treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / android / binder_alloc.c
blob2d8b9b91dee0ce29549968c5c6def1d89cb9601b
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* binder_alloc.c
4 * Android IPC Subsystem
6 * Copyright (C) 2007-2017 Google, Inc.
7 */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/list.h>
12 #include <linux/sched/mm.h>
13 #include <linux/module.h>
14 #include <linux/rtmutex.h>
15 #include <linux/rbtree.h>
16 #include <linux/seq_file.h>
17 #include <linux/vmalloc.h>
18 #include <linux/slab.h>
19 #include <linux/sched.h>
20 #include <linux/list_lru.h>
21 #include <linux/ratelimit.h>
22 #include <asm/cacheflush.h>
23 #include <linux/uaccess.h>
24 #include <linux/highmem.h>
25 #include <linux/sizes.h>
26 #include "binder_alloc.h"
27 #include "binder_trace.h"
29 struct list_lru binder_alloc_lru;
31 static DEFINE_MUTEX(binder_alloc_mmap_lock);
33 enum {
34 BINDER_DEBUG_USER_ERROR = 1U << 0,
35 BINDER_DEBUG_OPEN_CLOSE = 1U << 1,
36 BINDER_DEBUG_BUFFER_ALLOC = 1U << 2,
37 BINDER_DEBUG_BUFFER_ALLOC_ASYNC = 1U << 3,
39 static uint32_t binder_alloc_debug_mask = BINDER_DEBUG_USER_ERROR;
41 module_param_named(debug_mask, binder_alloc_debug_mask,
42 uint, 0644);
44 #define binder_alloc_debug(mask, x...) \
45 do { \
46 if (binder_alloc_debug_mask & mask) \
47 pr_info_ratelimited(x); \
48 } while (0)
50 static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer)
52 return list_entry(buffer->entry.next, struct binder_buffer, entry);
55 static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer)
57 return list_entry(buffer->entry.prev, struct binder_buffer, entry);
60 static size_t binder_alloc_buffer_size(struct binder_alloc *alloc,
61 struct binder_buffer *buffer)
63 if (list_is_last(&buffer->entry, &alloc->buffers))
64 return alloc->buffer + alloc->buffer_size - buffer->user_data;
65 return binder_buffer_next(buffer)->user_data - buffer->user_data;
68 static void binder_insert_free_buffer(struct binder_alloc *alloc,
69 struct binder_buffer *new_buffer)
71 struct rb_node **p = &alloc->free_buffers.rb_node;
72 struct rb_node *parent = NULL;
73 struct binder_buffer *buffer;
74 size_t buffer_size;
75 size_t new_buffer_size;
77 BUG_ON(!new_buffer->free);
79 new_buffer_size = binder_alloc_buffer_size(alloc, new_buffer);
81 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
82 "%d: add free buffer, size %zd, at %pK\n",
83 alloc->pid, new_buffer_size, new_buffer);
85 while (*p) {
86 parent = *p;
87 buffer = rb_entry(parent, struct binder_buffer, rb_node);
88 BUG_ON(!buffer->free);
90 buffer_size = binder_alloc_buffer_size(alloc, buffer);
92 if (new_buffer_size < buffer_size)
93 p = &parent->rb_left;
94 else
95 p = &parent->rb_right;
97 rb_link_node(&new_buffer->rb_node, parent, p);
98 rb_insert_color(&new_buffer->rb_node, &alloc->free_buffers);
101 static void binder_insert_allocated_buffer_locked(
102 struct binder_alloc *alloc, struct binder_buffer *new_buffer)
104 struct rb_node **p = &alloc->allocated_buffers.rb_node;
105 struct rb_node *parent = NULL;
106 struct binder_buffer *buffer;
108 BUG_ON(new_buffer->free);
110 while (*p) {
111 parent = *p;
112 buffer = rb_entry(parent, struct binder_buffer, rb_node);
113 BUG_ON(buffer->free);
115 if (new_buffer->user_data < buffer->user_data)
116 p = &parent->rb_left;
117 else if (new_buffer->user_data > buffer->user_data)
118 p = &parent->rb_right;
119 else
120 BUG();
122 rb_link_node(&new_buffer->rb_node, parent, p);
123 rb_insert_color(&new_buffer->rb_node, &alloc->allocated_buffers);
126 static struct binder_buffer *binder_alloc_prepare_to_free_locked(
127 struct binder_alloc *alloc,
128 uintptr_t user_ptr)
130 struct rb_node *n = alloc->allocated_buffers.rb_node;
131 struct binder_buffer *buffer;
132 void __user *uptr;
134 uptr = (void __user *)user_ptr;
136 while (n) {
137 buffer = rb_entry(n, struct binder_buffer, rb_node);
138 BUG_ON(buffer->free);
140 if (uptr < buffer->user_data)
141 n = n->rb_left;
142 else if (uptr > buffer->user_data)
143 n = n->rb_right;
144 else {
146 * Guard against user threads attempting to
147 * free the buffer when in use by kernel or
148 * after it's already been freed.
