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=-10.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 C53A3CA9EAF for ; Thu, 24 Oct 2019 19:00:38 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 2F0DF2166E for ; Thu, 24 Oct 2019 19:00:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F0DF2166E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46zc5H24MdzDqZX for ; Fri, 25 Oct 2019 06:00:35 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=permerror (SPF Permanent Error: Unknown mechanism found: ip:192.40.192.88/32) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46zZR40bwQzDqQw for ; Fri, 25 Oct 2019 04:45:51 +1100 (AEDT) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x9OHjkAJ010080; Thu, 24 Oct 2019 12:45:46 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id x9OHjjCA010079; Thu, 24 Oct 2019 12:45:45 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Thu, 24 Oct 2019 12:45:45 -0500 From: Segher Boessenkool To: Alexey Kardashevskiy Subject: Re: [PATCH] powerpc/boot: Fix the initrd being overwritten under qemu Message-ID: <20191024174545.GT28442@gate.crashing.org> References: <20191023013635.2512-1-oohall@gmail.com> <20191023112102.GN28442@gate.crashing.org> <90a0f702-6891-cd14-f190-5682d7c3778e@ozlabs.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <90a0f702-6891-cd14-f190-5682d7c3778e@ozlabs.ru> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, Oliver O'Halloran , stable@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Oct 24, 2019 at 12:31:24PM +1100, Alexey Kardashevskiy wrote: > > > On 23/10/2019 22:21, Segher Boessenkool wrote: > > On Wed, Oct 23, 2019 at 12:36:35PM +1100, Oliver O'Halloran wrote: > >> When booting under OF the zImage expects the initrd address and size to be > >> passed to it using registers r3 and r4. SLOF (guest firmware used by QEMU) > >> currently doesn't do this so the zImage is not aware of the initrd > >> location. This can result in initrd corruption either though the zImage > >> extracting the vmlinux over the initrd, or by the vmlinux overwriting the > >> initrd when relocating itself. > >> > >> QEMU does put the linux,initrd-start and linux,initrd-end properties into > >> the devicetree to vmlinux to find the initrd. We can work around the SLOF > >> bug by also looking those properties in the zImage. > > > > This is not a bug. What boot protocol requires passing the initrd start > > and size in GPR3, GPR4? > > So far I was unable to identify it... Maybe this comes from yaboot? https://git.ozlabs.org/?p=yaboot.git;a=blob;f=second/yaboot.c;h=9b66ab44e1be0ee82b88e386a5d0358428766e73;hb=HEAD#l1186 > > The CHRP binding (what SLOF implements) requires passing two zeroes here. > > And ePAPR requires passing the address of a device tree and a zero, plus > > something in GPR6 to allow distinguishing what it does. > > > > As Alexey says, initramfs works just fine, so please use that? initrd was > > deprecated when this code was written already. > > I did not say about anything working fine :) Yeah, I read that from your words, wrong it seems. Sorry. I often used INITRAMFS_SOURCE for kernels for use with SLOF, it's just so convenient. > In my case I was using a new QEMU which does full FDT on client-arch-support and that thing would put the original > linux,initrd-start/end to the FDT even though the initrd was unpacked and the properties were changes in SLOF. With that > fixed, this is an alternative fix for SLOF but I am not pushing it out as I have no idea about the bindings and this > also breaks "vmlinux". > > > diff --git a/slof/fs/client.fs b/slof/fs/client.fs > index 8a7f6ac4326d..138177e4c2a3 100644 > --- a/slof/fs/client.fs > +++ b/slof/fs/client.fs > @@ -45,6 +45,17 @@ VARIABLE client-callback \ Address of client's callback function > >r ciregs >r7 ! ciregs >r6 ! client-entry-point @ ciregs >r5 ! > \ Initialise client-stack-pointer > cistack ciregs >r1 ! > + > + s" linux,initrd-end" get-chosen IF decode-int -rot 2drop ELSE 0 THEN > + s" linux,initrd-start" get-chosen IF decode-int -rot 2drop ELSE 0 THEN > + 2dup - dup IF > + ciregs >r4 ! > + ciregs >r3 ! > + drop > + ELSE > + 3drop > + THEN Something like that should work fine. Do it in go-32 and go-64 though? Or is that the wrong spot? Segher 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=-10.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,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 E8350CA9EAF for ; Thu, 24 Oct 2019 17:45:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C584C20659 for ; Thu, 24 Oct 2019 17:45:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392216AbfJXRpz (ORCPT ); Thu, 24 Oct 2019 13:45:55 -0400 Received: from gate.crashing.org ([63.228.1.57]:54897 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729458AbfJXRpz (ORCPT ); Thu, 24 Oct 2019 13:45:55 -0400 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x9OHjkAJ010080; Thu, 24 Oct 2019 12:45:46 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id x9OHjjCA010079; Thu, 24 Oct 2019 12:45:45 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Thu, 24 Oct 2019 12:45:45 -0500 From: Segher Boessenkool To: Alexey Kardashevskiy Cc: "Oliver O'Halloran" , linuxppc-dev@lists.ozlabs.org, stable@vger.kernel.org Subject: Re: [PATCH] powerpc/boot: Fix the initrd being overwritten under qemu Message-ID: <20191024174545.GT28442@gate.crashing.org> References: <20191023013635.2512-1-oohall@gmail.com> <20191023112102.GN28442@gate.crashing.org> <90a0f702-6891-cd14-f190-5682d7c3778e@ozlabs.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <90a0f702-6891-cd14-f190-5682d7c3778e@ozlabs.ru> User-Agent: Mutt/1.4.2.3i Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, Oct 24, 2019 at 12:31:24PM +1100, Alexey Kardashevskiy wrote: > > > On 23/10/2019 22:21, Segher Boessenkool wrote: > > On Wed, Oct 23, 2019 at 12:36:35PM +1100, Oliver O'Halloran wrote: > >> When booting under OF the zImage expects the initrd address and size to be > >> passed to it using registers r3 and r4. SLOF (guest firmware used by QEMU) > >> currently doesn't do this so the zImage is not aware of the initrd > >> location. This can result in initrd corruption either though the zImage > >> extracting the vmlinux over the initrd, or by the vmlinux overwriting the > >> initrd when relocating itself. > >> > >> QEMU does put the linux,initrd-start and linux,initrd-end properties into > >> the devicetree to vmlinux to find the initrd. We can work around the SLOF > >> bug by also looking those properties in the zImage. > > > > This is not a bug. What boot protocol requires passing the initrd start > > and size in GPR3, GPR4? > > So far I was unable to identify it... Maybe this comes from yaboot? https://git.ozlabs.org/?p=yaboot.git;a=blob;f=second/yaboot.c;h=9b66ab44e1be0ee82b88e386a5d0358428766e73;hb=HEAD#l1186 > > The CHRP binding (what SLOF implements) requires passing two zeroes here. > > And ePAPR requires passing the address of a device tree and a zero, plus > > something in GPR6 to allow distinguishing what it does. > > > > As Alexey says, initramfs works just fine, so please use that? initrd was > > deprecated when this code was written already. > > I did not say about anything working fine :) Yeah, I read that from your words, wrong it seems. Sorry. I often used INITRAMFS_SOURCE for kernels for use with SLOF, it's just so convenient. > In my case I was using a new QEMU which does full FDT on client-arch-support and that thing would put the original > linux,initrd-start/end to the FDT even though the initrd was unpacked and the properties were changes in SLOF. With that > fixed, this is an alternative fix for SLOF but I am not pushing it out as I have no idea about the bindings and this > also breaks "vmlinux". > > > diff --git a/slof/fs/client.fs b/slof/fs/client.fs > index 8a7f6ac4326d..138177e4c2a3 100644 > --- a/slof/fs/client.fs > +++ b/slof/fs/client.fs > @@ -45,6 +45,17 @@ VARIABLE client-callback \ Address of client's callback function > >r ciregs >r7 ! ciregs >r6 ! client-entry-point @ ciregs >r5 ! > \ Initialise client-stack-pointer > cistack ciregs >r1 ! > + > + s" linux,initrd-end" get-chosen IF decode-int -rot 2drop ELSE 0 THEN > + s" linux,initrd-start" get-chosen IF decode-int -rot 2drop ELSE 0 THEN > + 2dup - dup IF > + ciregs >r4 ! > + ciregs >r3 ! > + drop > + ELSE > + 3drop > + THEN Something like that should work fine. Do it in go-32 and go-64 though? Or is that the wrong spot? Segher