On 08/26, Linus Torvalds wrote: > > On Mon, Aug 26, 2013 at 11:09 AM, Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > Patch looks ok to me, but since this has never worked and nobody has > > actually complained, I can't really convince myself that this is > > critical. > > Actually, let's back-track.. > > Did you try the other approach? Make /proc/self point to the thread > instead of the task? Yes, I thought about this. But I agree with Eric, we probably need another magic link, /proc/thread or whatever. And. I think that s/task_pid/task_tgid/ in proc_fd_permission() makes sense anyway. It is not only for /proc/self, why we should restrict the access to /proc/<sub-thread>/fd ? > The thread-group leader seems to have these extra files: > > - autogroup, coredump_filter, mountstats, net, task > Note really afaics. Yes, tgid_base_stuff and tid_base_stuff differ, but proc_root_lookup() uses tgid_base_stuff in any case, so /proc/<tid>/ also has task,mountstats,etc even if it is not leader. > Yes, it would be semantically different, And I am afraid this can break things. But I leave this to you and Eric. Personally I think that /proc/self pointing to "current" is better, and in fact I was surprised when I recently found that this is not true. But perhaps it is too late to change this old behaviour. > but it would mean that > "/proc/self/fd/" would actually make sense in a way that it currently > does *not* - which would seem fairly important, since the primary use > for it tends to be /dev/stdin. I think this doesn't matter "in practice", normally all threads have the same ->files. Who needs CLONE_THREAD without CLONE_FILES ? > And the other semantic differences might be much harder to notice. > Worth testing? Perhaps... Well, if Andrew takes this patch (assuming you and Eric ack it), we can see if we have any bug reports. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