150 if (!buffer->allow_user_free)
151 return ERR_PTR(-EPERM);
152 buffer->allow_user_free = 0;
153 return buffer;
156 return NULL;
160 * binder_alloc_prepare_to_free() - get buffer given user ptr
161 * @alloc: binder_alloc for this proc
162 * @user_ptr: User pointer to buffer data
164 * Validate userspace pointer to buffer data and return buffer corresponding to
165 * that user pointer. Search the rb tree for buffer that matches user data
166 * pointer.
168 * Return: Pointer to buffer or NULL
170 struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc,
171 uintptr_t user_ptr)
173 struct binder_buffer *buffer;
175 mutex_lock(&alloc->mutex);
176 buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr);
177 mutex_unlock(&alloc->mutex);
178 return buffer;
181 static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
182 void __user *start, void __user *end)
184 void __user *page_addr;
185 unsigned long user_page_addr;
186 struct binder_lru_page *page;
187 struct vm_area_struct *vma = NULL;
188 struct mm_struct *mm = NULL;
189 bool need_mm = false;
191 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
192 "%d: %s pages %pK-%pK\n", alloc->pid,
193 allocate ? "allocate" : "free", start, end);
195 if (end <= start)
196 return 0;
198 trace_binder_update_page_range(alloc, allocate, start, end);
200 if (allocate == 0)
201 goto free_range;
203 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
204 page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE];
205 if (!page->page_ptr) {
206 need_mm = true;
207 break;
211 if (need_mm && mmget_not_zero(alloc->vma_vm_mm))
212 mm = alloc->vma_vm_mm;
214 if (mm) {
215 down_read(&mm->mmap_sem);
216 vma = alloc->vma;
219 if (!vma && need_mm) {
220 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
221 "%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
222 alloc->pid);
223 goto err_no_vma;
226 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
227 int ret;
228 bool on_lru;
229 size_t index;
231 index = (page_addr - alloc->buffer) / PAGE_SIZE;
232 page = &alloc->pages[index];
234 if (page->page_ptr) {
235 trace_binder_alloc_lru_start(alloc, index);
237 on_lru = list_lru_del(&binder_alloc_lru, &page->lru);
238 WARN_ON(!on_lru);
240 trace_binder_alloc_lru_end(alloc, index);
241 continue;
244 if (WARN_ON(!vma))
245 goto err_page_ptr_cleared;
247 trace_binder_alloc_page_start(alloc, index);
248 page->page_ptr = alloc_page(GFP_KERNEL |
249 __GFP_HIGHMEM |
250 __GFP_ZERO);
251 if (!page->page_ptr) {
252 pr_err("%d: binder_alloc_buf failed for page at %pK\n",
253 alloc->pid, page_addr);
254 goto err_alloc_page_failed;
256 page->alloc = alloc;
257 INIT_LIST_HEAD(&page->lru);
259 user_page_addr = (uintptr_t)page_addr;
260 ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr);
261 if (ret) {
262 pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n",
263 alloc->pid, user_page_addr);
264 goto err_vm_insert_page_failed;
267 if (index + 1 > alloc->pages_high)
268 alloc->pages_high = index + 1;
270 trace_binder_alloc_page_end(alloc, index);
272 if (mm) {
273 up_read(&mm->mmap_sem);
274 mmput(mm);
276 return 0;
278 free_range:
279 for (page_addr = end - PAGE_SIZE; 1; page_addr -= PAGE_SIZE) {
280 bool ret;
281 size_t index;
283 index = (page_addr - alloc->buffer) / PAGE_SIZE;
284 page = &alloc->pages[index];
286 trace_binder_free_lru_start(alloc, index);
288 ret = list_lru_add(&binder_alloc_lru, &page->lru);
289 WARN_ON(!ret);
291 trace_binder_free_lru_end(alloc, index);
292 if (page_addr == start)
293 break;
294 continue;
296 err_vm_insert_page_failed:
297 __free_page(page->page_ptr);
298 page->page_ptr = NULL;
299 err_alloc_page_failed:
300 err_page_ptr_cleared:
301 if (page_addr == start)
302 break;
304 err_no_vma:
305 if (mm) {
306 up_read(&mm->mmap_sem);
307 mmput(mm);
309 return vma ? -ENOMEM : -ESRCH;
313 static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
314 struct vm_area_struct *vma)
316 if (vma)
317 alloc->vma_vm_mm = vma->vm_mm;
319 * If we see alloc->vma is not NULL, buffer data structures set up
320 * completely. Look at smp_rmb side binder_alloc_get_vma.
