3 * Android IPC Subsystem
5 * Copyright (C) 2007-2017 Google, Inc.
7 * This software is licensed under the terms of the GNU General Public
8 * License version 2, as published by the Free Software Foundation, and
9 * may be copied, distributed, and modified under those terms.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 #include <linux/list.h>
21 #include <linux/sched/mm.h>
22 #include <linux/module.h>
23 #include <linux/rtmutex.h>
24 #include <linux/rbtree.h>
25 #include <linux/seq_file.h>
26 #include <linux/vmalloc.h>
27 #include <linux/slab.h>
28 #include <linux/sched.h>
29 #include <linux/list_lru.h>
30 #include <linux/ratelimit.h>
31 #include <asm/cacheflush.h>
32 #include "binder_alloc.h"
33 #include "binder_trace.h"
35 struct list_lru binder_alloc_lru;
37 static DEFINE_MUTEX(binder_alloc_mmap_lock);
40 BINDER_DEBUG_USER_ERROR = 1U << 0,
41 BINDER_DEBUG_OPEN_CLOSE = 1U << 1,
42 BINDER_DEBUG_BUFFER_ALLOC = 1U << 2,
43 BINDER_DEBUG_BUFFER_ALLOC_ASYNC = 1U << 3,
45 static uint32_t binder_alloc_debug_mask = BINDER_DEBUG_USER_ERROR;
47 module_param_named(debug_mask, binder_alloc_debug_mask,
50 #define binder_alloc_debug(mask, x...) \
52 if (binder_alloc_debug_mask & mask) \
53 pr_info_ratelimited(x); \
56 static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer)
58 return list_entry(buffer->entry.next, struct binder_buffer, entry);
61 static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer)
63 return list_entry(buffer->entry.prev, struct binder_buffer, entry);
66 static size_t binder_alloc_buffer_size(struct binder_alloc *alloc,
67 struct binder_buffer *buffer)
69 if (list_is_last(&buffer->entry, &alloc->buffers))
70 return (u8 *)alloc->buffer +
71 alloc->buffer_size - (u8 *)buffer->data;
72 return (u8 *)binder_buffer_next(buffer)->data - (u8 *)buffer->data;
75 static void binder_insert_free_buffer(struct binder_alloc *alloc,
76 struct binder_buffer *new_buffer)
78 struct rb_node **p = &alloc->free_buffers.rb_node;
79 struct rb_node *parent = NULL;
80 struct binder_buffer *buffer;
82 size_t new_buffer_size;
84 BUG_ON(!new_buffer->free);
86 new_buffer_size = binder_alloc_buffer_size(alloc, new_buffer);
88 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
89 "%d: add free buffer, size %zd, at %pK\n",
90 alloc->pid, new_buffer_size, new_buffer);
94 buffer = rb_entry(parent, struct binder_buffer, rb_node);
95 BUG_ON(!buffer->free);
97 buffer_size = binder_alloc_buffer_size(alloc, buffer);
99 if (new_buffer_size < buffer_size)
100 p = &parent->rb_left;
102 p = &parent->rb_right;
104 rb_link_node(&new_buffer->rb_node, parent, p);
105 rb_insert_color(&new_buffer->rb_node, &alloc->free_buffers);
108 static void binder_insert_allocated_buffer_locked(
109 struct binder_alloc *alloc, struct binder_buffer *new_buffer)
111 struct rb_node **p = &alloc->allocated_buffers.rb_node;
112 struct rb_node *parent = NULL;
113 struct binder_buffer *buffer;
115 BUG_ON(new_buffer->free);
119 buffer = rb_entry(parent, struct binder_buffer, rb_node);
120 BUG_ON(buffer->free);
122 if (new_buffer->data < buffer->data)
123 p = &parent->rb_left;
124 else if (new_buffer->data > buffer->data)
125 p = &parent->rb_right;
129 rb_link_node(&new_buffer->rb_node, parent, p);
130 rb_insert_color(&new_buffer->rb_node, &alloc->allocated_buffers);
133 static struct binder_buffer *binder_alloc_prepare_to_free_locked(
134 struct binder_alloc *alloc,
137 struct rb_node *n = alloc->allocated_buffers.rb_node;
138 struct binder_buffer *buffer;
141 kern_ptr = (void *)(user_ptr - alloc->user_buffer_offset);
144 buffer = rb_entry(n, struct binder_buffer, rb_node);
145 BUG_ON(buffer->free);
147 if (kern_ptr < buffer->data)
149 else if (kern_ptr > buffer->data)
153 * Guard against user threads attempting to
154 * free the buffer twice
156 if (buffer->free_in_progress) {
157 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
158 "%d:%d FREE_BUFFER u%016llx user freed buffer twice\n",
159 alloc->pid, current->pid,
163 buffer->free_in_progress = 1;
171 * binder_alloc_buffer_lookup() - get buffer given user ptr
172 * @alloc: binder_alloc for this proc
173 * @user_ptr: User pointer to buffer data
175 * Validate userspace pointer to buffer data and return buffer corresponding to
176 * that user pointer. Search the rb tree for buffer that matches user data
179 * Return: Pointer to buffer or NULL
181 struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc,
184 struct binder_buffer *buffer;
186 mutex_lock(&alloc->mutex);
187 buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr);
188 mutex_unlock(&alloc->mutex);
192 static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
193 void *start, void *end)
196 unsigned long user_page_addr;
197 struct binder_lru_page *page;
198 struct vm_area_struct *vma = NULL;
199 struct mm_struct *mm = NULL;
200 bool need_mm = false;
202 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
203 "%d: %s pages %pK-%pK\n", alloc->pid,
204 allocate ? "allocate" : "free", start, end);
209 trace_binder_update_page_range(alloc, allocate, start, end);
214 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
215 page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE];
216 if (!page->page_ptr) {
222 if (need_mm && mmget_not_zero(alloc->vma_vm_mm))
223 mm = alloc->vma_vm_mm;
226 down_read(&mm->mmap_sem);
230 if (!vma && need_mm) {
231 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
232 "%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
237 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
242 index = (page_addr - alloc->buffer) / PAGE_SIZE;
243 page = &alloc->pages[index];
245 if (page->page_ptr) {
246 trace_binder_alloc_lru_start(alloc, index);
248 on_lru = list_lru_del(&binder_alloc_lru, &page->lru);
251 trace_binder_alloc_lru_end(alloc, index);
256 goto err_page_ptr_cleared;
258 trace_binder_alloc_page_start(alloc, index);
259 page->page_ptr = alloc_page(GFP_KERNEL |
262 if (!page->page_ptr) {
263 pr_err("%d: binder_alloc_buf failed for page at %pK\n",
264 alloc->pid, page_addr);
265 goto err_alloc_page_failed;
268 INIT_LIST_HEAD(&page->lru);
270 ret = map_kernel_range_noflush((unsigned long)page_addr,
271 PAGE_SIZE, PAGE_KERNEL,
273 flush_cache_vmap((unsigned long)page_addr,
274 (unsigned long)page_addr + PAGE_SIZE);
276 pr_err("%d: binder_alloc_buf failed to map page at %pK in kernel\n",
277 alloc->pid, page_addr);
278 goto err_map_kernel_failed;
281 (uintptr_t)page_addr + alloc->user_buffer_offset;
282 ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr);
284 pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n",
285 alloc->pid, user_page_addr);
286 goto err_vm_insert_page_failed;
289 if (index + 1 > alloc->pages_high)
290 alloc->pages_high = index + 1;
292 trace_binder_alloc_page_end(alloc, index);
293 /* vm_insert_page does not seem to increment the refcount */
296 up_read(&mm->mmap_sem);
302 for (page_addr = end - PAGE_SIZE; page_addr >= start;
303 page_addr -= PAGE_SIZE) {
307 index = (page_addr - alloc->buffer) / PAGE_SIZE;
308 page = &alloc->pages[index];
310 trace_binder_free_lru_start(alloc, index);
312 ret = list_lru_add(&binder_alloc_lru, &page->lru);
315 trace_binder_free_lru_end(alloc, index);
318 err_vm_insert_page_failed:
319 unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
320 err_map_kernel_failed:
321 __free_page(page->page_ptr);
322 page->page_ptr = NULL;
323 err_alloc_page_failed:
324 err_page_ptr_cleared:
329 up_read(&mm->mmap_sem);
332 return vma ? -ENOMEM : -ESRCH;
336 static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
337 struct vm_area_struct *vma)
340 alloc->vma_vm_mm = vma->vm_mm;
342 * If we see alloc->vma is not NULL, buffer data structures set up
343 * completely. Look at smp_rmb side binder_alloc_get_vma.
