On Tue, Dec 17, 2019 at 09:54:40AM +0100, Arnd Bergmann wrote: > On Tue, Dec 17, 2019 at 3:50 AM Sargun Dhillon <sargun@xxxxxxxxx> wrote: > > On Mon, Dec 16, 2019 at 5:50 PM Christian Brauner <christian.brauner@xxxxxxxxxx> wrote: > Finally, there is the question whether this should be an ioctl > operation at all, or > if it would better be done as a proper syscall. Functionally the two > are the same > here, but doing such a fundamental operation as an ioctl doesn't feel > quite right > to me. As a system call, this could be something like > > int pidfd_get_fd(int pidfd, int their_fd, int flags); > > along the lines of dup3(). Thanks for taking a look, Arnd! Yeah, Oleg hinted at this in the first version as well. I originally disagreed but we can sure also do this as a separate syscall. What we should keep in mind is that people already brought up adding new fds to a task. Which is not a problem just something to remember as it might potentially mean another syscall. Christian
