHIFT;
405 		nr = alloc_pages_bulk_array_node(GFP_KERNEL | __GFP_NOWARN,
406 						 NUMA_NO_NODE, more_pages, next_page);
407 		if (nr < more_pages ||
408 		    vmap_pages_range(addr, addr + (nr << PAGE_SHIFT), PAGE_KERNEL,
409 				     next_page, PAGE_SHIFT) < 0) {
410 			/* Clean up and error out */
411 			for (int i = 0; i < nr; i++)
412 				__free_page(next_page[i]);
413 			return -ENOMEM;
414 		}
415 		vm_module_tags->nr_pages += nr;
416 	}
417 
418 	return 0;
419 }
420 
421 static void *reserve_module_tags(struct module *mod, unsigned long size,
422 				 unsigned int prepend, unsigned long align)
423 {
424 	unsigned long section_size = module_tags.end_addr - module_tags.start_addr;
425 	MA_STATE(mas, &mod_area_mt, 0, section_size - 1);
426 	unsigned long offset;
427 	void *ret = NULL;
428 
429 	/* If no tags return error */
430 	if (size < sizeof(struct alloc_tag))
431 		return ERR_PTR(-EINVAL);
432 
433 	/*
434 	 * align is always power of 2, so we can use IS_ALIGNED and ALIGN.
435 	 * align 0 or 1 means no alignment, to simplify set to 1.
436 	 */
437 	if (!align)
438 		align = 1;
439 
440 	if (!ensure_alignment(align, &prepend)) {
441 		shutdown_mem_profiling(true);
442 		pr_err("%s: alignment %lu is incompatible with allocation tag indexing. Memory allocation profiling is disabled!\n",
443 			mod->name, align);
444 		return ERR_PTR(-EINVAL);
445 	}
446 
447 	mas_lock(&mas);
448 	if (!find_aligned_area(&mas, section_size, size, prepend, align)) {
449 		ret = ERR_PTR(-ENOMEM);
450 		goto unlock;
451 	}
452 
453 	/* Mark found area as reserved */
454 	offset = mas.index;
455 	offset += prepend;
456 	offset = ALIGN(offset, align);
457 	if (offset != mas.index) {
458 		unsigned long pad_start = mas.index;
459 
460 		mas.last = offset - 1;
461 		mas_store(&mas, &prepend_mod);
462 		if (mas_is_err(&mas)) {
463 			ret = ERR_PTR(xa_err(mas.node));
464 			goto unlock;
465 		}
466 		mas.index = offset;
467 		mas.last = offset + size - 1;
468 		mas_store(&mas, mod);
469 		if (mas_is_err(&mas)) {
470 			mas.index = pad_start;
471 			mas_erase(&mas);
472 			ret = ERR_PTR(xa_err(mas.node));
473 		}
474 	} else {
475 		mas.last = offset + size - 1;
476 		mas_store(&mas, mod);
477 		if (mas_is_err(&mas))
478 			ret = ERR_PTR(xa_err(mas.node));
479 	}
480 unlock:
481 	mas_unlock(&mas);
482 
483 	if (IS_ERR(ret))
484 		return ret;
485 
486 	if (module_tags.size < offset + size) {
487 		int grow_res;
488 
489 		module_tags.size = offset + size;
490 		if (mem_alloc_profiling_enabled() && !tags_addressable()) {
491 			shutdown_mem_profiling(true);
492 			pr_warn("With module %s there are too many tags to fit in %d page flag bits. Memory allocation profiling is disabled!\n",
493 				mod->name, NR_UNUSED_PAGEFLAG_BITS);
494 		}
495 
496 		grow_res = vm_module_tags_populate();
497 		if (grow_res) {
498 			shutdown_mem_profiling(true);
499 			pr_err("Failed to allocate memory for allocation tags in the module %s. Memory allocation profiling is disabled!\n",
500 			       mod->name);
501 			return ERR_PTR(grow_res);
502 		}
503 	}
504 
505 	return (struct alloc_tag *)(module_tags.start_addr + offset);