344 * We also want to guarantee new alloc->vma_vm_mm is always visible
345 * if alloc->vma is set.
351 static inline struct vm_area_struct *binder_alloc_get_vma(
352 struct binder_alloc *alloc)
354 struct vm_area_struct *vma = NULL;
357 /* Look at description in binder_alloc_set_vma */
364 static struct binder_buffer *binder_alloc_new_buf_locked(
365 struct binder_alloc *alloc,
368 size_t extra_buffers_size,
371 struct rb_node *n = alloc->free_buffers.rb_node;
372 struct binder_buffer *buffer;
374 struct rb_node *best_fit = NULL;
377 size_t size, data_offsets_size;
380 if (!binder_alloc_get_vma(alloc)) {
381 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
382 "%d: binder_alloc_buf, no vma\n",
384 return ERR_PTR(-ESRCH);
387 data_offsets_size = ALIGN(data_size, sizeof(void *)) +
388 ALIGN(offsets_size, sizeof(void *));
390 if (data_offsets_size < data_size || data_offsets_size < offsets_size) {
391 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
392 "%d: got transaction with invalid size %zd-%zd\n",
393 alloc->pid, data_size, offsets_size);
394 return ERR_PTR(-EINVAL);
396 size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *));
397 if (size < data_offsets_size || size < extra_buffers_size) {
398 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
399 "%d: got transaction with invalid extra_buffers_size %zd\n",
400 alloc->pid, extra_buffers_size);
401 return ERR_PTR(-EINVAL);
404 alloc->free_async_space < size + sizeof(struct binder_buffer)) {
405 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
406 "%d: binder_alloc_buf size %zd failed, no async space left\n",
408 return ERR_PTR(-ENOSPC);
411 /* Pad 0-size buffers so they get assigned unique addresses */
412 size = max(size, sizeof(void *));
415 buffer = rb_entry(n, struct binder_buffer, rb_node);
416 BUG_ON(!buffer->free);
417 buffer_size = binder_alloc_buffer_size(alloc, buffer);
419 if (size < buffer_size) {
422 } else if (size > buffer_size)
429 if (best_fit == NULL) {
430 size_t allocated_buffers = 0;
431 size_t largest_alloc_size = 0;
432 size_t total_alloc_size = 0;
433 size_t free_buffers = 0;
434 size_t largest_free_size = 0;
435 size_t total_free_size = 0;
437 for (n = rb_first(&alloc->allocated_buffers); n != NULL;
439 buffer = rb_entry(n, struct binder_buffer, rb_node);
440 buffer_size = binder_alloc_buffer_size(alloc, buffer);
442 total_alloc_size += buffer_size;
443 if (buffer_size > largest_alloc_size)
444 largest_alloc_size = buffer_size;
446 for (n = rb_first(&alloc->free_buffers); n != NULL;
448 buffer = rb_entry(n, struct binder_buffer, rb_node);
449 buffer_size = binder_alloc_buffer_size(alloc, buffer);
451 total_free_size += buffer_size;
452 if (buffer_size > largest_free_size)
453 largest_free_size = buffer_size;
455 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
456 "%d: binder_alloc_buf size %zd failed, no address space\n",
458 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
459 "allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
460 total_alloc_size, allocated_buffers,
461 largest_alloc_size, total_free_size,
462 free_buffers, largest_free_size);
463 return ERR_PTR(-ENOSPC);
466 buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
467 buffer_size = binder_alloc_buffer_size(alloc, buffer);
470 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
471 "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n",
472 alloc->pid, size, buffer, buffer_size);
475 (void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK);
476 WARN_ON(n && buffer_size != size);
478 (void *)PAGE_ALIGN((uintptr_t)buffer->data + size);
479 if (end_page_addr > has_page_addr)
480 end_page_addr = has_page_addr;
481 ret = binder_update_page_range(alloc, 1,
482 (void *)PAGE_ALIGN((uintptr_t)buffer->data), end_page_addr);
