From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1g5sch-0005fZ-UU for kexec@lists.infradead.org; Fri, 28 Sep 2018 13:16:01 +0000 Date: Fri, 28 Sep 2018 15:15:54 +0200 From: Borislav Petkov Subject: Re: [PATCH 1/3] x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one error Message-ID: <20180928131554.GC21895@zn.tnic> References: <153805773703.1157.14773321497580233478.stgit@bhelgaas-glaptop.roam.corp.google.com> <153805811578.1157.6948388946904655969.stgit@bhelgaas-glaptop.roam.corp.google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <153805811578.1157.6948388946904655969.stgit@bhelgaas-glaptop.roam.corp.google.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Bjorn Helgaas Cc: dan.j.williams@intel.com, brijesh.singh@amd.com, Lianbo Jiang , bhe@redhat.com, thomas.lendacky@amd.com, tiwai@suse.de, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, mingo@redhat.com, baiyaowei@cmss.chinamobile.com, hpa@zytor.com, tglx@linutronix.de, dyoung@redhat.com, akpm@linux-foundation.org, Vivek Goyal T24gVGh1LCBTZXAgMjcsIDIwMTggYXQgMDk6MjE6NTVBTSAtMDUwMCwgQmpvcm4gSGVsZ2FhcyB3 cm90ZToKPiBGcm9tOiBCam9ybiBIZWxnYWFzIDxiaGVsZ2Fhc0Bnb29nbGUuY29tPgo+IAo+IFRo ZSBvbmx5IHVzZSBvZiBLRVhFQ19CQUNLVVBfU1JDX0VORCBpcyBhcyBhbiBhcmd1bWVudCB0bwo+ IHdhbGtfc3lzdGVtX3JhbV9yZXMoKToKPiAKPiAgIGludCBjcmFzaF9sb2FkX3NlZ21lbnRzKHN0 cnVjdCBraW1hZ2UgKmltYWdlKQo+ICAgewo+ICAgICAuLi4KPiAgICAgd2Fsa19zeXN0ZW1fcmFt X3JlcyhLRVhFQ19CQUNLVVBfU1JDX1NUQVJULCBLRVhFQ19CQUNLVVBfU1JDX0VORCwKPiAgICAg ICAgICAgICAgICAgICAgICAgICBpbWFnZSwgZGV0ZXJtaW5lX2JhY2t1cF9yZWdpb24pOwo+IAo+ IHdhbGtfc3lzdGVtX3JhbV9yZXMoKSBleHBlY3RzICJzdGFydCwgZW5kIiBhcmd1bWVudHMgdGhh dCBhcmUgaW5jbHVzaXZlLAo+IGkuZS4sIHRoZSByYW5nZSB0byBiZSB3YWxrZWQgaW5jbHVkZXMg Ym90aCB0aGUgc3RhcnQgYW5kIGVuZCBhZGRyZXNzZXMuCj4gCj4gS0VYRUNfQkFDS1VQX1NSQ19F TkQgd2FzIHByZXZpb3VzbHkgZGVmaW5lZCBhcyAoNjQwICogMTAyNFVMKSwgd2hpY2ggaXMgdGhl Cj4gZmlyc3QgYWRkcmVzcyAqcGFzdCogdGhlIGRlc2lyZWQgMC02NDBLQiByYW5nZS4KPiAKPiBE ZWZpbmUgS0VYRUNfQkFDS1VQX1NSQ19FTkQgYXMgKDY0MCAqIDEwMjRVTCAtIDEpIHNvIHRoZSBL RVhFQ19CQUNLVVBfU1JDCj4gcmVnaW9uIGlzIFswLTB4OWZmZmZdLCBub3QgWzAtMHhhMDAwMF0u Cj4gCj4gRml4ZXM6IGRkNWY3MjYwNzZjYyAoImtleGVjOiBzdXBwb3J0IGZvciBrZXhlYyBvbiBw YW5pYyB1c2luZyBuZXcgc3lzdGVtIGNhbGwiKQo+IFNpZ25lZC1vZmYtYnk6IEJqb3JuIEhlbGdh YXMgPGJoZWxnYWFzQGdvb2dsZS5jb20+Cj4gLS0tCj4gIGFyY2gveDg2L2luY2x1ZGUvYXNtL2tl eGVjLmggfCAgICAyICstCj4gIDEgZmlsZSBjaGFuZ2VkLCAxIGluc2VydGlvbigrKSwgMSBkZWxl dGlvbigtKQo+IAo+IGRpZmYgLS1naXQgYS9hcmNoL3g4Ni9pbmNsdWRlL2FzbS9rZXhlYy5oIGIv YXJjaC94ODYvaW5jbHVkZS9hc20va2V4ZWMuaAo+IGluZGV4IGYzMjcyMzZmMGZhNy4uNTEyNWZj YTQ3MmJiIDEwMDY0NAo+IC0tLSBhL2FyY2gveDg2L2luY2x1ZGUvYXNtL2tleGVjLmgKPiArKysg Yi9hcmNoL3g4Ni9pbmNsdWRlL2FzbS9rZXhlYy5oCj4gQEAgLTY3LDcgKzY3LDcgQEAgc3RydWN0 IGtpbWFnZTsKPiAgCj4gIC8qIE1lbW9yeSB0byBiYWNrdXAgZHVyaW5nIGNyYXNoIGtkdW1wICov Cj4gICNkZWZpbmUgS0VYRUNfQkFDS1VQX1NSQ19TVEFSVAkoMFVMKQo+IC0jZGVmaW5lIEtFWEVD X0JBQ0tVUF9TUkNfRU5ECSg2NDAgKiAxMDI0VUwpCS8qIDY0MEsgKi8KPiArI2RlZmluZSBLRVhF Q19CQUNLVVBfU1JDX0VORAkoNjQwICogMTAyNFVMIC0gMSkJLyogNjQwSyAqLwo+ICAKPiAgLyoK PiAgICogQ1BVIGRvZXMgbm90IHNhdmUgc3MgYW5kIHNwIG9uIHN0YWNrIGlmIGV4ZWN1dGlvbiBp cyBhbHJlYWR5CgpSZXZpZXdlZC1ieTogQm9yaXNsYXYgUGV0a292IDxicEBzdXNlLmRlPgoKLS0g ClJlZ2FyZHMvR3J1c3MsCiAgICBCb3Jpcy4KClNVU0UgTGludXggR21iSCwgR0Y6IEZlbGl4IElt