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From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 13 Feb 2018 16:50:11 +0000
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Subject: Re: [Qemu-devel] [PATCH] linux-user: Use *at functions to implement
 interp_prefix
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To: Eric Blake <eblake@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>, Richard Henderson <richard.henderson@linaro.org>, QEMU Developers <qemu-devel@nongnu.org>

On 13 February 2018 at 16:43, Peter Maydell <peter.maydell@linaro.org> wrote:
> OTOH, maybe we should just go ahead without weird games with dup2 and
> see whether any real code gets confused...

Here's some real-world code that would break with this patch
as it stands, though dup2 games wouldn't be the fix in this case:
 https://github.com/xinetd-org/xinetd/blob/master/xinetd/init.c#L79

(it iterates through all fds above 2 closing them, and we don't
protect against the guest being able to perform syscalls on
interp_dirfd)

thanks
-- PMM