486 if (buffer_size != size) {
487 struct binder_buffer *new_buffer;
489 new_buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
491 pr_err("%s: %d failed to alloc new buffer struct\n",
492 __func__, alloc->pid);
493 goto err_alloc_buf_struct_failed;
495 new_buffer->data = (u8 *)buffer->data + size;
496 list_add(&new_buffer->entry, &buffer->entry);
497 new_buffer->free = 1;
498 binder_insert_free_buffer(alloc, new_buffer);
501 rb_erase(best_fit, &alloc->free_buffers);
503 buffer->free_in_progress = 0;
504 binder_insert_allocated_buffer_locked(alloc, buffer);
505 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
506 "%d: binder_alloc_buf size %zd got %pK\n",
507 alloc->pid, size, buffer);
508 buffer->data_size = data_size;
509 buffer->offsets_size = offsets_size;
510 buffer->async_transaction = is_async;
511 buffer->extra_buffers_size = extra_buffers_size;
513 alloc->free_async_space -= size + sizeof(struct binder_buffer);
514 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
515 "%d: binder_alloc_buf size %zd async free %zd\n",
516 alloc->pid, size, alloc->free_async_space);
520 err_alloc_buf_struct_failed:
521 binder_update_page_range(alloc, 0,
522 (void *)PAGE_ALIGN((uintptr_t)buffer->data),
524 return ERR_PTR(-ENOMEM);
528 * binder_alloc_new_buf() - Allocate a new binder buffer
529 * @alloc: binder_alloc for this proc
530 * @data_size: size of user data buffer
531 * @offsets_size: user specified buffer offset
532 * @extra_buffers_size: size of extra space for meta-data (eg, security context)
533 * @is_async: buffer for async transaction
535 * Allocate a new buffer given the requested sizes. Returns
536 * the kernel version of the buffer pointer. The size allocated
537 * is the sum of the three given sizes (each rounded up to
538 * pointer-sized boundary)
540 * Return: The allocated buffer or %NULL if error
542 struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
545 size_t extra_buffers_size,
548 struct binder_buffer *buffer;
550 mutex_lock(&alloc->mutex);
551 buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size,
552 extra_buffers_size, is_async);
553 mutex_unlock(&alloc->mutex);
557 static void *buffer_start_page(struct binder_buffer *buffer)
559 return (void *)((uintptr_t)buffer->data & PAGE_MASK);
562 static void *prev_buffer_end_page(struct binder_buffer *buffer)
564 return (void *)(((uintptr_t)(buffer->data) - 1) & PAGE_MASK);
567 static void binder_delete_free_buffer(struct binder_alloc *alloc,
568 struct binder_buffer *buffer)
570 struct binder_buffer *prev, *next = NULL;
572 BUG_ON(alloc->buffers.next == &buffer->entry);
573 prev = binder_buffer_prev(buffer);
575 if (prev_buffer_end_page(prev) == buffer_start_page(buffer)) {
577 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
578 "%d: merge free, buffer %pK share page with %pK\n",
579 alloc->pid, buffer->data, prev->data);
582 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
583 next = binder_buffer_next(buffer);
584 if (buffer_start_page(next) == buffer_start_page(buffer)) {
586 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
587 "%d: merge free, buffer %pK share page with %pK\n",
594 if (PAGE_ALIGNED(buffer->data)) {
595 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
596 "%d: merge free, buffer start %pK is page aligned\n",
597 alloc->pid, buffer->data);
602 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
603 "%d: merge free, buffer %pK do not share page with %pK or %pK\n",
604 alloc->pid, buffer->data,
605 prev->data, next ? next->data : NULL);
606 binder_update_page_range(alloc, 0, buffer_start_page(buffer),
607 buffer_start_page(buffer) + PAGE_SIZE);
609 list_del(&buffer->entry);
613 static void binder_free_buf_locked(struct binder_alloc *alloc,
614 struct binder_buffer *buffer)