506 }
507 
508 static void release_module_tags(struct module *mod, bool used)
509 {
510 	MA_STATE(mas, &mod_area_mt, module_tags.size, module_tags.size);
511 	struct alloc_tag *tag;
512 	struct module *val;
513 
514 	mas_lock(&mas);
515 	mas_for_each_rev(&mas, val, 0)
516 		if (val == mod)
517 			break;
518 
519 	if (!val) /* module not found */
520 		goto out;
521 
522 	if (!used)
523 		goto release_area;
524 
525 	/* Find out if the area is used */
526 	tag = find_used_tag((struct alloc_tag *)(module_tags.start_addr + mas.index),
527 			    (struct alloc_tag *)(module_tags.start_addr + mas.last));
528 	if (tag) {
529 		struct alloc_tag_counters counter = alloc_tag_read(tag);
530 
531 		pr_info("%s:%u module %s func:%s has %llu allocated at module unload\n",
532 			tag->ct.filename, tag->ct.lineno, tag->ct.modname,
533 			tag->ct.function, counter.bytes);
534 	} else {
535 		used = false;
536 	}
537 release_area:
538 	mas_store(&mas, used ? &unloaded_mod : NULL);
539 	val = mas_prev_range(&mas, 0);
540 	if (val == &prepend_mod)
541 		mas_store(&mas, NULL);
542 out:
543 	mas_unlock(&mas);
544 }
545 
546 static void replace_module(struct module *mod, struct module *new_mod)
547 {
548 	MA_STATE(mas, &mod_area_mt, 0, module_tags.size);
549 	struct module *val;
550 
551 	mas_lock(&mas);
552 	mas_for_each(&mas, val, module_tags.size) {
553 		if (val != mod)
554 			continue;
555 
556 		mas_store_gfp(&mas, new_mod, GFP_KERNEL);
557 		break;
558 	}
559 	mas_unlock(&mas);
560 }
561 
562 static int __init alloc_mod_tags_mem(void)
563 {
564 	/* Map space to copy allocation tags */
565 	vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
566 	if (!vm_module_tags) {
567 		pr_err("Failed to map %lu bytes for module allocation tags\n",
568 			MODULE_ALLOC_TAG_VMAP_SIZE);
569 		module_tags.start_addr = 0;
570 		return -ENOMEM;
571 	}
572 
573 	vm_module_tags->pages = kmalloc_array(get_vm_area_size(vm_module_tags) >> PAGE_SHIFT,
574 					sizeof(struct page *), GFP_KERNEL | __GFP_ZERO);
575 	if (!vm_module_tags->pages) {
576 		free_vm_area(vm_module_tags);
577 		return -ENOMEM;
578 	}
579 
580 	module_tags.start_addr = (unsigned long)vm_module_tags->addr;
581 	module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
582 	/* Ensure the base is alloc_tag aligned when required for indexing */
583 	module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
584 
585 	return 0;
586 }
587 
588 static void __init free_mod_tags_mem(void)
589 {
590 	int i;
591 
592 	module_tags.start_addr = 0;
593 	for (i = 0; i < vm_module_tags->nr_pages; i++)
594 		__free_page(vm_module_tags->pages[i]);
595 	kfree(vm_module_tags->pages);
596 	free_vm_area(vm_module_tags);
597 }
598 
599 #else /* CONFIG_MODULES */
600 
601 static inline int alloc_mod_tags_mem(void) { return 0; }
602 static inline void free_mod_tags_mem(void) {}
603 
604 #endif /* CONFIG_MODULES */
605 
606 /* See: Documentation/mm/allocation-profiling.rst */
607 static int __init setup_early_mem_profiling(char *str)
608 {
609 	bool compressed = false;
610 	bool enable;
611 
612 	if (!str || !str[0])
613 		return -EINVAL;
614 
615 	if (!strncmp(str, "never", 5)) {
616 		enable = false;
617 		mem_profiling_support = false;
618 		pr_info("Memory allocation profiling is disabled!\n");
619 	} else {
620 		char *token = strsep(&str, ",");
621 
622 		if (kstrtobool(token, &enable))
623 			return -EINVAL;
624 
625 		if (str) {
626 
627 			if (strcmp(str, "compressed"))
628 				return -EINVAL;
629 
630 			compressed = true;
631 		}
632 		mem_profiling_support = true;
633 		pr_info("Memory allocation profiling is enabled %s compression and is turned %s!\n",
634 			compressed ? "with" : "without", enable ? "on" : "off");
635 	}
636 
637 	if (enable != mem_alloc_profiling_enabled()) {
638 		if (enable)
639 			static_branch_enable(&mem_alloc_profiling_key);
640 		else
641 			static_branch_disable(&mem_alloc_profiling_key);
642 	}
643 	if (compressed != static_key_enabled(&mem_profiling_compressed)) {
644 		if (compressed)
645 			static_branch_enable(&mem_profiling_compressed);
646 		else
647 			static_branch_disable(&mem_profiling_compressed);
648 	}
649 
650 	return 0;
651 }
652 early_param("sysctl.vm.mem_profiling", setup_early_mem_profiling);
653 
654 static __init bool need_page_alloc_tagging(void)
655 {
656 	if (static_key_enabled(&mem_profiling_compressed))
657 		return false;
658 
659 	return mem_profiling_support;
660 }
661 
662 static __init void init_page_alloc_tagging(void)
663 {
664 }
665 
666 struct page_ext_operations page_alloc_tagging_ops = {
667 	.size = sizeof(union codetag_ref),
668 	.need = need_page_alloc_tagging,
669 	.init = init_page_alloc_tagging,
670 };
671 EXPORT_SYMBOL(page_alloc_tagging_ops);
672 
673 #ifdef CONFIG_SYSCTL
674 static struct ctl_table memory_allocation_profiling_sysctls[] = {
675 	{
676 		.procname	= "mem_profiling",
677 		.data		= &mem_alloc_profiling_key,
678 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
679 		.mode		= 0444,
680 #else
681 		.mode		= 0644,
682 #endif
683 		.proc_handler	= proc_do_static_key,
684 	},
685 };
686 
687 static void __init sysctl_init(void)
688 {
689 	if (!mem_profiling_support)
690 		memory_allocation_profiling_sysctls[0].mode = 0444;
691 
692 	register_sysctl_init("vm", memory_allocation_profiling_sysctls);
693 }
694 #else /* CONFIG_SYSCTL */
695 static inline void sysctl_init(void) {}
696 #endif /* CONFIG_SYSCTL */
697 
698 static int __init alloc_tag_init(void)
699 {
700 	const struct codetag_type_desc desc = {
701 		.section		= ALLOC_TAG_SECTION_NAME,
702 		.tag_size		= sizeof(struct alloc_tag),
703 #ifdef CONFIG_MODULES
704 		.needs_section_mem	= needs_section_mem,
705 		.alloc_section_mem	= reserve_module_tags,
706 		.free_section_mem	= release_module_tags,
707 		.module_replaced	= replace_module,
708 #endif
709 	};
710 	int res;
711 
712 	res = alloc_mod_tags_mem();
713 	if (res)
714 		return res;
715 
716 	alloc_tag_cttype = codetag_register_type(&desc);
717 	if (IS_ERR(alloc_tag_cttype)) {
718 		free_mod_tags_mem();
719 		return PTR_ERR(alloc_tag_cttype);
720 	}
721 
722 	sysctl_init();
723 	procfs_init();
724 
725 	return 0;
726 }
727 module_init(alloc_tag_init);
728