* Christian Brauner: >> Solaris has an fdwalk function: >> >> <https://docs.oracle.com/cd/E88353_01/html/E37843/closefrom-3c.html> >> >> So a different way to implement this would expose a nextfd system call > > Meh. If nextfd() then I would like it to be able to: > - get the nextfd(fd) >= fd > - get highest open fd e.g. nextfd(-1) The highest open descriptor isn't istering for fdwalk because nextfd would just fail. > But then I wonder if nextfd() needs to be a syscall and isn't just > either: > fcntl(fd, F_GET_NEXT)? > or > prctl(PR_GET_NEXT)? I think the fcntl route is a bit iffy because you might need it to get the *first* valid descriptor. >> to userspace, so that we can use that to implement both fdwalk and >> closefrom. But maybe fdwalk is just too obscure, given the existence of >> /proc. > > Yeah we probably don't need fdwalk. Agreed. Just wanted to bring it up for completeness. I certainly don't want to derail the implementation of close_range. Thanks, Florian
