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From:   David Howells <dhowells@redhat.com>
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To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     dhowells@redhat.com, Al Viro <viro@zeniv.linux.org.uk>,
        Miklos Szeredi <mszeredi@redhat.com>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] call_with_creds()
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Date:   Wed, 18 Jul 2018 22:27:43 +0100
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Linus Torvalds <torvalds@linux-foundation.org> wrote:

> and then read/write/open could just inc/dec the cred_poison counter
> (when the debug option is set).

As I may have said, I have tried modifying the kernel to pass the cred pointer
down.  The drivers and ioctl() implementations are/were particularly nasty in
this respect.  So many of them were doing checks against the current thread,
not f_cred.

I think I need to work out some way to automate the process of adding in the
extra parameter as it's not something that I think can be trivially done with
coccinelle.

David