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 #include <linux/kmemleak.h>
14
15 #define ALLOCINFO_FILE_NAME "allocinfo"
16 #define MODULE_ALLOC_TAG_VMAP_SIZE (100000UL * sizeof(struct alloc_tag))
17 #define SECTION_START(NAME) (CODETAG_SECTION_START_PREFIX NAME)
18 #define SECTION_STOP(NAME) (CODETAG_SECTION_STOP_PREFIX NAME)
19
20 #ifdef CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
21 static bool mem_profiling_support = true;
22 #else
23 static bool mem_profiling_support;
24 #endif
25
26 static struct codetag_type *alloc_tag_cttype;
27
28 DEFINE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
29 EXPORT_SYMBOL(_shared_alloc_tag);
30
31 DEFINE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
32 mem_alloc_profiling_key);
33 EXPORT_SYMBOL(mem_alloc_profiling_key);
34
35 DEFINE_STATIC_KEY_FALSE(mem_profiling_compressed);
36
37 struct alloc_tag_kernel_section kernel_tags = { NULL, 0 };
38 unsigned long alloc_tag_ref_mask;
39 int alloc_tag_ref_offs;
40
41 struct allocinfo_private {
42 struct codetag_iterator iter;
43 bool print_header;
44 };
45
allocinfo_start(struct seq_file * m,loff_t * pos)46 static void *allocinfo_start(struct seq_file *m, loff_t *pos)
47 {
48 struct allocinfo_private *priv;
49 struct codetag *ct;
50 loff_t node = *pos;
51
52 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
53 m->private = priv;
54 if (!priv)
55 return NULL;
56
57 priv->print_header = (node == 0);
58 codetag_lock_module_list(alloc_tag_cttype, true);
59 priv->iter = codetag_get_ct_iter(alloc_tag_cttype);
60 while ((ct = codetag_next_ct(&priv->iter)) != NULL && node)
61 node--;
62
63 return ct ? priv : NULL;
64 }
65
allocinfo_next(struct seq_file * m,void * arg,loff_t * pos)66 static void *allocinfo_next(struct seq_file *m, void *arg, loff_t *pos)
67 {
68 struct allocinfo_private *priv = (struct allocinfo_private *)arg;
69 struct codetag *ct = codetag_next_ct(&priv->iter);
70
71 (*pos)++;
72 if (!ct)
73 return NULL;
74
75 return priv;
76 }
77
allocinfo_stop(struct seq_file * m,void * arg)78 static void allocinfo_stop(struct seq_file *m, void *arg)
79 {
80 struct allocinfo_private *priv = (struct allocinfo_private *)m->private;
81
82 if (priv) {
83 codetag_lock_module_list(alloc_tag_cttype, false);
84 kfree(priv);
85 }
86 }
87
print_allocinfo_header(struct seq_buf * buf)88 static void print_allocinfo_header(struct seq_buf *buf)
89 {
90 /* Output format version, so we can change it. */
91 seq_buf_printf(buf, "allocinfo - version: 1.0\n");
92 seq_buf_printf(buf, "# <size> <calls> <tag info>\n");
93 }
94
alloc_tag_to_text(struct seq_buf * out,struct codetag * ct)95 static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct)
96 {
97 struct alloc_tag *tag = ct_to_alloc_tag(ct);
98 struct alloc_tag_counters counter = alloc_tag_read(tag);
99 s64 bytes = counter.bytes;
100
101 seq_buf_printf(out, "%12lli %8llu ", bytes, counter.calls);
102 codetag_to_text(out, ct);
103 seq_buf_putc(out, ' ');
104 seq_buf_putc(out, '\n');
105 }
106
allocinfo_show(struct seq_file * m,void * arg)107 static int allocinfo_show(struct seq_file *m, void *arg)
108 {
109 struct allocinfo_private *priv = (struct allocinfo_private *)arg;
110 char *bufp;
111 size_t n = seq_get_buf(m, &bufp);
112 struct seq_buf buf;
113
114 seq_buf_init(&buf, bufp, n);
115 if (priv->print_header) {
116 print_allocinfo_header(&buf);
117 priv->print_header = false;
118 }
119 alloc_tag_to_text(&buf, priv->iter.ct);
120 seq_commit(m, seq_buf_used(&buf));
121 return 0;
122 }
123
124 static const struct seq_operations allocinfo_seq_op = {
125 .start = allocinfo_start,
126 .next = allocinfo_next,
127 .stop = allocinfo_stop,
128 .show = allocinfo_show,
129 };
130
alloc_tag_top_users(struct codetag_bytes * tags,size_t count,bool can_sleep)131 size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep)
132 {
133 struct codetag_iterator iter;
134 struct codetag *ct;
135 struct codetag_bytes n;
136 unsigned int i, nr = 0;
137
138 if (can_sleep)
139 codetag_lock_module_list(alloc_tag_cttype, true);
140 else if (!codetag_trylock_module_list(alloc_tag_cttype))
141 return 0;
142
143 iter = codetag_get_ct_iter(alloc_tag_cttype);
144 while ((ct = codetag_next_ct(&iter))) {
145 struct alloc_tag_counters counter = alloc_tag_read(ct_to_alloc_tag(ct));
146
147 n.ct = ct;
148 n.bytes = counter.bytes;
149
150 for (i = 0; i < nr; i++)
151 if (n.bytes > tags[i].bytes)
152 break;
153
154 if (i < count) {
155 nr -= nr == count;
156 memmove(&tags[i + 1],
157 &tags[i],
158 sizeof(tags[0]) * (nr - i));
159 nr++;
160 tags[i] = n;
161 }
162 }
163
164 codetag_lock_module_list(alloc_tag_cttype, false);
165
166 return nr;
167 }
168
pgalloc_tag_split(struct folio * folio,int old_order,int new_order)169 void pgalloc_tag_split(struct folio *folio, int old_order, int new_order)
170 {
171 int i;
172 struct alloc_tag *tag;
173 unsigned int nr_pages = 1 << new_order;
174
175 if (!mem_alloc_profiling_enabled())
176 return;
177
178 tag = __pgalloc_tag_get(&folio->page);
179 if (!tag)
180 return;
181
182 for (i = nr_pages; i < (1 << old_order); i += nr_pages) {
183 union pgtag_ref_handle handle;
184 union codetag_ref ref;
185
186 if (get_page_tag_ref(folio_page(folio, i), &ref, &handle)) {
187 /* Set new reference to point to the original tag */
188 alloc_tag_ref_set(&ref, tag);
189 update_page_tag_ref(handle, &ref);
190 put_page_tag_ref(handle);
191 }
192 }
193 }
194
pgalloc_tag_swap(struct folio * new,struct folio * old)195 void pgalloc_tag_swap(struct folio *new, struct folio *old)
196 {
197 union pgtag_ref_handle handle_old, handle_new;
198 union codetag_ref ref_old, ref_new;
199 struct alloc_tag *tag_old, *tag_new;
200
201 if (!mem_alloc_profiling_enabled())
202 return;
203
204 tag_old = __pgalloc_tag_get(&old->page);
205 if (!tag_old)
206 return;
207 tag_new = __pgalloc_tag_get(&new->page);
208 if (!tag_new)
209 return;
210
211 if (!get_page_tag_ref(&old->page, &ref_old, &handle_old))
212 return;
213 if (!get_page_tag_ref(&new->page, &ref_new, &handle_new)) {
214 put_page_tag_ref(handle_old);
215 return;
216 }
217
218 /*
219 * Clear tag references to avoid debug warning when using
220 * __alloc_tag_ref_set() with non-empty reference.
221 */
222 set_codetag_empty(&ref_old);
223 set_codetag_empty(&ref_new);
224
225 /* swap tags */
226 __alloc_tag_ref_set(&ref_old, tag_new);
227 update_page_tag_ref(handle_old, &ref_old);
228 __alloc_tag_ref_set(&ref_new, tag_old);
229 update_page_tag_ref(handle_new, &ref_new);
230
231 put_page_tag_ref(handle_old);
232 put_page_tag_ref(handle_new);
233 }
234
shutdown_mem_profiling(bool remove_file)235 static void shutdown_mem_profiling(bool remove_file)
236 {
237 if (mem_alloc_profiling_enabled())
238 static_branch_disable(&mem_alloc_profiling_key);
239
240 if (!mem_profiling_support)
241 return;
242
243 if (remove_file)
244 remove_proc_entry(ALLOCINFO_FILE_NAME, NULL);
245 mem_profiling_support = false;
246 }
247
alloc_tag_sec_init(void)248 void __init alloc_tag_sec_init(void)
249 {
250 struct alloc_tag *last_codetag;
251
252 if (!mem_profiling_support)
253 return;
254
255 if (!static_key_enabled(&mem_profiling_compressed))
256 return;
257
258 kernel_tags.first_tag = (struct alloc_tag *)kallsyms_lookup_name(
259 SECTION_START(ALLOC_TAG_SECTION_NAME));
260 last_codetag = (struct alloc_tag *)kallsyms_lookup_name(
261 SECTION_STOP(ALLOC_TAG_SECTION_NAME));
262 kernel_tags.count = last_codetag - kernel_tags.first_tag;
263
264 /* Check if kernel tags fit into page flags */
265 if (kernel_tags.count > (1UL << NR_UNUSED_PAGEFLAG_BITS)) {
266 shutdown_mem_profiling(false); /* allocinfo file does not exist yet */
267 pr_err("%lu allocation tags cannot be references using %d available page flag bits. Memory allocation profiling is disabled!\n",
268 kernel_tags.count, NR_UNUSED_PAGEFLAG_BITS);
269 return;
270 }
271
272 alloc_tag_ref_offs = (LRU_REFS_PGOFF - NR_UNUSED_PAGEFLAG_BITS);
273 alloc_tag_ref_mask = ((1UL << NR_UNUSED_PAGEFLAG_BITS) - 1);
274 pr_debug("Memory allocation profiling compression is using %d page flag bits!\n",
275 NR_UNUSED_PAGEFLAG_BITS);
276 }
277
278 #ifdef CONFIG_MODULES
279
280 static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
281 static struct vm_struct *vm_module_tags;
282 /* A dummy object used to indicate an unloaded module */
283 static struct module unloaded_mod;
284 /* A dummy object used to indicate a module prepended area */
285 static struct module prepend_mod;
286
287 struct alloc_tag_module_section module_tags;
288
alloc_tag_align(unsigned long val)289 static inline unsigned long alloc_tag_align(unsigned long val)
290 {
291 if (!static_key_enabled(&mem_profiling_compressed)) {
292 /* No alignment requirements when we are not indexing the tags */
293 return val;
294 }
295
296 if (val % sizeof(struct alloc_tag) == 0)
297 return val;
298 return ((val / sizeof(struct alloc_tag)) + 1) * sizeof(struct alloc_tag);
299 }
300
ensure_alignment(unsigned long align,unsigned int * prepend)301 static bool ensure_alignment(unsigned long align, unsigned int *prepend)
302 {
303 if (!static_key_enabled(&mem_profiling_compressed)) {
304 /* No alignment requirements when we are not indexing the tags */
305 return true;
306 }
307
308 /*
309 * If alloc_tag size is not a multiple of required alignment, tag
310 * indexing does not work.
311 */
312 if (!IS_ALIGNED(sizeof(struct alloc_tag), align))
313 return false;
314
315 /* Ensure prepend consumes multiple of alloc_tag-sized blocks */
316 if (*prepend)
317 *prepend = alloc_tag_align(*prepend);
318
319 return true;
320 }
321
tags_addressable(void)322 static inline bool tags_addressable(void)
323 {
324 unsigned long tag_idx_count;
325
326 if (!static_key_enabled(&mem_profiling_compressed))
327 return true; /* with page_ext tags are always addressable */
328
329 tag_idx_count = CODETAG_ID_FIRST + kernel_tags.count +
330 module_tags.size / sizeof(struct alloc_tag);
331
332 return tag_idx_count < (1UL << NR_UNUSED_PAGEFLAG_BITS);
333 }
334
needs_section_mem(struct module * mod,unsigned long size)335 static bool needs_section_mem(struct module *mod, unsigned long size)
