On Tue, May 25, 2021 at 04:14:23PM +0100, Will Deacon wrote: > @@ -2426,20 +2421,166 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, > > __do_set_cpus_allowed(p, new_mask, flags); > > - return affine_move_task(rq, p, &rf, dest_cpu, flags); > + if (flags & SCA_USER) > + release_user_cpus_ptr(p); > + > + return affine_move_task(rq, p, rf, dest_cpu, flags); > > out: > - task_rq_unlock(rq, p, &rf); > + task_rq_unlock(rq, p, rf); > > return ret; > } So sys_sched_setaffinity() releases the user_cpus_ptr thingy ?! How does that work? I thought the intended semantics were somethings like: A - 0xff B restrict(0xf) // user: 0xff eff: 0xf sched_setaffinity(A, 0x3c) // user: 0x3c eff: 0xc relax() // user: NULL, eff: 0x3c
