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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Mon, 17 Jun 2019 10:49:44 -0700
Message-ID: <CAHk-=wjCwnk0nfgCcMYqqX6o9bBrutDtut_fzZ-2VwiZR1y4kw@mail.gmail.com>
Subject: Re: [PATCH] uapi: avoid namespace conflict in linux/posix_types.h
To:     Florian Weimer <fweimer@redhat.com>
Cc:     Joseph Myers <joseph@codesourcery.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Linux API <linux-api@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        Netdev <netdev@vger.kernel.org>,
        Laura Abbott <labbott@redhat.com>,
        Paul Burton <pburton@wavecomp.com>,
        Deepa Dinamani <deepa.kernel@gmail.com>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>
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On Mon, Jun 17, 2019 at 4:45 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> I wanted to introduce a new header, <asm/kernel_long_t.h>, and include
> it where the definition of __kernel_long_t is needed, something like
> this (incomplete, untested):

So this doesn't look interesting to me: __kernel_long_t is neither
interesting as a type anyway (it's just a way for user space to
override "long"), nor is it a namespace violation.

So honestly, user space could do whatever it wants for __kernel_long_t anyway.

The thing that I think we should try to fix is just the "val[]" thing, ie

> A different approach would rename <asm/posix_types.h> to something more
> basic, exclude the two structs, and move all internal #includes which do
> need the structs to the new header.

In fact, I wouldn't even rename <posix_types.h> at all, I'd just make
sure it's namespace-clean.

I _think_ the only thing causing problems is  '__kernel_fsid_t' due to
that "val[]" thing, so just remove ity entirely, and add it to
<statfs.h> instead.

And yeah, then we'd need to maybe make sure that the (couple) of
__kernel_fsid_t users properly include that statfs.h file.

Hmm?

               Linus