ZW5kw7ZyZmZlciwgSmFuZSBTbWl0aGFyZCwgR3JhaGFtIE5vcnRvbiwgSFJCIDIxMjg0IChBRyBO w7xybmJlcmcpCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f XwprZXhlYyBtYWlsaW5nIGxpc3QKa2V4ZWNAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlz dHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2tleGVjCg== 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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 36546C43382 for ; Fri, 28 Sep 2018 13:15:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01B17214C3 for ; Fri, 28 Sep 2018 13:15:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 01B17214C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729174AbeI1Tje (ORCPT ); Fri, 28 Sep 2018 15:39:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:52888 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726068AbeI1Tjd (ORCPT ); Fri, 28 Sep 2018 15:39:33 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8021CAD90; Fri, 28 Sep 2018 13:15:48 +0000 (UTC) Date: Fri, 28 Sep 2018 15:15:54 +0200 From: Borislav Petkov To: Bjorn Helgaas Cc: linux-kernel@vger.kernel.org, Lianbo Jiang , Vivek Goyal , kexec@lists.infradead.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, akpm@linux-foundation.org, dan.j.williams@intel.com, thomas.lendacky@amd.com, baiyaowei@cmss.chinamobile.com, tiwai@suse.de, brijesh.singh@amd.com, dyoung@redhat.com, bhe@redhat.com Subject: Re: [PATCH 1/3] x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one error Message-ID: <20180928131554.GC21895@zn.tnic> References: <153805773703.1157.14773321497580233478.stgit@bhelgaas-glaptop.roam.corp.google.com> <153805811578.1157.6948388946904655969.stgit@bhelgaas-glaptop.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <153805811578.1157.6948388946904655969.stgit@bhelgaas-glaptop.roam.corp.google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 27, 2018 at 09:21:55AM -0500, Bjorn Helgaas wrote: > From: Bjorn Helgaas > > The only use of KEXEC_BACKUP_SRC_END is as an argument to > walk_system_ram_res(): > > int crash_load_segments(struct kimage *image) > { > ... > walk_system_ram_res(KEXEC_BACKUP_SRC_START, KEXEC_BACKUP_SRC_END, > image, determine_backup_region); > > walk_system_ram_res() expects "start, end" arguments that are inclusive, > i.e., the range to be walked includes both the start and end addresses. > > KEXEC_BACKUP_SRC_END was previously defined as (640 * 1024UL), which is the > first address *past* the desired 0-640KB range. > > Define KEXEC_BACKUP_SRC_END as (640 * 1024UL - 1) so the KEXEC_BACKUP_SRC > region is [0-0x9ffff], not [0-0xa0000]. > > Fixes: dd5f726076cc ("kexec: support for kexec on panic using new system call") > Signed-off-by: Bjorn Helgaas > --- > arch/x86/include/asm/kexec.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h > index f327236f0fa7..5125fca472bb 100644 > --- a/arch/x86/include/asm/kexec.h > +++ b/arch/x86/include/asm/kexec.h > @@ -67,7 +67,7 @@ struct kimage; > > /* Memory to backup during crash kdump */ > #define KEXEC_BACKUP_SRC_START (0UL) > -#define KEXEC_BACKUP_SRC_END (640 * 1024UL) /* 640K */ > +#define KEXEC_BACKUP_SRC_END (640 * 1024UL - 1) /* 640K */ > > /* > * CPU does not save ss and sp on stack if execution is already Reviewed-by: Borislav Petkov -- Regards/Gruss, Boris. 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