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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 5C7D5C433B4 for ; Wed, 28 Apr 2021 20:49:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05E3D6144C for ; Wed, 28 Apr 2021 20:49:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230370AbhD1Ut4 (ORCPT ); Wed, 28 Apr 2021 16:49:56 -0400 Received: from mga05.intel.com ([192.55.52.43]:44235 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229549AbhD1Utz (ORCPT ); Wed, 28 Apr 2021 16:49:55 -0400 IronPort-SDR: oQslHqnxWIgintvtE7RYF1lX4vyqNHwVIRBySiHaDWo/pNx7jMxmRt1Mk+KLOoYXKf9T0ImSEs OjHlDktm57hQ== X-IronPort-AV: E=McAfee;i="6200,9189,9968"; a="282185508" X-IronPort-AV: E=Sophos;i="5.82,258,1613462400"; d="scan'208";a="282185508" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2021 13:49:10 -0700 IronPort-SDR: vGWnJwbrgfpkN2beMuwcFAXncWISz0cuUun5JLR7YTtvYQETrR84ByQZ5LM6c2xCSLqPBh62Yf yPkIg66jONag== X-IronPort-AV: E=Sophos;i="5.82,258,1613462400"; d="scan'208";a="423708019" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.209.133.34]) ([10.209.133.34]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2021 13:49:09 -0700 Subject: Re: [PATCH v26 6/9] x86/vdso: Insert endbr32/endbr64 to vDSO To: Kees Cook Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang References: <20210427204720.25007-1-yu-cheng.yu@intel.com> <20210427204720.25007-7-yu-cheng.yu@intel.com> <202104281332.94A153C@keescook> From: "Yu, Yu-cheng" Message-ID: <88dc2e45-5fd4-9a1a-c493-3ff868a627f4@intel.com> Date: Wed, 28 Apr 2021 13:49:08 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <202104281332.94A153C@keescook> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/28/2021 1:33 PM, Kees Cook wrote: > On Tue, Apr 27, 2021 at 01:47:17PM -0700, Yu-cheng Yu wrote: >> From: "H.J. Lu" >> >> When Indirect Branch Tracking (IBT) is enabled, vDSO functions may be >> called indirectly, and must have ENDBR32 or ENDBR64 as the first >> instruction. The compiler must support -fcf-protection=branch so that it >> can be used to compile vDSO. > > If you respin this, you can maybe rephrase this since CONFIG_X86_IBT > has already tested for the compiler support. > Yes, I will fix this. Thanks for reviewing! Yu-cheng >> >> Signed-off-by: H.J. Lu >> Signed-off-by: Yu-cheng Yu >> Cc: Andy Lutomirski >> Cc: Kees Cook > > Reviewed-by: Kees Cook > > -Kees > >> --- >> v24: >> - Replace CONFIG_X86_CET with CONFIG_X86_IBT to reflect splitting of shadow >> stack and ibt. >> >> arch/x86/entry/vdso/Makefile | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile >> index 05c4abc2fdfd..a773a5f03b63 100644 >> --- a/arch/x86/entry/vdso/Makefile >> +++ b/arch/x86/entry/vdso/Makefile >> @@ -93,6 +93,10 @@ endif >> >> $(vobjs): KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL) >> >> +ifdef CONFIG_X86_IBT >> +$(vobjs) $(vobjs32): KBUILD_CFLAGS += -fcf-protection=branch >> +endif >> + >> # >> # vDSO code runs in userspace and -pg doesn't help with profiling anyway. >> # >> -- >> 2.21.0 >> >