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 when in use by kernel or
153 * after it's already been freed.
155 if (!buffer->allow_user_free)
156 return ERR_PTR(-EPERM);
157 buffer->allow_user_free = 0;
165 * binder_alloc_buffer_lookup() - get buffer given user ptr
166 * @alloc: binder_alloc for this proc
167 * @user_ptr: User pointer to buffer data
169 * Validate userspace pointer to buffer data and return buffer corresponding to
170 * that user pointer. Search the rb tree for buffer that matches user data
173 * Return: Pointer to buffer or NULL
175 struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc,
178 struct binder_buffer *buffer;
180 mutex_lock(&alloc->mutex);
181 buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr);
182 mutex_unlock(&alloc->mutex);
186 static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
187 void *start, void *end,
188 struct vm_area_struct *vma)
191 unsigned long user_page_addr;
192 struct binder_lru_page *page;
193 struct mm_struct *mm = NULL;
194 bool need_mm = false;
196 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
197 "%d: %s pages %pK-%pK\n", alloc->pid,
198 allocate ? "allocate" : "free", start, end);
203 trace_binder_update_page_range(alloc, allocate, start, end);
208 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
209 page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE];
210 if (!page->page_ptr) {
216 if (!vma && need_mm && mmget_not_zero(alloc->vma_vm_mm))
217 mm = alloc->vma_vm_mm;
220 down_write(&mm->mmap_sem);
224 if (!vma && need_mm) {
225 pr_err("%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
230 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
235 index = (page_addr - alloc->buffer) / PAGE_SIZE;
236 page = &alloc->pages[index];
238 if (page->page_ptr) {
239 trace_binder_alloc_lru_start(alloc, index);
241 on_lru = list_lru_del(&binder_alloc_lru, &page->lru);
244 trace_binder_alloc_lru_end(alloc, index);
249 goto err_page_ptr_cleared;
251 trace_binder_alloc_page_start(alloc, index);
252 page->page_ptr = alloc_page(GFP_KERNEL |
255 if (!page->page_ptr) {
256 pr_err("%d: binder_alloc_buf failed for page at %pK\n",
257 alloc->pid, page_addr);
258 goto err_alloc_page_failed;
261 INIT_LIST_HEAD(&page->lru);
263 ret = map_kernel_range_noflush((unsigned long)page_addr,
264 PAGE_SIZE, PAGE_KERNEL,
266 flush_cache_vmap((unsigned long)page_addr,
267 (unsigned long)page_addr + PAGE_SIZE);
269 pr_err("%d: binder_alloc_buf failed to map page at %pK in kernel\n",
270 alloc->pid, page_addr);
271 goto err_map_kernel_failed;
274 (uintptr_t)page_addr + alloc->user_buffer_offset;
275 ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr);
277 pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n",
278 alloc->pid, user_page_addr);
279 goto err_vm_insert_page_failed;
282 trace_binder_alloc_page_end(alloc, index);
283 /* vm_insert_page does not seem to increment the refcount */
286 up_write(&mm->mmap_sem);
292 for (page_addr = end - PAGE_SIZE; 1; page_addr -= PAGE_SIZE) {
296 index = (page_addr - alloc->buffer) / PAGE_SIZE;
297 page = &alloc->pages[index];
299 trace_binder_free_lru_start(alloc, index);
301 ret = list_lru_add(&binder_alloc_lru, &page->lru);
304 trace_binder_free_lru_end(alloc, index);
305 if (page_addr == start)
309 err_vm_insert_page_failed:
310 unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
311 err_map_kernel_failed:
312 __free_page(page->page_ptr);
313 page->page_ptr = NULL;
314 err_alloc_page_failed:
315 err_page_ptr_cleared:
316 if (page_addr == start)
321 up_write(&mm->mmap_sem);
324 return vma ? -ENOMEM : -ESRCH;
327 static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
328 struct vm_area_struct *vma)
331 alloc->vma_vm_mm = vma->vm_mm;
333 * If we see alloc->vma is not NULL, buffer data structures set up
334 * completely. Look at smp_rmb side binder_alloc_get_vma.
