On 2018/10/26 22:04, Oleg Nesterov wrote: >> Suppose p1 == p2->real_parent and p2 == p3->real_parent, and p1 exited >> when p2 tried to attach on p1, p2->real_parent was pointing to already >> (or about to be) freed p1. > > No, p2->real_parent will be updated. If p1 exits it will re-parent its > children including p2.
My error. Suppose p1 == p2->real_parent and p2 == p3->real_parent, and p1 exited when someone tried to attach on p2, p2->real_parent was pointing to already (or about to be) freed p1. So, the puzzle part is why p2->real_parent was still pointing p1 even after p1 was freed... > > Again, did you read my previous email? Yes. But I still can't be convinced that pid_alive() test helps.
