On Fri, Dec 07, 2018 at 12:17:45AM +0100, Christian Brauner wrote: > On Thu, Dec 06, 2018 at 11:39:48PM +0100, Christian Brauner wrote: > > On Thu, Dec 06, 2018 at 03:46:53PM -0600, Eric W. Biederman wrote: > > > Christian Brauner <christian@xxxxxxxxxx> writes: > > > > > > >> Your intention is to add the thread case to support pthreads once the > > > >> process case is sorted out. So this is something that needs to be made > > > >> clear. Did I miss how you plan to handle threads? > > > > > > > > Yeah, maybe you missed it in the commit message [2] which is based on a > > > > discussion with Andy [3] and Arnd [4]: > > > > > > Looking at your references I haven't missed it. You are not deciding > > > anything as of yet to keep it simple. Except you are returning > > > EOPNOTSUPP. You are very much intending to do something. > > > > That was clear all along and was pointed at every occassion in the > > threads. I even went through the hazzle to give you all of the > > references when there's lore.kernel.org. > > > > > > > > Decide. Do you use the flags parameter or is the width of the > > > target depending on the flags. > > Ok, let's try to be constructive. I understand the general concern for > the future so let's put a contract into the commit message stating that > the width of the target aka *what is signaled* will be based on a flag > parameter if we ever extend it: > > taskfd_send_signal(fd, SIGSTOP, NULL, TASKFD_PGID); > taskfd_send_signal(fd, SIGSTOP, NULL, TASKFD_TID); > > with the current default being > > taskfd_send_signal(fd, SIGSTOP, NULL, TASKFD_PID); > > This seems to me the cleanest solution as we only use one type of file > descriptor. Can everyone be on board with this? If so I'm going to send > out a new version of the patch. > > Christian I'm on board with this, but I think you need to also clarify what exactly the fd stands for. I think that (a) userspace should not have to care about the struct pid implementation, and so (b) the procfd should stand for all the pids. So when taskfd_send_signal(fd, SIGSTOP, NULL, TASKFD_PGID) becomes implemented, then open(/proc/5) will pin all three pids, as will open(/proc/5/task/6). -serge
