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Date:   Wed, 25 May 2022 09:34:09 -0500
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Jiri Slaby <jirislaby@kernel.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        "Michael S . Tsirkin" <mst@redhat.com>, llvm@lists.linux.dev,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH v2 1/2] linux/types.h: Remove unnecessary __bitwise__
Message-ID: <20220525143409.GA292780@bhelgaas>
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On Wed, May 25, 2022 at 08:51:29AM +0200, Jiri Slaby wrote:
> On 15. 03. 22, 16:30, Bjorn Helgaas wrote:
> > From: Bjorn Helgaas <bhelgaas@google.com>
> > 
> > There are no users of "__bitwise__" except the definition of "__bitwise".
> > Remove __bitwise__ and define __bitwise directly.
> > 
> > This is a follow-up to 05de97003c77 ("linux/types.h: enable endian checks
> > for all sparse builds").
> > 
> > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Michael S. Tsirkin <mst@redhat.com>
> > ---
> >   include/uapi/linux/types.h  | 5 ++---
> >   tools/include/linux/types.h | 5 ++---
> >   2 files changed, 4 insertions(+), 6 deletions(-)
> > 
> > diff --git a/include/uapi/linux/types.h b/include/uapi/linux/types.h
> > index f6d2f83cbe29..71696f424ac8 100644
> > --- a/include/uapi/linux/types.h
> > +++ b/include/uapi/linux/types.h
> > @@ -20,11 +20,10 @@
> >    */
> >   #ifdef __CHECKER__
> > -#define __bitwise__ __attribute__((bitwise))
> > +#define __bitwise	__attribute__((bitwise))
> >   #else
> > -#define __bitwise__
> > +#define __bitwise
> >   #endif
> > -#define __bitwise __bitwise__
> 
> Hi,
> 
> this broke userspace, like open-iscsi:
> > [   34s] In file included from session_info.h:9,
> > [   34s]                  from iscsi_util.c:38:
> > [   34s] ../include/iscsi_proto.h:66:30: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'itt_t'
> > [   34s]    66 | typedef uint32_t __bitwise__ itt_t;
> > [   34s]       |                              ^~~~~
> 
> It looks like we need __bitwise__ back.

Crap, sorry.  I don't know why I thought it would be safe to remove
something from uapi.  I'll send a revert.

Bjorn