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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 2CFCDC5CFEB for ; Wed, 11 Jul 2018 16:32:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9EDC20846 for ; Wed, 11 Jul 2018 16:32:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9EDC20846 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ab.jp.nec.com 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 S2387947AbeGKQhy (ORCPT ); Wed, 11 Jul 2018 12:37:54 -0400 Received: from tyo161.gate.nec.co.jp ([114.179.232.161]:59959 "EHLO tyo161.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387727AbeGKQhy (ORCPT ); Wed, 11 Jul 2018 12:37:54 -0400 Received: from mailgate02.nec.co.jp ([114.179.233.122]) by tyo161.gate.nec.co.jp (8.15.1/8.15.1) with ESMTPS id w6BGWLOX007142 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 12 Jul 2018 01:32:21 +0900 Received: from mailsv02.nec.co.jp (mailgate-v.nec.co.jp [10.204.236.94]) by mailgate02.nec.co.jp (8.15.1/8.15.1) with ESMTP id w6BGWLJF021870; Thu, 12 Jul 2018 01:32:21 +0900 Received: from mail02.kamome.nec.co.jp (mail02.kamome.nec.co.jp [10.25.43.5]) by mailsv02.nec.co.jp (8.15.1/8.15.1) with ESMTP id w6BGWLXD002287; Thu, 12 Jul 2018 01:32:21 +0900 Received: from bpxc99gp.gisp.nec.co.jp ([10.38.151.140] [10.38.151.140]) by mail02.kamome.nec.co.jp with ESMTP id BT-MMP-1905699; Thu, 12 Jul 2018 01:31:16 +0900 Received: from BPXM09GP.gisp.nec.co.jp ([10.38.151.201]) by BPXC12GP.gisp.nec.co.jp ([10.38.151.140]) with mapi id 14.03.0319.002; Thu, 12 Jul 2018 01:31:15 +0900 From: Kazuhito Hagio To: Tetsuo Handa CC: Linus Torvalds , Kees Cook , Linux Kernel Mailing List , "kexec@lists.infradead.org" , Masaki Tachibana , Kazuhito Hagio Subject: RE: [PATCH] uts: Don't randomize "struct uts_namespace". Thread-Topic: [PATCH] uts: Don't randomize "struct uts_namespace". Thread-Index: AQHUFX6ASnXzCzL8XECr2n/5vacVkaSKO0hA Date: Wed, 11 Jul 2018 16:31:15 +0000 Message-ID: <4AE2DC15AC0B8543882A74EA0D43DBEC035582C1@BPXM09GP.gisp.nec.co.jp> References: <1530871650-3582-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <271dcdcd-d622-552c-338a-5eeca5e2b4a0@i-love.sakura.ne.jp> In-Reply-To: <271dcdcd-d622-552c-338a-5eeca5e2b4a0@i-love.sakura.ne.jp> Accept-Language: ja-JP, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [143.101.133.131] Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 MIME-Version: 1.0 X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org SGkgVGV0c3VvLA0KDQpUaGFua3MgZm9yIHlvdXIgcmVwb3J0Lg0KDQpPbiBGcmlkYXksIEp1bHkg NiwgMjAxOCA3OjEwIFBNLCBUZXRzdW8gSGFuZGEgd3JvdGU6DQo+IEhlbGxvIEtlbidpY2hpLA0K PiANCj4gSSBub3RpY2VkIHRoYXQgbWFrZWR1bXBmaWxlICggaHR0cHM6Ly9zb3VyY2Vmb3JnZS5u ZXQvcC9tYWtlZHVtcGZpbGUvY29kZS8gKQ0KPiBjYW4gbm8gbG9uZ2VyIGRldGVjdCBrZXJuZWwg dmVyc2lvbiBjb3JyZWN0bHkgYmVjYXVzZSAic3RydWN0IHV0c19uYW1lc3BhY2UiDQo+ICh3aGlj aCBpcyBleHBvc2VkIHRvIHVzZXJzcGFjZSB2aWEgdm1jb3JlaW5mbykgaXMgc3ViamVjdGVkIHRv IHJhbmRvbWl6YXRpb24NCj4gYnkgR0NDX1BMVUdJTl9SQU5EU1RSVUNUIGtlcm5lbCBjb25maWcg b3B0aW9uIHNpbmNlIDQuMTMuDQo+IA0KPiBUaGUgY29kZSB3YXMgaW50cm9kdWNlZCBieSBiZWxv dyBjb21taXQuDQo+IA0KPiAgIGNvbW1pdCBiZmM4ZmUxODFjODIyYWQwZDg0OTVjZWRhM2M3MTA5 YTQwNzE5MmYwDQo+ICAgQXV0aG9yOiBrZW4xX29obWljaGkgPGtlbjFfb2htaWNoaT4NCj4gICBE YXRlOiAgIEZyaSBEZWMgMjIgMDc6NDE6MTQgMjAwNiArMDAwMA0KPiANCj4gICAgICAgbGludXgt Mi42LjE5IHN1cHBvcnQuDQo+ICAgICAgIE9uIGxpbnV4LTIuNi4xOCBvciBmb3JtZXIsIHRoZSBy ZWxlYXNlIGluZm9ybWF0aW9uIGNvdWxkIGJlIGdvdHRlbiBmcm9tDQo+ICAgICAgIHRoZSBzeW1i b2wgInN5c3RlbV91dHNuYW1lIi4gQnV0IG9uIGxpbnV4LTIuNi4xOSwgaXQgY2FuIGJlIGRvbmUg ZnJvbSB0aGUNCj4gICAgICAgc3ltYm9sICJpbml0X3V0c19ucyIuIEEgbmV3IG1ha2VkdW1wZmls ZSBjYW4gZ2V0IHRoZSByZWxlYXNlIGluZm9ybWF0aW9uDQo+ICAgICAgIGZyb20gdGhlIGV4aXN0 aW5nIHN5bWJvbC4NCj4gDQo+IENhbiB5b3UgZGV0ZWN0IGtlcm5lbCB2ZXJzaW9uIHdpdGhvdXQg dXNpbmcgInN0cnVjdCB1dHNfbmFtZXNwYWNlIiA/DQoNCm1ha2VkdW1wZmlsZSBuZWVkcyBhIHdo b2xlICJzdHJ1Y3QgbmV3X3V0c25hbWUiIGRhdGEgaW4gInN0cnVjdCB1dHNfbmFtZXNwYWNlIg0K YmVjYXVzZSBpdCBoYXMgdG8gd3JpdGUgdGhlIGRhdGEgb3V0IHRvIGR1bXAgZmlsZSBoZWFkZXIs IHNvIHdlIG5lZWQgdG8gYWRkDQp0aGUgb2Zmc2V0IG9mIHV0c19uYW1lc3BhY2UubmFtZSB0byB2 bWNvcmVpbmZvIG9yIGdldCBpdCBmcm9tIHZtbGludXguDQpCdXQgSSdtIG5vdCBzdXJlIHdoZXRo ZXIgaXQgaXMgYWxsIHRvIGdldCBtYWtlZHVtcGZpbGUgd29ya2luZyB3ZWxsIHdpdGggdGhlDQpy YW5kb21pemF0aW9uLCBlLmcuIHNvbWUgYWRkaXRpb25hbCBvZmZzZXQgZXhwb3N1cmVzIG1pZ2h0 IGJlIG5lZWRlZC4NCg0KQW5kIEkgc2F3IGEgcmVwb3J0IHRvIHRoZSBjcmFzaCB1dGlsaXR5IG1h aWxpbmcgbGlzdCB0aGF0IGNyYXNoIGFsc28gY291bGRuJ3QNCndvcmsgd2l0aCB0aGUgcmFuZG9t aXphdGlvbiBkdWUgdG8gYSB2bWxpbnV4IGlzc3VlLCBzbyBpZiBpdCBpcyBzdGlsbCBub3QgZml4 ZWQsDQpldmVuIGlmIG1ha2VkdW1wZmlsZSAoYW5kIGtlcm5lbCkgaXMgZml4ZWQsIHdlIGNhbm5v dCB1c2UgY3Jhc2guDQoNCiogW0NyYXNoLXV0aWxpdHldIFVzaW5nIGNyYXNoIHdpdGggc3RydWN0 dXJlIGxheW91dCByYW5kb21pemVkIGtlcm5lbA0KICBodHRwczovL3d3dy5yZWRoYXQuY29tL2Fy Y2hpdmVzL2NyYXNoLXV0aWxpdHkvMjAxOC1KYW51YXJ5L3RocmVhZC5odG1sIzAwMDM1DQoNClRo YW5rcywNCkthenUNCg0KPiANCj4gT24gMjAxOC8wNy8wNyAxOjExLCBMaW51cyBUb3J2YWxkcyB3 cm90ZToNCj4gPiBPbiBGcmksIEp1bCA2LCAyMDE4IGF0IDM6MDcgQU0gVGV0c3VvIEhhbmRhDQo+ ID4gPHBlbmd1aW4ta2VybmVsQGktbG92ZS5zYWt1cmEubmUuanA+IHdyb3RlOg0KPiA+Pg0KPiA+ PiBJIG5vdGljZWQgdGhhdCBtYWtlZHVtcGZpbGUgdXRpbGl0eSBpcyBmYWlsaW5nIHRvIGNoZWNr IGtlcm5lbCB2ZXJzaW9uLCBmb3INCj4gPj4gaXQgZGVwZW5kcyBvbiBvZmZzZXQgb2YgInN0cnVj dCB1dHNfbmFtZXNwYWNlIi0+bmFtZSBiZWluZyBzaXplb2YoaW50KS4NCj4gPg0KPiA+IEZvciBz b21ldGhpbmcgbGlrZSB0aGlzLCB3ZSBmaXggbWFrZWR1bXBmaWxlIGluc3RlYWQuIFRoaXMgaXMg bm90IGENCj4gPiAidXNlciBwcm9ncmFtIiB1c2luZyBzeXN0ZW0gY2FsbHMgZXRjLCB0aGlzIGlz IHNvbWV0aGluZyB0aGF0IGRlbHZlcw0KPiA+IGludG8gdGhlIGtlcm5lbCBkdW1wIGFuZCB0cmll cyB0byBtYWtlIHNlbnNlIG9mIGl0Lg0KPiA+DQo+ID4gV2hlcmUgaXMgdGhlIG1ha2VkdW1wZmls ZSBzb3VyY2UgY29kZT8gV2hhdCBpcyBpdCB0cnlpbmcgdG8gZG8sIGFuZCB3aHk/DQo+ID4NCj4g PiBPbmUgb3B0aW9uIGlzIHRvIGp1c3Qgc2F5ICJoZXksIHlvdSBjYW4ndCBtYWtlIG11Y2ggc2Vu c2Ugb2YgYQ0KPiA+IHJhbmRvbWl6ZWQga2VybmVsIGR1bXAgYW55d2F5LCBzbyBkb24ndCBldmVu IHRyeSIuDQo+ID4NCj4gPiAgICAgICAgICAgICAgICAgIExpbnVzDQo+ID4NCj4gDQoNCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from tyo161.gate.nec.co.jp ([114.179.232.161]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fdI2h-0004cF-DE for kexec@lists.infradead.org; Wed, 11 Jul 2018 16:32:44 +0000 From: Kazuhito Hagio Subject: RE: [PATCH] uts: Don't randomize "struct uts_namespace". Date: Wed, 11 Jul 2018 16:31:15 +0000 Message-ID: <4AE2DC15AC0B8543882A74EA0D43DBEC035582C1@BPXM09GP.gisp.nec.co.jp> References: <1530871650-3582-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <271dcdcd-d622-552c-338a-5eeca5e2b4a0@i-love.sakura.ne.jp> In-Reply-To: <271dcdcd-d622-552c-338a-5eeca5e2b4a0@i-love.sakura.ne.jp> Content-Language: en-US MIME-Version: 1.0 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: Tetsuo Handa Cc: Masaki Tachibana , Kazuhito Hagio , Kees Cook , "kexec@lists.infradead.org" , Linux Kernel Mailing List , Linus Torvalds Hi Tetsuo, Thanks for your report. On Friday, July 6, 2018 7:10 PM, Tetsuo Handa wrote: > Hello Ken'ichi, > > I noticed that makedumpfile ( https://sourceforge.net/p/makedumpfile/code/ ) > can no longer detect kernel version correctly because "struct uts_namespace" > (which is exposed to userspace via vmcoreinfo) is subjected to randomization > by GCC_PLUGIN_RANDSTRUCT kernel config option since 4.13. > > The code was introduced by below commit. > > commit bfc8fe181c822ad0d8495ceda3c7109a407192f0 > Author: ken1_ohmichi > Date: Fri Dec 22 07:41:14 2006 +0000 > > linux-2.6.19 support. > On linux-2.6.18 or former, the release information could be gotten from > the symbol "system_utsname". But on linux-2.6.19, it can be done from the > symbol "init_uts_ns". A new makedumpfile can get the release information > from the existing symbol. > > Can you detect kernel version without using "struct uts_namespace" ? makedumpfile needs a whole "struct new_utsname" data in "struct uts_namespace" because it has to write the data out to dump file header, so we need to add the offset of uts_namespace.name to vmcoreinfo or get it from vmlinux. But I'm not sure whether it is all to get makedumpfile working well with the randomization, e.g. some additional offset exposures might be needed. And I saw a report to the crash utility mailing list that crash also couldn't work with the randomization due to a vmlinux issue, so if it is still not fixed, even if makedumpfile (and kernel) is fixed, we cannot use crash. * [Crash-utility] Using crash with structure layout randomized kernel https://www.redhat.com/archives/crash-utility/2018-January/thread.html#00035 Thanks, Kazu > > On 2018/07/07 1:11, Linus Torvalds wrote: > > On Fri, Jul 6, 2018 at 3:07 AM Tetsuo Handa > > wrote: > >> > >> I noticed that makedumpfile utility is failing to check kernel version, for > >> it depends on offset of "struct uts_namespace"->name being sizeof(int). > > > > For something like this, we fix makedumpfile instead. This is not a > > "user program" using system calls etc, this is something that delves > > into the kernel dump and tries to make sense of it. > > > > Where is the makedumpfile source code? What is it trying to do, and why? > > > > One option is to just say "hey, you can't make much sense of a > > randomized kernel dump anyway, so don't even try". > > > > Linus > > > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec