From 5ab9ecc3c6d80a97a6409e10042ee2e74d593dc9 Mon Sep 17 00:00:00 2001 From: Todd Kjos Date: Tue, 27 Jun 2017 15:18:51 -0700 Subject: [PATCH] Revert "android: binder: Sanity check at binder ioctl" This reverts commit a906d6931f3ccaf7de805643190765ddd7378e27. The patch introduced a race in the binder driver. An attempt to fix the race was submitted in "[PATCH v2] android: binder: fix dangling pointer comparison", however the conclusion in the discussion for that patch was that the original patch should be reverted. The reversion is being done as part of the fine-grained locking patchset since the patch would need to be refactored when proc->vmm_vm_mm is removed from struct binder_proc and added in the binder allocator. Also needs reversion in 4.9 LTS Change-Id: I9777ece955c07ac30432187bb968f87cf73271d8 Signed-off-by: Todd Kjos --- drivers/android/binder.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 6e85c79cf9f8..9105f416ce46 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3247,10 +3247,6 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) /*pr_info("binder_ioctl: %d:%d %x %lx\n", proc->pid, current->pid, cmd, arg);*/ - if (unlikely(current->mm != proc->vma_vm_mm)) { - pr_err("current mm mismatch proc mm\n"); - return -EINVAL; - } trace_binder_ioctl(cmd, arg); ret = wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2); @@ -3466,7 +3462,6 @@ static int binder_open(struct inode *nodp, struct file *filp) return -ENOMEM; get_task_struct(current->group_leader); proc->tsk = current->group_leader; - proc->vma_vm_mm = current->group_leader->mm; INIT_LIST_HEAD(&proc->todo); init_waitqueue_head(&proc->wait); proc->default_priority = task_nice(current); -- 2.20.1