Re: [PATCH][RFC] pseudo: intercept syscall() and return ENOTSUP for renameat2

[Seebs <seebs@seebs.net>]

On Tue, 27 Mar 2018 16:48:02 +0100
Ross Burton <ross.burton@intel.com> wrote:

> This patch intercepts syscall() and returns ENOTSUP if renameat2() is
> being called.

I am inclined to NAK this until we have a clearer understanding of the
mechanics observed in glibc's syscall implementation; it's doing magic
that this will not do, and will in fact undo, and we don't know *why*
it does that magic. It seems dangerous to break a thing without first
knowing why it was there in the first place.

If we want to wrap this, at a bare minimum, we should be using a
custom wrapper which doesn't use any of the standard wrapper magic. At
that point, we can *probably* pass args along and just return
immediately after the real_syscall call and get usable results? (And
bail prematurely if it's a call we need to prevent.)

-s