616 size_t size, buffer_size;
618 buffer_size = binder_alloc_buffer_size(alloc, buffer);
620 size = ALIGN(buffer->data_size, sizeof(void *)) +
621 ALIGN(buffer->offsets_size, sizeof(void *)) +
622 ALIGN(buffer->extra_buffers_size, sizeof(void *));
624 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
625 "%d: binder_free_buf %pK size %zd buffer_size %zd\n",
626 alloc->pid, buffer, size, buffer_size);
628 BUG_ON(buffer->free);
629 BUG_ON(size > buffer_size);
630 BUG_ON(buffer->transaction != NULL);
631 BUG_ON(buffer->data < alloc->buffer);
632 BUG_ON(buffer->data > alloc->buffer + alloc->buffer_size);
634 if (buffer->async_transaction) {
635 alloc->free_async_space += size + sizeof(struct binder_buffer);
637 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
638 "%d: binder_free_buf size %zd async free %zd\n",
639 alloc->pid, size, alloc->free_async_space);
642 binder_update_page_range(alloc, 0,
643 (void *)PAGE_ALIGN((uintptr_t)buffer->data),
644 (void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK));
646 rb_erase(&buffer->rb_node, &alloc->allocated_buffers);
648 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
649 struct binder_buffer *next = binder_buffer_next(buffer);
652 rb_erase(&next->rb_node, &alloc->free_buffers);
653 binder_delete_free_buffer(alloc, next);
656 if (alloc->buffers.next != &buffer->entry) {
657 struct binder_buffer *prev = binder_buffer_prev(buffer);
660 binder_delete_free_buffer(alloc, buffer);
661 rb_erase(&prev->rb_node, &alloc->free_buffers);
665 binder_insert_free_buffer(alloc, buffer);
669 * binder_alloc_free_buf() - free a binder buffer
670 * @alloc: binder_alloc for this proc
671 * @buffer: kernel pointer to buffer
673 * Free the buffer allocated via binder_alloc_new_buffer()
675 void binder_alloc_free_buf(struct binder_alloc *alloc,
676 struct binder_buffer *buffer)
678 mutex_lock(&alloc->mutex);
679 binder_free_buf_locked(alloc, buffer);
680 mutex_unlock(&alloc->mutex);
684 * binder_alloc_mmap_handler() - map virtual address space for proc
685 * @alloc: alloc structure for this proc
686 * @vma: vma passed to mmap()
688 * Called by binder_mmap() to initialize the space specified in
689 * vma for allocating binder buffers
693 * -EBUSY = address space already mapped
694 * -ENOMEM = failed to map memory to given address space
696 int binder_alloc_mmap_handler(struct binder_alloc *alloc,
697 struct vm_area_struct *vma)
700 struct vm_struct *area;
701 const char *failure_string;
702 struct binder_buffer *buffer;
704 mutex_lock(&binder_alloc_mmap_lock);
707 failure_string = "already mapped";
708 goto err_already_mapped;
711 area = get_vm_area(vma->vm_end - vma->vm_start, VM_ALLOC);
714 failure_string = "get_vm_area";
715 goto err_get_vm_area_failed;
717 alloc->buffer = area->addr;
718 alloc->user_buffer_offset =
719 vma->vm_start - (uintptr_t)alloc->buffer;
720 mutex_unlock(&binder_alloc_mmap_lock);
722 #ifdef CONFIG_CPU_CACHE_VIPT
723 if (cache_is_vipt_aliasing()) {
725 (vma->vm_start ^ (uint32_t)alloc->buffer))) {
726 pr_info("%s: %d %lx-%lx maps %pK bad alignment\n",
727 __func__, alloc->pid, vma->vm_start,
728 vma->vm_end, alloc->buffer);
729 vma->vm_start += PAGE_SIZE;
733 alloc->pages = kcalloc((vma->vm_end - vma->vm_start) / PAGE_SIZE,
734 sizeof(alloc->pages[0]),
736 if (alloc->pages == NULL) {
738 failure_string = "alloc page array";
739 goto err_alloc_pages_failed;
741 alloc->buffer_size = vma->vm_end - vma->vm_start;
743 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
746 failure_string = "alloc buffer struct";
747 goto err_alloc_buf_struct_failed;
750 buffer->data = alloc->buffer;
751 list_add(&buffer->entry, &alloc->buffers);
753 binder_insert_free_buffer(alloc, buffer);
754 alloc->free_async_space = alloc->buffer_size / 2;
755 binder_alloc_set_vma(alloc, vma);
