diff options
| -rw-r--r-- | drivers/android/binder_alloc.c | 25 | ||||
| -rw-r--r-- | drivers/android/binder_alloc.h | 1 |
2 files changed, 12 insertions, 14 deletions
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index cfc3f5664015..b95da16fd938 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -215,17 +215,13 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate, } } - if (need_mm) - mm = get_task_mm(alloc->tsk); + /* Same as mmget_not_zero() in later kernel versions */ + if (need_mm && atomic_inc_not_zero(&alloc->vma_vm_mm->mm_users)) + 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) { @@ -718,6 +714,8 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc, barrier(); alloc->vma = vma; alloc->vma_vm_mm = vma->vm_mm; + /* Same as mmgrab() in later kernel versions */ + atomic_inc(&alloc->vma_vm_mm->mm_count); return 0; @@ -793,6 +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", @@ -887,7 +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); } /** @@ -924,9 +923,10 @@ enum lru_status binder_alloc_free_page(struct list_head *item, page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE; vma = alloc->vma; if (vma) { - mm = get_task_mm(alloc->tsk); - if (!mm) - goto err_get_task_mm_failed; + /* Same as mmget_not_zero() in later kernel versions */ + if (!atomic_inc_not_zero(&alloc->vma_vm_mm->mm_users)) + goto err_mmget; + mm = alloc->vma_vm_mm; if (!down_write_trylock(&mm->mmap_sem)) goto err_down_write_mmap_sem_failed; } @@ -962,7 +962,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item, err_down_write_mmap_sem_failed: mmput_async(mm); -err_get_task_mm_failed: +err_mmget: err_page_already_freed: mutex_unlock(&alloc->mutex); err_get_alloc_mutex_failed: @@ -1001,7 +1001,6 @@ 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); diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h index a3a3602c689c..2dd33b6df104 100644 --- a/drivers/android/binder_alloc.h +++ b/drivers/android/binder_alloc.h @@ -100,7 +100,6 @@ struct binder_lru_page { */ struct binder_alloc { struct mutex mutex; - struct task_struct *tsk; struct vm_area_struct *vma; struct mm_struct *vma_vm_mm; void *buffer; |