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References: <20220405071314.3225832-1-guoren@kernel.org> <20220405071314.3225832-3-guoren@kernel.org>
 <20220608094108.GA18122@asgard.redhat.com>
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From:   Guo Ren <guoren@kernel.org>
Date:   Mon, 13 Jun 2022 09:15:48 +0800
Message-ID: <CAJF2gTQhFbN3mK0jco=NAKZr4qCgvX4zkw3h6jdffr66Rz7REQ@mail.gmail.com>
Subject: Re: [PATCH V12 02/20] uapi: always define F_GETLK64/F_SETLK64/F_SETLKW64
 in fcntl.h
To:     Eugene Syromiatnikov <esyr@redhat.com>
Cc:     Christoph Hellwig <hch@lst.de>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Naresh Kamboju <naresh.kamboju@linaro.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        linux-s390 <linux-s390@vger.kernel.org>,
        sparclinux <sparclinux@vger.kernel.org>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        Parisc List <linux-parisc@vger.kernel.org>,
        "open list:BROADCOM NVRAM DRIVER" <linux-mips@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        =?UTF-8?Q?Heiko_St=C3=BCbner?= <heiko@sntech.de>, ldv@strace.io
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On Wed, Jun 8, 2022 at 5:41 PM Eugene Syromiatnikov <esyr@redhat.com> wrote=
:
>
> On Tue, Apr 05, 2022 at 03:12:56PM +0800, guoren@kernel.org wrote:
> > From: Christoph Hellwig <hch@lst.de>
> >
> > Note that before this change they were never visible to userspace due
> > to the fact that CONFIG_64BIT is only set for kernel builds.
>
> > -#ifndef CONFIG_64BIT
> > +#if __BITS_PER_LONG =3D=3D 32 || defined(__KERNEL__)
>
> Actually, it's quite the opposite: "ifndef" usage made it vailable at all=
 times
> to the userspace, and this change has actually broken building strace
> with the latest kernel headers[1][2].  There could be some debate
> whether having these F_*64 definitions exposed to the user space 64-bit
> applications, but it seems that were no harm (as they were exposed alread=
y
> for quite some time), and they are useful at least for strace for compat
> application tracing purposes.
>
> [1] https://github.com/strace/strace/runs/6779763146?check_suite_focus=3D=
true#step:4:3222
> [2] https://pipelines.actions.githubusercontent.com/serviceHosts/e5309ebd=
-8a2f-43f4-a212-b52080275b5d/_apis/pipelines/1/runs/1473/signedlogcontent/1=
2?urlExpires=3D2022-06-08T09%3A37%3A13.9248496Z&urlSigningMethod=3DHMACV1&u=
rlSignature=3DfIT7vd0O4NNRwzwKWLXY4UVZBIIF3XiVI9skAsGvV0I%3D
>
Yes, there is no CONFIG_64BIT in userspace, we shouldn't limit it with
(__BITS_PER_LONG =3D=3D 32 || defined(__KERNEL__)) to break the
compatibility. Just export F_*64 definitions permanently.

--=20
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/