}
}
- 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) {
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;
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",
void binder_alloc_vma_close(struct binder_alloc *alloc)
{
WRITE_ONCE(alloc->vma, NULL);
- WRITE_ONCE(alloc->vma_vm_mm, NULL);
}
/**
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;
}
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:
*/
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);