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 <asm/cacheflush.h>
21 #include <linux/list.h>
22 #include <linux/sched/mm.h>
23 #include <linux/module.h>
24 #include <linux/rtmutex.h>
25 #include <linux/rbtree.h>
26 #include <linux/seq_file.h>
27 #include <linux/vmalloc.h>
28 #include <linux/slab.h>
29 #include <linux/sched.h>
30 #include <linux/list_lru.h>
31 #include "binder_alloc.h"
32 #include "binder_trace.h"
34 struct list_lru binder_alloc_lru;
36 static DEFINE_MUTEX(binder_alloc_mmap_lock);
39 BINDER_DEBUG_OPEN_CLOSE = 1U << 1,
40 BINDER_DEBUG_BUFFER_ALLOC = 1U << 2,
41 BINDER_DEBUG_BUFFER_ALLOC_ASYNC = 1U << 3,
43 static uint32_t binder_alloc_debug_mask;
45 module_param_named(debug_mask, binder_alloc_debug_mask,
48 #define binder_alloc_debug(mask, x...) \
50 if (binder_alloc_debug_mask & mask) \
54 static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer)
56 return list_entry(buffer->entry.next, struct binder_buffer, entry);
59 static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer)
61 return list_entry(buffer->entry.prev, struct binder_buffer, entry);
64 static size_t binder_alloc_buffer_size(struct binder_alloc *alloc,
65 struct binder_buffer *buffer)
67 if (list_is_last(&buffer->entry, &alloc->buffers))
68 return (u8 *)alloc->buffer +
69 alloc->buffer_size - (u8 *)buffer->data;
70 return (u8 *)binder_buffer_next(buffer)->data - (u8 *)buffer->data;
73 static void binder_insert_free_buffer(struct binder_alloc *alloc,
74 struct binder_buffer *new_buffer)
76 struct rb_node **p = &alloc->free_buffers.rb_node;
77 struct rb_node *parent = NULL;
78 struct binder_buffer *buffer;
80 size_t new_buffer_size;
82 BUG_ON(!new_buffer->free);
84 new_buffer_size = binder_alloc_buffer_size(alloc, new_buffer);
86 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
87 "%d: add free buffer, size %zd, at %pK\n",
88 alloc->pid, new_buffer_size, new_buffer);
92 buffer = rb_entry(parent, struct binder_buffer, rb_node);
93 BUG_ON(!buffer->free);
95 buffer_size = binder_alloc_buffer_size(alloc, buffer);
97 if (new_buffer_size < buffer_size)
100 p = &parent->rb_right;
102 rb_link_node(&new_buffer->rb_node, parent, p);
103 rb_insert_color(&new_buffer->rb_node, &alloc->free_buffers);
106 static void binder_insert_allocated_buffer_locked(
107 struct binder_alloc *alloc, struct binder_buffer *new_buffer)
109 struct rb_node **p = &alloc->allocated_buffers.rb_node;
110 struct rb_node *parent = NULL;
111 struct binder_buffer *buffer;
113 BUG_ON(new_buffer->free);
117 buffer = rb_entry(parent, struct binder_buffer, rb_node);
118 BUG_ON(buffer->free);
120 if (new_buffer->data < buffer->data)
121 p = &parent->rb_left;
122 else if (new_buffer->data > buffer->data)
123 p = &parent->rb_right;
127 rb_link_node(&new_buffer->rb_node, parent, p);
128 rb_insert_color(&new_buffer->rb_node, &alloc->allocated_buffers);
131 static struct binder_buffer *binder_alloc_prepare_to_free_locked(
132 struct binder_alloc *alloc,
135 struct rb_node *n = alloc->allocated_buffers.rb_node;
136 struct binder_buffer *buffer;
139 kern_ptr = (void *)(user_ptr - alloc->user_buffer_offset);
142 buffer = rb_entry(n, struct binder_buffer, rb_node);
143 BUG_ON(buffer->free);
145 if (kern_ptr < buffer->data)
147 else if (kern_ptr > buffer->data)
151 * Guard against user threads attempting to
152 * free the buffer twice
154 if (buffer->free_in_progress) {
155 pr_err("%d:%d FREE_BUFFER u%016llx user freed buffer twice\n",
156 alloc->pid, current->pid, (u64)user_ptr);
159 buffer->free_in_progress = 1;
167 * binder_alloc_buffer_lookup() - get buffer given user ptr
168 * @alloc: binder_alloc for this proc
169 * @user_ptr: User pointer to buffer data
171 * Validate userspace pointer to buffer data and return buffer corresponding to
172 * that user pointer. Search the rb tree for buffer that matches user data
175 * Return: Pointer to buffer or NULL
177 struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc,
180 struct binder_buffer *buffer;
182 mutex_lock(&alloc->mutex);
183 buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr);
184 mutex_unlock(&alloc->mutex);
188 static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
189 void *start, void *end)
192 unsigned long user_page_addr;
193 struct binder_lru_page *page;
194 struct vm_area_struct *vma = NULL;
195 struct mm_struct *mm = NULL;
196 bool need_mm = false;
198 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
199 "%d: %s pages %pK-%pK\n", alloc->pid,
200 allocate ? "allocate" : "free", start, end);
205 trace_binder_update_page_range(alloc, allocate, start, end);
210 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
211 page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE];
212 if (!page->page_ptr) {
218 if (need_mm && mmget_not_zero(alloc->vma_vm_mm))
219 mm = alloc->vma_vm_mm;
222 down_write(&mm->mmap_sem);
226 if (!vma && need_mm) {
227 pr_err("%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
232 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
237 index = (page_addr - alloc->buffer) / PAGE_SIZE;
238 page = &alloc->pages[index];
240 if (page->page_ptr) {
241 trace_binder_alloc_lru_start(alloc, index);
243 on_lru = list_lru_del(&binder_alloc_lru, &page->lru);
246 trace_binder_alloc_lru_end(alloc, index);
251 goto err_page_ptr_cleared;
253 trace_binder_alloc_page_start(alloc, index);
254 page->page_ptr = alloc_page(GFP_KERNEL |
257 if (!page->page_ptr) {
258 pr_err("%d: binder_alloc_buf failed for page at %pK\n",
259 alloc->pid, page_addr);
260 goto err_alloc_page_failed;
263 INIT_LIST_HEAD(&page->lru);
265 ret = map_kernel_range_noflush((unsigned long)page_addr,
266 PAGE_SIZE, PAGE_KERNEL,
268 flush_cache_vmap((unsigned long)page_addr,
269 (unsigned long)page_addr + PAGE_SIZE);
271 pr_err("%d: binder_alloc_buf failed to map page at %pK in kernel\n",
272 alloc->pid, page_addr);
273 goto err_map_kernel_failed;
276 (uintptr_t)page_addr + alloc->user_buffer_offset;
277 ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr);
279 pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n",
280 alloc->pid, user_page_addr);
281 goto err_vm_insert_page_failed;
284 trace_binder_alloc_page_end(alloc, index);
285 /* vm_insert_page does not seem to increment the refcount */
288 up_write(&mm->mmap_sem);
294 for (page_addr = end - PAGE_SIZE; page_addr >= start;
295 page_addr -= PAGE_SIZE) {
299 index = (page_addr - alloc->buffer) / PAGE_SIZE;
300 page = &alloc->pages[index];
302 trace_binder_free_lru_start(alloc, index);
304 ret = list_lru_add(&binder_alloc_lru, &page->lru);
307 trace_binder_free_lru_end(alloc, index);
310 err_vm_insert_page_failed:
311 unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
312 err_map_kernel_failed:
313 __free_page(page->page_ptr);
314 page->page_ptr = NULL;
315 err_alloc_page_failed:
316 err_page_ptr_cleared:
321 up_write(&mm->mmap_sem);
324 return vma ? -ENOMEM : -ESRCH;
327 struct binder_buffer *binder_alloc_new_buf_locked(struct binder_alloc *alloc,
330 size_t extra_buffers_size,
333 struct rb_node *n = alloc->free_buffers.rb_node;
334 struct binder_buffer *buffer;
336 struct rb_node *best_fit = NULL;
339 size_t size, data_offsets_size;
342 if (alloc->vma == NULL) {
343 pr_err("%d: binder_alloc_buf, no vma\n",
345 return ERR_PTR(-ESRCH);
348 data_offsets_size = ALIGN(data_size, sizeof(void *)) +
349 ALIGN(offsets_size, sizeof(void *));
351 if (data_offsets_size < data_size || data_offsets_size < offsets_size) {
352 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
353 "%d: got transaction with invalid size %zd-%zd\n",
354 alloc->pid, data_size, offsets_size);
355 return ERR_PTR(-EINVAL);
357 size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *));
358 if (size < data_offsets_size || size < extra_buffers_size) {
359 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
360 "%d: got transaction with invalid extra_buffers_size %zd\n",
361 alloc->pid, extra_buffers_size);
362 return ERR_PTR(-EINVAL);
365 alloc->free_async_space < size + sizeof(struct binder_buffer)) {
366 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
367 "%d: binder_alloc_buf size %zd failed, no async space left\n",
369 return ERR_PTR(-ENOSPC);
372 /* Pad 0-size buffers so they get assigned unique addresses */
373 size = max(size, sizeof(void *));
376 buffer = rb_entry(n, struct binder_buffer, rb_node);
377 BUG_ON(!buffer->free);
378 buffer_size = binder_alloc_buffer_size(alloc, buffer);
380 if (size < buffer_size) {
383 } else if (size > buffer_size)
390 if (best_fit == NULL) {
391 size_t allocated_buffers = 0;
392 size_t largest_alloc_size = 0;
393 size_t total_alloc_size = 0;
394 size_t free_buffers = 0;
395 size_t largest_free_size = 0;
396 size_t total_free_size = 0;
398 for (n = rb_first(&alloc->allocated_buffers); n != NULL;
400 buffer = rb_entry(n, struct binder_buffer, rb_node);
401 buffer_size = binder_alloc_buffer_size(alloc, buffer);
403 total_alloc_size += buffer_size;
404 if (buffer_size > largest_alloc_size)
405 largest_alloc_size = buffer_size;
407 for (n = rb_first(&alloc->free_buffers); n != NULL;
409 buffer = rb_entry(n, struct binder_buffer, rb_node);
410 buffer_size = binder_alloc_buffer_size(alloc, buffer);
412 total_free_size += buffer_size;
413 if (buffer_size > largest_free_size)
414 largest_free_size = buffer_size;
416 pr_err("%d: binder_alloc_buf size %zd failed, no address space\n",
418 pr_err("allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
419 total_alloc_size, allocated_buffers, largest_alloc_size,
420 total_free_size, free_buffers, largest_free_size);
421 return ERR_PTR(-ENOSPC);
424 buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
425 buffer_size = binder_alloc_buffer_size(alloc, buffer);
428 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
429 "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n",
430 alloc->pid, size, buffer, buffer_size);
433 (void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK);
434 WARN_ON(n && buffer_size != size);
436 (void *)PAGE_ALIGN((uintptr_t)buffer->data + size);
437 if (end_page_addr > has_page_addr)
438 end_page_addr = has_page_addr;
439 ret = binder_update_page_range(alloc, 1,
440 (void *)PAGE_ALIGN((uintptr_t)buffer->data), end_page_addr);
444 if (buffer_size != size) {
445 struct binder_buffer *new_buffer;
447 new_buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
449 pr_err("%s: %d failed to alloc new buffer struct\n",
450 __func__, alloc->pid);
451 goto err_alloc_buf_struct_failed;
453 new_buffer->data = (u8 *)buffer->data + size;
454 list_add(&new_buffer->entry, &buffer->entry);
455 new_buffer->free = 1;
456 binder_insert_free_buffer(alloc, new_buffer);
459 rb_erase(best_fit, &alloc->free_buffers);
461 buffer->free_in_progress = 0;
462 binder_insert_allocated_buffer_locked(alloc, buffer);
463 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
464 "%d: binder_alloc_buf size %zd got %pK\n",
465 alloc->pid, size, buffer);
466 buffer->data_size = data_size;
467 buffer->offsets_size = offsets_size;
468 buffer->async_transaction = is_async;
469 buffer->extra_buffers_size = extra_buffers_size;
471 alloc->free_async_space -= size + sizeof(struct binder_buffer);
472 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
473 "%d: binder_alloc_buf size %zd async free %zd\n",
474 alloc->pid, size, alloc->free_async_space);
478 err_alloc_buf_struct_failed:
479 binder_update_page_range(alloc, 0,
480 (void *)PAGE_ALIGN((uintptr_t)buffer->data),
482 return ERR_PTR(-ENOMEM);
486 * binder_alloc_new_buf() - Allocate a new binder buffer
487 * @alloc: binder_alloc for this proc
488 * @data_size: size of user data buffer
489 * @offsets_size: user specified buffer offset
490 * @extra_buffers_size: size of extra space for meta-data (eg, security context)
491 * @is_async: buffer for async transaction
493 * Allocate a new buffer given the requested sizes. Returns
494 * the kernel version of the buffer pointer. The size allocated
495 * is the sum of the three given sizes (each rounded up to
496 * pointer-sized boundary)
498 * Return: The allocated buffer or %NULL if error
500 struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
503 size_t extra_buffers_size,
506 struct binder_buffer *buffer;
508 mutex_lock(&alloc->mutex);
509 buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size,
510 extra_buffers_size, is_async);
511 mutex_unlock(&alloc->mutex);
515 static void *buffer_start_page(struct binder_buffer *buffer)
517 return (void *)((uintptr_t)buffer->data & PAGE_MASK);
520 static void *prev_buffer_end_page(struct binder_buffer *buffer)
522 return (void *)(((uintptr_t)(buffer->data) - 1) & PAGE_MASK);
525 static void binder_delete_free_buffer(struct binder_alloc *alloc,
526 struct binder_buffer *buffer)
528 struct binder_buffer *prev, *next = NULL;
530 BUG_ON(alloc->buffers.next == &buffer->entry);
531 prev = binder_buffer_prev(buffer);
533 if (prev_buffer_end_page(prev) == buffer_start_page(buffer)) {
535 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
536 "%d: merge free, buffer %pK share page with %pK\n",
537 alloc->pid, buffer->data, prev->data);
540 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
541 next = binder_buffer_next(buffer);
542 if (buffer_start_page(next) == buffer_start_page(buffer)) {
544 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
545 "%d: merge free, buffer %pK share page with %pK\n",
552 if (PAGE_ALIGNED(buffer->data)) {
553 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
554 "%d: merge free, buffer start %pK is page aligned\n",
555 alloc->pid, buffer->data);
560 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
561 "%d: merge free, buffer %pK do not share page with %pK or %pK\n",
562 alloc->pid, buffer->data,
563 prev->data, next ? next->data : NULL);
564 binder_update_page_range(alloc, 0, buffer_start_page(buffer),
565 buffer_start_page(buffer) + PAGE_SIZE);
567 list_del(&buffer->entry);
571 static void binder_free_buf_locked(struct binder_alloc *alloc,
572 struct binder_buffer *buffer)
574 size_t size, buffer_size;
576 buffer_size = binder_alloc_buffer_size(alloc, buffer);
578 size = ALIGN(buffer->data_size, sizeof(void *)) +
579 ALIGN(buffer->offsets_size, sizeof(void *)) +
580 ALIGN(buffer->extra_buffers_size, sizeof(void *));
582 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
583 "%d: binder_free_buf %pK size %zd buffer_size %zd\n",
584 alloc->pid, buffer, size, buffer_size);
586 BUG_ON(buffer->free);
587 BUG_ON(size > buffer_size);
588 BUG_ON(buffer->transaction != NULL);
589 BUG_ON(buffer->data < alloc->buffer);
590 BUG_ON(buffer->data > alloc->buffer + alloc->buffer_size);
592 if (buffer->async_transaction) {
593 alloc->free_async_space += size + sizeof(struct binder_buffer);
595 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
596 "%d: binder_free_buf size %zd async free %zd\n",
597 alloc->pid, size, alloc->free_async_space);
600 binder_update_page_range(alloc, 0,
601 (void *)PAGE_ALIGN((uintptr_t)buffer->data),
602 (void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK));
604 rb_erase(&buffer->rb_node, &alloc->allocated_buffers);
606 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
607 struct binder_buffer *next = binder_buffer_next(buffer);
610 rb_erase(&next->rb_node, &alloc->free_buffers);
611 binder_delete_free_buffer(alloc, next);
614 if (alloc->buffers.next != &buffer->entry) {
615 struct binder_buffer *prev = binder_buffer_prev(buffer);
618 binder_delete_free_buffer(alloc, buffer);
619 rb_erase(&prev->rb_node, &alloc->free_buffers);
623 binder_insert_free_buffer(alloc, buffer);
627 * binder_alloc_free_buf() - free a binder buffer
628 * @alloc: binder_alloc for this proc
629 * @buffer: kernel pointer to buffer
631 * Free the buffer allocated via binder_alloc_new_buffer()
633 void binder_alloc_free_buf(struct binder_alloc *alloc,
634 struct binder_buffer *buffer)
636 mutex_lock(&alloc->mutex);
637 binder_free_buf_locked(alloc, buffer);
638 mutex_unlock(&alloc->mutex);
642 * binder_alloc_mmap_handler() - map virtual address space for proc
643 * @alloc: alloc structure for this proc
