From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hIszV-0001Rd-DB for kexec@lists.infradead.org; Tue, 23 Apr 2019 10:49:54 +0000 Date: Tue, 23 Apr 2019 18:49:24 +0800 From: Dave Young Subject: Re: [PATCH] x86/kexec: always ensure EFI systab region is mapped Message-ID: <20190423104924.GA1730@dhcp-128-65.nay.redhat.com> References: <20190422092804.15534-1-kasong@redhat.com> <965f770a-b103-72fb-eaef-cb337ebe8290@ce.jp.nec.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <965f770a-b103-72fb-eaef-cb337ebe8290@ce.jp.nec.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Junichi Nomura Cc: "x86@kernel.org" , Kairui Song , Baoquan He , Chao Fan , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Borislav Petkov , Thomas Gleixner On 04/23/19 at 06:20am, Junichi Nomura wrote: > On 4/22/19 6:28 PM, Kairui Song wrote: > > The reason is the systab region is not mapped by the identity mapping > > provided by kexec. Currently kexec only create identity mapping for > > mem regions, wihch won't cover the systab. So second kernel will be > > accessing a not mapped memory region and cause fault. > > But as kexec tend to pad the map region up to PUD size, the > > systab could be included in the map by accident, so it worked on > > some machines, but that will be broken easily and unstable. > > Is the mapping of ACPI tables just by luck, too? Hmm, guess it should be mapped by luck, here is the range on the T420: da99f000 - dae9efff Reserved (efi systab fall in this region) daf9f000 - daffefff ACPI tables Thanks Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec