From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rwXGF3n8YzDrF8 for ; Fri, 22 Jul 2016 10:53:57 +1000 (AEST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u6M0rq9h107319 for ; Thu, 21 Jul 2016 20:53:54 -0400 Received: from e23smtp04.au.ibm.com (e23smtp04.au.ibm.com [202.81.31.146]) by mx0b-001b2d01.pphosted.com with ESMTP id 24ay1uc90y-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 21 Jul 2016 20:53:54 -0400 Received: from localhost by e23smtp04.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 22 Jul 2016 10:53:47 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 9820F2BB0054 for ; Fri, 22 Jul 2016 10:53:45 +1000 (EST) Received: from d23av06.au.ibm.com (d23av06.au.ibm.com [9.190.235.151]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u6M0rj6H13959168 for ; Fri, 22 Jul 2016 10:53:45 +1000 Received: from d23av06.au.ibm.com (localhost [127.0.0.1]) by d23av06.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u6M0riXT017028 for ; Fri, 22 Jul 2016 10:53:45 +1000 Subject: Re: [RFC 0/3] extend kexec_file_load system call To: Thiago Jung Bauermann , Arnd Bergmann References: <20160712014201.11456-1-takahiro.akashi@linaro.org> <3489461.zQnV5C1bXR@wuerfel> <1808359.GMbkTHC4O6@hactar> <4197460.etrDupniY8@hactar> Cc: Russell King - ARM Linux , Vivek Goyal , Mark Rutland , Stewart Smith , Mimi Zohar , bhe@redhat.com, linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, AKASHI Takahiro , "Eric W. Biederman" , Samuel Mendoza-Jonas , Dave Young , linux-arm-kernel@lists.infradead.org, Jeremy Kerr , Michael Ellerman From: Jeremy Kerr Date: Fri, 22 Jul 2016 08:53:41 +0800 MIME-Version: 1.0 In-Reply-To: <4197460.etrDupniY8@hactar> Content-Type: text/plain; charset=windows-1252 Message-Id: <7619c6f9-689e-f062-08d4-0d11a2df66ad@au.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Thiago, > So even if not ideal, the solution above is desirable for powerpc. We would > like to preserve the ability of allowing userspace to pass parameters to the > OS via the DTB, even if secure boot is enabled. > > I would like to turn the above into a proposal: > > Extend the syscall as shown in this RFC from Takahiro AKASHI, but instead of > accepting a complete DTB from userspace, the syscall accepts a DTB > containing only a /chosen node. If the DTB contains any other node, the > syscall fails with EINVAL. If the DTB contains any subnode in /chosen, or if > there's a compatible or device_type property in /chosen, the syscall fails > with EINVAL as well. This works for me. We could even have it as just a DTB fragment that is merged *at* the /chosen/ node of the kernel-device tree - so would not contain a /chosen node itself, and it would be impossible to provide nodes outside of /chosen. Either is fine. Thanks! Jeremy