335 * We also want to guarantee new alloc->vma_vm_mm is always visible
336 * if alloc->vma is set.
342 static inline struct vm_area_struct *binder_alloc_get_vma(
343 struct binder_alloc *alloc)
345 struct vm_area_struct *vma = NULL;
348 /* Look at description in binder_alloc_set_vma */
355 struct binder_buffer *binder_alloc_new_buf_locked(struct binder_alloc *alloc,
358 size_t extra_buffers_size,
361 struct rb_node *n = alloc->free_buffers.rb_node;
362 struct binder_buffer *buffer;
364 struct rb_node *best_fit = NULL;
367 size_t size, data_offsets_size;
370 if (!binder_alloc_get_vma(alloc)) {
371 pr_err("%d: binder_alloc_buf, no vma\n",
373 return ERR_PTR(-ESRCH);
376 data_offsets_size = ALIGN(data_size, sizeof(void *)) +
377 ALIGN(offsets_size, sizeof(void *));
379 if (data_offsets_size < data_size || data_offsets_size < offsets_size) {
380 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
381 "%d: got transaction with invalid size %zd-%zd\n",
382 alloc->pid, data_size, offsets_size);
383 return ERR_PTR(-EINVAL);
385 size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *));
386 if (size < data_offsets_size || size < extra_buffers_size) {
387 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
388 "%d: got transaction with invalid extra_buffers_size %zd\n",
389 alloc->pid, extra_buffers_size);
390 return ERR_PTR(-EINVAL);
393 alloc->free_async_space < size + sizeof(struct binder_buffer)) {
394 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
395 "%d: binder_alloc_buf size %zd failed, no async space left\n",
397 return ERR_PTR(-ENOSPC);
400 /* Pad 0-size buffers so they get assigned unique addresses */
401 size = max(size, sizeof(void *));
404 buffer = rb_entry(n, struct binder_buffer, rb_node);
405 BUG_ON(!buffer->free);
406 buffer_size = binder_alloc_buffer_size(alloc, buffer);
408 if (size < buffer_size) {
411 } else if (size > buffer_size)
418 if (best_fit == NULL) {
419 size_t allocated_buffers = 0;
420 size_t largest_alloc_size = 0;
421 size_t total_alloc_size = 0;
422 size_t free_buffers = 0;
423 size_t largest_free_size = 0;
424 size_t total_free_size = 0;
426 for (n = rb_first(&alloc->allocated_buffers); n != NULL;
428 buffer = rb_entry(n, struct binder_buffer, rb_node);
429 buffer_size = binder_alloc_buffer_size(alloc, buffer);
431 total_alloc_size += buffer_size;
432 if (buffer_size > largest_alloc_size)
433 largest_alloc_size = buffer_size;
435 for (n = rb_first(&alloc->free_buffers); n != NULL;
437 buffer = rb_entry(n, struct binder_buffer, rb_node);
438 buffer_size = binder_alloc_buffer_size(alloc, buffer);
440 total_free_size += buffer_size;
441 if (buffer_size > largest_free_size)
442 largest_free_size = buffer_size;
444 pr_err("%d: binder_alloc_buf size %zd failed, no address space\n",
446 pr_err("allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
447 total_alloc_size, allocated_buffers, largest_alloc_size,
448 total_free_size, free_buffers, largest_free_size);
449 return ERR_PTR(-ENOSPC);
452 buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
453 buffer_size = binder_alloc_buffer_size(alloc, buffer);
456 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
457 "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n",
458 alloc->pid, size, buffer, buffer_size);
461 (void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK);
462 WARN_ON(n && buffer_size != size);
464 (void *)PAGE_ALIGN((uintptr_t)buffer->data + size);
465 if (end_page_addr > has_page_addr)
466 end_page_addr = has_page_addr;
467 ret = binder_update_page_range(alloc, 1,
468 (void *)PAGE_ALIGN((uintptr_t)buffer->data), end_page_addr, NULL);
472 if (buffer_size != size) {
473 struct binder_buffer *new_buffer;
475 new_buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
477 pr_err("%s: %d failed to alloc new buffer struct\n",
478 __func__, alloc->pid);
479 goto err_alloc_buf_struct_failed;
481 new_buffer->data = (u8 *)buffer->data + size;
482 list_add(&new_buffer->entry, &buffer->entry);
483 new_buffer->free = 1;
484 binder_insert_free_buffer(alloc, new_buffer);
487 rb_erase(best_fit, &alloc->free_buffers);
489 buffer->allow_user_free = 0;
490 binder_insert_allocated_buffer_locked(alloc, buffer);
491 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
492 "%d: binder_alloc_buf size %zd got %pK\n",
493 alloc->pid, size, buffer);
494 buffer->data_size = data_size;
495 buffer->offsets_size = offsets_size;
496 buffer->async_transaction = is_async;
497 buffer->extra_buffers_size = extra_buffers_size;
499 alloc->free_async_space -= size + sizeof(struct binder_buffer);
500 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
501 "%d: binder_alloc_buf size %zd async free %zd\n",
502 alloc->pid, size, alloc->free_async_space);
506 err_alloc_buf_struct_failed:
507 binder_update_page_range(alloc, 0,
508 (void *)PAGE_ALIGN((uintptr_t)buffer->data),
509 end_page_addr, NULL);
510 return ERR_PTR(-ENOMEM);
514 * binder_alloc_new_buf() - Allocate a new binder buffer
515 * @alloc: binder_alloc for this proc
516 * @data_size: size of user data buffer
517 * @offsets_size: user specified buffer offset
518 * @extra_buffers_size: size of extra space for meta-data (eg, security context)
519 * @is_async: buffer for async transaction
521 * Allocate a new buffer given the requested sizes. Returns
522 * the kernel version of the buffer pointer. The size allocated
523 * is the sum of the three given sizes (each rounded up to
524 * pointer-sized boundary)
526 * Return: The allocated buffer or %NULL if error
528 struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
531 size_t extra_buffers_size,
534 struct binder_buffer *buffer;
536 mutex_lock(&alloc->mutex);
537 buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size,
538 extra_buffers_size, is_async);
539 mutex_unlock(&alloc->mutex);
543 static void *buffer_start_page(struct binder_buffer *buffer)
545 return (void *)((uintptr_t)buffer->data & PAGE_MASK);
548 static void *prev_buffer_end_page(struct binder_buffer *buffer)
550 return (void *)(((uintptr_t)(buffer->data) - 1) & PAGE_MASK);
553 static void binder_delete_free_buffer(struct binder_alloc *alloc,
554 struct binder_buffer *buffer)
556 struct binder_buffer *prev, *next = NULL;
558 BUG_ON(alloc->buffers.next == &buffer->entry);
559 prev = binder_buffer_prev(buffer);
561 if (prev_buffer_end_page(prev) == buffer_start_page(buffer)) {
563 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
564 "%d: merge free, buffer %pK share page with %pK\n",
565 alloc->pid, buffer->data, prev->data);
568 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
569 next = binder_buffer_next(buffer);
570 if (buffer_start_page(next) == buffer_start_page(buffer)) {
572 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
573 "%d: merge free, buffer %pK share page with %pK\n",
580 if (PAGE_ALIGNED(buffer->data)) {
581 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
582 "%d: merge free, buffer start %pK is page aligned\n",
583 alloc->pid, buffer->data);
588 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
589 "%d: merge free, buffer %pK do not share page with %pK or %pK\n",
590 alloc->pid, buffer->data,
591 prev->data, next ? next->data : NULL);
592 binder_update_page_range(alloc, 0, buffer_start_page(buffer),
593 buffer_start_page(buffer) + PAGE_SIZE,
596 list_del(&buffer->entry);
600 static void binder_free_buf_locked(struct binder_alloc *alloc,
601 struct binder_buffer *buffer)
603 size_t size, buffer_size;
605 buffer_size = binder_alloc_buffer_size(alloc, buffer);
607 size = ALIGN(buffer->data_size, sizeof(void *)) +
608 ALIGN(buffer->offsets_size, sizeof(void *)) +
609 ALIGN(buffer->extra_buffers_size, sizeof(void *));
611 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
612 "%d: binder_free_buf %pK size %zd buffer_size %zd\n",
613 alloc->pid, buffer, size, buffer_size);
615 BUG_ON(buffer->free);
616 BUG_ON(size > buffer_size);
617 BUG_ON(buffer->transaction != NULL);
618 BUG_ON(buffer->data < alloc->buffer);
619 BUG_ON(buffer->data > alloc->buffer + alloc->buffer_size);
621 if (buffer->async_transaction) {
622 alloc->free_async_space += size + sizeof(struct binder_buffer);
624 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
625 "%d: binder_free_buf size %zd async free %zd\n",
626 alloc->pid, size, alloc->free_async_space);
629 binder_update_page_range(alloc, 0,
630 (void *)PAGE_ALIGN((uintptr_t)buffer->data),
631 (void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK),
634 rb_erase(&buffer->rb_node, &alloc->allocated_buffers);
636 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
637 struct binder_buffer *next = binder_buffer_next(buffer);
640 rb_erase(&next->rb_node, &alloc->free_buffers);
641 binder_delete_free_buffer(alloc, next);
644 if (alloc->buffers.next != &buffer->entry) {
645 struct binder_buffer *prev = binder_buffer_prev(buffer);
648 binder_delete_free_buffer(alloc, buffer);
649 rb_erase(&prev->rb_node, &alloc->free_buffers);
653 binder_insert_free_buffer(alloc, buffer);
657 * binder_alloc_free_buf() - free a binder buffer
658 * @alloc: binder_alloc for this proc
659 * @buffer: kernel pointer to buffer
661 * Free the buffer allocated via binder_alloc_new_buffer()
663 void binder_alloc_free_buf(struct binder_alloc *alloc,
664 struct binder_buffer *buffer)
666 mutex_lock(&alloc->mutex);
667 binder_free_buf_locked(alloc, buffer);
668 mutex_unlock(&alloc->mutex);
672 * binder_alloc_mmap_handler() - map virtual address space for proc
673 * @alloc: alloc structure for this proc
674 * @vma: vma passed to mmap()
676 * Called by binder_mmap() to initialize the space specified in
677 * vma for allocating binder buffers
681 * -EBUSY = address space already mapped
682 * -ENOMEM = failed to map memory to given address space
684 int binder_alloc_mmap_handler(struct binder_alloc *alloc,
685 struct vm_area_struct *vma)
688 struct vm_struct *area;
689 const char *failure_string;
690 struct binder_buffer *buffer;
692 mutex_lock(&binder_alloc_mmap_lock);
695 failure_string = "already mapped";
696 goto err_already_mapped;
699 area = get_vm_area(vma->vm_end - vma->vm_start, VM_ALLOC);
702 failure_string = "get_vm_area";
703 goto err_get_vm_area_failed;
705 alloc->buffer = area->addr;
706 alloc->user_buffer_offset =
707 vma->vm_start - (uintptr_t)alloc->buffer;
708 mutex_unlock(&binder_alloc_mmap_lock);
710 #ifdef CONFIG_CPU_CACHE_VIPT
711 if (cache_is_vipt_aliasing()) {
713 (vma->vm_start ^ (uint32_t)alloc->buffer))) {
714 pr_info("%s: %d %lx-%lx maps %pK bad alignment\n",
715 __func__, alloc->pid, vma->vm_start,
716 vma->vm_end, alloc->buffer);
717 vma->vm_start += PAGE_SIZE;
721 alloc->pages = kzalloc(sizeof(alloc->pages[0]) *
722 ((vma->vm_end - vma->vm_start) / PAGE_SIZE),
724 if (alloc->pages == NULL) {
726 failure_string = "alloc page array";
727 goto err_alloc_pages_failed;
729 alloc->buffer_size = vma->vm_end - vma->vm_start;
731 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
734 failure_string = "alloc buffer struct";
735 goto err_alloc_buf_struct_failed;
738 buffer->data = alloc->buffer;
739 list_add(&buffer->entry, &alloc->buffers);
741 binder_insert_free_buffer(alloc, buffer);
742 alloc->free_async_space = alloc->buffer_size / 2;