321 * We also want to guarantee new alloc->vma_vm_mm is always visible
322 * if alloc->vma is set.
324 smp_wmb();
325 alloc->vma = vma;
328 static inline struct vm_area_struct *binder_alloc_get_vma(
329 struct binder_alloc *alloc)
331 struct vm_area_struct *vma = NULL;
333 if (alloc->vma) {
334 /* Look at description in binder_alloc_set_vma */
335 smp_rmb();
336 vma = alloc->vma;
338 return vma;
341 static struct binder_buffer *binder_alloc_new_buf_locked(
342 struct binder_alloc *alloc,
343 size_t data_size,
344 size_t offsets_size,
345 size_t extra_buffers_size,
346 int is_async)
348 struct rb_node *n = alloc->free_buffers.rb_node;
349 struct binder_buffer *buffer;
350 size_t buffer_size;
351 struct rb_node *best_fit = NULL;
352 void __user *has_page_addr;
353 void __user *end_page_addr;
354 size_t size, data_offsets_size;
355 int ret;
357 if (!binder_alloc_get_vma(alloc)) {
358 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
359 "%d: binder_alloc_buf, no vma\n",
360 alloc->pid);
361 return ERR_PTR(-ESRCH);
364 data_offsets_size = ALIGN(data_size, sizeof(void *)) +
365 ALIGN(offsets_size, sizeof(void *));
367 if (data_offsets_size < data_size || data_offsets_size < offsets_size) {
368 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
369 "%d: got transaction with invalid size %zd-%zd\n",
370 alloc->pid, data_size, offsets_size);
371 return ERR_PTR(-EINVAL);
373 size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *));
374 if (size < data_offsets_size || size < extra_buffers_size) {
375 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
376 "%d: got transaction with invalid extra_buffers_size %zd\n",
377 alloc->pid, extra_buffers_size);
378 return ERR_PTR(-EINVAL);
380 if (is_async &&
381 alloc->free_async_space < size + sizeof(struct binder_buffer)) {
382 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
383 "%d: binder_alloc_buf size %zd failed, no async space left\n",
384 alloc->pid, size);
385 return ERR_PTR(-ENOSPC);
388 /* Pad 0-size buffers so they get assigned unique addresses */
389 size = max(size, sizeof(void *));
391 while (n) {
392 buffer = rb_entry(n, struct binder_buffer, rb_node);
393 BUG_ON(!buffer->free);
394 buffer_size = binder_alloc_buffer_size(alloc, buffer);
396 if (size < buffer_size) {
397 best_fit = n;
398 n = n->rb_left;
399 } else if (size > buffer_size)
400 n = n->rb_right;
401 else {
402 best_fit = n;
403 break;
406 if (best_fit == NULL) {
407 size_t allocated_buffers = 0;
408 size_t largest_alloc_size = 0;
409 size_t total_alloc_size = 0;
410 size_t free_buffers = 0;
411 size_t largest_free_size = 0;
412 size_t total_free_size = 0;
414 for (n = rb_first(&alloc->allocated_buffers); n != NULL;
415 n = rb_next(n)) {
416 buffer = rb_entry(n, struct binder_buffer, rb_node);
417 buffer_size = binder_alloc_buffer_size(alloc, buffer);
418 allocated_buffers++;
419 total_alloc_size += buffer_size;
420 if (buffer_size > largest_alloc_size)
421 largest_alloc_size = buffer_size;
423 for (n = rb_first(&alloc->free_buffers); n != NULL;
424 n = rb_next(n)) {
425 buffer = rb_entry(n, struct binder_buffer, rb_node);
426 buffer_size = binder_alloc_buffer_size(alloc, buffer);
427 free_buffers++;
428 total_free_size += buffer_size;
429 if (buffer_size > largest_free_size)
430 largest_free_size = buffer_size;
432 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
433 "%d: binder_alloc_buf size %zd failed, no address space\n",
434 alloc->pid, size);
435 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
436 "allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
437 total_alloc_size, allocated_buffers,
438 largest_alloc_size, total_free_size,
439 free_buffers, largest_free_size);
440 return ERR_PTR(-ENOSPC);
442 if (n == NULL) {
443 buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
444 buffer_size = binder_alloc_buffer_size(alloc, buffer);
447 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
448 "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n",
449 alloc->pid, size, buffer, buffer_size);
451 has_page_addr = (void __user *)
452 (((uintptr_t)buffer->user_data + buffer_size) & PAGE_MASK);
453 WARN_ON(n && buffer_size != size);
454 end_page_addr =
455 (void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data + size);
