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[23.128.96.18]) by mx.google.com with ESMTP id lf22si1618495ejb.20.2020.10.22.14.21.07; Thu, 22 Oct 2020 14:21:59 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=IM7WAkzC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 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 S2897505AbgJVLro (ORCPT + 99 others); Thu, 22 Oct 2020 07:47:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2503040AbgJVLro (ORCPT ); Thu, 22 Oct 2020 07:47:44 -0400 Received: from mail-oi1-x243.google.com (mail-oi1-x243.google.com [IPv6:2607:f8b0:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A72F4C0613CE for ; Thu, 22 Oct 2020 04:47:42 -0700 (PDT) Received: by mail-oi1-x243.google.com with SMTP id q136so1381287oic.8 for ; Thu, 22 Oct 2020 04:47:42 -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=nQ90kVlYCVdEBMkM5DxKx4SDCKnOT8r71z3S9jFcYrw=; b=IM7WAkzCbG3CrmjDRgKySlMHcg6geFJubdFIFWTCLNiC8GRrLOINQiJkAxazsg/m3e NtbadpAkKWOZoityShtNKDMNNMojYHzBVBOGjXoDPT8fz/VxeyXhuj975FVLGc3yrAGd UosVRlVe4RlwuP54X+HtTDjVMgjK0zmsT6b81uwZLpo4I986t/DquxK84O63u67LHELe YtNExNaH2go4Rf3t7EHqyTYKgycFvkaINoI5+EdZ28L5dhoSZwqsvNe1G2385rscGl2X cfenB59KJMdLWxvB+bI7GkoEHCg6q3VQzInrw5tICb/iKe+bVT48ntkGE458EVdpUD9a /JUg== 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=nQ90kVlYCVdEBMkM5DxKx4SDCKnOT8r71z3S9jFcYrw=; b=oJrREl3MUjir2e/Vh26UhgAeS0T6AZoBEHErwnCFsPGO/RGO4UTKYLU1+HX3rAx9oI RHk1XhUkTDVwzDW07QgApeBhQU/tOdz2jYGvEuq73TdBvyUk3pHcVLxhhKqwpVuujW8Q xjbuXO1ZZMuU/sU1yrsHMQtjUIrL0SQejhj+25hi3YiJgO6Jq+hwRMLAPfsWGcgILEOu QJ1Jzhu7Hd/dmL3uBJFmMzygSH2TeB1loJxHmhwVIwLiqzjM4eddS3cKPgeqTs0Pe2T9 2+5SGGvIRojlEI5dxW5enE6KiNazVuTz00WD8aYxyvs77t8tHKiw2Y0YeTSJOZP12pPG s7SA== X-Gm-Message-State: AOAM530q6FFc9pmlNTHsF4M39xFG+pLWe8gsNHSMMQvmRHqaoyt0AZAU 4OP21PjqrFqAc8kZra9rdWkihtJJRoe1ttpOZ34nig== X-Received: by 2002:aca:6206:: with SMTP id w6mr1303294oib.121.1603367261918; Thu, 22 Oct 2020 04:47:41 -0700 (PDT) MIME-Version: 1.0 References: <20201022112956.2356757-1-elver@google.com> In-Reply-To: <20201022112956.2356757-1-elver@google.com> From: Marco Elver Date: Thu, 22 Oct 2020 13:47:30 +0200 Message-ID: Subject: Re: [PATCH] kcsan: Never set up watchpoints on NULL pointers To: Marco Elver , "Paul E. McKenney" Cc: Mark Rutland , Dmitry Vyukov , kasan-dev , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 22 Oct 2020 at 13:30, Marco Elver wrote: > > Avoid setting up watchpoints on NULL pointers, as otherwise we would > crash inside the KCSAN runtime (when checking for value changes) instead > of the instrumented code. > > Because that may be confusing, skip any address less than PAGE_SIZE. > > Signed-off-by: Marco Elver > --- Please use the series at: https://lkml.kernel.org/r/20201022114553.2440135-1-elver@google.com which includes a prerequisite patch that was missing. Thanks, -- Marco