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path: root/drivers/android/binder_alloc.c
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Diffstat (limited to 'drivers/android/binder_alloc.c')
-rw-r--r--drivers/android/binder_alloc.c42
1 files changed, 22 insertions, 20 deletions
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 8fe165844e47..c2819a3d58a6 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -215,17 +215,12 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
}
}
- if (!vma && need_mm)
- mm = get_task_mm(alloc->tsk);
+ if (!vma && need_mm && mmget_not_zero(alloc->vma_vm_mm))
+ mm = alloc->vma_vm_mm;
if (mm) {
down_write(&mm->mmap_sem);
vma = alloc->vma;
- if (vma && mm != alloc->vma_vm_mm) {
- pr_err("%d: vma mm and task mm mismatch\n",
- alloc->pid);
- vma = NULL;
- }
}
if (!vma && need_mm) {
@@ -565,7 +560,7 @@ static void binder_delete_free_buffer(struct binder_alloc *alloc,
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->data);
+ prev->data, next ? next->data : NULL);
binder_update_page_range(alloc, 0, buffer_start_page(buffer),
buffer_start_page(buffer) + PAGE_SIZE,
NULL);
@@ -720,6 +715,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
barrier();
alloc->vma = vma;
alloc->vma_vm_mm = vma->vm_mm;
+ mmgrab(alloc->vma_vm_mm);
return 0;
@@ -795,6 +791,8 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
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",
@@ -889,7 +887,6 @@ int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
void binder_alloc_vma_close(struct binder_alloc *alloc)
{
WRITE_ONCE(alloc->vma, NULL);
- WRITE_ONCE(alloc->vma_vm_mm, NULL);
}
/**
@@ -913,6 +910,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
struct binder_alloc *alloc;
uintptr_t page_addr;
size_t index;
+ struct vm_area_struct *vma;
alloc = page->alloc;
if (!mutex_trylock(&alloc->mutex))
@@ -923,16 +921,22 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
index = page - alloc->pages;
page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
- if (alloc->vma) {
- mm = get_task_mm(alloc->tsk);
- if (!mm)
- goto err_get_task_mm_failed;
+ vma = alloc->vma;
+ 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(alloc->vma,
+ zap_page_range(vma,
page_addr + alloc->user_buffer_offset,
PAGE_SIZE);
@@ -950,14 +954,13 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
trace_binder_unmap_kernel_end(alloc, index);
- list_lru_isolate(lru, item);
-
+ spin_lock(lock);
mutex_unlock(&alloc->mutex);
- return LRU_REMOVED;
+ return LRU_REMOVED_RETRY;
err_down_write_mmap_sem_failed:
- mmput(mm);
-err_get_task_mm_failed:
+ mmput_async(mm);
+err_mmget:
err_page_already_freed:
mutex_unlock(&alloc->mutex);
err_get_alloc_mutex_failed:
@@ -996,7 +999,6 @@ struct shrinker binder_shrinker = {
*/
void binder_alloc_init(struct binder_alloc *alloc)
{
- alloc->tsk = current->group_leader;
alloc->pid = current->group_leader->pid;
mutex_init(&alloc->mutex);
INIT_LIST_HEAD(&alloc->buffers);