From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6746BC433DF for ; Thu, 27 Aug 2020 12:48:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4072922CAE for ; Thu, 27 Aug 2020 12:48:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="uYOH6B48" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729120AbgH0MsD (ORCPT ); Thu, 27 Aug 2020 08:48:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729093AbgH0Me4 (ORCPT ); Thu, 27 Aug 2020 08:34:56 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AF84C061264 for ; Thu, 27 Aug 2020 05:34:43 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id x143so3383932pfc.4 for ; Thu, 27 Aug 2020 05:34:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+QQzTLJnBa36P3H2hTUyCcrUla2gQmiA7N8bvUye5ww=; b=uYOH6B48y6njJ6nOhh7bzhqeTJ3WdinzCFT9hIYxW7pf23M1KEtMkaICjyHIIwiEDq Kbsn9tO6FZclxYcMvNLidIbrOHlY6EsI1Uf5yHVFu2UW05R82qWxv6f4SajSvSUYY5wd o1Jo+t+JhODnJqU6BOGDHGZatMyUTgFPKUJvClaQHt7gTc8KMBmmt1okOso2IkCEHeu5 /9ibjpOa5mKRBm6BW7OhWyU93dSuRCZIwDokWjVbp0VsnwBtMoHG0WDo0OQsNOMHWIYu RRJhyggJcTDJT7WlGga3bFYCCaPJ07RFE+iFNIGWfNZSlLTVIAgdDBHP41ECZTpzT6ty 3utA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+QQzTLJnBa36P3H2hTUyCcrUla2gQmiA7N8bvUye5ww=; b=Ca1V3Trdooe8TfkGBrrD4Zst3itnfBp0hpbgnqWGttlfAr18IX2MmS1EEiC6RdHh/1 aV1iJMGJQMuh2E2qKdajdaazGm6rGmhLZy02Rys0HjQTJ1ADUV2PZlbned8N2hqVM/pB L1IAItDXrI+b6ZRewgFHHVd75uwxbPqJt9C3CJMkKoZnopYgjd7dzwZCZk8KbQzM2q/O +UGvFtAGOxYmNnXl5ZBnQrmB4uN6ugzqerhL+SZFTQBtVYg0zqO7+OOu1n0F29NAW60A knjQ7FW4qIFsZFCnibrp0g/yLpZMyrLkQSbMIEHzTNeCklq7n+90BvY3sA7c++fzYgaK /jGQ== X-Gm-Message-State: AOAM531VvasAGxkboEjBvaLmMzGnUXPQJBkmnGTTPGQeToe7A4dmphSL F3lw6Au4RJgOnqCoE7MKedLNX5n7QPph6gVAkJJhMg== X-Google-Smtp-Source: ABdhPJwQvcLUtER5Ks8hleRdsk9c2HrTabX2FVUhlXdZKYuGVbjvNQk+xGe46zGntRyn3AgYfTecHAxmWoF1WxIPLG0= X-Received: by 2002:a17:902:bb82:: with SMTP id m2mr16297954pls.115.1598531682160; Thu, 27 Aug 2020 05:34:42 -0700 (PDT) MIME-Version: 1.0 References: <4691d6019ef00c11007787f5190841b47ba576c4.1597425745.git.andreyknvl@google.com> <20200827104816.GI29264@gaia> In-Reply-To: <20200827104816.GI29264@gaia> From: Andrey Konovalov Date: Thu, 27 Aug 2020 14:34:31 +0200 Message-ID: Subject: Re: [PATCH 32/35] kasan, arm64: print report from tag fault handler To: Catalin Marinas , Vincenzo Frascino Cc: Dmitry Vyukov , kasan-dev , Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Elena Petrova , Branislav Rankov , Kevin Brodsky , Will Deacon , Andrew Morton , Linux ARM , Linux Memory Management List , LKML 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 Thu, Aug 27, 2020 at 12:48 PM Catalin Marinas wrote: > > On Fri, Aug 14, 2020 at 07:27:14PM +0200, Andrey Konovalov wrote: > > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > > index c62c8ba85c0e..cf00b3942564 100644 > > --- a/arch/arm64/mm/fault.c > > +++ b/arch/arm64/mm/fault.c > > @@ -14,6 +14,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -314,11 +315,19 @@ static void report_tag_fault(unsigned long addr, unsigned int esr, > > { > > bool is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0; > > > > +#ifdef CONFIG_KASAN_HW_TAGS > > + /* > > + * SAS bits aren't set for all faults reported in EL1, so we can't > > + * find out access size. > > + */ > > + kasan_report(addr, 0, is_write, regs->pc); > > +#else > > pr_alert("Memory Tagging Extension Fault in %pS\n", (void *)regs->pc); > > pr_alert(" %s at address %lx\n", is_write ? "Write" : "Read", addr); > > pr_alert(" Pointer tag: [%02x], memory tag: [%02x]\n", > > mte_get_ptr_tag(addr), > > mte_get_mem_tag((void *)addr)); > > +#endif > > } > > More dead code. So what's the point of keeping the pr_alert() introduced > earlier? CONFIG_KASAN_HW_TAGS is always on for in-kernel MTE. If MTE is > disabled, this function isn't called anyway. I was considering that we can enable in-kernel MTE without enabling CONFIG_KASAN_HW_TAGS, but perhaps this isn't what we want. I'll drop this part in v2, but then we also need to make sure that in-kernel MTE is only enabled when CONFIG_KASAN_HW_TAGS is enabled. Do we need more ifdefs in arm64 patches when we write to MTE-related registers, or does this work as is?