Re: [PATCHv10 man-pages 5/5] execveat.2: initial man page for execveat(2)

[Al Viro <viro@ZenIV.linux.org.uk>]

On Fri, Jan 09, 2015 at 05:17:28PM -0500, Rich Felker wrote:
> > Back then the procfs-free environments had been pushed as a serious argument
> > in favour of merging the damn thing.  Now you guys turn around and say that
> > we not only need procfs mounted, we need a yet-to-be-added kludge in there
> > to cope with the actual intended uses.
> 
> Reverting does not fix the problem. There is no way to make fexecve
> work for scripts without kernel support, and the needed kernel support
> without fexecve would be even nastier, since handling of /proc/self/fd
> magic-symlinks would need to be special-cased. The added fexecveat
> syscall supports fully /proc-less operation for non-scripts.

Oh, yes it does.  It's not *our* problem if it's out of tree and not
a part of ABI.  That way if you need it, *you* get to come up with clean
implementation.  If it's in-tree you get leverage to push ugly kludges
further in.  And frankly, I don't trust you to abstain from using that
leverage in rather nasty ways.

Out of curiosity, how would you expect that "open only once" to work?
All reliable variants I see are beyond sick...