v4.19.13 snapshot.
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
new file mode 100644
index 0000000..030c98f
--- /dev/null
+++ b/drivers/android/binder_alloc.c
@@ -0,0 +1,1054 @@
+/* binder_alloc.c
+ *
+ * Android IPC Subsystem
+ *
+ * Copyright (C) 2007-2017 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/list.h>
+#include <linux/sched/mm.h>
+#include <linux/module.h>
+#include <linux/rtmutex.h>
+#include <linux/rbtree.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/list_lru.h>
+#include <linux/ratelimit.h>
+#include <asm/cacheflush.h>
+#include "binder_alloc.h"
+#include "binder_trace.h"
+
+struct list_lru binder_alloc_lru;
+
+static DEFINE_MUTEX(binder_alloc_mmap_lock);
+
+enum {
+ BINDER_DEBUG_USER_ERROR = 1U << 0,
+ BINDER_DEBUG_OPEN_CLOSE = 1U << 1,
+ BINDER_DEBUG_BUFFER_ALLOC = 1U << 2,
+ BINDER_DEBUG_BUFFER_ALLOC_ASYNC = 1U << 3,
+};
+static uint32_t binder_alloc_debug_mask = BINDER_DEBUG_USER_ERROR;
+
+module_param_named(debug_mask, binder_alloc_debug_mask,
+ uint, 0644);
+
+#define binder_alloc_debug(mask, x...) \
+ do { \
+ if (binder_alloc_debug_mask & mask) \
+ pr_info_ratelimited(x); \
+ } while (0)
+
+static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer)
+{
+ return list_entry(buffer->entry.next, struct binder_buffer, entry);
+}
+
+static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer)
+{
+ return list_entry(buffer->entry.prev, struct binder_buffer, entry);
+}
+
+static size_t binder_alloc_buffer_size(struct binder_alloc *alloc,
+ struct binder_buffer *buffer)
+{
+ if (list_is_last(&buffer->entry, &alloc->buffers))
+ return (u8 *)alloc->buffer +
+ alloc->buffer_size - (u8 *)buffer->data;
+ return (u8 *)binder_buffer_next(buffer)->data - (u8 *)buffer->data;
+}
+
+static void binder_insert_free_buffer(struct binder_alloc *alloc,
+ struct binder_buffer *new_buffer)
+{
+ struct rb_node **p = &alloc->free_buffers.rb_node;
+ struct rb_node *parent = NULL;
+ struct binder_buffer *buffer;
+ size_t buffer_size;
+ size_t new_buffer_size;
+
+ BUG_ON(!new_buffer->free);
+
+ new_buffer_size = binder_alloc_buffer_size(alloc, new_buffer);
+
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: add free buffer, size %zd, at %pK\n",
+ alloc->pid, new_buffer_size, new_buffer);
+
+ while (*p) {
+ parent = *p;
+ buffer = rb_entry(parent, struct binder_buffer, rb_node);
+ BUG_ON(!buffer->free);
+
+ buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+ if (new_buffer_size < buffer_size)
+ p = &parent->rb_left;
+ else
+ p = &parent->rb_right;
+ }
+ rb_link_node(&new_buffer->rb_node, parent, p);
+ rb_insert_color(&new_buffer->rb_node, &alloc->free_buffers);
+}
+
+static void binder_insert_allocated_buffer_locked(
+ struct binder_alloc *alloc, struct binder_buffer *new_buffer)
+{
+ struct rb_node **p = &alloc->allocated_buffers.rb_node;
+ struct rb_node *parent = NULL;
+ struct binder_buffer *buffer;
+
+ BUG_ON(new_buffer->free);
+
+ while (*p) {
+ parent = *p;
+ buffer = rb_entry(parent, struct binder_buffer, rb_node);
+ BUG_ON(buffer->free);
+
+ if (new_buffer->data < buffer->data)
+ p = &parent->rb_left;
+ else if (new_buffer->data > buffer->data)
+ p = &parent->rb_right;
+ else
+ BUG();
+ }
+ rb_link_node(&new_buffer->rb_node, parent, p);
+ rb_insert_color(&new_buffer->rb_node, &alloc->allocated_buffers);
+}
+
+static struct binder_buffer *binder_alloc_prepare_to_free_locked(
+ struct binder_alloc *alloc,
+ uintptr_t user_ptr)
+{
+ struct rb_node *n = alloc->allocated_buffers.rb_node;
+ struct binder_buffer *buffer;
+ void *kern_ptr;
+
+ kern_ptr = (void *)(user_ptr - alloc->user_buffer_offset);
+
+ while (n) {
+ buffer = rb_entry(n, struct binder_buffer, rb_node);
+ BUG_ON(buffer->free);
+
+ if (kern_ptr < buffer->data)
+ n = n->rb_left;
+ else if (kern_ptr > buffer->data)
+ n = n->rb_right;
+ else {
+ /*
+ * Guard against user threads attempting to
+ * free the buffer when in use by kernel or
+ * after it's already been freed.
