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Copy pathbinder_alloc.c
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1188 lines (1034 loc) · 31.9 KB
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/* 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 <linux/uaccess.h>
#include <linux/highmem.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 alloc->buffer + alloc->buffer_size - buffer->user_data;
return binder_buffer_next(buffer)->user_data - buffer->user_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->user_data < buffer->user_data)
p = &parent->rb_left;
else if (new_buffer->user_data > buffer->user_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 __user *uptr;
uptr = (void __user *)user_ptr;
while (n) {
buffer = rb_entry(n, struct binder_buffer, rb_node);
BUG_ON(buffer->free);
if (uptr < buffer->user_data)
n = n->rb_left;
else if (uptr > buffer->user_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 __user *start, void __user *end)
{
void __user *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);
user_page_addr = (uintptr_t)page_addr;
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:
__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 __user *has_page_addr;
void __user *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 __user *)
(((uintptr_t)buffer->user_data + buffer_size) & PAGE_MASK);
WARN_ON(n && buffer_size != size);
end_page_addr =
(void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data + size);
if (end_page_addr > has_page_addr)
end_page_addr = has_page_addr;
ret = binder_update_page_range(alloc, 1, (void __user *)
PAGE_ALIGN((uintptr_t)buffer->user_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->user_data = (u8 __user *)buffer->user_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 __user *)
PAGE_ALIGN((uintptr_t)buffer->user_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 __user *buffer_start_page(struct binder_buffer *buffer)
{
return (void __user *)((uintptr_t)buffer->user_data & PAGE_MASK);
}
static void __user *prev_buffer_end_page(struct binder_buffer *buffer)
{
return (void __user *)
(((uintptr_t)(buffer->user_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->user_data,
prev->user_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->user_data,
next->user_data);
}
}
if (PAGE_ALIGNED(buffer->user_data)) {
binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
"%d: merge free, buffer start %pK is page aligned\n",
alloc->pid, buffer->user_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->user_data,
prev->user_data,
next ? next->user_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->user_data < alloc->buffer);
BUG_ON(buffer->user_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 __user *)PAGE_ALIGN((uintptr_t)buffer->user_data),
(void __user *)(((uintptr_t)
buffer->user_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;
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;
}
alloc->buffer = (void __user *)vma->vm_start;
mutex_unlock(&binder_alloc_mmap_lock);
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->user_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);
alloc->buffer = NULL;
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 __user *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");
__free_page(alloc->pages[i].page_ptr);
page_count++;
}
kfree(alloc->pages);
}
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->user_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)
__must_hold(lock)
{
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;
mm = alloc->vma_vm_mm;
if (!mmget_not_zero(mm))
goto err_mmget;
if (!down_read_trylock(&mm->mmap_sem))
goto err_down_read_mmap_sem_failed;
vma = binder_alloc_get_vma(alloc);
list_lru_isolate(lru, item);
spin_unlock(lock);
if (vma) {
trace_binder_unmap_user_start(alloc, index);
zap_page_range(vma, page_addr, PAGE_SIZE);
trace_binder_unmap_user_end(alloc, index);
}
up_read(&mm->mmap_sem);
mmput(mm);
trace_binder_unmap_kernel_start(alloc, index);
__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_read_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
*/
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