On Mon, 2019-10-14 at 17:10 +0200, Jann Horn wrote: > On Mon, Oct 14, 2019 at 12:32 PM Christian Brauner wrote: > > On Mon, Oct 14, 2019 at 11:43:01AM +0200, Christian Kellner wrote: > > You could probably do: > > > > #ifdef CONFIG_PID_NS > > seq_put_decimal_ull(m, "\nNSpid:\t", nr); > > for (i = ns->level + 1; i <= pid->level && nr; i++) > > seq_put_decimal_ull(m, "\t", pid->numbers[i].nr); > > #endif > > Personally, I dislike hiding the precondition for running the loop in > the loop statement like that. While it makes the code more concise, > it somewhat obfuscates the high-level logic at a first glance. I agree and it has the side-effect of needing another #ifdef at the end of the variable block for "i". I think I will go with: if (nr) { int i; /* If nr is non-zero it means that 'pid' is valid and that * ns, i.e. the pid namespace associated with the procfs * instance, is in the pid namespace hierarchy of pid. * Start at one below the already printed level. */ for (i = ns->level + 1; i <= pid->level; i++) seq_put_decimal_ull(m, "\t", pid->numbers[i].nr); } I will re-work the comment block and then send a new version of the patch. Thanks, Christian