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[209.85.208.182]) by smtp.gmail.com with ESMTPSA id 5sm3606817ljf.86.2019.02.27.09.36.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Feb 2019 09:36:28 -0800 (PST) Received: by mail-lj1-f182.google.com with SMTP id d24so14419891ljc.12 for ; Wed, 27 Feb 2019 09:36:28 -0800 (PST) X-Received: by 2002:a2e:9786:: with SMTP id y6mr1959575lji.79.1551288987853; Wed, 27 Feb 2019 09:36:27 -0800 (PST) MIME-Version: 1.0 References: <20190225124330.613028745@infradead.org> <20190225125232.191698923@infradead.org> <20190227140830.GP32494@hirez.programming.kicks-ass.net> <20190227173046.GU32494@hirez.programming.kicks-ass.net> In-Reply-To: <20190227173046.GU32494@hirez.programming.kicks-ass.net> From: Linus Torvalds Date: Wed, 27 Feb 2019 09:36:11 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 5/6] objtool: Add UACCESS validation To: Peter Zijlstra Cc: Thomas Gleixner , Peter Anvin , Julien Thierry , Will Deacon , Andy Lutomirski , Ingo Molnar , Catalin Marinas , James Morse , valentin.schneider@arm.com, Brian Gerst , Josh Poimboeuf , Andrew Lutomirski , Borislav Petkov , Denys Vlasenko , Linux List Kernel Mailing , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 27, 2019 at 9:30 AM Peter Zijlstra wrote: > > Right, but I was hoping to avoid having to do that; and I think we can > do that if we push all of kasan_report into an exception, like that > 'patch' I just posted. > > If I'm not mistaken the regular kasan house-keeping crud just prods at > the shadow memory with simple code and should be perfectly safe. Fair enough. I do agree it would be nice to not have the save/restore simply because "it cannot matter" and we have the static tool to prove that. Linus