+ */
+ if (!buffer->allow_user_free)
+ return ERR_PTR(-EPERM);
+ buffer->allow_user_free = 0;
+ return buffer;
+ }
+ }
+ return NULL;
+}
+
+/**
+ * binder_alloc_buffer_lookup() - get buffer given user ptr
+ * @alloc: binder_alloc for this proc
+ * @user_ptr: User pointer to buffer data
+ *
+ * Validate userspace pointer to buffer data and return buffer corresponding to
+ * that user pointer. Search the rb tree for buffer that matches user data
+ * pointer.
+ *
+ * Return: Pointer to buffer or NULL
+ */
+struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc,
+ uintptr_t user_ptr)
+{
+ struct binder_buffer *buffer;
+
+ mutex_lock(&alloc->mutex);
+ buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr);
+ mutex_unlock(&alloc->mutex);
+ return buffer;
+}
+
+static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
+ void *start, void *end)
+{
+ void *page_addr;
+ unsigned long user_page_addr;
+ struct binder_lru_page *page;
+ struct vm_area_struct *vma = NULL;
+ struct mm_struct *mm = NULL;
+ bool need_mm = false;
+
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: %s pages %pK-%pK\n", alloc->pid,
+ allocate ? "allocate" : "free", start, end);
+
+ if (end <= start)
+ return 0;
+
+ trace_binder_update_page_range(alloc, allocate, start, end);
+
+ if (allocate == 0)
+ goto free_range;
+
+ for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
+ page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE];
+ if (!page->page_ptr) {
+ need_mm = true;
+ break;
+ }
+ }
+
+ if (need_mm && mmget_not_zero(alloc->vma_vm_mm))
+ mm = alloc->vma_vm_mm;
+
+ if (mm) {
+ down_read(&mm->mmap_sem);
+ vma = alloc->vma;
+ }
+
+ if (!vma && need_mm) {
+ binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+ "%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
+ alloc->pid);
+ goto err_no_vma;
+ }
+
+ for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
+ int ret;
+ bool on_lru;
+ size_t index;
+
+ index = (page_addr - alloc->buffer) / PAGE_SIZE;
+ page = &alloc->pages[index];
+
+ if (page->page_ptr) {
+ trace_binder_alloc_lru_start(alloc, index);
+
+ on_lru = list_lru_del(&binder_alloc_lru, &page->lru);
+ WARN_ON(!on_lru);
+
+ trace_binder_alloc_lru_end(alloc, index);
+ continue;
+ }
+
+ if (WARN_ON(!vma))
+ goto err_page_ptr_cleared;
+
+ trace_binder_alloc_page_start(alloc, index);
+ page->page_ptr = alloc_page(GFP_KERNEL |
+ __GFP_HIGHMEM |
+ __GFP_ZERO);
+ if (!page->page_ptr) {
+ pr_err("%d: binder_alloc_buf failed for page at %pK\n",
+ alloc->pid, page_addr);
+ goto err_alloc_page_failed;
+ }
+ page->alloc = alloc;
+ INIT_LIST_HEAD(&page->lru);
+
+ ret = map_kernel_range_noflush((unsigned long)page_addr,
+ PAGE_SIZE, PAGE_KERNEL,
+ &page->page_ptr);
+ flush_cache_vmap((unsigned long)page_addr,
+ (unsigned long)page_addr + PAGE_SIZE);
+ if (ret != 1) {
+ pr_err("%d: binder_alloc_buf failed to map page at %pK in kernel\n",
+ alloc->pid, page_addr);
+ goto err_map_kernel_failed;
+ }
+ user_page_addr =
+ (uintptr_t)page_addr + alloc->user_buffer_offset;
+ ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr);
+ if (ret) {
+ pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n",
+ alloc->pid, user_page_addr);
+ goto err_vm_insert_page_failed;
+ }
+
+ if (index + 1 > alloc->pages_high)
+ alloc->pages_high = index + 1;
+
+ trace_binder_alloc_page_end(alloc, index);
+ /* vm_insert_page does not seem to increment the refcount */
+ }
+ if (mm) {
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ }
+ return 0;
+
+free_range:
+ for (page_addr = end - PAGE_SIZE; page_addr >= start;
+ page_addr -= PAGE_SIZE) {
+ bool ret;
+ size_t index;
+
+ index = (page_addr - alloc->buffer) / PAGE_SIZE;
+ page = &alloc->pages[index];
+
+ trace_binder_free_lru_start(alloc, index);
+
+ ret = list_lru_add(&binder_alloc_lru, &page->lru);
+ WARN_ON(!ret);
+
+ trace_binder_free_lru_end(alloc, index);
+ continue;
+
+err_vm_insert_page_failed:
+ unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
+err_map_kernel_failed:
+ __free_page(page->page_ptr);
+ page->page_ptr = NULL;
+err_alloc_page_failed:
+err_page_ptr_cleared:
+ ;
+ }
+err_no_vma:
+ if (mm) {
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ }
+ return vma ? -ENOMEM : -ESRCH;
+}
+
+
+static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
+ struct vm_area_struct *vma)
+{
+ if (vma)
+ alloc->vma_vm_mm = vma->vm_mm;
+ /*
+ * If we see alloc->vma is not NULL, buffer data structures set up
+ * completely. Look at smp_rmb side binder_alloc_get_vma.
+ * We also want to guarantee new alloc->vma_vm_mm is always visible
+ * if alloc->vma is set.
+ */
+ smp_wmb();
+ alloc->vma = vma;
+}
+
+static inline struct vm_area_struct *binder_alloc_get_vma(
+ struct binder_alloc *alloc)
+{
+ struct vm_area_struct *vma = NULL;
+
+ if (alloc->vma) {
+ /* Look at description in binder_alloc_set_vma */
+ smp_rmb();
+ vma = alloc->vma;
+ }
+ return vma;
+}
+
+static struct binder_buffer *binder_alloc_new_buf_locked(
+ struct binder_alloc *alloc,
+ size_t data_size,
+ size_t offsets_size,
+ size_t extra_buffers_size,
+ int is_async)
+{
+ struct rb_node *n = alloc->free_buffers.rb_node;
+ struct binder_buffer *buffer;
+ size_t buffer_size;
+ struct rb_node *best_fit = NULL;
+ void *has_page_addr;
+ void *end_page_addr;
+ size_t size, data_offsets_size;
+ int ret;
+
+ if (!binder_alloc_get_vma(alloc)) {
+ binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+ "%d: binder_alloc_buf, no vma\n",
+ alloc->pid);
+ return ERR_PTR(-ESRCH);
+ }
+
+ data_offsets_size = ALIGN(data_size, sizeof(void *)) +
+ ALIGN(offsets_size, sizeof(void *));
+
+ if (data_offsets_size < data_size || data_offsets_size < offsets_size) {
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: got transaction with invalid size %zd-%zd\n",
+ alloc->pid, data_size, offsets_size);
+ return ERR_PTR(-EINVAL);
+ }
+ size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *));
+ if (size < data_offsets_size || size < extra_buffers_size) {
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: got transaction with invalid extra_buffers_size %zd\n",
+ alloc->pid, extra_buffers_size);
+ return ERR_PTR(-EINVAL);
+ }
+ if (is_async &&
+ alloc->free_async_space < size + sizeof(struct binder_buffer)) {
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: binder_alloc_buf size %zd failed, no async space left\n",
+ alloc->pid, size);
+ return ERR_PTR(-ENOSPC);
+ }
+
+ /* Pad 0-size buffers so they get assigned unique addresses */
+ size = max(size, sizeof(void *));
+
+ while (n) {
+ buffer = rb_entry(n, struct binder_buffer, rb_node);
+ BUG_ON(!buffer->free);
+ buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+ if (size < buffer_size) {
+ best_fit = n;
+ n = n->rb_left;
+ } else if (size > buffer_size)
+ n = n->rb_right;
+ else {
+ best_fit = n;
+ break;
+ }
+ }
+ if (best_fit == NULL) {
+ size_t allocated_buffers = 0;
+ size_t largest_alloc_size = 0;
+ size_t total_alloc_size = 0;
+ size_t free_buffers = 0;
+ size_t largest_free_size = 0;
+ size_t total_free_size = 0;
+
