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Date:   Wed, 17 Apr 2019 22:19:34 +0100
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     linux-fsdevel@vger.kernel.org, y2038@lists.linaro.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 08/26] compat_ioctl: add compat_ptr_ioctl()
Message-ID: <20190417211934.GW2217@ZenIV.linux.org.uk>
References: <20190416202013.4034148-1-arnd@arndb.de>
 <20190416202013.4034148-9-arnd@arndb.de>
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On Tue, Apr 16, 2019 at 10:19:46PM +0200, Arnd Bergmann wrote:
> Many drivers have ioctl() handlers that are completely compatible between
> 32-bit and 64-bit architectures, except for the argument that is passed
> down from user space and may have to be passed through compat_ptr()
> in order to become a valid 64-bit pointer.
> 
> Using ".compat_ptr = compat_ptr_ioctl" in file operations should let
> us simplify a lot of those drivers to avoid #ifdef checks, and convert
> additional drivers that don't have proper compat handling yet.

You forgot to mention that it even gets the previous commit to build ;-)
IOW, that needs to be reordered.