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[209.132.180.67]) by mx.google.com with ESMTP id f9si9025949oti.44.2020.02.25.10.01.39; Tue, 25 Feb 2020 10:01:52 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=anCpnV7x; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728818AbgBYRzu (ORCPT + 99 others); Tue, 25 Feb 2020 12:55:50 -0500 Received: from mail-qk1-f193.google.com ([209.85.222.193]:38056 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728483AbgBYRzt (ORCPT ); Tue, 25 Feb 2020 12:55:49 -0500 Received: by mail-qk1-f193.google.com with SMTP id z19so31672qkj.5 for ; Tue, 25 Feb 2020 09:55:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=3hs8ic9vVHZ01buQwpJNWy/TUEvM8U2pC7/qWbn+NOM=; b=anCpnV7xlItClBNqfKJKEuX0+Ll9aQf2pYeHeWhibo96ELCS4mv/g9IL2Xb7fs3lyr j1JDfFE4rGpZL/Ix0EtPr0d4kCD9h8fsgdWl4iLv4nYZBEO6xYJxjIU+Rdv+mceqBjV4 Yb5g5P3dJJ0HIVFjoVjbYiWCCWKAd4CqQO6jsXShonwl+kMlgNahDe89OP6j5XrPF05c j10vzCk7IhnTQNHfIyua1PlwNWWjKeZrPFdOTbTYlpZ9wD4iIcz8slu13oWL7Z8L9AT2 lhVDbdERuZHoZj/ZH2NwMygGo6nrclUnZ1jAa3EJDcFPLVp9T+Aj99UqE+UBcet/BdXT m/Qw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:date:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=3hs8ic9vVHZ01buQwpJNWy/TUEvM8U2pC7/qWbn+NOM=; b=RVTsOgwUVASEGD9XTc9GYhfUpomR6NQWjKBYwyblbjNRqlTB3yCRJ+rJtQlhFo2T8r MN59i8BiD4EARpqPZeeirhJWOznGAcoh42s0izLNqDQtjwUTqeuQHzGeE+VURzTR7fZl yRNftHoo5a7va7rHeHpk7xufmb/cuynJPNl+BVY2xuGJt50ow3WsV0tv0dNEJf60vX6O WU3E34YWFTK27oTBi2p48LVY4T7IbHq9XweTYlkXgBWp1dYo3teNIQwQvHmZ8V/6QdGZ 6TrcN9qRdit+tvUPKJqHXzceaLsFcu4arqGp51cjTXLJjJjUbTiB1PwnY6+oOQN/rE9V LA4A== X-Gm-Message-State: APjAAAXVHH7xC0I3mfZuExKUuxJgAsda6XlH16EOfYywWclSm7ODCBBJ vdweXZAg8iU+ElkEzGYpVH4= X-Received: by 2002:ae9:e204:: with SMTP id c4mr10263743qkc.429.1582653348476; Tue, 25 Feb 2020 09:55:48 -0800 (PST) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id 11sm7536873qko.76.2020.02.25.09.55.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Feb 2020 09:55:48 -0800 (PST) From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Tue, 25 Feb 2020 12:55:46 -0500 To: Kristen Carlson Accardi Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, arjan@linux.intel.com, keescook@chromium.org, rick.p.edgecombe@intel.com, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Subject: Re: [RFC PATCH 05/11] x86: Makefile: Add build and config option for CONFIG_FG_KASLR Message-ID: <20200225175544.GA1385238@rani.riverdale.lan> References: <20200205223950.1212394-1-kristen@linux.intel.com> <20200205223950.1212394-6-kristen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200205223950.1212394-6-kristen@linux.intel.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 Wed, Feb 05, 2020 at 02:39:44PM -0800, Kristen Carlson Accardi wrote: > Allow user to select CONFIG_FG_KASLR if dependencies are met. Change > the make file to build with -ffunction-sections if CONFIG_FG_KASLR > > Signed-off-by: Kristen Carlson Accardi > --- > Makefile | 4 ++++ > arch/x86/Kconfig | 13 +++++++++++++ > 2 files changed, 17 insertions(+) > > diff --git a/Makefile b/Makefile > index c50ef91f6136..41438a921666 100644 > --- a/Makefile > +++ b/Makefile > @@ -846,6 +846,10 @@ ifdef CONFIG_LIVEPATCH > KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone) > endif > > +ifdef CONFIG_FG_KASLR > +KBUILD_CFLAGS += -ffunction-sections > +endif > + With -ffunction-sections I get a few unreachable code warnings from objtool. arch/x86/kernel/dumpstack.o: warning: objtool: show_iret_regs()+0x10: unreachable instruction fs/sysfs/dir.o: warning: objtool: sysfs_create_mount_point()+0x4f: unreachable instruction kernel/time/clocksource.o: warning: objtool: __clocksource_register_scale()+0x21: unreachable instruction drivers/tty/sysrq.o: warning: objtool: sysrq_filter()+0x2ef: unreachable instruction arch/x86/mm/fault.o: warning: objtool: pgtable_bad()+0x3f: unreachable instruction drivers/acpi/pci_root.o: warning: objtool: acpi_pci_osc_control_set()+0x123: unreachable instruction drivers/rtc/class.o: warning: objtool: devm_rtc_device_register()+0x40: unreachable instruction kernel/power/process.o: warning: objtool: freeze_processes.cold()+0x0: unreachable instruction drivers/pnp/quirks.o: warning: objtool: quirk_awe32_resources()+0x42: unreachable instruction drivers/acpi/utils.o: warning: objtool: acpi_evaluate_dsm()+0xf1: unreachable instruction kernel/reboot.o: warning: objtool: __do_sys_reboot()+0x1b6: unreachable instruction kernel/power/swap.o: warning: objtool: swsusp_read()+0x185: unreachable instruction drivers/hid/hid-core.o: warning: objtool: hid_hw_start()+0x38: unreachable instruction drivers/acpi/battery.o: warning: objtool: sysfs_add_battery.cold()+0x1a: unreachable instruction arch/x86/kernel/cpu/mce/core.o: warning: objtool: do_machine_check.cold()+0x33: unreachable instruction drivers/pcmcia/cistpl.o: warning: objtool: pccard_store_cis()+0x4e: unreachable instruction drivers/gpu/vga/vgaarb.o: warning: objtool: pci_notify()+0x35: unreachable instruction arch/x86/kernel/tsc.o: warning: objtool: determine_cpu_tsc_frequencies()+0x45: unreachable instruction drivers/pcmcia/yenta_socket.o: warning: objtool: ti1250_override()+0x50: unreachable instruction fs/proc/proc_sysctl.o: warning: objtool: sysctl_print_dir.isra.0()+0x19: unreachable instruction drivers/iommu/intel-iommu.o: warning: objtool: intel_iommu_init()+0x4f4: unreachable instruction net/mac80211/ibss.o: warning: objtool: ieee80211_ibss_work.cold()+0x157: unreachable instruction drivers/net/ethernet/intel/e1000/e1000_main.o: warning: objtool: e1000_clean.cold()+0x0: unreachable instruction net/core/skbuff.o: warning: objtool: skb_dump.cold()+0x3fd: unreachable instruction