From: Arvind Sankar <nivedita@alum.mit.edu>
To: Kristen Carlson Accardi <kristen@linux.intel.com>
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
Date: Tue, 25 Feb 2020 12:55:46 -0500 [thread overview]
Message-ID: <20200225175544.GA1385238@rani.riverdale.lan> (raw)
In-Reply-To: <20200205223950.1212394-6-kristen@linux.intel.com>
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 <kristen@linux.intel.com>
> ---
> 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
next prev parent reply other threads:[~2020-02-25 17:56 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-05 22:39 [RFC PATCH 00/11] Finer grained kernel address space randomization Kristen Carlson Accardi
2020-02-05 22:39 ` [RFC PATCH 01/11] modpost: Support >64K sections Kristen Carlson Accardi
2020-02-06 12:38 ` Kees Cook
2020-02-05 22:39 ` [RFC PATCH 02/11] x86: tools/relocs: Support >64K section headers Kristen Carlson Accardi
2020-02-06 12:39 ` Kees Cook
2020-02-05 22:39 ` [RFC PATCH 03/11] x86/boot: Allow a "silent" kaslr random byte fetch Kristen Carlson Accardi
2020-02-06 1:08 ` Andy Lutomirski
2020-02-06 11:48 ` Kees Cook
2020-02-06 16:58 ` Kristen Carlson Accardi
2020-02-05 22:39 ` [RFC PATCH 04/11] x86/boot/KASLR: Introduce PRNG for faster shuffling Kristen Carlson Accardi
2020-02-06 1:11 ` Andy Lutomirski
2020-02-06 15:10 ` Jason A. Donenfeld
2020-02-07 7:23 ` Jean-Philippe Aumasson
2020-02-07 9:05 ` Kees Cook
2020-02-07 16:52 ` Kristen Carlson Accardi
2020-02-05 22:39 ` [RFC PATCH 05/11] x86: Makefile: Add build and config option for CONFIG_FG_KASLR Kristen Carlson Accardi
2020-02-06 10:30 ` Peter Zijlstra
2020-02-06 11:52 ` Kees Cook
2020-02-25 17:55 ` Arvind Sankar [this message]
2020-02-26 19:13 ` Kristen Carlson Accardi
2020-03-24 21:24 ` Kristen Carlson Accardi
2020-03-25 15:34 ` Kees Cook
2020-02-05 22:39 ` [RFC PATCH 06/11] x86: make sure _etext includes function sections Kristen Carlson Accardi
2020-02-06 12:26 ` Kees Cook
2020-02-06 13:15 ` Jann Horn
2020-02-06 16:27 ` David Laight
2020-02-06 14:39 ` Arvind Sankar
2020-02-06 15:29 ` Arvind Sankar
2020-02-06 16:11 ` Andy Lutomirski
2020-02-06 14:57 ` Arvind Sankar
2020-02-06 15:45 ` Arvind Sankar
2020-02-06 19:41 ` Kristen Carlson Accardi
2020-02-06 20:02 ` Andy Lutomirski
2020-02-07 9:24 ` Peter Zijlstra
2020-02-10 1:43 ` Kees Cook
2020-02-10 10:51 ` Peter Zijlstra
2020-02-10 15:54 ` Arjan van de Ven
2020-02-10 16:36 ` Arvind Sankar
2020-02-21 19:50 ` Josh Poimboeuf
2020-02-21 23:05 ` Arvind Sankar
2020-02-05 22:39 ` [RFC PATCH 07/11] x86/tools: Adding relative relocs for randomized functions Kristen Carlson Accardi
2020-02-06 12:37 ` Kees Cook
2020-02-05 22:39 ` [RFC PATCH 08/11] x86: Add support for finer grained KASLR Kristen Carlson Accardi
2020-02-06 1:17 ` Andy Lutomirski
2020-02-06 11:56 ` Kees Cook
2020-02-06 17:36 ` Kristen Carlson Accardi
2020-02-06 10:38 ` Peter Zijlstra
2020-02-06 12:06 ` Kees Cook
2020-02-06 14:52 ` Peter Zijlstra
2020-02-06 17:25 ` Kristen Carlson Accardi
2020-02-06 17:35 ` Peter Zijlstra
2020-02-06 17:43 ` Kristen Carlson Accardi
2020-02-25 17:49 ` Arvind Sankar
2020-02-26 19:26 ` Kristen Carlson Accardi
2020-02-05 22:39 ` [RFC PATCH 09/11] kallsyms: hide layout and expose seed Kristen Carlson Accardi
2020-02-06 12:32 ` Kees Cook
2020-02-06 17:51 ` Kristen Carlson Accardi
2020-02-06 19:27 ` Jann Horn
2020-03-02 19:01 ` Kristen Carlson Accardi
2020-03-02 19:08 ` Kees Cook
2020-03-02 19:19 ` Kristen Carlson Accardi
2020-02-27 2:42 ` Baoquan He
2020-02-27 16:02 ` Kees Cook
2020-02-28 3:36 ` Baoquan He
2020-02-05 22:39 ` [RFC PATCH 10/11] module: Reorder functions Kristen Carlson Accardi
2020-02-06 12:41 ` Kees Cook
2020-02-11 12:39 ` Jessica Yu
2020-02-05 22:39 ` [RFC PATCH 11/11] x86/boot: Move "boot heap" out of .bss Kristen Carlson Accardi
2020-02-06 0:11 ` Arvind Sankar
2020-02-06 0:33 ` Kristen Carlson Accardi
2020-02-06 11:13 ` Kees Cook
2020-02-06 14:25 ` Arvind Sankar
2020-02-06 21:32 ` Kees Cook
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