Re: [PATCH -tip v2] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

2017-09-11 Thread Paul E. McKenney
On Tue, Sep 12, 2017 at 10:10:51AM +0900, Masami Hiramatsu wrote: > To enable jump optimized probe with CONFIG_PREEMPT, use > synchronize_rcu_tasks() to wait for all tasks preempted > on trampoline code back on track. > > Since the jump optimized kprobes can replace multiple > instructions, there

[PATCH -tip v2] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

2017-09-11 Thread Masami Hiramatsu
To enable jump optimized probe with CONFIG_PREEMPT, use synchronize_rcu_tasks() to wait for all tasks preempted on trampoline code back on track. Since the jump optimized kprobes can replace multiple instructions, there can be tasks which are interrupted on the 2nd (or 3rd) instructions. If the kp