From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Tue, 25 Jan 2022 00:20:54 +0000
Subject: Re: [PATCH -next v2] ia64: make IA64_MCA_RECOVERY bool instead of tristate
Message-Id: <87ee4w1x95.fsf@email.froward.int.ebiederm.org>
List-Id: <linux-ia64.vger.kernel.org>
References: <20220124213129.29306-1-rdunlap@infradead.org>
In-Reply-To: <20220124213129.29306-1-rdunlap@infradead.org> (Randy Dunlap's
        message of "Mon, 24 Jan 2022 13:31:29 -0800")
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To: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-kernel@vger.kernel.org, Andrew Morton <akpm@linux-foundation.org>, linux-ia64@vger.kernel.org, Tony Luck <tony.luck@intel.com>, kernel test robot <lkp@intel.com>, Christoph Hellwig <hch@infradead.org>

Randy Dunlap <rdunlap@infradead.org> writes:

> In linux-next, IA64_MCA_RECOVERY uses the (new) function make_task_dead(),
> which is not exported for use by modules. Instead of exporting it for
> one user, convert IA64_MCA_RECOVERY to be a bool Kconfig symbol.
>
> In a config file from "kernel test robot <lkp@intel.com>" for a
> different problem, this linker error was exposed when
> CONFIG_IA64_MCA_RECOVERY=m.
>
> Fixes this build error:
>
> ERROR: modpost: "make_task_dead" [arch/ia64/kernel/mca_recovery.ko] undefined!

Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>

I looked and ia64_unreg_MCA_extension has no synchronization so I don't
think it has ever been safe to this code when built as a module.


> Fixes: 0e25498f8cd4 ("exit: Add and use make_task_dead.")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Cc: "Eric W. Biederman" <ebiederm@xmission.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-ia64@vger.kernel.org
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: kernel test robot <lkp@intel.com>
> Suggested-by: Christoph Hellwig <hch@infradead.org>
> ---
> v1 was [PATCH -next] exit: export make_task_dead().
> Christoph suggests and prefers that IA64 MCA recovery code just be
> forced to be builtin if it is enabled.
>
>  arch/ia64/Kconfig |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- linux-next-20220121.orig/arch/ia64/Kconfig
> +++ linux-next-20220121/arch/ia64/Kconfig
> @@ -318,7 +318,7 @@ config ARCH_PROC_KCORE_TEXT
>  	depends on PROC_KCORE
>  
>  config IA64_MCA_RECOVERY
> -	tristate "MCA recovery from errors other than TLB."
> +	bool "MCA recovery from errors other than TLB."
>  
>  config IA64_PALINFO
>  	tristate "/proc/pal support"