+ for (n = rb_first(&alloc->allocated_buffers); n != NULL;
+ n = rb_next(n)) {
+ buffer = rb_entry(n, struct binder_buffer, rb_node);
+ buffer_size = binder_alloc_buffer_size(alloc, buffer);
+ allocated_buffers++;
+ total_alloc_size += buffer_size;
+ if (buffer_size > largest_alloc_size)
+ largest_alloc_size = buffer_size;
+ }
+ for (n = rb_first(&alloc->free_buffers); n != NULL;
+ n = rb_next(n)) {
+ buffer = rb_entry(n, struct binder_buffer, rb_node);
+ buffer_size = binder_alloc_buffer_size(alloc, buffer);
+ free_buffers++;
+ total_free_size += buffer_size;
+ if (buffer_size > largest_free_size)
+ largest_free_size = buffer_size;
+ }
+ binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+ "%d: binder_alloc_buf size %zd failed, no address space\n",
+ alloc->pid, size);
+ binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+ "allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
+ total_alloc_size, allocated_buffers,
+ largest_alloc_size, total_free_size,
+ free_buffers, largest_free_size);
+ return ERR_PTR(-ENOSPC);
+ }
+ if (n == NULL) {
+ buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
+ buffer_size = binder_alloc_buffer_size(alloc, buffer);
+ }
+
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n",
+ alloc->pid, size, buffer, buffer_size);
+
+ has_page_addr =
+ (void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK);
+ WARN_ON(n && buffer_size != size);
+ end_page_addr =
+ (void *)PAGE_ALIGN((uintptr_t)buffer->data + size);
+ if (end_page_addr > has_page_addr)
+ end_page_addr = has_page_addr;
+ ret = binder_update_page_range(alloc, 1,
+ (void *)PAGE_ALIGN((uintptr_t)buffer->data), end_page_addr);
+ if (ret)
+ return ERR_PTR(ret);
+
+ if (buffer_size != size) {
+ struct binder_buffer *new_buffer;
+
+ new_buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+ if (!new_buffer) {
+ pr_err("%s: %d failed to alloc new buffer struct\n",
+ __func__, alloc->pid);
+ goto err_alloc_buf_struct_failed;
+ }
+ new_buffer->data = (u8 *)buffer->data + size;
+ list_add(&new_buffer->entry, &buffer->entry);
+ new_buffer->free = 1;
+ binder_insert_free_buffer(alloc, new_buffer);
+ }
+
+ rb_erase(best_fit, &alloc->free_buffers);
+ buffer->free = 0;
+ buffer->allow_user_free = 0;
+ binder_insert_allocated_buffer_locked(alloc, buffer);
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: binder_alloc_buf size %zd got %pK\n",
+ alloc->pid, size, buffer);
+ buffer->data_size = data_size;
+ buffer->offsets_size = offsets_size;
+ buffer->async_transaction = is_async;
+ buffer->extra_buffers_size = extra_buffers_size;
+ if (is_async) {
+ alloc->free_async_space -= size + sizeof(struct binder_buffer);
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
+ "%d: binder_alloc_buf size %zd async free %zd\n",
+ alloc->pid, size, alloc->free_async_space);
+ }
+ return buffer;
+
+err_alloc_buf_struct_failed:
+ binder_update_page_range(alloc, 0,
+ (void *)PAGE_ALIGN((uintptr_t)buffer->data),
+ end_page_addr);
+ return ERR_PTR(-ENOMEM);
+}
+
+/**
+ * binder_alloc_new_buf() - Allocate a new binder buffer
+ * @alloc: binder_alloc for this proc
+ * @data_size: size of user data buffer
+ * @offsets_size: user specified buffer offset
+ * @extra_buffers_size: size of extra space for meta-data (eg, security context)
+ * @is_async: buffer for async transaction
+ *
+ * Allocate a new buffer given the requested sizes. Returns
+ * the kernel version of the buffer pointer. The size allocated
+ * is the sum of the three given sizes (each rounded up to
+ * pointer-sized boundary)
+ *
+ * Return: The allocated buffer or %NULL if error
+ */
+struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
+ size_t data_size,
+ size_t offsets_size,
+ size_t extra_buffers_size,
+ int is_async)
+{
+ struct binder_buffer *buffer;
+
+ mutex_lock(&alloc->mutex);
+ buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size,
+ extra_buffers_size, is_async);
+ mutex_unlock(&alloc->mutex);
+ return buffer;
+}
+
+static void *buffer_start_page(struct binder_buffer *buffer)
+{
+ return (void *)((uintptr_t)buffer->data & PAGE_MASK);
+}
+
+static void *prev_buffer_end_page(struct binder_buffer *buffer)
+{
+ return (void *)(((uintptr_t)(buffer->data) - 1) & PAGE_MASK);
+}
+
+static void binder_delete_free_buffer(struct binder_alloc *alloc,
+ struct binder_buffer *buffer)
+{
+ struct binder_buffer *prev, *next = NULL;
+ bool to_free = true;
+ BUG_ON(alloc->buffers.next == &buffer->entry);
+ prev = binder_buffer_prev(buffer);
+ BUG_ON(!prev->free);
+ if (prev_buffer_end_page(prev) == buffer_start_page(buffer)) {
+ to_free = false;
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: merge free, buffer %pK share page with %pK\n",
+ alloc->pid, buffer->data, prev->data);
+ }
+
+ if (!list_is_last(&buffer->entry, &alloc->buffers)) {
+ next = binder_buffer_next(buffer);
+ if (buffer_start_page(next) == buffer_start_page(buffer)) {
+ to_free = false;
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: merge free, buffer %pK share page with %pK\n",
+ alloc->pid,
+ buffer->data,
+ next->data);
+ }
+ }
+
+ if (PAGE_ALIGNED(buffer->data)) {
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: merge free, buffer start %pK is page aligned\n",
+ alloc->pid, buffer->data);
+ to_free = false;
+ }
+
+ if (to_free) {
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: merge free, buffer %pK do not share page with %pK or %pK\n",
+ alloc->pid, buffer->data,
+ prev->data, next ? next->data : NULL);
+ binder_update_page_range(alloc, 0, buffer_start_page(buffer),
+ buffer_start_page(buffer) + PAGE_SIZE);
+ }
+ list_del(&buffer->entry);
+ kfree(buffer);
+}
+
+static void binder_free_buf_locked(struct binder_alloc *alloc,
+ struct binder_buffer *buffer)
+{
+ size_t size, buffer_size;
+
+ buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+ size = ALIGN(buffer->data_size, sizeof(void *)) +
+ ALIGN(buffer->offsets_size, sizeof(void *)) +
+ ALIGN(buffer->extra_buffers_size, sizeof(void *));
+
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%d: binder_free_buf %pK size %zd buffer_size %zd\n",
+ alloc->pid, buffer, size, buffer_size);
+
+ BUG_ON(buffer->free);
+ BUG_ON(size > buffer_size);
+ BUG_ON(buffer->transaction != NULL);
+ BUG_ON(buffer->data < alloc->buffer);
+ BUG_ON(buffer->data > alloc->buffer + alloc->buffer_size);
+
+ if (buffer->async_transaction) {
+ alloc->free_async_space += size + sizeof(struct binder_buffer);
+
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
+ "%d: binder_free_buf size %zd async free %zd\n",
+ alloc->pid, size, alloc->free_async_space);
+ }
+
+ binder_update_page_range(alloc, 0,
+ (void *)PAGE_ALIGN((uintptr_t)buffer->data),
+ (void *)(((uintptr_t)buffer->data + buffer_size) & PAGE_MASK));
+
+ rb_erase(&buffer->rb_node, &alloc->allocated_buffers);
+ buffer->free = 1;
+ if (!list_is_last(&buffer->entry, &alloc->buffers)) {
+ struct binder_buffer *next = binder_buffer_next(buffer);
+
+ if (next->free) {
+ rb_erase(&next->rb_node, &alloc->free_buffers);
+ binder_delete_free_buffer(alloc, next);
+ }
+ }
+ if (alloc->buffers.next != &buffer->entry) {
+ struct binder_buffer *prev = binder_buffer_prev(buffer);
+
+ if (prev->free) {
+ binder_delete_free_buffer(alloc, buffer);
+ rb_erase(&prev->rb_node, &alloc->free_buffers);
+ buffer = prev;
+ }
+ }
+ binder_insert_free_buffer(alloc, buffer);
+}
+
+/**
+ * binder_alloc_free_buf() - free a binder buffer
+ * @alloc: binder_alloc for this proc
+ * @buffer: kernel pointer to buffer
+ *
+ * Free the buffer allocated via binder_alloc_new_buffer()
+ */
+void binder_alloc_free_buf(struct binder_alloc *alloc,
+ struct binder_buffer *buffer)
+{
+ mutex_lock(&alloc->mutex);
+ binder_free_buf_locked(alloc, buffer);
+ mutex_unlock(&alloc->mutex);
+}
+
+/**
+ * binder_alloc_mmap_handler() - map virtual address space for proc
+ * @alloc: alloc structure for this proc
+ * @vma: vma passed to mmap()
+ *
+ * Called by binder_mmap() to initialize the space specified in
+ * vma for allocating binder buffers
+ *
+ * Return:
+ * 0 = success
+ * -EBUSY = address space already mapped
+ * -ENOMEM = failed to map memory to given address space
+ */
+int binder_alloc_mmap_handler(struct binder_alloc *alloc,
+ struct vm_area_struct *vma)
+{
+ int ret;
+ struct vm_struct *area;
+ const char *failure_string;
+ struct binder_buffer *buffer;
+
+ mutex_lock(&binder_alloc_mmap_lock);
+ if (alloc->buffer) {
+ ret = -EBUSY;
+ failure_string = "already mapped";
+ goto err_already_mapped;
+ }
+
+ area = get_vm_area(vma->vm_end - vma->vm_start, VM_ALLOC);
+ if (area == NULL) {
+ ret = -ENOMEM;
+ failure_string = "get_vm_area";
+ goto err_get_vm_area_failed;
+ }
+ alloc->buffer = area->addr;
+ alloc->user_buffer_offset =
+ vma->vm_start - (uintptr_t)alloc->buffer;
+ mutex_unlock(&binder_alloc_mmap_lock);
+
+#ifdef CONFIG_CPU_CACHE_VIPT
+ if (cache_is_vipt_aliasing()) {
+ while (CACHE_COLOUR(
+ (vma->vm_start ^ (uint32_t)alloc->buffer))) {
+ pr_info("%s: %d %lx-%lx maps %pK bad alignment\n",
+ __func__, alloc->pid, vma->vm_start,
+ vma->vm_end, alloc->buffer);
+ vma->vm_start += PAGE_SIZE;
+ }
+ }
+#endif
+ alloc->pages = kcalloc((vma->vm_end - vma->vm_start) / PAGE_SIZE,
+ sizeof(alloc->pages[0]),
+ GFP_KERNEL);
+ if (alloc->pages == NULL) {
+ ret = -ENOMEM;
+ failure_string = "alloc page array";
+ goto err_alloc_pages_failed;
+ }
+ alloc->buffer_size = vma->vm_end - vma->vm_start;
+
+ buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+ if (!buffer) {
+ ret = -ENOMEM;
+ failure_string = "alloc buffer struct";
+ goto err_alloc_buf_struct_failed;
+ }
+
+ buffer->data = alloc->buffer;
+ list_add(&buffer->entry, &alloc->buffers);
+ buffer->free = 1;
+ binder_insert_free_buffer(alloc, buffer);
+ alloc->free_async_space = alloc->buffer_size / 2;
+ binder_alloc_set_vma(alloc, vma);
+ mmgrab(alloc->vma_vm_mm);
+
+ return 0;
+
+err_alloc_buf_struct_failed:
+ kfree(alloc->pages);
+ alloc->pages = NULL;
+err_alloc_pages_failed:
+ mutex_lock(&binder_alloc_mmap_lock);
+ vfree(alloc->buffer);
+ alloc->buffer = NULL;
+err_get_vm_area_failed:
+err_already_mapped:
+ mutex_unlock(&binder_alloc_mmap_lock);
+ binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+ "%s: %d %lx-%lx %s failed %d\n", __func__,
+ alloc->pid, vma->vm_start, vma->vm_end,
+ failure_string, ret);
+ return ret;
+}
+
+
+void binder_alloc_deferred_release(struct binder_alloc *alloc)
+{
+ struct rb_node *n;
+ int buffers, page_count;
+ struct binder_buffer *buffer;
+
+ buffers = 0;
+ mutex_lock(&alloc->mutex);
+ BUG_ON(alloc->vma);
+
+ while ((n = rb_first(&alloc->allocated_buffers))) {
+ buffer = rb_entry(n, struct binder_buffer, rb_node);
+
+ /* Transaction should already have been freed */
+ BUG_ON(buffer->transaction);
+
+ binder_free_buf_locked(alloc, buffer);
+ buffers++;
+ }
+
+ while (!list_empty(&alloc->buffers)) {
+ buffer = list_first_entry(&alloc->buffers,
+ struct binder_buffer, entry);
+ WARN_ON(!buffer->free);
+
+ list_del(&buffer->entry);
+ WARN_ON_ONCE(!list_empty(&alloc->buffers));
+ kfree(buffer);
+ }
+
+ page_count = 0;
+ if (alloc->pages) {
+ int i;
+
+ for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+ void *page_addr;
+ bool on_lru;
+
+ if (!alloc->pages[i].page_ptr)
+ continue;
+
+ on_lru = list_lru_del(&binder_alloc_lru,
+ &alloc->pages[i].lru);
+ page_addr = alloc->buffer + i * PAGE_SIZE;
+ binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+ "%s: %d: page %d at %pK %s\n",
+ __func__, alloc->pid, i, page_addr,
+ on_lru ? "on lru" : "active");
+ unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
+ __free_page(alloc->pages[i].page_ptr);
+ page_count++;
+ }
+ kfree(alloc->pages);
+ vfree(alloc->buffer);
+ }
+ mutex_unlock(&alloc->mutex);
+ if (alloc->vma_vm_mm)
+ mmdrop(alloc->vma_vm_mm);
+
+ binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
+ "%s: %d buffers %d, pages %d\n",
+ __func__, alloc->pid, buffers, page_count);
+}
+
+static void print_binder_buffer(struct seq_file *m, const char *prefix,
+ struct binder_buffer *buffer)
+{
+ seq_printf(m, "%s %d: %pK size %zd:%zd:%zd %s\n",
+ prefix, buffer->debug_id, buffer->data,
+ buffer->data_size, buffer->offsets_size,
+ buffer->extra_buffers_size,
+ buffer->transaction ? "active" : "delivered");
+}
+
+/**
+ * binder_alloc_print_allocated() - print buffer info
+ * @m: seq_file for output via seq_printf()
+ * @alloc: binder_alloc for this proc
+ *
+ * Prints information about every buffer associated with
+ * the binder_alloc state to the given seq_file
+ */
+void binder_alloc_print_allocated(struct seq_file *m,
+ struct binder_alloc *alloc)
+{
+ struct rb_node *n;
+
+ mutex_lock(&alloc->mutex);
+ for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
+ print_binder_buffer(m, " buffer",
+ rb_entry(n, struct binder_buffer, rb_node));
+ mutex_unlock(&alloc->mutex);
+}
+
+/**
+ * binder_alloc_print_pages() - print page usage
+ * @m: seq_file for output via seq_printf()
+ * @alloc: binder_alloc for this proc
+ */
+void binder_alloc_print_pages(struct seq_file *m,
+ struct binder_alloc *alloc)
+{
+ struct binder_lru_page *page;
+ int i;
+ int active = 0;
+ int lru = 0;
+ int free = 0;
+
+ mutex_lock(&alloc->mutex);
+ for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+ page = &alloc->pages[i];
+ if (!page->page_ptr)
+ free++;
+ else if (list_empty(&page->lru))
+ active++;
+ else
+ lru++;
+ }
+ mutex_unlock(&alloc->mutex);
+ seq_printf(m, " pages: %d:%d:%d\n", active, lru, free);
+ seq_printf(m, " pages high watermark: %zu\n", alloc->pages_high);
+}
+
+/**
+ * binder_alloc_get_allocated_count() - return count of buffers
+ * @alloc: binder_alloc for this proc
+ *
+ * Return: count of allocated buffers
+ */
+int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
+{
+ struct rb_node *n;
+ int count = 0;
+
+ mutex_lock(&alloc->mutex);
+ for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
+ count++;
+ mutex_unlock(&alloc->mutex);
+ return count;
+}
+
+
+/**
+ * binder_alloc_vma_close() - invalidate address space
+ * @alloc: binder_alloc for this proc
+ *
+ * Called from binder_vma_close() when releasing address space.
+ * Clears alloc->vma to prevent new incoming transactions from
+ * allocating more buffers.
+ */
+void binder_alloc_vma_close(struct binder_alloc *alloc)
+{
+ binder_alloc_set_vma(alloc, NULL);
+}
+
+/**
+ * binder_alloc_free_page() - shrinker callback to free pages
+ * @item: item to free
+ * @lock: lock protecting the item
+ * @cb_arg: callback argument
+ *
+ * Called from list_lru_walk() in binder_shrink_scan() to free
+ * up pages when the system is under memory pressure.
+ */
+enum lru_status binder_alloc_free_page(struct list_head *item,
+ struct list_lru_one *lru,
+ spinlock_t *lock,
+ void *cb_arg)
+{
+ struct mm_struct *mm = NULL;
+ struct binder_lru_page *page = container_of(item,
+ struct binder_lru_page,
+ lru);
+ struct binder_alloc *alloc;
+ uintptr_t page_addr;
+ size_t index;
+ struct vm_area_struct *vma;
+
+ alloc = page->alloc;
+ if (!mutex_trylock(&alloc->mutex))
+ goto err_get_alloc_mutex_failed;
+
+ if (!page->page_ptr)
+ goto err_page_already_freed;
+
+ index = page - alloc->pages;
+ page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
+ vma = binder_alloc_get_vma(alloc);
+ if (vma) {
+ if (!mmget_not_zero(alloc->vma_vm_mm))
+ goto err_mmget;
+ mm = alloc->vma_vm_mm;
+ if (!down_write_trylock(&mm->mmap_sem))
+ goto err_down_write_mmap_sem_failed;
+ }
+
+ list_lru_isolate(lru, item);
+ spin_unlock(lock);
+
+ if (vma) {
+ trace_binder_unmap_user_start(alloc, index);
+
+ zap_page_range(vma,
+ page_addr + alloc->user_buffer_offset,
+ PAGE_SIZE);
+
+ trace_binder_unmap_user_end(alloc, index);
+
+ up_write(&mm->mmap_sem);
+ mmput(mm);
+ }
+
+ trace_binder_unmap_kernel_start(alloc, index);
+
+ unmap_kernel_range(page_addr, PAGE_SIZE);
+ __free_page(page->page_ptr);
+ page->page_ptr = NULL;
+
+ trace_binder_unmap_kernel_end(alloc, index);
+
+ spin_lock(lock);
+ mutex_unlock(&alloc->mutex);
+ return LRU_REMOVED_RETRY;
+
+err_down_write_mmap_sem_failed:
+ mmput_async(mm);
+err_mmget:
+err_page_already_freed:
+ mutex_unlock(&alloc->mutex);
+err_get_alloc_mutex_failed:
+ return LRU_SKIP;
+}
+
+static unsigned long
+binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ unsigned long ret = list_lru_count(&binder_alloc_lru);
+ return ret;
+}
+
+static unsigned long
+binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ unsigned long ret;
+
+ ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
+ NULL, sc->nr_to_scan);
+ return ret;
+}
+
+static struct shrinker binder_shrinker = {
+ .count_objects = binder_shrink_count,
+ .scan_objects = binder_shrink_scan,
+ .seeks = DEFAULT_SEEKS,
+};
+
+/**
+ * binder_alloc_init() - called by binder_open() for per-proc initialization
+ * @alloc: binder_alloc for this proc
+ *
+ * Called from binder_open() to initialize binder_alloc fields for
+ * new binder proc
+ */
+void binder_alloc_init(struct binder_alloc *alloc)
+{
+ alloc->pid = current->group_leader->pid;
+ mutex_init(&alloc->mutex);
+ INIT_LIST_HEAD(&alloc->buffers);
+}
+
+int binder_alloc_shrinker_init(void)
+{
+ int ret = list_lru_init(&binder_alloc_lru);
+
+ if (ret == 0) {
+ ret = register_shrinker(&binder_shrinker);
+ if (ret)
+ list_lru_destroy(&binder_alloc_lru);
+ }
+ return ret;
+}