xref: /linux/lib/alloc_tag.c (revision 13b6931c44969ff057ad2a3aa1c20a1b28b79b6f)
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_swap(struct folio *new, struct folio *old)
193 {
194 	union pgtag_ref_handle handle_old, handle_new;
195 	union codetag_ref ref_old, ref_new;
196 	struct alloc_tag *tag_old, *tag_new;
197 
198 	if (!mem_alloc_profiling_enabled())
199 		return;
200 
201 	tag_old = pgalloc_tag_get(&old->page);
202 	if (!tag_old)
203 		return;
204 	tag_new = pgalloc_tag_get(&new->page);
205 	if (!tag_new)
206 		return;
207 
208 	if (!get_page_tag_ref(&old->page, &ref_old, &handle_old))
209 		return;
210 	if (!get_page_tag_ref(&new->page, &ref_new, &handle_new)) {
211 		put_page_tag_ref(handle_old);
212 		return;
213 	}
214 
215 	/*
216 	 * Clear tag references to avoid debug warning when using
217 	 * __alloc_tag_ref_set() with non-empty reference.
218 	 */
219 	set_codetag_empty(&ref_old);
220 	set_codetag_empty(&ref_new);
221 
222 	/* swap tags */
223 	__alloc_tag_ref_set(&ref_old, tag_new);
224 	update_page_tag_ref(handle_old, &ref_old);
225 	__alloc_tag_ref_set(&ref_new, tag_old);
226 	update_page_tag_ref(handle_new, &ref_new);
227 
228 	put_page_tag_ref(handle_old);
229 	put_page_tag_ref(handle_new);
230 }
231 
232 static void shutdown_mem_profiling(bool remove_file)
233 {
234 	if (mem_alloc_profiling_enabled())
235 		static_branch_disable(&mem_alloc_profiling_key);
236 
237 	if (!mem_profiling_support)
238 		return;
239 
240 	if (remove_file)
241 		remove_proc_entry(ALLOCINFO_FILE_NAME, NULL);
242 	mem_profiling_support = false;
243 }
244 
245 static void __init procfs_init(void)
246 {
247 	if (!mem_profiling_support)
248 		return;
249 
250 	if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
251 		pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
252 		shutdown_mem_profiling(false);
253 	}
254 }
255 
256 void __init alloc_tag_sec_init(void)
257 {
258 	struct alloc_tag *last_codetag;
259 
260 	if (!mem_profiling_support)
261 		return;
262 
263 	if (!static_key_enabled(&mem_profiling_compressed))
264 		return;
265 
266 	kernel_tags.first_tag = (struct alloc_tag *)kallsyms_lookup_name(
267 					SECTION_START(ALLOC_TAG_SECTION_NAME));
268 	last_codetag = (struct alloc_tag *)kallsyms_lookup_name(
269 					SECTION_STOP(ALLOC_TAG_SECTION_NAME));
270 	kernel_tags.count = last_codetag - kernel_tags.first_tag;
271 
272 	/* Check if kernel tags fit into page flags */
273 	if (kernel_tags.count > (1UL << NR_UNUSED_PAGEFLAG_BITS)) {
274 		shutdown_mem_profiling(false); /* allocinfo file does not exist yet */
275 		pr_err("%lu allocation tags cannot be references using %d available page flag bits. Memory allocation profiling is disabled!\n",
276 			kernel_tags.count, NR_UNUSED_PAGEFLAG_BITS);
277 		return;
278 	}
279 
280 	alloc_tag_ref_offs = (LRU_REFS_PGOFF - NR_UNUSED_PAGEFLAG_BITS);
281 	alloc_tag_ref_mask = ((1UL << NR_UNUSED_PAGEFLAG_BITS) - 1);
282 	pr_debug("Memory allocation profiling compression is using %d page flag bits!\n",
283 		 NR_UNUSED_PAGEFLAG_BITS);
284 }
285 
286 #ifdef CONFIG_MODULES
287 
288 static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
289 static struct vm_struct *vm_module_tags;
290 /* A dummy object used to indicate an unloaded module */
291 static struct module unloaded_mod;
292 /* A dummy object used to indicate a module prepended area */
293 static struct module prepend_mod;
294 
295 struct alloc_tag_module_section module_tags;
296 
297 static inline unsigned long alloc_tag_align(unsigned long val)
298 {
299 	if (!static_key_enabled(&mem_profiling_compressed)) {
300 		/* No alignment requirements when we are not indexing the tags */
301 		return val;
302 	}
303 
304 	if (val % sizeof(struct alloc_tag) == 0)
305 		return val;
306 	return ((val / sizeof(struct alloc_tag)) + 1) * sizeof(struct alloc_tag);
307 }
308 
309 static bool ensure_alignment(unsigned long align, unsigned int *prepend)
310 {
311 	if (!static_key_enabled(&mem_profiling_compressed)) {
312 		/* No alignment requirements when we are not indexing the tags */
313 		return true;
314 	}
315 
316 	/*
317 	 * If alloc_tag size is not a multiple of required alignment, tag
318 	 * indexing does not work.
