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[209.132.180.67]) by mx.google.com with ESMTP id x70-v6si9662789pfa.108.2018.06.29.10.34.38; Fri, 29 Jun 2018 10:34:53 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=JeIYMbIX; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967090AbeF2QgQ (ORCPT + 99 others); Fri, 29 Jun 2018 12:36:16 -0400 Received: from mail-io0-f193.google.com ([209.85.223.193]:39871 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967070AbeF2QgM (ORCPT ); Fri, 29 Jun 2018 12:36:12 -0400 Received: by mail-io0-f193.google.com with SMTP id e13-v6so8984687iof.6 for ; Fri, 29 Jun 2018 09:36:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=ukCGltYwtD7YajTlWIOjEevOj1qICTIHzaLGC+IF44g=; b=JeIYMbIX3IAluQh6MhELO7TmAfHyd6W5UTGw3TRp98mmofrXYoYtTUtXjEsX6Ja/lq AzFWQLQA9opUNjazc24TrHLOeQqIUBty+fE+AMmdg8MNi5Vb8PFN6M+zWbl2VQqqz7KG XqUmwT2Po6HofXqvK2C0KMAsyjjp2HvNqI7CqGGTFPAALmXM/GDAZn7Tjw8qiX5v6D05 kIFhixws/cWz1KdMi+3IfGVUFdfBUdbfZ3B2vnOmkjv5MiD9YLK21PanXHrDwaRD+IsY FH96sKlVbvIL+Uxlidq2LSVZwjAmrtRyptb5HeFJI/vP8FoN07z1OAYievrniflL+eZu hnmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=ukCGltYwtD7YajTlWIOjEevOj1qICTIHzaLGC+IF44g=; b=GmUuyn6/Tm3zY0WffzfCLLIR4IUaZVNlBLXQIEjeu30JzzlzNEqqUKT469ram+vsjL slXsvGgAPvr8x9e660PpENFbC0nOfkc7XulGv8FOGxgiINqBiHHCdz762k2UDeMfQfbT 6iLXpDmIkegpaG/qk5U7hYBWfKnz8cc/bO/SEE6Xpr7kK71gEsb0/xa51XYanhe2q3Ov 0NwXVn7XpzUSM6Zg51CWfvT2iNaR7XdAc56kLd3N7GMHGETjzkvc9ky+rXNNmLsVpEQH /r73xtnZOXGCDulaBlapDEcNjtST3o3nrezqDtXoFpG4xsyXYcwotcRZB3wvBTZ9VBNW 26rg== X-Gm-Message-State: APt69E1ZeuaHy3jWof9CmipK24sSh6Vw/AAnaWQgO7RHMNyo6nlplOHq 8aG+8RyYSupXOIC99b5Qf3FyBDkQMBb32SlOLvH5KQ== X-Received: by 2002:a6b:5002:: with SMTP id e2-v6mr13329662iob.31.1530290171709; Fri, 29 Jun 2018 09:36:11 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a02:9082:0:0:0:0:0 with HTTP; Fri, 29 Jun 2018 09:36:10 -0700 (PDT) In-Reply-To: <20180629110709.GA17859@arm.com> References: <20180628105057.GA26019@e103592.cambridge.arm.com> <20180629110709.GA17859@arm.com> From: Andrey Konovalov Date: Fri, 29 Jun 2018 18:36:10 +0200 Message-ID: Subject: Re: [PATCH v4 00/17] khwasan: kernel hardware assisted address sanitizer To: Will Deacon Cc: Dave Martin , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Catalin Marinas , Christoph Lameter , Andrew Morton , Mark Rutland , Nick Desaulniers , Marc Zyngier , Ard Biesheuvel , "Eric W . Biederman" , Ingo Molnar , Paul Lawrence , Geert Uytterhoeven , Arnd Bergmann , "Kirill A . Shutemov" , Greg Kroah-Hartman , Kate Stewart , Mike Rapoport , kasan-dev , linux-doc@vger.kernel.org, LKML , Linux ARM , linux-sparse@vger.kernel.org, Linux Memory Management List , Linux Kbuild mailing list , Chintan Pandya , Jacob Bramley , Jann Horn , Ruben Ayrapetyan , Lee Smith , Kostya Serebryany , Mark Brand , Ramana Radhakrishnan , Evgeniy Stepanov 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 Fri, Jun 29, 2018 at 1:07 PM, Will Deacon wrote: > It might not seen sensible, but we could still be relying on this in the > kernel and so this change would introduce a regression. I think we need > a way to identify such pointer usage before these patches can seriously be > considered for mainline inclusion. Another point that I have here is that KHWASAN is a debugging tool not meant to be used in production. We're not trying to change the ABI or something like that (referring to the other HWASAN patchset). We can fix up the non obvious places where untagging is needed in a case by case basis with additional patches when testing reveals it.