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Date: Thu, 28 Jun 2018 08:17:59 +0200
From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: Re: [PATCH v4 0/7] arm64: untag user pointers passed to the kernel
Message-ID: <20180628061758.j6bytsaj5jk4aocg@ltop.local>
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To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>, Andrey Konovalov <andreyknvl@google.com>, Mark Rutland <Mark.Rutland@arm.com>, Kate Stewart <kstewart@linuxfoundation.org>, "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>, Will Deacon <Will.Deacon@arm.com>, Kostya Serebryany <kcc@google.com>, "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>, Chintan Pandya <cpandya@codeaurora.org>, Shuah Khan <shuah@kernel.org>, Ingo Molnar <mingo@kernel.org>, "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>, Jacob Bramley <Jacob.Bramley@arm.com>, Dmitry Vyukov <dvyukov@google.com>, Evgeniy Stepanov <eugenis@google.com>, Kees Cook <keescook@chromium.org>, Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>, Al Viro <viro@zeniv.linux.org.uk>nd <nd@arm.com>, Linux ARM <linux-arm-kernel@lists.infradead.org>, Linux Memory Management List <linux-mm@kvack.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, LKML <linux-kernel@vger.kernel.org>, Lee Smith <Lee.Smith@arm.com>, Andrew Morton <akpm@linux-foundation.org>, Robin Murphy <Robin.Murphy@arm.com>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>

On Wed, Jun 27, 2018 at 06:17:58PM +0100, Catalin Marinas wrote:
> 
> sparse is indeed an option. The current implementation doesn't warn on
> an explicit cast from (void __user *) to (unsigned long) since that's a
> valid thing in the kernel. I couldn't figure out if there's any other
> __attribute__ that could be used to warn of such conversion.

Hi,

sparse doesn't have such attribute but would an new option that would warn
on such cast be a solution for your case?

-- Luc