319 	 */
320 	if (!IS_ALIGNED(sizeof(struct alloc_tag), align))
321 		return false;
322 
323 	/* Ensure prepend consumes multiple of alloc_tag-sized blocks */
324 	if (*prepend)
325 		*prepend = alloc_tag_align(*prepend);
326 
327 	return true;
328 }
329 
330 static inline bool tags_addressable(void)
331 {
332 	unsigned long tag_idx_count;
333 
334 	if (!static_key_enabled(&mem_profiling_compressed))
335 		return true; /* with page_ext tags are always addressable */
336 
337 	tag_idx_count = CODETAG_ID_FIRST + kernel_tags.count +
338 			module_tags.size / sizeof(struct alloc_tag);
339 
340 	return tag_idx_count < (1UL << NR_UNUSED_PAGEFLAG_BITS);
341 }
342 
343 static bool needs_section_mem(struct module *mod, unsigned long size)
344 {
345 	if (!mem_profiling_support)
346 		return false;
347 
348 	return size >= sizeof(struct alloc_tag);
349 }
350 
351 static struct alloc_tag *find_used_tag(struct alloc_tag *from, struct alloc_tag *to)
352 {
353 	while (from <= to) {
354 		struct alloc_tag_counters counter;
355 
356 		counter = alloc_tag_read(from);
357 		if (counter.bytes)
358 			return from;
359 		from++;
360 	}
361 
362 	return NULL;
363 }
364 
365 /* Called with mod_area_mt locked */
366 static void clean_unused_module_areas_locked(void)
367 {
368 	MA_STATE(mas, &mod_area_mt, 0, module_tags.size);
369 	struct module *val;
370 
371 	mas_for_each(&mas, val, module_tags.size) {
372 		if (val != &unloaded_mod)
373 			continue;
374 
375 		/* Release area if all tags are unused */
376 		if (!find_used_tag((struct alloc_tag *)(module_tags.start_addr + mas.index),
377 				   (struct alloc_tag *)(module_tags.start_addr + mas.last)))
378 			mas_erase(&mas);
379 	}
380 }
381 
382 /* Called with mod_area_mt locked */
383 static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
384 			      unsigned long size, unsigned int prepend, unsigned long align)
385 {
386 	bool cleanup_done = false;
387 
388 repeat:
389 	/* Try finding exact size and hope the start is aligned */
390 	if (!mas_empty_area(mas, 0, section_size - 1, prepend + size)) {
391 		if (IS_ALIGNED(mas->index + prepend, align))
392 			return true;
393 
394 		/* Try finding larger area to align later */
395 		mas_reset(mas);
396 		if (!mas_empty_area(mas, 0, section_size - 1,
397 				    size + prepend + align - 1))
398 			return true;
399 	}
400 
401 	/* No free area, try cleanup stale data and repeat the search once */
402 	if (!cleanup_done) {
403 		clean_unused_module_areas_locked();
404 		cleanup_done = true;
405 		mas_reset(mas);
406 		goto repeat;
407 	}
408 
409 	return false;
410 }
411 
412 static int vm_module_tags_populate(void)
413 {
414 	unsigned long phys_end = ALIGN_DOWN(module_tags.start_addr, PAGE_SIZE) +
415 				 (vm_module_tags->nr_pages << PAGE_SHIFT);
416 	unsigned long new_end = module_tags.start_addr + module_tags.size;
417 
418 	if (phys_end < new_end) {
419 		struct page **next_page = vm_module_tags->pages + vm_module_tags->nr_pages;
420 		unsigned long old_shadow_end = ALIGN(phys_end, MODULE_ALIGN);
421 		unsigned long new_shadow_end = ALIGN(new_end, MODULE_ALIGN);
422 		unsigned long more_pages;
423 		unsigned long nr;
424 
425 		more_pages = ALIGN(new_end - phys_end, PAGE_SIZE) >> PAGE_SHIFT;
426 		nr = alloc_pages_bulk_array_node(GFP_KERNEL | __GFP_NOWARN,
427 						 NUMA_NO_NODE, more_pages, next_page);
428 		if (nr < more_pages ||
429 		    vmap_pages_range(phys_end, phys_end + (nr << PAGE_SHIFT), PAGE_KERNEL,
430 				     next_page, PAGE_SHIFT) < 0) {
431 			/* Clean up and error out */
432 			for (int i = 0; i < nr; i++)
433 				__free_page(next_page[i]);
434 			return -ENOMEM;
435 		}
436 
437 		vm_module_tags->nr_pages += nr;
438 
439 		/*
440 		 * Kasan allocates 1 byte of shadow for every 8 bytes of data.
441 		 * When kasan_alloc_module_shadow allocates shadow memory,
442 		 * its unit of allocation is a page.
443 		 * Therefore, here we need to align to MODULE_ALIGN.
444 		 */
445 		if (old_shadow_end < new_shadow_end)
446 			kasan_alloc_module_shadow((void *)old_shadow_end,
447 						  new_shadow_end - old_shadow_end,
448 						  GFP_KERNEL);
449 	}
450 
451 	/*
452 	 * Mark the pages as accessible, now that they are mapped.
453 	 * With hardware tag-based KASAN, marking is skipped for
454 	 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
455 	 */
456 	kasan_unpoison_vmalloc((void *)module_tags.start_addr,
457 				new_end - module_tags.start_addr,
458 				KASAN_VMALLOC_PROT_NORMAL);
459 
460 	return 0;
461 }
462 
463 static void *reserve_module_tags(struct module *mod, unsigned long size,
464 				 unsigned int prepend, unsigned long align)
465 {
466 	unsigned long section_size = module_tags.end_addr - module_tags.start_addr;
467 	MA_STATE(mas, &mod_area_mt, 0, section_size - 1);
468 	unsigned long offset;
469 	void *ret = NULL;
470 
471 	/* If no tags return error */
472 	if (size < sizeof(struct alloc_tag))
473 		return ERR_PTR(-EINVAL);
474 
475 	/*
476 	 * align is always power of 2, so we can use IS_ALIGNED and ALIGN.
477 	 * align 0 or 1 means no alignment, to simplify set to 1.
478 	 */
479 	if (!align)
480 		align = 1;
481 
482 	if (!ensure_alignment(align, &prepend)) {
483 		shutdown_mem_profiling(true);
484 		pr_err("%s: alignment %lu is incompatible with allocation tag indexing. Memory allocation profiling is disabled!\n",
485 			mod->name, align);
486 		return ERR_PTR(-EINVAL);
487 	}
488 
489 	mas_lock(&mas);
490 	if (!find_aligned_area(&mas, section_size, size, prepend, align)) {
491 		ret = ERR_PTR(-ENOMEM);
492 		goto unlock;
493 	}
494 
495 	/* Mark found area as reserved */
496 	offset = mas.index;
497 	offset += prepend;
498 	offset = ALIGN(offset, align);
499 	if (offset != mas.index) {
500 		unsigned long pad_start = mas.index;
501 
502 		mas.last = offset - 1;
503 		mas_store(&mas, &prepend_mod);
504 		if (mas_is_err(&mas)) {
505 			ret = ERR_PTR(xa_err(mas.node));
506 			goto unlock;
507 		}
508 		mas.index = offset;
509 		mas.last = offset + size - 1;
510 		mas_store(&mas, mod);
511 		if (mas_is_err(&mas)) {
512 			mas.index = pad_start;
513 			mas_erase(&mas);
514 			ret = ERR_PTR(xa_err(mas.node));
515 		}
516 	} else {
517 		mas.last = offset + size - 1;
518 		mas_store(&mas, mod);
519 		if (mas_is_err(&mas))
520 			ret = ERR_PTR(xa_err(mas.node));
521 	}
522 unlock:
523 	mas_unlock(&mas);
524 
525 	if (IS_ERR(ret))
526 		return ret;
527 
528 	if (module_tags.size < offset + size) {
529 		int grow_res;
530 
531 		module_tags.size = offset + size;
532 		if (mem_alloc_profiling_enabled() && !tags_addressable()) {
533 			shutdown_mem_profiling(true);
534 			pr_warn("With module %s there are too many tags to fit in %d page flag bits. Memory allocation profiling is disabled!\n",
535 				mod->name, NR_UNUSED_PAGEFLAG_BITS);
536 		}
537 
538 		grow_res = vm_module_tags_populate();
539 		if (grow_res) {
540 			shutdown_mem_profiling(true);
541 			pr_err("Failed to allocate memory for allocation tags in the module %s. Memory allocation profiling is disabled!\n",
542 			       mod->name);
543 			return ERR_PTR(grow_res);
544 		}
545 	}
546 
547 	return (struct alloc_tag *)(module_tags.start_addr + offset);
548 }
549 
550 static void release_module_tags(struct module *mod, bool used)
551 {
552 	MA_STATE(mas, &mod_area_mt, module_tags.size, module_tags.size);
553 	struct alloc_tag *tag;
554 	struct module *val;
555 
556 	mas_lock(&mas);
557 	mas_for_each_rev(&mas, val, 0)
558 		if (val == mod)
559 			break;
560 
561 	if (!val) /* module not found */
562 		goto out;
563 
564 	if (!used)
565 		goto release_area;
566 
567 	/* Find out if the area is used */
568 	tag = find_used_tag((struct alloc_tag *)(module_tags.start_addr + mas.index),
569 			    (struct alloc_tag *)(module_tags.start_addr + mas.last));
570 	if (tag) {
571 		struct alloc_tag_counters counter = alloc_tag_read(tag);
572 
573 		pr_info("%s:%u module %s func:%s has %llu allocated at module unload\n",
574 			tag->ct.filename, tag->ct.lineno, tag->ct.modname,
575 			tag->ct.function, counter.bytes);
576 	} else {
577 		used = false;
578 	}
579 release_area:
580 	mas_store(&mas, used ? &unloaded_mod : NULL);
581 	val = mas_prev_range(&mas, 0);
582 	if (val == &prepend_mod)
583 		mas_store(&mas, NULL);
584 out:
585 	mas_unlock(&mas);
586 }
587 
588 static void replace_module(struct module *mod, struct module *new_mod)
589 {
590 	MA_STATE(mas, &mod_area_mt, 0, module_tags.size);
591 	struct module *val;
592 
593 	mas_lock(&mas);
594 	mas_for_each(&mas, val, module_tags.size) {
595 		if (val != mod)
596 			continue;
597 
598 		mas_store_gfp(&mas, new_mod, GFP_KERNEL);
599 		break;
600 	}
601 	mas_unlock(&mas);
602 }
603 
604 static int __init alloc_mod_tags_mem(void)
605 {
606 	/* Map space to copy allocation tags */
607 	vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
608 	if (!vm_module_tags) {
609 		pr_err("Failed to map %lu bytes for module allocation tags\n",
610 			MODULE_ALLOC_TAG_VMAP_SIZE);
611 		module_tags.start_addr = 0;
612 		return -ENOMEM;
613 	}
614 
615 	vm_module_tags->pages = kmalloc_array(get_vm_area_size(vm_module_tags) >> PAGE_SHIFT,
616 					sizeof(struct page *), GFP_KERNEL | __GFP_ZERO);
617 	if (!vm_module_tags->pages) {
618 		free_vm_area(vm_module_tags);
619 		return -ENOMEM;
620 	}
621 
622 	module_tags.start_addr = (unsigned long)vm_module_tags->addr;
623 	module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
624 	/* Ensure the base is alloc_tag aligned when required for indexing */
625 	module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
626 
627 	return 0;
628 }
629 
630 static void __init free_mod_tags_mem(void)
631 {
632 	int i;
633 
634 	module_tags.start_addr = 0;
635 	for (i = 0; i < vm_module_tags->nr_pages; i++)
636 		__free_page(vm_module_tags->pages[i]);
637 	kfree(vm_module_tags->pages);
638 	free_vm_area(vm_module_tags);
639 }
640 
641 #else /* CONFIG_MODULES */
642 
643 static inline int alloc_mod_tags_mem(void) { return 0; }
644 static inline void free_mod_tags_mem(void) {}
645 
646 #endif /* CONFIG_MODULES */
647 
648 /* See: Documentation/mm/allocation-profiling.rst */
649 static int __init setup_early_mem_profiling(char *str)
650 {
651 	bool compressed = false;
652 	bool enable;
653 
654 	if (!str || !str[0])
655 		return -EINVAL;
656 
657 	if (!strncmp(str, "never", 5)) {
658 		enable = false;
659 		mem_profiling_support = false;
660 		pr_info("Memory allocation profiling is disabled!\n");
661 	} else {
662 		char *token = strsep(&str, ",");
663 
664 		if (kstrtobool(token, &enable))
665 			return -EINVAL;
666 
667 		if (str) {
668 
669 			if (strcmp(str, "compressed"))
670 				return -EINVAL;
671 
672 			compressed = true;
673 		}
674 		mem_profiling_support = true;
675 		pr_info("Memory allocation profiling is enabled %s compression and is turned %s!\n",
676 			compressed ? "with" : "without", enable ? "on" : "off");
677 	}
678 
679 	if (enable != mem_alloc_profiling_enabled()) {
680 		if (enable)
681 			static_branch_enable(&mem_alloc_profiling_key);
682 		else
683 			static_branch_disable(&mem_alloc_profiling_key);
684 	}
685 	if (compressed != static_key_enabled(&mem_profiling_compressed)) {
686 		if (compressed)
687 			static_branch_enable(&mem_profiling_compressed);
688 		else
689 			static_branch_disable(&mem_profiling_compressed);
690 	}
691 
692 	return 0;
693 }
694 early_param("sysctl.vm.mem_profiling", setup_early_mem_profiling);
695 
696 static __init bool need_page_alloc_tagging(void)
697 {
698 	if (static_key_enabled(&mem_profiling_compressed))
699 		return false;
700 
701 	return mem_profiling_support;
702 }
703 
704 static __init void init_page_alloc_tagging(void)
705 {
706 }
707 
708 struct page_ext_operations page_alloc_tagging_ops = {
709 	.size = sizeof(union codetag_ref),
710 	.need = need_page_alloc_tagging,
711 	.init = init_page_alloc_tagging,
712 };
713 EXPORT_SYMBOL(page_alloc_tagging_ops);
714 
715 #ifdef CONFIG_SYSCTL
716 static struct ctl_table memory_allocation_profiling_sysctls[] = {
717 	{
718 		.procname	= "mem_profiling",
719 		.data		= &mem_alloc_profiling_key,
720 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
721 		.mode		= 0444,
722 #else
723 		.mode		= 0644,
724 #endif
725 		.proc_handler	= proc_do_static_key,
726 	},
727 };
728 
729 static void __init sysctl_init(void)
730 {
731 	if (!mem_profiling_support)
732 		memory_allocation_profiling_sysctls[0].mode = 0444;
733 
734 	register_sysctl_init("vm", memory_allocation_profiling_sysctls);
735 }
736 #else /* CONFIG_SYSCTL */
737 static inline void sysctl_init(void) {}
738 #endif /* CONFIG_SYSCTL */
739 
740 static int __init alloc_tag_init(void)
741 {
742 	const struct codetag_type_desc desc = {
743 		.section		= ALLOC_TAG_SECTION_NAME,
744 		.tag_size		= sizeof(struct alloc_tag),
745 #ifdef CONFIG_MODULES
746 		.needs_section_mem	= needs_section_mem,
747 		.alloc_section_mem	= reserve_module_tags,
748 		.free_section_mem	= release_module_tags,
749 		.module_replaced	= replace_module,
750 #endif
751 	};
752 	int res;
753 
754 	res = alloc_mod_tags_mem();
755 	if (res)
756 		return res;
757 
758 	alloc_tag_cttype = codetag_register_type(&desc);
759 	if (IS_ERR(alloc_tag_cttype)) {
760 		free_mod_tags_mem();
761 		return PTR_ERR(alloc_tag_cttype);
762 	}
763 
764 	sysctl_init();
765 	procfs_init();
766 
767 	return 0;
768 }
769 module_init(alloc_tag_init);
770