Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) client-ip=23.128.96.33;
MIME-Version: 1.0
References: <20231203232017.994963-1-ubizjak@gmail.com> <20231203232017.994963-3-ubizjak@gmail.com>
In-Reply-To: <20231203232017.994963-3-ubizjak@gmail.com>
From:   Uros Bizjak <ubizjak@gmail.com>
Date:   Mon, 4 Dec 2023 15:03:11 +0100
Message-ID: <CAFULd4aPtQ4YmBunxYf_jkSkw50rLgYqD_upnYqt8PH3NzYNWg@mail.gmail.com>
Subject: Re: [PATCH -tip v2 3/3] x86/percpu: Avoid sparse warning with cast to
 named address space
To:     x86@kernel.org, linux-kernel@vger.kernel.org
Cc:     kernel test robot <lkp@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Mon, Dec 4, 2023 at 12:20=E2=80=AFAM Uros Bizjak <ubizjak@gmail.com> wro=
te:
>
> Currently sparse does not know about __seg_fs and __seg_fs named
> address space qualifiers. Avoid thousands of warnings about unexpected
> keyword at the end of cast operator by removing named address space
> qualifier from __my_cpu_type() when __CHECKER__ is defined.

We have discussed this issue a bit on the linux-sparse ML [1], and the
proposed solution is to define:

+#define __seg_gs __attribute__((address_space(__seg_gs)))
+#define __seg_fs __attribute__((address_space(__seg_fs)))

as done in the attached patch.

[1] https://lore.kernel.org/linux-sparse/CAFULd4YMcHhkSR4P5tq3ghLQyUCkiTOKS=
6PQd1Bec-2NicUiwQ@mail.gmail.com/T/#md048c918cd2145c822727e3aa401326e166084=
2f

Uros.