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=-10.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 9C747C433E0 for ; Wed, 13 Jan 2021 17:18:06 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 45A2523432 for ; Wed, 13 Jan 2021 17:18:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 45A2523432 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=cAtqP+ArbndKrHCweevHyzprvmNB4Q9DDAXXTI9Z5VI=; b=QyW4zLfC8x6jQtIzMhLUzVw4c 3TBZiErMBm//tyH15CNWN3/TictMdNfxO5qx37WrR9+NwtWVubxgOo1fced936EbQVvePWLLR2xAv wylPfsUSr8hmHDOJVTjuMjs3SnIdVzaQ5W4/uuRtJgdcYkyg97r92iO65JeEZ7NNj4qo1XCshqRiZ Ljy6+GNCMr4nhCWGXXabD0NLLW0nhXbpQQRh0qFXTb4EhBU6VM3VVr37MF3tiiDKDJXse/Ngfn0CZ HOwkXkXkxJPORMmNzgTq0xWh5quDHUaldCQy4eyrxutyWzhfm5PWKlZ2I2jXR3TUwJFfH4ZnOy4az 44FGc+S6g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kzjkj-00017p-4t; Wed, 13 Jan 2021 17:16:13 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kzjkf-00017M-1N for linux-arm-kernel@lists.infradead.org; Wed, 13 Jan 2021 17:16:10 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 32FBF233FD; Wed, 13 Jan 2021 17:16:05 +0000 (UTC) Date: Wed, 13 Jan 2021 17:16:02 +0000 From: Catalin Marinas To: Vincenzo Frascino Subject: Re: [PATCH v2 1/4] kasan, arm64: Add KASAN light mode Message-ID: <20210113171602.GD27045@gaia> References: <20210107172908.42686-1-vincenzo.frascino@arm.com> <20210107172908.42686-2-vincenzo.frascino@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210107172908.42686-2-vincenzo.frascino@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210113_121609_203269_83FDB7EB X-CRM114-Status: GOOD ( 15.19 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Branislav Rankov , Marco Elver , Andrey Konovalov , Evgenii Stepanov , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, Alexander Potapenko , linux-arm-kernel@lists.infradead.org, Andrey Ryabinin , Will Deacon , Dmitry Vyukov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jan 07, 2021 at 05:29:05PM +0000, Vincenzo Frascino wrote: > Architectures supported by KASAN HW can provide a light mode of > execution. On an MTE enabled arm64 hw for example this can be identified > with the asynch mode of execution. If an async exception occurs, the > arm64 core updates a register which is asynchronously detected the next > time in which the kernel is accessed. What do you mean by "the kernel is accessed"? Also, there is no "exception" as such, only a bit in a register updated asynchronously. So the last sentence could be something like: In this mode, if a tag check fault occurs, the TFSR_EL1 register is updated asynchronously. The kernel checks the corresponding bits periodically. (or you can be more precise on when the kernel checks for such faults) > KASAN requires a specific mode of execution to make use of this hw feature. > > Add KASAN HW light execution mode. Shall we call it "fast"? ;) > --- /dev/null > +++ b/include/linux/kasan_def.h > @@ -0,0 +1,25 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef _LINUX_KASAN_DEF_H > +#define _LINUX_KASAN_DEF_H > + > +enum kasan_arg_mode { > + KASAN_ARG_MODE_DEFAULT, > + KASAN_ARG_MODE_OFF, > + KASAN_ARG_MODE_LIGHT, > + KASAN_ARG_MODE_PROD, > + KASAN_ARG_MODE_FULL, > +}; > + > +enum kasan_arg_stacktrace { > + KASAN_ARG_STACKTRACE_DEFAULT, > + KASAN_ARG_STACKTRACE_OFF, > + KASAN_ARG_STACKTRACE_ON, > +}; > + > +enum kasan_arg_fault { > + KASAN_ARG_FAULT_DEFAULT, > + KASAN_ARG_FAULT_REPORT, > + KASAN_ARG_FAULT_PANIC, > +}; > + > +#endif /* _LINUX_KASAN_DEF_H */ I thought we agreed not to expose the KASAN internal but come up with another abstraction. Maybe this was after you posted these patches. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel