Nathaniel Yazdani <n1ght.4nd....@gmail.com> wrote:
> + * stores triggered eventpoll entries in the 'out' array. The input array is
> + * _not_ read-only, because the resulting event mask gets written back to
> each
> + * entry's ->ep_events field. When successful, this will be the same as
> before
> + * (plus EPOLLERR & EPOLLHUP). If ->ep_events gets cleared, then it is
> reasonable
> + * to infer that the entry's ->ep_fildes was a bad file descriptor.
> + */
> + if (!access_ok(VERIFY_WRITE, in, inc * sizeof(struct epoll)))
> + goto out;
> + for (i = 0; i < inc; ++i) {
> + int fd, io;
> + long long id;
> +
> + ret = -EFAULT;
> + if (__get_user(fd, &in[i].ep_fildes) ||
> + __get_user(io, &in[i].ep_events) ||
> + __get_user(id, &in[i].ep_ident))
> + goto out;
> +
> + ep_control(file->private_data, fd, &io, id, 0);
> + ret = -EFAULT;
> + if (__put_user(io, &in[i].ep_events))
> + goto out;
I don't think we should waste cycles writing to 'in' on success.
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