644 * @vma: vma passed to mmap()
646 * Called by binder_mmap() to initialize the space specified in
647 * vma for allocating binder buffers
651 * -EBUSY = address space already mapped
652 * -ENOMEM = failed to map memory to given address space
654 int binder_alloc_mmap_handler(struct binder_alloc *alloc,
655 struct vm_area_struct *vma)
658 struct vm_struct *area;
659 const char *failure_string;
660 struct binder_buffer *buffer;
662 mutex_lock(&binder_alloc_mmap_lock);
665 failure_string = "already mapped";
666 goto err_already_mapped;
669 area = get_vm_area(vma->vm_end - vma->vm_start, VM_IOREMAP);
672 failure_string = "get_vm_area";
673 goto err_get_vm_area_failed;
675 alloc->buffer = area->addr;
676 alloc->user_buffer_offset =
677 vma->vm_start - (uintptr_t)alloc->buffer;
678 mutex_unlock(&binder_alloc_mmap_lock);
680 #ifdef CONFIG_CPU_CACHE_VIPT
681 if (cache_is_vipt_aliasing()) {
683 (vma->vm_start ^ (uint32_t)alloc->buffer))) {
684 pr_info("%s: %d %lx-%lx maps %pK bad alignment\n",
685 __func__, alloc->pid, vma->vm_start,
686 vma->vm_end, alloc->buffer);
687 vma->vm_start += PAGE_SIZE;
691 alloc->pages = kzalloc(sizeof(alloc->pages[0]) *
692 ((vma->vm_end - vma->vm_start) / PAGE_SIZE),
694 if (alloc->pages == NULL) {
696 failure_string = "alloc page array";
697 goto err_alloc_pages_failed;
699 alloc->buffer_size = vma->vm_end - vma->vm_start;
701 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
704 failure_string = "alloc buffer struct";
705 goto err_alloc_buf_struct_failed;
708 buffer->data = alloc->buffer;
709 list_add(&buffer->entry, &alloc->buffers);
711 binder_insert_free_buffer(alloc, buffer);
712 alloc->free_async_space = alloc->buffer_size / 2;
715 alloc->vma_vm_mm = vma->vm_mm;
716 mmgrab(alloc->vma_vm_mm);
720 err_alloc_buf_struct_failed:
723 err_alloc_pages_failed:
724 mutex_lock(&binder_alloc_mmap_lock);
725 vfree(alloc->buffer);
726 alloc->buffer = NULL;
727 err_get_vm_area_failed:
729 mutex_unlock(&binder_alloc_mmap_lock);
730 pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
731 alloc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
736 void binder_alloc_deferred_release(struct binder_alloc *alloc)
739 int buffers, page_count;
740 struct binder_buffer *buffer;
745 mutex_lock(&alloc->mutex);
746 while ((n = rb_first(&alloc->allocated_buffers))) {
747 buffer = rb_entry(n, struct binder_buffer, rb_node);
749 /* Transaction should already have been freed */
750 BUG_ON(buffer->transaction);
752 binder_free_buf_locked(alloc, buffer);
756 while (!list_empty(&alloc->buffers)) {
757 buffer = list_first_entry(&alloc->buffers,
758 struct binder_buffer, entry);
759 WARN_ON(!buffer->free);
761 list_del(&buffer->entry);
762 WARN_ON_ONCE(!list_empty(&alloc->buffers));
770 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
774 if (!alloc->pages[i].page_ptr)
777 on_lru = list_lru_del(&binder_alloc_lru,
778 &alloc->pages[i].lru);
779 page_addr = alloc->buffer + i * PAGE_SIZE;
780 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
781 "%s: %d: page %d at %pK %s\n",
782 __func__, alloc->pid, i, page_addr,
783 on_lru ? "on lru" : "active");
784 unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
785 __free_page(alloc->pages[i].page_ptr);
789 vfree(alloc->buffer);
791 mutex_unlock(&alloc->mutex);
792 if (alloc->vma_vm_mm)
793 mmdrop(alloc->vma_vm_mm);
795 binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
796 "%s: %d buffers %d, pages %d\n",
797 __func__, alloc->pid, buffers, page_count);
800 static void print_binder_buffer(struct seq_file *m, const char *prefix,
801 struct binder_buffer *buffer)
803 seq_printf(m, "%s %d: %pK size %zd:%zd:%zd %s\n",
804 prefix, buffer->debug_id, buffer->data,
805 buffer->data_size, buffer->offsets_size,
806 buffer->extra_buffers_size,
807 buffer->transaction ? "active" : "delivered");
811 * binder_alloc_print_allocated() - print buffer info
812 * @m: seq_file for output via seq_printf()
813 * @alloc: binder_alloc for this proc
815 * Prints information about every buffer associated with
