Re: [BUG] racy access to p->mm in membarrier_global_expedited()

2019-01-28 Thread Paul E. McKenney
On Mon, Jan 28, 2019 at 11:10:00AM -0500, Mathieu Desnoyers wrote: > - On Jan 28, 2019, at 9:15 AM, paulmck paul...@linux.ibm.com wrote: > > > On Fri, Jan 25, 2019 at 06:26:47PM +0100, Jann Horn wrote: > >> membarrier_global_expedited() runs the following code (introduced in > >> commit

Re: [BUG] racy access to p->mm in membarrier_global_expedited()

2019-01-28 Thread Mathieu Desnoyers
- On Jan 28, 2019, at 9:15 AM, paulmck paul...@linux.ibm.com wrote: > On Fri, Jan 25, 2019 at 06:26:47PM +0100, Jann Horn wrote: >> membarrier_global_expedited() runs the following code (introduced in >> commit c5f58bd58f43), protected only by an RCU read-side critical >> section and the

Re: [BUG] racy access to p->mm in membarrier_global_expedited()

2019-01-28 Thread Paul E. McKenney
On Fri, Jan 25, 2019 at 06:26:47PM +0100, Jann Horn wrote: > membarrier_global_expedited() runs the following code (introduced in > commit c5f58bd58f43), protected only by an RCU read-side critical > section and the cpu_hotplug_lock: > > p = task_rcu_dereference(_rq(cpu)->curr); >

[BUG] racy access to p->mm in membarrier_global_expedited()

2019-01-25 Thread Jann Horn
membarrier_global_expedited() runs the following code (introduced in commit c5f58bd58f43), protected only by an RCU read-side critical section and the cpu_hotplug_lock: p = task_rcu_dereference(_rq(cpu)->curr); if (p && p->mm && (atomic_read(>mm->membarrier_state) &