On Wed, Apr 27, 2022 at 05:14:57PM +0200, Oleg Nesterov wrote: > On 04/26, Eric W. Biederman wrote: > > > > Asking wait_task_inactive to verify that tsk->__state == __TASK_TRACED > > was needed to detect the when ptrace_stop would decide not to stop > > after calling "set_special_state(TASK_TRACED)". With the recent > > cleanups ptrace_stop will always stop after calling set_special_state. > > > > Take advatnage of this by no longer asking wait_task_inactive to > > verify the state. If a bug is hit and wait_task_inactive does not > > succeed warn and return -ESRCH. > > ACK, but I think that the changelog is wrong. > > We could do this right after may_ptrace_stop() has gone. This doesn't > depend on the previous changes in this series.
It very much does rely on there not being any blocking between set_special_state() and schedule() tho. So all those PREEMPT_RT spinlock->rt_mutex things need to be gone. That is also the reason I couldn't do wait_task_inactive(task, 0) in the other patch, I had to really match 'TASK_TRACED or TASK_FROZEN' any other state must fail (specifically TASK_RTLOCK_WAIT must not match). _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um
