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Date:   Tue, 11 Oct 2022 12:33:53 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Jia He <justin.he@arm.com>
Cc:     Len Brown <lenb@kernel.org>, James Morse <james.morse@arm.com>,
        Tony Luck <tony.luck@intel.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Robert Richter <rric@kernel.org>,
        Robert Moore <robert.moore@intel.com>,
        Qiuxu Zhuo <qiuxu.zhuo@intel.com>,
        Yazen Ghannam <yazen.ghannam@amd.com>,
        Jan Luebbe <jlu@pengutronix.de>,
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        Kani Toshi <toshi.kani@hpe.com>,
        Ard Biesheuvel <ardb@kernel.org>, linux-acpi@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org,
        devel@acpica.org, "Rafael J . Wysocki" <rafael@kernel.org>,
        Shuai Xue <xueshuai@linux.alibaba.com>,
        Jarkko Sakkinen <jarkko@kernel.org>, linux-efi@vger.kernel.org,
        nd@arm.com, kernel test robot <lkp@intel.com>
Subject: Re: [PATCH v8 6/7] apei/ghes: Use unrcu_pointer for cmpxchg
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References: <20221010023559.69655-1-justin.he@arm.com>
 <20221010023559.69655-7-justin.he@arm.com>
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On Mon, Oct 10, 2022 at 02:35:58AM +0000, Jia He wrote:
> ghes_estatus_caches should be add rcu annotation to avoid sparse warnings.
>    drivers/acpi/apei/ghes.c:733:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
>    drivers/acpi/apei/ghes.c:733:25: sparse:    struct ghes_estatus_cache [noderef] __rcu *
>    drivers/acpi/apei/ghes.c:733:25: sparse:    struct ghes_estatus_cache *
>    drivers/acpi/apei/ghes.c:813:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
>    drivers/acpi/apei/ghes.c:813:25: sparse:    struct ghes_estatus_cache [noderef] __rcu *
>    drivers/acpi/apei/ghes.c:813:25: sparse:    struct ghes_estatus_cache *
> 
> unrcu_pointer is to strip the __rcu in cmpxchg.

Is this only to shut up sparse or actually fixing anything?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette