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Date:   Wed, 22 Sep 2021 09:17:44 +0200
From:   Boris Kolpackov <boris@codesynthesis.com>
To:     Richard Weinberger <richard@nod.at>
Cc:     masahiroy@kernel.org, linux-kernel@vger.kernel.org,
        linux-kbuild@vger.kernel.org
Subject: Re: [PATCH 2/2] kconfig: Deny command substitution in string values
Message-ID: <boris.20210922090732@codesynthesis.com>
References: <20210920213957.1064-1-richard@nod.at>
 <20210920213957.1064-2-richard@nod.at>
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Richard Weinberger <richard@nod.at> writes:

> The post processed .config file will get included in shell
> and makefiles.

That depends on who you ask: a number of projects other than the
Linux kernel use kconfig for configuration and some of them do
neither of those. I also don't believe the Linux kernel sources
.config in shell (but I may be wrong).


> So make sure that a string does not contain
> symbols that allow command substitution.
> If such a malformed string is found, return empty string
> and report it.

So effectively it's now impossible to include ` or $ in kconfig
string values. Seems like a major, backwards-incompatible
restriction.

I think if this is really desired, then it should be re-done with
escaping (similar to ") rather than outright banning inconvenient 
characters.