336 {
337 if (!mem_profiling_support)
338 return false;
339
340 return size >= sizeof(struct alloc_tag);
341 }
342
clean_unused_counters(struct alloc_tag * start_tag,struct alloc_tag * end_tag)343 static bool clean_unused_counters(struct alloc_tag *start_tag,
344 struct alloc_tag *end_tag)
345 {
346 struct alloc_tag *tag;
347 bool ret = true;
348
349 for (tag = start_tag; tag <= end_tag; tag++) {
350 struct alloc_tag_counters counter;
351
352 if (!tag->counters)
353 continue;
354
355 counter = alloc_tag_read(tag);
356 if (!counter.bytes) {
357 free_percpu(tag->counters);
358 tag->counters = NULL;
359 } else {
360 ret = false;
361 }
362 }
363
364 return ret;
365 }
366
367 /* Called with mod_area_mt locked */
clean_unused_module_areas_locked(void)368 static void clean_unused_module_areas_locked(void)
369 {
370 MA_STATE(mas, &mod_area_mt, 0, module_tags.size);
371 struct module *val;
372
373 mas_for_each(&mas, val, module_tags.size) {
374 struct alloc_tag *start_tag;
375 struct alloc_tag *end_tag;
376
377 if (val != &unloaded_mod)
378 continue;
379
380 /* Release area if all tags are unused */
381 start_tag = (struct alloc_tag *)(module_tags.start_addr + mas.index);
382 end_tag = (struct alloc_tag *)(module_tags.start_addr + mas.last);
383 if (clean_unused_counters(start_tag, end_tag))
384 mas_erase(&mas);
385 }
386 }
387
388 /* 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)389 static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
390 unsigned long size, unsigned int prepend, unsigned long align)
391 {
392 bool cleanup_done = false;
393
394 repeat:
395 /* Try finding exact size and hope the start is aligned */
396 if (!mas_empty_area(mas, 0, section_size - 1, prepend + size)) {
397 if (IS_ALIGNED(mas->index + prepend, align))
398 return true;
399
400 /* Try finding larger area to align later */
401 mas_reset(mas);
402 if (!mas_empty_area(mas, 0, section_size - 1,
403 size + prepend + align - 1))
404 return true;
405 }
406
407 /* No free area, try cleanup stale data and repeat the search once */
408 if (!cleanup_done) {
409 clean_unused_module_areas_locked();
410 cleanup_done = true;
411 mas_reset(mas);
412 goto repeat;
413 }
414
415 return false;
416 }
417
vm_module_tags_populate(void)418 static int vm_module_tags_populate(void)
419 {
420 unsigned long phys_end = ALIGN_DOWN(module_tags.start_addr, PAGE_SIZE) +
421 (vm_module_tags->nr_pages << PAGE_SHIFT);
422 unsigned long new_end = module_tags.start_addr + module_tags.size;
423
424 if (phys_end < new_end) {
425 struct page **next_page = vm_module_tags->pages + vm_module_tags->nr_pages;
426 unsigned long old_shadow_end = ALIGN(phys_end, MODULE_ALIGN);
427 unsigned long new_shadow_end = ALIGN(new_end, MODULE_ALIGN);
428 unsigned long more_pages;
429 unsigned long nr = 0;
430
431 more_pages = ALIGN(new_end - phys_end, PAGE_SIZE) >> PAGE_SHIFT;
432 while (nr < more_pages) {
433 unsigned long allocated;
434
435 allocated = alloc_pages_bulk_node(GFP_KERNEL | __GFP_NOWARN,
436 NUMA_NO_NODE, more_pages - nr, next_page + nr);
437
438 if (!allocated)
439 break;
440 nr += allocated;
441 }
442
443 if (nr < more_pages ||
444 vmap_pages_range(phys_end, phys_end + (nr << PAGE_SHIFT), PAGE_KERNEL,
445 next_page, PAGE_SHIFT) < 0) {
446 /* Clean up and error out */
447 for (int i = 0; i < nr; i++)
448 __free_page(next_page[i]);
449 return -ENOMEM;
450 }
451
452 vm_module_tags->nr_pages += nr;
453
454 /*
455 * Kasan allocates 1 byte of shadow for every 8 bytes of data.
456 * When kasan_alloc_module_shadow allocates shadow memory,
457 * its unit of allocation is a page.
458 * Therefore, here we need to align to MODULE_ALIGN.
459 */
460 if (old_shadow_end < new_shadow_end)
461 kasan_alloc_module_shadow((void *)old_shadow_end,
462 new_shadow_end - old_shadow_end,
463 GFP_KERNEL);
464 }
465
466 /*
467 * Mark the pages as accessible, now that they are mapped.
468 * With hardware tag-based KASAN, marking is skipped for
469 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
470 */
471 kasan_unpoison_vmalloc((void *)module_tags.start_addr,
472 new_end - module_tags.start_addr,
473 KASAN_VMALLOC_PROT_NORMAL);
474
475 return 0;
476 }
477
reserve_module_tags(struct module * mod,unsigned long size,unsigned int prepend,unsigned long align)478 static void *reserve_module_tags(struct module *mod, unsigned long size,
479 unsigned int prepend, unsigned long align)
480 {
481 unsigned long section_size = module_tags.end_addr - module_tags.start_addr;
482 MA_STATE(mas, &mod_area_mt, 0, section_size - 1);
483 unsigned long offset;
484 void *ret = NULL;
485
486 /* If no tags return error */
487 if (size < sizeof(struct alloc_tag))
488 return ERR_PTR(-EINVAL);
489
490 /*
491 * align is always power of 2, so we can use IS_ALIGNED and ALIGN.
492 * align 0 or 1 means no alignment, to simplify set to 1.
493 */
494 if (!align)
495 align = 1;
496
497 if (!ensure_alignment(align, &prepend)) {
498 shutdown_mem_profiling(true);
499 pr_err("%s: alignment %lu is incompatible with allocation tag indexing. Memory allocation profiling is disabled!\n",
500 mod->name, align);
501 return ERR_PTR(-EINVAL);
502 }
503
504 mas_lock(&mas);
505 if (!find_aligned_area(&mas, section_size, size, prepend, align)) {
506 ret = ERR_PTR(-ENOMEM);
507 goto unlock;
508 }
509
510 /* Mark found area as reserved */
511 offset = mas.index;
512 offset += prepend;
513 offset = ALIGN(offset, align);
514 if (offset != mas.index) {
515 unsigned long pad_start = mas.index;
516
517 mas.last = offset - 1;
518 mas_store(&mas, &prepend_mod);
519 if (mas_is_err(&mas)) {
520 ret = ERR_PTR(xa_err(mas.node));
521 goto unlock;
522 }
523 mas.index = offset;
524 mas.last = offset + size - 1;
525 mas_store(&mas, mod);
526 if (mas_is_err(&mas)) {
527 mas.index = pad_start;
528 mas_erase(&mas);
529 ret = ERR_PTR(xa_err(mas.node));
530 }
531 } else {
532 mas.last = offset + size - 1;
533 mas_store(&mas, mod);
534 if (mas_is_err(&mas))
535 ret = ERR_PTR(xa_err(mas.node));
536 }
537 unlock:
538 mas_unlock(&mas);
539
540 if (IS_ERR(ret))
541 return ret;
542
543 if (module_tags.size < offset + size) {
544 int grow_res;
545
546 module_tags.size = offset + size;
547 if (mem_alloc_profiling_enabled() && !tags_addressable()) {
548 shutdown_mem_profiling(true);
549 pr_warn("With module %s there are too many tags to fit in %d page flag bits. Memory allocation profiling is disabled!\n",
550 mod->name, NR_UNUSED_PAGEFLAG_BITS);
551 }
552
553 grow_res = vm_module_tags_populate();
554 if (grow_res) {
555 shutdown_mem_profiling(true);
556 pr_err("Failed to allocate memory for allocation tags in the module %s. Memory allocation profiling is disabled!\n",
557 mod->name);
558 return ERR_PTR(grow_res);
559 }
560 }
561
562 return (struct alloc_tag *)(module_tags.start_addr + offset);
563 }
564
release_module_tags(struct module * mod,bool used)565 static void release_module_tags(struct module *mod, bool used)
566 {
567 MA_STATE(mas, &mod_area_mt, module_tags.size, module_tags.size);
568 struct alloc_tag *start_tag;
569 struct alloc_tag *end_tag;
570 struct module *val;
571
572 mas_lock(&mas);
573 mas_for_each_rev(&mas, val, 0)
574 if (val == mod)
575 break;
576
577 if (!val) /* module not found */
578 goto out;
579
580 if (!used)
581 goto release_area;
582
583 start_tag = (struct alloc_tag *)(module_tags.start_addr + mas.index);
584 end_tag = (struct alloc_tag *)(module_tags.start_addr + mas.last);
585 if (!clean_unused_counters(start_tag, end_tag)) {
586 struct alloc_tag *tag;
587
588 for (tag = start_tag; tag <= end_tag; tag++) {
589 struct alloc_tag_counters counter;
590
591 if (!tag->counters)
592 continue;
593
594 counter = alloc_tag_read(tag);
595 pr_info("%s:%u module %s func:%s has %llu allocated at module unload\n",
596 tag->ct.filename, tag->ct.lineno, tag->ct.modname,
597 tag->ct.function, counter.bytes);
598 }
599 } else {
600 used = false;
601 }
602 release_area:
603 mas_store(&mas, used ? &unloaded_mod : NULL);
604 val = mas_prev_range(&mas, 0);
605 if (val == &prepend_mod)
606 mas_store(&mas, NULL);
607 out:
608 mas_unlock(&mas);
609 }
610
load_module(struct module * mod,struct codetag * start,struct codetag * stop)611 static int load_module(struct module *mod, struct codetag *start, struct codetag *stop)
612 {
613 /* Allocate module alloc_tag percpu counters */
614 struct alloc_tag *start_tag;
615 struct alloc_tag *stop_tag;
616 struct alloc_tag *tag;
617
618 /* percpu counters for core allocations are already statically allocated */
619 if (!mod)
620 return 0;
621
622 start_tag = ct_to_alloc_tag(start);
623 stop_tag = ct_to_alloc_tag(stop);
624 for (tag = start_tag; tag < stop_tag; tag++) {
625 WARN_ON(tag->counters);
626 tag->counters = alloc_percpu(struct alloc_tag_counters);
627 if (!tag->counters) {
628 while (--tag >= start_tag) {
629 free_percpu(tag->counters);
630 tag->counters = NULL;
631 }
632 pr_err("Failed to allocate memory for allocation tag percpu counters in the module %s\n",
633 mod->name);
634 return -ENOMEM;
635 }
636
637 /*
638 * Avoid a kmemleak false positive. The pointer to the counters is stored
639 * in the alloc_tag section of the module and cannot be directly accessed.
640 */
641 kmemleak_ignore_percpu(tag->counters);
642 }
643 return 0;
644 }
645
replace_module(struct module * mod,struct module * new_mod)646 static void replace_module(struct module *mod, struct module *new_mod)
647 {
648 MA_STATE(mas, &mod_area_mt, 0, module_tags.size);
649 struct module *val;
650
651 mas_lock(&mas);
652 mas_for_each(&mas, val, module_tags.size) {
653 if (val != mod)
654 continue;
655
656 mas_store_gfp(&mas, new_mod, GFP_KERNEL);
657 break;
658 }
659 mas_unlock(&mas);
660 }
661
alloc_mod_tags_mem(void)662 static int __init alloc_mod_tags_mem(void)
663 {
664 /* Map space to copy allocation tags */
665 vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
666 if (!vm_module_tags) {
667 pr_err("Failed to map %lu bytes for module allocation tags\n",
668 MODULE_ALLOC_TAG_VMAP_SIZE);
669 module_tags.start_addr = 0;
670 return -ENOMEM;
671 }
672
673 vm_module_tags->pages = kmalloc_array(get_vm_area_size(vm_module_tags) >> PAGE_SHIFT,
674 sizeof(struct page *), GFP_KERNEL | __GFP_ZERO);
675 if (!vm_module_tags->pages) {
676 free_vm_area(vm_module_tags);
677 return -ENOMEM;
678 }
679
680 module_tags.start_addr = (unsigned long)vm_module_tags->addr;
681 module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
682 /* Ensure the base is alloc_tag aligned when required for indexing */
683 module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
684
685 return 0;
686 }
687
free_mod_tags_mem(void)688 static void __init free_mod_tags_mem(void)
689 {
690 int i;
691
692 module_tags.start_addr = 0;
693 for (i = 0; i < vm_module_tags->nr_pages; i++)
694 __free_page(vm_module_tags->pages[i]);
695 kfree(vm_module_tags->pages);
696 free_vm_area(vm_module_tags);
697 }
698
699 #else /* CONFIG_MODULES */
700
alloc_mod_tags_mem(void)701 static inline int alloc_mod_tags_mem(void) { return 0; }
free_mod_tags_mem(void)702 static inline void free_mod_tags_mem(void) {}
703
704 #endif /* CONFIG_MODULES */
705
706 /* See: Documentation/mm/allocation-profiling.rst */
setup_early_mem_profiling(char * str)707 static int __init setup_early_mem_profiling(char *str)
708 {
709 bool compressed = false;
710 bool enable;
711
712 if (!str || !str[0])
713 return -EINVAL;
714
715 if (!strncmp(str, "never", 5)) {
716 enable = false;
717 mem_profiling_support = false;
718 pr_info("Memory allocation profiling is disabled!\n");
719 } else {
720 char *token = strsep(&str, ",");
721
722 if (kstrtobool(token, &enable))
723 return -EINVAL;
724
725 if (str) {
726
727 if (strcmp(str, "compressed"))
728 return -EINVAL;
729
730 compressed = true;
731 }
732 mem_profiling_support = true;
733 pr_info("Memory allocation profiling is enabled %s compression and is turned %s!\n",
734 compressed ? "with" : "without", enable ? "on" : "off");
735 }
736
737 if (enable != mem_alloc_profiling_enabled()) {
738 if (enable)
739 static_branch_enable(&mem_alloc_profiling_key);
740 else
741 static_branch_disable(&mem_alloc_profiling_key);
742 }
743 if (compressed != static_key_enabled(&mem_profiling_compressed)) {
744 if (compressed)
745 static_branch_enable(&mem_profiling_compressed);
746 else
747 static_branch_disable(&mem_profiling_compressed);
748 }
749
750 return 0;
751 }
752 early_param("sysctl.vm.mem_profiling", setup_early_mem_profiling);
753
need_page_alloc_tagging(void)754 static __init bool need_page_alloc_tagging(void)
755 {
756 if (static_key_enabled(&mem_profiling_compressed))
757 return false;
758
759 return mem_profiling_support;
760 }
761
init_page_alloc_tagging(void)762 static __init void init_page_alloc_tagging(void)
763 {
764 }
765
766 struct page_ext_operations page_alloc_tagging_ops = {
767 .size = sizeof(union codetag_ref),
768 .need = need_page_alloc_tagging,
769 .init = init_page_alloc_tagging,
770 };
771 EXPORT_SYMBOL(page_alloc_tagging_ops);
772
773 #ifdef CONFIG_SYSCTL
774 static struct ctl_table memory_allocation_profiling_sysctls[] = {
775 {
776 .procname = "mem_profiling",
777 .data = &mem_alloc_profiling_key,
778 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
779 .mode = 0444,
780 #else
781 .mode = 0644,
782 #endif
783 .proc_handler = proc_do_static_key,
784 },
785 };
786
sysctl_init(void)787 static void __init sysctl_init(void)
788 {
789 if (!mem_profiling_support)
790 memory_allocation_profiling_sysctls[0].mode = 0444;
791
792 register_sysctl_init("vm", memory_allocation_profiling_sysctls);
793 }
794 #else /* CONFIG_SYSCTL */
sysctl_init(void)795 static inline void sysctl_init(void) {}
796 #endif /* CONFIG_SYSCTL */
797
alloc_tag_init(void)798 static int __init alloc_tag_init(void)
799 {
800 const struct codetag_type_desc desc = {
801 .section = ALLOC_TAG_SECTION_NAME,
802 .tag_size = sizeof(struct alloc_tag),
803 #ifdef CONFIG_MODULES
804 .needs_section_mem = needs_section_mem,
805 .alloc_section_mem = reserve_module_tags,
806 .free_section_mem = release_module_tags,
807 .module_load = load_module,
808 .module_replaced = replace_module,
809 #endif
810 };
811 int res;
812
813 sysctl_init();
814
815 if (!mem_profiling_support) {
816 pr_info("Memory allocation profiling is not supported!\n");
817 return 0;
818 }
819
820 if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
821 pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
822 shutdown_mem_profiling(false);
823 return -ENOMEM;
824 }
825
826 res = alloc_mod_tags_mem();
827 if (res) {
828 pr_err("Failed to reserve address space for module tags, errno = %d\n", res);
829 shutdown_mem_profiling(true);
830 return res;
831 }
832
833 alloc_tag_cttype = codetag_register_type(&desc);
834 if (IS_ERR(alloc_tag_cttype)) {
835 pr_err("Allocation tags registration failed, errno = %ld\n", PTR_ERR(alloc_tag_cttype));
836 free_mod_tags_mem();
837 shutdown_mem_profiling(true);
838 return PTR_ERR(alloc_tag_cttype);
839 }
840
841 return 0;
842 }
843 module_init(alloc_tag_init);
844