756 mmgrab(alloc->vma_vm_mm);
760 err_alloc_buf_struct_failed:
763 err_alloc_pages_failed:
764 mutex_lock(&binder_alloc_mmap_lock);
765 vfree(alloc->buffer);
766 alloc->buffer = NULL;
767 err_get_vm_area_failed:
769 mutex_unlock(&binder_alloc_mmap_lock);
770 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
771 "%s: %d %lx-%lx %s failed %d\n", __func__,
772 alloc->pid, vma->vm_start, vma->vm_end,
773 failure_string, ret);
778 void binder_alloc_deferred_release(struct binder_alloc *alloc)
781 int buffers, page_count;
782 struct binder_buffer *buffer;
785 mutex_lock(&alloc->mutex);
788 while ((n = rb_first(&alloc->allocated_buffers))) {
789 buffer = rb_entry(n, struct binder_buffer, rb_node);
791 /* Transaction should already have been freed */
792 BUG_ON(buffer->transaction);
794 binder_free_buf_locked(alloc, buffer);
798 while (!list_empty(&alloc->buffers)) {
799 buffer = list_first_entry(&alloc->buffers,
800 struct binder_buffer, entry);
801 WARN_ON(!buffer->free);
803 list_del(&buffer->entry);
804 WARN_ON_ONCE(!list_empty(&alloc->buffers));
812 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
816 if (!alloc->pages[i].page_ptr)
819 on_lru = list_lru_del(&binder_alloc_lru,
820 &alloc->pages[i].lru);
821 page_addr = alloc->buffer + i * PAGE_SIZE;
822 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
823 "%s: %d: page %d at %pK %s\n",
824 __func__, alloc->pid, i, page_addr,
825 on_lru ? "on lru" : "active");
826 unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
827 __free_page(alloc->pages[i].page_ptr);
831 vfree(alloc->buffer);
833 mutex_unlock(&alloc->mutex);
834 if (alloc->vma_vm_mm)
835 mmdrop(alloc->vma_vm_mm);
837 binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
838 "%s: %d buffers %d, pages %d\n",
839 __func__, alloc->pid, buffers, page_count);
842 static void print_binder_buffer(struct seq_file *m, const char *prefix,
843 struct binder_buffer *buffer)
845 seq_printf(m, "%s %d: %pK size %zd:%zd:%zd %s\n",
846 prefix, buffer->debug_id, buffer->data,
847 buffer->data_size, buffer->offsets_size,
848 buffer->extra_buffers_size,
849 buffer->transaction ? "active" : "delivered");
853 * binder_alloc_print_allocated() - print buffer info
854 * @m: seq_file for output via seq_printf()
855 * @alloc: binder_alloc for this proc
857 * Prints information about every buffer associated with
858 * the binder_alloc state to the given seq_file
860 void binder_alloc_print_allocated(struct seq_file *m,
861 struct binder_alloc *alloc)
865 mutex_lock(&alloc->mutex);
866 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
867 print_binder_buffer(m, " buffer",
868 rb_entry(n, struct binder_buffer, rb_node));
869 mutex_unlock(&alloc->mutex);
873 * binder_alloc_print_pages() - print page usage
874 * @m: seq_file for output via seq_printf()
875 * @alloc: binder_alloc for this proc
877 void binder_alloc_print_pages(struct seq_file *m,
878 struct binder_alloc *alloc)
880 struct binder_lru_page *page;
886 mutex_lock(&alloc->mutex);
887 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
888 page = &alloc->pages[i];
891 else if (list_empty(&page->lru))
896 mutex_unlock(&alloc->mutex);
897 seq_printf(m, " pages: %d:%d:%d\n", active, lru, free);
898 seq_printf(m, " pages high watermark: %zu\n", alloc->pages_high);
902 * binder_alloc_get_allocated_count() - return count of buffers
903 * @alloc: binder_alloc for this proc
905 * Return: count of allocated buffers
907 int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
912 mutex_lock(&alloc->mutex);
913 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
915 mutex_unlock(&alloc->mutex);
921 * binder_alloc_vma_close() - invalidate address space
922 * @alloc: binder_alloc for this proc
924 * Called from binder_vma_close() when releasing address space.
925 * Clears alloc->vma to prevent new incoming transactions from
926 * allocating more buffers.
928 void binder_alloc_vma_close(struct binder_alloc *alloc)
930 binder_alloc_set_vma(alloc, NULL);
934 * binder_alloc_free_page() - shrinker callback to free pages
935 * @item: item to free
936 * @lock: lock protecting the item
937 * @cb_arg: callback argument
939 * Called from list_lru_walk() in binder_shrink_scan() to free
940 * up pages when the system is under memory pressure.
942 enum lru_status binder_alloc_free_page(struct list_head *item,
943 struct list_lru_one *lru,
947 struct mm_struct *mm = NULL;
948 struct binder_lru_page *page = container_of(item,
949 struct binder_lru_page,
951 struct binder_alloc *alloc;
954 struct vm_area_struct *vma;
957 if (!mutex_trylock(&alloc->mutex))
958 goto err_get_alloc_mutex_failed;
961 goto err_page_already_freed;
963 index = page - alloc->pages;
964 page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
965 vma = binder_alloc_get_vma(alloc);
967 if (!mmget_not_zero(alloc->vma_vm_mm))
969 mm = alloc->vma_vm_mm;
970 if (!down_write_trylock(&mm->mmap_sem))
971 goto err_down_write_mmap_sem_failed;
974 list_lru_isolate(lru, item);
978 trace_binder_unmap_user_start(alloc, index);
981 page_addr + alloc->user_buffer_offset,
984 trace_binder_unmap_user_end(alloc, index);
986 up_write(&mm->mmap_sem);
990 trace_binder_unmap_kernel_start(alloc, index);
992 unmap_kernel_range(page_addr, PAGE_SIZE);
993 __free_page(page->page_ptr);
994 page->page_ptr = NULL;
996 trace_binder_unmap_kernel_end(alloc, index);
999 mutex_unlock(&alloc->mutex);
1000 return LRU_REMOVED_RETRY;
1002 err_down_write_mmap_sem_failed:
1005 err_page_already_freed:
1006 mutex_unlock(&alloc->mutex);
1007 err_get_alloc_mutex_failed:
1011 static unsigned long
1012 binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
1014 unsigned long ret = list_lru_count(&binder_alloc_lru);
1018 static unsigned long
1019 binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
1023 ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
1024 NULL, sc->nr_to_scan);
1028 static struct shrinker binder_shrinker = {
1029 .count_objects = binder_shrink_count,
1030 .scan_objects = binder_shrink_scan,
1031 .seeks = DEFAULT_SEEKS,
1035 * binder_alloc_init() - called by binder_open() for per-proc initialization
1036 * @alloc: binder_alloc for this proc
1038 * Called from binder_open() to initialize binder_alloc fields for
1041 void binder_alloc_init(struct binder_alloc *alloc)
1043 alloc->pid = current->group_leader->pid;
1044 mutex_init(&alloc->mutex);
1045 INIT_LIST_HEAD(&alloc->buffers);
1048 int binder_alloc_shrinker_init(void)
1050 int ret = list_lru_init(&binder_alloc_lru);
1053 ret = register_shrinker(&binder_shrinker);
1055 list_lru_destroy(&binder_alloc_lru);