456 if (end_page_addr > has_page_addr)
457 end_page_addr = has_page_addr;
458 ret = binder_update_page_range(alloc, 1, (void __user *)
459 PAGE_ALIGN((uintptr_t)buffer->user_data), end_page_addr);
460 if (ret)
461 return ERR_PTR(ret);
463 if (buffer_size != size) {
464 struct binder_buffer *new_buffer;
466 new_buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
467 if (!new_buffer) {
468 pr_err("%s: %d failed to alloc new buffer struct\n",
469 __func__, alloc->pid);
470 goto err_alloc_buf_struct_failed;
472 new_buffer->user_data = (u8 __user *)buffer->user_data + size;
473 list_add(&new_buffer->entry, &buffer->entry);
474 new_buffer->free = 1;
475 binder_insert_free_buffer(alloc, new_buffer);
478 rb_erase(best_fit, &alloc->free_buffers);
479 buffer->free = 0;
480 buffer->allow_user_free = 0;
481 binder_insert_allocated_buffer_locked(alloc, buffer);
482 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
483 "%d: binder_alloc_buf size %zd got %pK\n",
484 alloc->pid, size, buffer);
485 buffer->data_size = data_size;
486 buffer->offsets_size = offsets_size;
487 buffer->async_transaction = is_async;
488 buffer->extra_buffers_size = extra_buffers_size;
489 if (is_async) {
490 alloc->free_async_space -= size + sizeof(struct binder_buffer);
491 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
492 "%d: binder_alloc_buf size %zd async free %zd\n",
493 alloc->pid, size, alloc->free_async_space);
495 return buffer;
497 err_alloc_buf_struct_failed:
498 binder_update_page_range(alloc, 0, (void __user *)
499 PAGE_ALIGN((uintptr_t)buffer->user_data),
500 end_page_addr);
501 return ERR_PTR(-ENOMEM);
505 * binder_alloc_new_buf() - Allocate a new binder buffer
506 * @alloc: binder_alloc for this proc
507 * @data_size: size of user data buffer
508 * @offsets_size: user specified buffer offset
509 * @extra_buffers_size: size of extra space for meta-data (eg, security context)
510 * @is_async: buffer for async transaction
512 * Allocate a new buffer given the requested sizes. Returns
513 * the kernel version of the buffer pointer. The size allocated
514 * is the sum of the three given sizes (each rounded up to
515 * pointer-sized boundary)
517 * Return: The allocated buffer or %NULL if error
519 struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
520 size_t data_size,
521 size_t offsets_size,
522 size_t extra_buffers_size,
523 int is_async)
525 struct binder_buffer *buffer;
527 mutex_lock(&alloc->mutex);
528 buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size,
529 extra_buffers_size, is_async);
530 mutex_unlock(&alloc->mutex);
531 return buffer;
534 static void __user *buffer_start_page(struct binder_buffer *buffer)
536 return (void __user *)((uintptr_t)buffer->user_data & PAGE_MASK);
539 static void __user *prev_buffer_end_page(struct binder_buffer *buffer)
541 return (void __user *)
542 (((uintptr_t)(buffer->user_data) - 1) & PAGE_MASK);
545 static void binder_delete_free_buffer(struct binder_alloc *alloc,
546 struct binder_buffer *buffer)
548 struct binder_buffer *prev, *next = NULL;
549 bool to_free = true;
550 BUG_ON(alloc->buffers.next == &buffer->entry);
551 prev = binder_buffer_prev(buffer);
552 BUG_ON(!prev->free);
553 if (prev_buffer_end_page(prev) == buffer_start_page(buffer)) {
554 to_free = false;
555 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
556 "%d: merge free, buffer %pK share page with %pK\n",
557 alloc->pid, buffer->user_data,
558 prev->user_data);
561 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
562 next = binder_buffer_next(buffer);
563 if (buffer_start_page(next) == buffer_start_page(buffer)) {
564 to_free = false;
565 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
566 "%d: merge free, buffer %pK share page with %pK\n",
567 alloc->pid,
568 buffer->user_data,
569 next->user_data);
573 if (PAGE_ALIGNED(buffer->user_data)) {
574 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
575 "%d: merge free, buffer start %pK is page aligned\n",
576 alloc->pid, buffer->user_data);
577 to_free = false;
580 if (to_free) {
581 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
582 "%d: merge free, buffer %pK do not share page with %pK or %pK\n",
583 alloc->pid, buffer->user_data,
584 prev->user_data,
585 next ? next->user_data : NULL);
586 binder_update_page_range(alloc, 0, buffer_start_page(buffer),
587 buffer_start_page(buffer) + PAGE_SIZE);
589 list_del(&buffer->entry);
590 kfree(buffer);
593 static void binder_free_buf_locked(struct binder_alloc *alloc,
594 struct binder_buffer *buffer)
596 size_t size, buffer_size;
598 buffer_size = binder_alloc_buffer_size(alloc, buffer);
600 size = ALIGN(buffer->data_size, sizeof(void *)) +
601 ALIGN(buffer->offsets_size, sizeof(void *)) +
602 ALIGN(buffer->extra_buffers_size, sizeof(void *));
604 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
605 "%d: binder_free_buf %pK size %zd buffer_size %zd\n",
606 alloc->pid, buffer, size, buffer_size);
608 BUG_ON(buffer->free);
609 BUG_ON(size > buffer_size);
610 BUG_ON(buffer->transaction != NULL);
611 BUG_ON(buffer->user_data < alloc->buffer);
612 BUG_ON(buffer->user_data > alloc->buffer + alloc->buffer_size);
614 if (buffer->async_transaction) {
615 alloc->free_async_space += size + sizeof(struct binder_buffer);
617 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
618 "%d: binder_free_buf size %zd async free %zd\n",
619 alloc->pid, size, alloc->free_async_space);
622 binder_update_page_range(alloc, 0,
623 (void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data),
624 (void __user *)(((uintptr_t)
625 buffer->user_data + buffer_size) & PAGE_MASK));
627 rb_erase(&buffer->rb_node, &alloc->allocated_buffers);
628 buffer->free = 1;
629 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
630 struct binder_buffer *next = binder_buffer_next(buffer);
632 if (next->free) {
633 rb_erase(&next->rb_node, &alloc->free_buffers);
634 binder_delete_free_buffer(alloc, next);
637 if (alloc->buffers.next != &buffer->entry) {
638 struct binder_buffer *prev = binder_buffer_prev(buffer);
640 if (prev->free) {
641 binder_delete_free_buffer(alloc, buffer);
642 rb_erase(&prev->rb_node, &alloc->free_buffers);
643 buffer = prev;
646 binder_insert_free_buffer(alloc, buffer);
650 * binder_alloc_free_buf() - free a binder buffer
651 * @alloc: binder_alloc for this proc
652 * @buffer: kernel pointer to buffer
654 * Free the buffer allocated via binder_alloc_new_buffer()
656 void binder_alloc_free_buf(struct binder_alloc *alloc,
657 struct binder_buffer *buffer)
659 mutex_lock(&alloc->mutex);
660 binder_free_buf_locked(alloc, buffer);
661 mutex_unlock(&alloc->mutex);
665 * binder_alloc_mmap_handler() - map virtual address space for proc
666 * @alloc: alloc structure for this proc
667 * @vma: vma passed to mmap()
669 * Called by binder_mmap() to initialize the space specified in
670 * vma for allocating binder buffers
672 * Return:
673 * 0 = success
674 * -EBUSY = address space already mapped
675 * -ENOMEM = failed to map memory to given address space
677 int binder_alloc_mmap_handler(struct binder_alloc *alloc,
678 struct vm_area_struct *vma)
680 int ret;
681 const char *failure_string;
682 struct binder_buffer *buffer;
684 mutex_lock(&binder_alloc_mmap_lock);
685 if (alloc->buffer_size) {
686 ret = -EBUSY;
687 failure_string = "already mapped";
688 goto err_already_mapped;
690 alloc->buffer_size = min_t(unsigned long, vma->vm_end - vma->vm_start,
691 SZ_4M);
692 mutex_unlock(&binder_alloc_mmap_lock);
694 alloc->buffer = (void __user *)vma->vm_start;
696 alloc->pages = kcalloc(alloc->buffer_size / PAGE_SIZE,
697 sizeof(alloc->pages[0]),
698 GFP_KERNEL);
699 if (alloc->pages == NULL) {
700 ret = -ENOMEM;
701 failure_string = "alloc page array";
702 goto err_alloc_pages_failed;
705 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
706 if (!buffer) {
707 ret = -ENOMEM;
708 failure_string = "alloc buffer struct";
709 goto err_alloc_buf_struct_failed;
712 buffer->user_data = alloc->buffer;
713 list_add(&buffer->entry, &alloc->buffers);
714 buffer->free = 1;
715 binder_insert_free_buffer(alloc, buffer);
716 alloc->free_async_space = alloc->buffer_size / 2;
717 binder_alloc_set_vma(alloc, vma);
718 mmgrab(alloc->vma_vm_mm);
720 return 0;
722 err_alloc_buf_struct_failed:
723 kfree(alloc->pages);
724 alloc->pages = NULL;
725 err_alloc_pages_failed:
726 alloc->buffer = NULL;
727 mutex_lock(&binder_alloc_mmap_lock);
728 alloc->buffer_size = 0;
729 err_already_mapped:
730 mutex_unlock(&binder_alloc_mmap_lock);
731 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
732 "%s: %d %lx-%lx %s failed %d\n", __func__,
733 alloc->pid, vma->vm_start, vma->vm_end,
734 failure_string, ret);
735 return ret;
739 void binder_alloc_deferred_release(struct binder_alloc *alloc)
741 struct rb_node *n;
742 int buffers, page_count;
743 struct binder_buffer *buffer;
745 buffers = 0;
746 mutex_lock(&alloc->mutex);
747 BUG_ON(alloc->vma);
749 while ((n = rb_first(&alloc->allocated_buffers))) {
750 buffer = rb_entry(n, struct binder_buffer, rb_node);
752 /* Transaction should already have been freed */
753 BUG_ON(buffer->transaction);
755 binder_free_buf_locked(alloc, buffer);
756 buffers++;
759 while (!list_empty(&alloc->buffers)) {
760 buffer = list_first_entry(&alloc->buffers,
761 struct binder_buffer, entry);
762 WARN_ON(!buffer->free);
764 list_del(&buffer->entry);
765 WARN_ON_ONCE(!list_empty(&alloc->buffers));
766 kfree(buffer);
769 page_count = 0;
770 if (alloc->pages) {
771 int i;
773 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
774 void __user *page_addr;
775 bool on_lru;
777 if (!alloc->pages[i].page_ptr)
778 continue;
780 on_lru = list_lru_del(&binder_alloc_lru,
781 &alloc->pages[i].lru);
782 page_addr = alloc->buffer + i * PAGE_SIZE;
783 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
784 "%s: %d: page %d at %pK %s\n",
785 __func__, alloc->pid, i, page_addr,
786 on_lru ? "on lru" : "active");
787 __free_page(alloc->pages[i].page_ptr);
788 page_count++;
790 kfree(alloc->pages);
792 mutex_unlock(&alloc->mutex);
793 if (alloc->vma_vm_mm)
794 mmdrop(alloc->vma_vm_mm);
796 binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
797 "%s: %d buffers %d, pages %d\n",
798 __func__, alloc->pid, buffers, page_count);
801 static void print_binder_buffer(struct seq_file *m, const char *prefix,
802 struct binder_buffer *buffer)
804 seq_printf(m, "%s %d: %pK size %zd:%zd:%zd %s\n",
805 prefix, buffer->debug_id, buffer->user_data,
806 buffer->data_size, buffer->offsets_size,
807 buffer->extra_buffers_size,
808 buffer->transaction ? "active" : "delivered");
812 * binder_alloc_print_allocated() - print buffer info
813 * @m: seq_file for output via seq_printf()
814 * @alloc: binder_alloc for this proc
816 * Prints information about every buffer associated with
817 * the binder_alloc state to the given seq_file
819 void binder_alloc_print_allocated(struct seq_file *m,
820 struct binder_alloc *alloc)
822 struct rb_node *n;
824 mutex_lock(&alloc->mutex);
825 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
826 print_binder_buffer(m, " buffer",
827 rb_entry(n, struct binder_buffer, rb_node));
828 mutex_unlock(&alloc->mutex);
832 * binder_alloc_print_pages() - print page usage
833 * @m: seq_file for output via seq_printf()
834 * @alloc: binder_alloc for this proc
836 void binder_alloc_print_pages(struct seq_file *m,
837 struct binder_alloc *alloc)
839 struct binder_lru_page *page;
840 int i;
841 int active = 0;
842 int lru = 0;
843 int free = 0;
845 mutex_lock(&alloc->mutex);
847 * Make sure the binder_alloc is fully initialized, otherwise we might
848 * read inconsistent state.
850 if (binder_alloc_get_vma(alloc) != NULL) {
851 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
852 page = &alloc->pages[i];
853 if (!page->page_ptr)
854 free++;
855 else if (list_empty(&page->lru))
856 active++;
857 else
858 lru++;
861 mutex_unlock(&alloc->mutex);
862 seq_printf(m, " pages: %d:%d:%d\n", active, lru, free);
863 seq_printf(m, " pages high watermark: %zu\n", alloc->pages_high);
867 * binder_alloc_get_allocated_count() - return count of buffers
868 * @alloc: binder_alloc for this proc
870 * Return: count of allocated buffers
872 int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
874 struct rb_node *n;
875 int count = 0;
877 mutex_lock(&alloc->mutex);
878 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
879 count++;
880 mutex_unlock(&alloc->mutex);
881 return count;
886 * binder_alloc_vma_close() - invalidate address space
887 * @alloc: binder_alloc for this proc
889 * Called from binder_vma_close() when releasing address space.
890 * Clears alloc->vma to prevent new incoming transactions from
891 * allocating more buffers.
893 void binder_alloc_vma_close(struct binder_alloc *alloc)
895 binder_alloc_set_vma(alloc, NULL);
899 * binder_alloc_free_page() - shrinker callback to free pages
900 * @item: item to free
901 * @lock: lock protecting the item
902 * @cb_arg: callback argument
904 * Called from list_lru_walk() in binder_shrink_scan() to free
905 * up pages when the system is under memory pressure.
907 enum lru_status binder_alloc_free_page(struct list_head *item,
908 struct list_lru_one *lru,
909 spinlock_t *lock,
910 void *cb_arg)
911 __must_hold(lock)
913 struct mm_struct *mm = NULL;
914 struct binder_lru_page *page = container_of(item,
915 struct binder_lru_page,
916 lru);
917 struct binder_alloc *alloc;
918 uintptr_t page_addr;
919 size_t index;
920 struct vm_area_struct *vma;
922 alloc = page->alloc;
923 if (!mutex_trylock(&alloc->mutex))
924 goto err_get_alloc_mutex_failed;
926 if (!page->page_ptr)
927 goto err_page_already_freed;
929 index = page - alloc->pages;
930 page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
932 mm = alloc->vma_vm_mm;
933 if (!mmget_not_zero(mm))
934 goto err_mmget;
935 if (!down_read_trylock(&mm->mmap_sem))
936 goto err_down_read_mmap_sem_failed;
937 vma = binder_alloc_get_vma(alloc);
939 list_lru_isolate(lru, item);
940 spin_unlock(lock);
942 if (vma) {
943 trace_binder_unmap_user_start(alloc, index);
945 zap_page_range(vma, page_addr, PAGE_SIZE);
947 trace_binder_unmap_user_end(alloc, index);
949 up_read(&mm->mmap_sem);
950 mmput(mm);
952 trace_binder_unmap_kernel_start(alloc, index);
954 __free_page(page->page_ptr);
955 page->page_ptr = NULL;
957 trace_binder_unmap_kernel_end(alloc, index);
959 spin_lock(lock);
960 mutex_unlock(&alloc->mutex);
961 return LRU_REMOVED_RETRY;
963 err_down_read_mmap_sem_failed:
964 mmput_async(mm);
965 err_mmget:
966 err_page_already_freed:
967 mutex_unlock(&alloc->mutex);
968 err_get_alloc_mutex_failed:
969 return LRU_SKIP;
972 static unsigned long
973 binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
975 unsigned long ret = list_lru_count(&binder_alloc_lru);
976 return ret;
979 static unsigned long
980 binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
982 unsigned long ret;
984 ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
985 NULL, sc->nr_to_scan);
986 return ret;
989 static struct shrinker binder_shrinker = {
990 .count_objects = binder_shrink_count,
991 .scan_objects = binder_shrink_scan,
992 .seeks = DEFAULT_SEEKS,
996 * binder_alloc_init() - called by binder_open() for per-proc initialization
997 * @alloc: binder_alloc for this proc
999 * Called from binder_open() to initialize binder_alloc fields for
1000 * new binder proc
1002 void binder_alloc_init(struct binder_alloc *alloc)
1004 alloc->pid = current->group_leader->pid;
1005 mutex_init(&alloc->mutex);
1006 INIT_LIST_HEAD(&alloc->buffers);
1009 int binder_alloc_shrinker_init(void)
1011 int ret = list_lru_init(&binder_alloc_lru);
1013 if (ret == 0) {
1014 ret = register_shrinker(&binder_shrinker);
1015 if (ret)
1016 list_lru_destroy(&binder_alloc_lru);
1018 return ret;
1022 * check_buffer() - verify that buffer/offset is safe to access
1023 * @alloc: binder_alloc for this proc
1024 * @buffer: binder buffer to be accessed
1025 * @offset: offset into @buffer data
1026 * @bytes: bytes to access from offset
1028 * Check that the @offset/@bytes are within the size of the given
1029 * @buffer and that the buffer is currently active and not freeable.
1030 * Offsets must also be multiples of sizeof(u32). The kernel is
1031 * allowed to touch the buffer in two cases:
1033 * 1) when the buffer is being created:
1034 * (buffer->free == 0 && buffer->allow_user_free == 0)
1035 * 2) when the buffer is being torn down:
1036 * (buffer->free == 0 && buffer->transaction == NULL).
1038 * Return: true if the buffer is safe to access
1040 static inline bool check_buffer(struct binder_alloc *alloc,
1041 struct binder_buffer *buffer,
1042 binder_size_t offset, size_t bytes)
1044 size_t buffer_size = binder_alloc_buffer_size(alloc, buffer);
1046 return buffer_size >= bytes &&
1047 offset <= buffer_size - bytes &&
1048 IS_ALIGNED(offset, sizeof(u32)) &&
1049 !buffer->free &&
1050 (!buffer->allow_user_free || !buffer->transaction);
1054 * binder_alloc_get_page() - get kernel pointer for given buffer offset
1055 * @alloc: binder_alloc for this proc
1056 * @buffer: binder buffer to be accessed
1057 * @buffer_offset: offset into @buffer data
1058 * @pgoffp: address to copy final page offset to
1060 * Lookup the struct page corresponding to the address
1061 * at @buffer_offset into @buffer->user_data. If @pgoffp is not
1062 * NULL, the byte-offset into the page is written there.
1064 * The caller is responsible to ensure that the offset points
1065 * to a valid address within the @buffer and that @buffer is
1066 * not freeable by the user. Since it can't be freed, we are
1067 * guaranteed that the corresponding elements of @alloc->pages[]
1068 * cannot change.
1070 * Return: struct page
1072 static struct page *binder_alloc_get_page(struct binder_alloc *alloc,
1073 struct binder_buffer *buffer,
1074 binder_size_t buffer_offset,
1075 pgoff_t *pgoffp)
1077 binder_size_t buffer_space_offset = buffer_offset +
1078 (buffer->user_data - alloc->buffer);
1079 pgoff_t pgoff = buffer_space_offset & ~PAGE_MASK;
1080 size_t index = buffer_space_offset >> PAGE_SHIFT;
1081 struct binder_lru_page *lru_page;
1083 lru_page = &alloc->pages[index];
1084 *pgoffp = pgoff;
1085 return lru_page->page_ptr;
1089 * binder_alloc_copy_user_to_buffer() - copy src user to tgt user
1090 * @alloc: binder_alloc for this proc
1091 * @buffer: binder buffer to be accessed
1092 * @buffer_offset: offset into @buffer data
1093 * @from: userspace pointer to source buffer
1094 * @bytes: bytes to copy
1096 * Copy bytes from source userspace to target buffer.
1098 * Return: bytes remaining to be copied
1100 unsigned long
1101 binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
1102 struct binder_buffer *buffer,
1103 binder_size_t buffer_offset,
1104 const void __user *from,
1105 size_t bytes)
1107 if (!check_buffer(alloc, buffer, buffer_offset, bytes))
1108 return bytes;
1110 while (bytes) {
1111 unsigned long size;
1112 unsigned long ret;
1113 struct page *page;
1114 pgoff_t pgoff;
1115 void *kptr;
1117 page = binder_alloc_get_page(alloc, buffer,
1118 buffer_offset, &pgoff);
1119 size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
1120 kptr = kmap(page) + pgoff;
1121 ret = copy_from_user(kptr, from, size);
1122 kunmap(page);
1123 if (ret)
1124 return bytes - size + ret;
1125 bytes -= size;
1126 from += size;
1127 buffer_offset += size;
1129 return 0;
1132 static int binder_alloc_do_buffer_copy(struct binder_alloc *alloc,
1133 bool to_buffer,
1134 struct binder_buffer *buffer,
1135 binder_size_t buffer_offset,
1136 void *ptr,
1137 size_t bytes)
1139 /* All copies must be 32-bit aligned and 32-bit size */
1140 if (!check_buffer(alloc, buffer, buffer_offset, bytes))
1141 return -EINVAL;
1143 while (bytes) {
1144 unsigned long size;
1145 struct page *page;
1146 pgoff_t pgoff;
1147 void *tmpptr;
1148 void *base_ptr;
1150 page = binder_alloc_get_page(alloc, buffer,
1151 buffer_offset, &pgoff);
1152 size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
1153 base_ptr = kmap_atomic(page);
1154 tmpptr = base_ptr + pgoff;
1155 if (to_buffer)
1156 memcpy(tmpptr, ptr, size);
1157 else
1158 memcpy(ptr, tmpptr, size);
1160 * kunmap_atomic() takes care of flushing the cache
1161 * if this device has VIVT cache arch
1163 kunmap_atomic(base_ptr);
1164 bytes -= size;
1165 pgoff = 0;
1166 ptr = ptr + size;
1167 buffer_offset += size;
1169 return 0;
1172 int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
1173 struct binder_buffer *buffer,
1174 binder_size_t buffer_offset,
1175 void *src,
1176 size_t bytes)
1178 return binder_alloc_do_buffer_copy(alloc, true, buffer, buffer_offset,
1179 src, bytes);
1182 int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
1183 void *dest,
1184 struct binder_buffer *buffer,
1185 binder_size_t buffer_offset,
1186 size_t bytes)
1188 return binder_alloc_do_buffer_copy(alloc, false, buffer, buffer_offset,
1189 dest, bytes);