816 * the binder_alloc state to the given seq_file
818 void binder_alloc_print_allocated(struct seq_file *m,
819 struct binder_alloc *alloc)
823 mutex_lock(&alloc->mutex);
824 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
825 print_binder_buffer(m, " buffer",
826 rb_entry(n, struct binder_buffer, rb_node));
827 mutex_unlock(&alloc->mutex);
831 * binder_alloc_print_pages() - print page usage
832 * @m: seq_file for output via seq_printf()
833 * @alloc: binder_alloc for this proc
835 void binder_alloc_print_pages(struct seq_file *m,
836 struct binder_alloc *alloc)
838 struct binder_lru_page *page;
844 mutex_lock(&alloc->mutex);
845 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
846 page = &alloc->pages[i];
849 else if (list_empty(&page->lru))
854 mutex_unlock(&alloc->mutex);
855 seq_printf(m, " pages: %d:%d:%d\n", active, lru, free);
859 * binder_alloc_get_allocated_count() - return count of buffers
860 * @alloc: binder_alloc for this proc
862 * Return: count of allocated buffers
864 int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
869 mutex_lock(&alloc->mutex);
870 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
872 mutex_unlock(&alloc->mutex);
878 * binder_alloc_vma_close() - invalidate address space
879 * @alloc: binder_alloc for this proc
881 * Called from binder_vma_close() when releasing address space.
882 * Clears alloc->vma to prevent new incoming transactions from
883 * allocating more buffers.
885 void binder_alloc_vma_close(struct binder_alloc *alloc)
887 WRITE_ONCE(alloc->vma, NULL);
891 * binder_alloc_free_page() - shrinker callback to free pages
892 * @item: item to free
893 * @lock: lock protecting the item
894 * @cb_arg: callback argument
896 * Called from list_lru_walk() in binder_shrink_scan() to free
897 * up pages when the system is under memory pressure.
899 enum lru_status binder_alloc_free_page(struct list_head *item,
900 struct list_lru_one *lru,
904 struct mm_struct *mm = NULL;
905 struct binder_lru_page *page = container_of(item,
906 struct binder_lru_page,
908 struct binder_alloc *alloc;
911 struct vm_area_struct *vma;
914 if (!mutex_trylock(&alloc->mutex))
915 goto err_get_alloc_mutex_failed;
918 goto err_page_already_freed;
920 index = page - alloc->pages;
921 page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
924 if (!mmget_not_zero(alloc->vma_vm_mm))
926 mm = alloc->vma_vm_mm;
927 if (!down_write_trylock(&mm->mmap_sem))
928 goto err_down_write_mmap_sem_failed;
931 list_lru_isolate(lru, item);
935 trace_binder_unmap_user_start(alloc, index);
938 page_addr + alloc->user_buffer_offset,
941 trace_binder_unmap_user_end(alloc, index);
943 up_write(&mm->mmap_sem);
947 trace_binder_unmap_kernel_start(alloc, index);
949 unmap_kernel_range(page_addr, PAGE_SIZE);
950 __free_page(page->page_ptr);
951 page->page_ptr = NULL;
953 trace_binder_unmap_kernel_end(alloc, index);
956 mutex_unlock(&alloc->mutex);
957 return LRU_REMOVED_RETRY;
959 err_down_write_mmap_sem_failed:
962 err_page_already_freed:
963 mutex_unlock(&alloc->mutex);
964 err_get_alloc_mutex_failed:
969 binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
971 unsigned long ret = list_lru_count(&binder_alloc_lru);
976 binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
980 ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
981 NULL, sc->nr_to_scan);
985 static struct shrinker binder_shrinker = {
986 .count_objects = binder_shrink_count,
987 .scan_objects = binder_shrink_scan,
988 .seeks = DEFAULT_SEEKS,
992 * binder_alloc_init() - called by binder_open() for per-proc initialization
993 * @alloc: binder_alloc for this proc
995 * Called from binder_open() to initialize binder_alloc fields for
998 void binder_alloc_init(struct binder_alloc *alloc)
1000 alloc->pid = current->group_leader->pid;
1001 mutex_init(&alloc->mutex);
1002 INIT_LIST_HEAD(&alloc->buffers);
1005 void binder_alloc_shrinker_init(void)
1007 list_lru_init(&binder_alloc_lru);
1008 register_shrinker(&binder_shrinker);