Revert "android: binder: fix dangling pointer comparison"

This reverts commit 7b142d8fd0bd4c9bf06ccb72ac4daedb503f0124.

It doesn't seem to be correct, no one seems to have tested it, and the
email address of the submitter now bounces :(

So revert it.

Cc: Jann Horn <jannh@google.com>
Cc: Chen Feng <puck.chen@hisilicon.com>
Cc: stable <stable@vger.kernel.org>
Cc: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 09fdb425e2f5c68ed07f159f9c4b3dfc37ce1721..16288e777ec3dfdb50db2b133dd44f7e0045d8ad 100644 (file)
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2962,7 +2962,6 @@ static int binder_open(struct inode *nodp, struct file *filp)
                return -ENOMEM;
        get_task_struct(current);
        proc->tsk = current;
-       atomic_inc(&current->mm->mm_count);
        proc->vma_vm_mm = current->mm;
        INIT_LIST_HEAD(&proc->todo);
        init_waitqueue_head(&proc->wait);
@@ -3168,7 +3167,6 @@ static void binder_deferred_release(struct binder_proc *proc)
                vfree(proc->buffer);
        }
 
-       mmdrop(proc->vma_vm_mm);
        put_task_struct(proc->tsk);
 
        binder_debug(BINDER_DEBUG_OPEN_CLOSE,