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Date:   Wed, 23 Sep 2020 20:11:36 +0200
From:   Solar Designer <solar@openwall.com>
To:     Florian Weimer <fweimer@redhat.com>
Cc:     Pavel Machek <pavel@ucw.cz>, madvenka@linux.microsoft.com,
        kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
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        linux-kernel@vger.kernel.org,
        linux-security-module@vger.kernel.org, oleg@redhat.com,
        x86@kernel.org, luto@kernel.org, David.Laight@ACULAB.COM,
        mark.rutland@arm.com, mic@digikod.net,
        Rich Felker <dalias@libc.org>
Subject: Re: [PATCH v2 0/4] [RFC] Implement Trampoline File Descriptor
Message-ID: <20200923181136.GA8846@openwall.com>
References: <20200922215326.4603-1-madvenka@linux.microsoft.com> <20200923081426.GA30279@amd> <20200923091456.GA6177@openwall.com> <87wo0ko8v0.fsf@oldenburg2.str.redhat.com>
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On Wed, Sep 23, 2020 at 04:39:31PM +0200, Florian Weimer wrote:
> * Solar Designer:
> 
> > While I share my opinion here, I don't mean that to block Madhavan's
> > work.  I'd rather defer to people more knowledgeable in current userland
> > and ABI issues/limitations and plans on dealing with those, especially
> > to Florian Weimer.  I haven't seen Florian say anything specific for or
> > against Madhavan's proposal, and I'd like to.  (Have I missed that?)

[...]
> I think it's unnecessary for the libffi use case.
[...]

> I don't know if kernel support could
> make sense in this context, but it would be a completely different
> patch.

Thanks.  Are there currently relevant use cases where the proposed
trampfd would be useful and likely actually made use of by userland -
e.g., specific userland project developers saying they'd use it, or
Madhavan intending to develop and contribute userland patches?

Alexander