743 binder_alloc_set_vma(alloc, vma);
744 mmgrab(alloc->vma_vm_mm);
748 err_alloc_buf_struct_failed:
751 err_alloc_pages_failed:
752 mutex_lock(&binder_alloc_mmap_lock);
753 vfree(alloc->buffer);
754 alloc->buffer = NULL;
755 err_get_vm_area_failed:
757 mutex_unlock(&binder_alloc_mmap_lock);
758 pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
759 alloc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
764 void binder_alloc_deferred_release(struct binder_alloc *alloc)
767 int buffers, page_count;
768 struct binder_buffer *buffer;
771 mutex_lock(&alloc->mutex);
774 while ((n = rb_first(&alloc->allocated_buffers))) {
775 buffer = rb_entry(n, struct binder_buffer, rb_node);
777 /* Transaction should already have been freed */
778 BUG_ON(buffer->transaction);
780 binder_free_buf_locked(alloc, buffer);
784 while (!list_empty(&alloc->buffers)) {
785 buffer = list_first_entry(&alloc->buffers,
786 struct binder_buffer, entry);
787 WARN_ON(!buffer->free);
789 list_del(&buffer->entry);
790 WARN_ON_ONCE(!list_empty(&alloc->buffers));
798 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
802 if (!alloc->pages[i].page_ptr)
805 on_lru = list_lru_del(&binder_alloc_lru,
806 &alloc->pages[i].lru);
807 page_addr = alloc->buffer + i * PAGE_SIZE;
808 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
809 "%s: %d: page %d at %pK %s\n",
810 __func__, alloc->pid, i, page_addr,
811 on_lru ? "on lru" : "active");
812 unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
813 __free_page(alloc->pages[i].page_ptr);
817 vfree(alloc->buffer);
819 mutex_unlock(&alloc->mutex);
820 if (alloc->vma_vm_mm)
821 mmdrop(alloc->vma_vm_mm);
823 binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
824 "%s: %d buffers %d, pages %d\n",
825 __func__, alloc->pid, buffers, page_count);
828 static void print_binder_buffer(struct seq_file *m, const char *prefix,
829 struct binder_buffer *buffer)
831 seq_printf(m, "%s %d: %pK size %zd:%zd:%zd %s\n",
832 prefix, buffer->debug_id, buffer->data,
833 buffer->data_size, buffer->offsets_size,
834 buffer->extra_buffers_size,
835 buffer->transaction ? "active" : "delivered");
839 * binder_alloc_print_allocated() - print buffer info
840 * @m: seq_file for output via seq_printf()
841 * @alloc: binder_alloc for this proc
843 * Prints information about every buffer associated with
844 * the binder_alloc state to the given seq_file
846 void binder_alloc_print_allocated(struct seq_file *m,
847 struct binder_alloc *alloc)
851 mutex_lock(&alloc->mutex);
852 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
853 print_binder_buffer(m, " buffer",
854 rb_entry(n, struct binder_buffer, rb_node));
855 mutex_unlock(&alloc->mutex);
859 * binder_alloc_print_pages() - print page usage
860 * @m: seq_file for output via seq_printf()
861 * @alloc: binder_alloc for this proc
863 void binder_alloc_print_pages(struct seq_file *m,
864 struct binder_alloc *alloc)
866 struct binder_lru_page *page;
872 mutex_lock(&alloc->mutex);
873 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
874 page = &alloc->pages[i];
877 else if (list_empty(&page->lru))
882 mutex_unlock(&alloc->mutex);
883 seq_printf(m, " pages: %d:%d:%d\n", active, lru, free);
887 * binder_alloc_get_allocated_count() - return count of buffers
888 * @alloc: binder_alloc for this proc
890 * Return: count of allocated buffers
892 int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
897 mutex_lock(&alloc->mutex);
898 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
900 mutex_unlock(&alloc->mutex);
906 * binder_alloc_vma_close() - invalidate address space
907 * @alloc: binder_alloc for this proc
909 * Called from binder_vma_close() when releasing address space.
910 * Clears alloc->vma to prevent new incoming transactions from
911 * allocating more buffers.
913 void binder_alloc_vma_close(struct binder_alloc *alloc)
915 binder_alloc_set_vma(alloc, NULL);
919 * binder_alloc_free_page() - shrinker callback to free pages
920 * @item: item to free
921 * @lock: lock protecting the item
922 * @cb_arg: callback argument
924 * Called from list_lru_walk() in binder_shrink_scan() to free
925 * up pages when the system is under memory pressure.
927 enum lru_status binder_alloc_free_page(struct list_head *item,
928 struct list_lru_one *lru,
932 struct mm_struct *mm = NULL;
933 struct binder_lru_page *page = container_of(item,
934 struct binder_lru_page,
936 struct binder_alloc *alloc;
939 struct vm_area_struct *vma;
942 if (!mutex_trylock(&alloc->mutex))
943 goto err_get_alloc_mutex_failed;
946 goto err_page_already_freed;
948 index = page - alloc->pages;
949 page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
951 mm = alloc->vma_vm_mm;
952 if (!mmget_not_zero(mm))
954 if (!down_read_trylock(&mm->mmap_sem))
955 goto err_down_read_mmap_sem_failed;
956 vma = binder_alloc_get_vma(alloc);
958 list_lru_isolate(lru, item);
962 trace_binder_unmap_user_start(alloc, index);
965 page_addr + alloc->user_buffer_offset,
968 trace_binder_unmap_user_end(alloc, index);
970 up_read(&mm->mmap_sem);
973 trace_binder_unmap_kernel_start(alloc, index);
975 unmap_kernel_range(page_addr, PAGE_SIZE);
976 __free_page(page->page_ptr);
977 page->page_ptr = NULL;
979 trace_binder_unmap_kernel_end(alloc, index);
982 mutex_unlock(&alloc->mutex);
983 return LRU_REMOVED_RETRY;
985 err_down_read_mmap_sem_failed:
988 err_page_already_freed:
989 mutex_unlock(&alloc->mutex);
990 err_get_alloc_mutex_failed:
995 binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
997 unsigned long ret = list_lru_count(&binder_alloc_lru);
1001 static unsigned long
1002 binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
1006 ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
1007 NULL, sc->nr_to_scan);
1011 struct shrinker binder_shrinker = {
1012 .count_objects = binder_shrink_count,
1013 .scan_objects = binder_shrink_scan,
1014 .seeks = DEFAULT_SEEKS,
1018 * binder_alloc_init() - called by binder_open() for per-proc initialization
1019 * @alloc: binder_alloc for this proc
1021 * Called from binder_open() to initialize binder_alloc fields for
1024 void binder_alloc_init(struct binder_alloc *alloc)
1026 alloc->pid = current->group_leader->pid;
1027 mutex_init(&alloc->mutex);
1028 INIT_LIST_HEAD(&alloc->buffers);
1031 void binder_alloc_shrinker_init(void)
1033 list_lru_init(&binder_alloc_lru);
1034 register_shrinker(&binder_shrinker);