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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,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 8340BC31E45 for ; Thu, 13 Jun 2019 20:48:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5809B21537 for ; Thu, 13 Jun 2019 20:48:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729552AbfFMUsE (ORCPT ); Thu, 13 Jun 2019 16:48:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40314 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725747AbfFMUsE (ORCPT ); Thu, 13 Jun 2019 16:48:04 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 01294308427C; Thu, 13 Jun 2019 20:48:04 +0000 (UTC) Received: from [10.10.120.121] (ovpn-120-121.rdu2.redhat.com [10.10.120.121]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 593B060FBD; Thu, 13 Jun 2019 20:48:03 +0000 (UTC) Subject: Re: [PATCH v4 00/10] klp-convert livepatch build tooling From: Joe Lawrence To: Miroslav Benes Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, linux-kbuild@vger.kernel.org References: <20190509143859.9050-1-joe.lawrence@redhat.com> Message-ID: Date: Thu, 13 Jun 2019 16:48:02 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Thu, 13 Jun 2019 20:48:04 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/13/19 9:15 AM, Joe Lawrence wrote: > On 6/13/19 9:00 AM, Miroslav Benes wrote: >> Hi Joe, >> >> first, I'm sorry for the lack of response so far. >> >> Maybe you've already noticed but the selftests fail. Well, at least in >> my VM. When test_klp_convert1.ko is loaded, the process is killed with >> >> [ 518.041826] BUG: kernel NULL pointer dereference, address: 0000000000000000 >> [ 518.042816] #PF: supervisor read access in kernel mode >> [ 518.043393] #PF: error_code(0x0000) - not-present page >> [ 518.043981] PGD 0 P4D 0 >> [ 518.044185] Oops: 0000 [#1] SMP PTI >> [ 518.044518] CPU: 2 PID: 2255 Comm: insmod Tainted: G O K 5.1.0-klp_convert_v4-193435-g67748576637e #2 >> [ 518.045784] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014 >> [ 518.046940] RIP: 0010:test_klp_convert_init+0x1c/0x40 [test_klp_convert1] >> [ 518.047611] Code: 1b a0 48 89 c6 e9 a8 c0 f4 e0 0f 1f 40 00 0f 1f 44 00 00 53 48 c7 c7 00 30 1b a0 e8 5e 33 f6 e0 85 c0 89 c3 74 04 89 d8 5b c3 <48> 8b 35 5d ef e4 5f 48 c7 c7 28 20 1b a0 e8 75 c0 f4 e0 e8 6c ff >> [ 518.049779] RSP: 0018:ffffc90000f37cc8 EFLAGS: 00010246 >> [ 518.050243] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000027de0 >> [ 518.050922] RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff88807ab54f40 >> [ 518.051619] RBP: ffffffffa01b1080 R08: 0000000096efde7a R09: 0000000000000001 >> [ 518.052332] R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffffffff >> [ 518.053012] R13: 0000000000000000 R14: ffff888078b55000 R15: ffffc90000f37ea0 >> [ 518.053714] FS: 00007febece1fb80(0000) GS:ffff88807d400000(0000) knlGS:0000000000000000 >> [ 518.054514] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> [ 518.055078] CR2: 0000000000000000 CR3: 000000007a56a000 CR4: 00000000000006e0 >> [ 518.055818] Call Trace: >> [ 518.056007] do_one_initcall+0x6a/0x2da >> [ 518.056340] ? do_init_module+0x22/0x230 >> [ 518.056702] ? rcu_read_lock_sched_held+0x96/0xa0 >> [ 518.057125] ? kmem_cache_alloc_trace+0x284/0x2e0 >> [ 518.057493] do_init_module+0x5a/0x230 >> [ 518.057900] load_module+0x17bc/0x1f50 >> [ 518.058214] ? __symbol_put+0x40/0x40 >> [ 518.058499] ? vfs_read+0x12d/0x160 >> [ 518.058766] __do_sys_finit_module+0x83/0xc0 >> [ 518.059122] do_syscall_64+0x57/0x190 >> [ 518.059407] entry_SYSCALL_64_after_hwframe+0x49/0xbe >> ... >> >> It crashes right in test_klp_convert_init() when print_*() using >> supposed-to-be-converted symbols are called. I'll debug it next week. Can >> you reproduce it too? > > Hey, thanks for the report.. > > I don't recall the tests crashing, but I had put this patchset on the > side for a few weeks now. I'll try to fire up a VM and see what happens > today. > Hmm, I haven't been able to reproduce using my original base (Linux 5.1-rc6) or when rebased ontop of livepatching.git/master + 997a55f3fb6d("stacktrace: Unbreak stack_trace_save_tsk_reliable()") FWIW, my test_klp_convert1.ko has these klp-converted relocations: Relocation section [36] '.klp.rela.vmlinux..text.unlikely' for section [ 5] '.text.unlikely' at offset 0x4a6b8 contains 1 entry: Offset Type Value Addend Name 0x0000000000000003 X86_64_PC32 000000000000000000 -4 .klp.sym.vmlinux.saved_command_line,0 Relocation section [37] '.klp.rela.test_klp_convert_mod..text.unlikely' for section [ 5] '.text.unlikely' at offset 0x4a6d0 contains 4 entries: Offset Type Value Addend Name 0x000000000000004e X86_64_PC32 000000000000000000 -4 .klp.sym.test_klp_convert_mod.get_homonym_string,1 0x000000000000003d X86_64_32S 000000000000000000 +0 .klp.sym.test_klp_convert_mod.homonym_string,1 0x0000000000000027 X86_64_PC32 000000000000000000 -4 .klp.sym.test_klp_convert_mod.get_driver_name,0 0x0000000000000016 X86_64_32S 000000000000000000 +0 .klp.sym.test_klp_convert_mod.driver_name,0 -- Joe