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Date: Wed, 20 Dec 2023 08:39:20 +0100 (CET)
From: Julia Lawall <julia.lawall@inria.fr>
To: Luis Chamberlain <mcgrof@kernel.org>
cc: =?ISO-8859-15?Q?Thomas_Wei=DFschuh?= <linux@weissschuh.net>, 
    Joel Granados <j.granados@samsung.com>, 
    Dan Carpenter <dan.carpenter@linaro.org>, 
    Kees Cook <keescook@chromium.org>, 
    "Gustavo A. R. Silva" <gustavoars@kernel.org>, 
    Iurii Zaikin <yzaikin@google.com>, 
    Greg Kroah-Hartman <gregkh@linuxfoundation.org>, 
    linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, 
    linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2 00/18] sysctl: constify sysctl ctl_tables
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On Tue, 19 Dec 2023, Luis Chamberlain wrote:

> On Tue, Dec 19, 2023 at 10:21:25PM +0100, Julia Lawall wrote:
> > > As I noted, I think this is a generically neat endeavor and so I think
> > > it would be nice to shorthand *any* member of the struct. ctl->any.
> > > Julia, is that possible?
> >
> > What do you mean by *any* member?
>
> I meant when any code tries to assign a new variable to any of the
> members of the struct ctl_table *foo, so any foo->*any*

Declaring any to be an identifier metavariable would be sufficient.

>
> > If any is an identifier typed
> > metavariable then that would get any immediate member.  But maybe you want
> > something like
> >
> > <+...ctl->any...+>
> >
> > that will match anything that has ctl->any as a subexpression?
>
> If as just an expression, then no, we really want this to be tied to
> the data struture in question we want to modify.

What about foo->a.b?  Or maybe that doesn't occur in your structure?

julia