On Tue, Jan 7, 2020 at 6:59 PM Sargun Dhillon <sargun@xxxxxxxxx> wrote: > +/** > + * sys_pidfd_getfd() - Get a file descriptor from another process > + * > + * @pidfd: the pidfd file descriptor of the process > + * @fd: the file descriptor number to get > + * @flags: flags on how to get the fd (reserved) > + * > + * This syscall gets a copy of a file descriptor from another process > + * based on the pidfd, and file descriptor number. It requires that > + * the calling process has the ability to ptrace the process represented > + * by the pidfd. The process which is having its file descriptor copied > + * is otherwise unaffected. > + * > + * Return: On success, a cloexec file descriptor is returned. > + * On error, a negative errno number will be returned. > + */ > +SYSCALL_DEFINE3(pidfd_getfd, int, pidfd, int, fd, > + unsigned int, flags) This is the most sensible definition I can see. I can not tell whether we should or want to have it, but if everyone thinks this is a good idea, then this ABI makes sense. Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
