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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7C11C43334 for ; Wed, 15 Jun 2022 13:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348404AbiFONhk (ORCPT ); Wed, 15 Jun 2022 09:37:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348465AbiFONhh (ORCPT ); Wed, 15 Jun 2022 09:37:37 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EC6F9CE3; Wed, 15 Jun 2022 06:37:32 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BF271153B; Wed, 15 Jun 2022 06:37:32 -0700 (PDT) Received: from FVFF77S0Q05N (unknown [10.57.38.208]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7E3BB3F7F5; Wed, 15 Jun 2022 06:37:30 -0700 (PDT) Date: Wed, 15 Jun 2022 14:37:26 +0100 From: Mark Rutland To: "Ivan T. Ivanov" Cc: madvenka@linux.microsoft.com, jpoimboe@redhat.com, peterz@infradead.org, chenzhongjin@huawei.com, broonie@kernel.org, nobuta.keiya@fujitsu.com, sjitindarsingh@gmail.com, catalin.marinas@arm.com, will@kernel.org, jamorris@linux.microsoft.com, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 00/20] arm64: livepatch: Use ORC for dynamic frame pointer validation Message-ID: References: <20220524001637.1707472-1-madvenka@linux.microsoft.com> <20220615121844.34v7cos5kcz2hufk@suse> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220615121844.34v7cos5kcz2hufk@suse> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 15, 2022 at 03:18:44PM +0300, Ivan T. Ivanov wrote: > I have run following [1] livepatch tests on kernel build from your repository. > Overall results looks good, but when I run klp_tc_13.shI there is something which > I still can not understand completely. It is because of kaslr. > > [ 36.817617] livepatch: enabling patch 'klp_tc_13_livepatch' > [ 36.819602] branch_imm_common: offset out of range > [ 36.820113] branch_imm_common: offset out of range > [ 36.820643] ------------[ ftrace bug ]------------ > [ 36.821172] ftrace failed to modify > [ 36.821173] [] orig_do_read_active_livepatch_id+0x4/0xa8 [klp_test_support_mod] > [ 36.822465] actual: e4:01:00:94 > [ 36.822821] Updating ftrace call site to call a different ftrace function > [ 36.823537] ftrace record flags: e4000002 > [ 36.823953] (2) R > [ 36.823953] expected tramp: ffffdde96882e224 > [ 36.824619] ------------[ cut here ]------------ > [ 36.825125] WARNING: CPU: 0 PID: 950 at kernel/trace/ftrace.c:2085 ftrace_bug+0x98/0x280 > [ 36.826027] Modules linked in: klp_tc_13_livepatch(OK+) klp_test_support_mod(O) crct10dif_ce > [ 36.826943] CPU: 0 PID: 950 Comm: insmod Tainted: G O K 5.18.0-rc1-00020-g1ffee6fdcfda #39 > [ 36.827987] Hardware name: linux,dummy-virt (DT) > [ 36.828546] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > [ 36.829348] pc : ftrace_bug+0x98/0x280 > [ 36.829790] lr : ftrace_bug+0x228/0x280 > [ 36.830224] sp : ffff8000084038e0 > [ 36.830620] x29: ffff8000084038e0 x28: ffff00000485a920 x27: ffffdde931176804 > [ 36.831419] x26: ffffdde93117d1a0 x25: ffff00000485a900 x24: ffffdde96aea1000 > [ 36.832226] x23: 0000000000000000 x22: 0000000000000001 x21: ffffdde96a124da0 > [ 36.833024] x20: ffff0000045620f0 x19: ffffdde96b54a358 x18: ffffffffffffffff > [ 36.833818] x17: 5b20386178302f34 x16: 78302b64695f6863 x15: ffffdde96a3078f8 > [ 36.834621] x14: 0000000000000000 x13: 3432326532383836 x12: ffffdde96ae9b3d8 > [ 36.835425] x11: 0000000000000001 x10: 0000000000000001 x9 : ffffdde96891305c > [ 36.836221] x8 : c0000000ffffefff x7 : 0000000000017fe8 x6 : ffffdde96ae83398 > [ 36.837023] x5 : 0000000000057fa8 x4 : 0000000000000000 x3 : 00000000ffffefff > [ 36.837836] x2 : e32439832ffb9700 x1 : 0000000000000000 x0 : 0000000000000022 > [ 36.838635] Call trace: > [ 36.838923] ftrace_bug+0x98/0x280 > [ 36.839319] ftrace_replace_code+0xa0/0xb8 > [ 36.839768] ftrace_modify_all_code+0xc0/0x160 > [ 36.840273] arch_ftrace_update_code+0x14/0x20 > [ 36.840780] ftrace_run_update_code+0x24/0x78 > [ 36.841283] ftrace_startup_enable+0x50/0x60 > [ 36.841781] ftrace_startup+0xb4/0x178 > [ 36.842214] register_ftrace_function+0x68/0x88 > [ 36.842738] klp_patch_object+0x1c8/0x330 > [ 36.843196] klp_enable_patch+0x468/0x828 IIUC that splat specifically is due to ftrace_modify_call() missing module PLT lookups. That should be fixed by: https://lore.kernel.org/all/20220614080944.1349146-3-mark.rutland@arm.com/ I have not looked at the rest of this series (yet). Thanks, Mark.