From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Mon, 20 Sep 2021 11:15:33 +0200 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1mSFOf-0007dh-0J for lore@lore.pengutronix.de; Mon, 20 Sep 2021 11:15:33 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mSFOe-0008VF-1u for lore@pengutronix.de; Mon, 20 Sep 2021 11:15:32 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:Cc:To:Subject:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=CgBNB4XR2A65OfYvnBfH+Mi7Ysf77CpPyak53nwLiSk=; b=LEKwodlU575hBMWhW/X7s1EPOm 1vB0y87M/mn67SYLuRuEmB/O4JH+R+rzqYFfQto84BBnUkrJlA7L7a6slDU/ebY++0sxOnFDdzQe7 LOjHANYkvhRIdbEJqjTXC/GSoV1CZlPsrA22ALvOvWj4pz/Kt4fNh2DYBpQy0fzxPKAZ19RfIgdYv CuaC+7RKGmpjPeM3irRd7l7N0TOSdkvUZbEvLL1p+LuPHJJubSlH/223XiEhDQYdco00AU6YPST7/ FiE2CpdGDvjT4QE9mGHjCfxJVPpitq2TNem1oP7M+9Sgn4GzLFnpMEGrsSoDrPe5C1j5CTy2G9J6w GjBCrOGQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mSFNI-0013xC-Tm; Mon, 20 Sep 2021 09:14:08 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mSFNE-0013wq-G6 for barebox@lists.infradead.org; Mon, 20 Sep 2021 09:14:06 +0000 Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=[IPv6:::1]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1mSFNC-0008Jb-SJ; Mon, 20 Sep 2021 11:14:02 +0200 To: Peter Rosin , Rouven Czerwinski , Sascha Hauer , Ahmad Fatoum Cc: Barebox List References: <781e128b-14f3-3577-e433-f6a13fff8159@axentia.se> <02b09328-e300-f36e-4cc4-daa7afb47ad5@axentia.se> From: Ahmad Fatoum Message-ID: Date: Mon, 20 Sep 2021 11:14:01 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <02b09328-e300-f36e-4cc4-daa7afb47ad5@axentia.se> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210920_021404_590092_2BF4202C X-CRM114-Status: GOOD ( 24.59 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:e::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.3 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 3/4] Revert "ARM: mmu: use client domain permissions to support ARMv7 eXecute Never" X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) Hi Peter, On 19.09.21 09:50, Peter Rosin wrote: > On 2021-09-19 09:06, Rouven Czerwinski wrote: >> Hi Peter, >> >> while this may break for your board, it fundamentally introduces the >> possibility to speculate out of the RAM area on speculation happy > > I'm aware of that. For me, speculation is not an issue since *any* > rogue code running on the embedded device in question is a major fail. We have seen Cortex-A7 CPUs speculatively executing I/O memory. That's why we mar everything eXecute-Never except for known memory banks and expect board code to mark any further regions that are safe to execute manually. > Also, from the cover letter: > > "I'm going to follow up with patches. I very much realize that > these patches are most likely not acceptable as-is, but I do > include them since they are probably the best description of > where the problems are." > >> processors. Are you calling into SAMA5D3 ROM code somewhere? If so an > > *I* am not calling anything. Maybe the board code for sama5d3xek is, > but I have no idea as it's not "my" code. How can I figure out if it > does? If you don't revert this patch. Do you get any output at all? If not, enable DEBUG_LL and see how far you get before hanging. Cheers, Ahad > > Cheers, > Peter > >> exception can be added similar to the handling for the HAB code >> (arch/arm/cpu/mmu_early.c): >> >> if (IS_ENABLED(CONFIG_HABV4) && IS_ENABLED(CONFIG_ARCH_IMX6)) >> map_region(0x0, SZ_1M, PMD_SECT_DEF_CACHED); >> >> which allows calls into the NXP boot ROM to retrieve the HAB status. > > _______________________________________________ > barebox mailing list > barebox@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/barebox > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox