From patchwork Thu Mar 19 13:04:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229030 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 B52A1C4332D for ; Thu, 19 Mar 2020 13:28:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D56D2080C for ; Thu, 19 Mar 2020 13:28:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624500; bh=BQ890SzTEouptVcWzFCmIJWKxJvivRGqcLrFbeFHC+w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QOPtOXT+h3l8im2dANEH06CGe051jRVNoa/S6w04YdbEJ2SX08RCgRlb23G43TC9H hRUwLX5eORz5Nc1XCYRTu7PPZaHM2yFIGohxMq44++udUVweM92E4rW5NvYUA7B8vm 5hJ0xnDfxEjtc+R2fi8PTv5I4IEn2U5Ek4lVFEJ8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730682AbgCSN1d (ORCPT ); Thu, 19 Mar 2020 09:27:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:55822 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727977AbgCSN1b (ORCPT ); Thu, 19 Mar 2020 09:27:31 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B4D32208D6; Thu, 19 Mar 2020 13:27:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624450; bh=BQ890SzTEouptVcWzFCmIJWKxJvivRGqcLrFbeFHC+w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jnSKiJMFggo64i/RmfzTrTruVsF97pvVOQjfadqYAQi6zdSC8Cb8S0zolLR6z6zdv +FZnIJzPPy204Amkt4Hc6zof8tHAf4oGlTAxSy4EOsLmV3KhbzppbbaRHi3VA/c/x0 +zPX1Cz0Tj0Ic5cbWlLAiGWprzvL4SVsrrnQ1oW0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Merlijn Wajer , Tony Lindgren , Kees Cook , Masahiro Yamada , Ard Biesheuvel , Russell King Subject: [PATCH 5.5 64/65] ARM: 8961/2: Fix Kbuild issue caused by per-task stack protector GCC plugin Date: Thu, 19 Mar 2020 14:04:46 +0100 Message-Id: <20200319123946.468269055@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123926.466988514@linuxfoundation.org> References: <20200319123926.466988514@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ard Biesheuvel commit 89604523a76eb3e13014b2bdab7f8870becee284 upstream. When using plugins, GCC requires that the -fplugin= options precedes any of its plugin arguments appearing on the command line as well. This is usually not a concern, but as it turns out, this requirement is causing some issues with ARM's per-task stack protector plugin and Kbuild's implementation of $(cc-option). When the per-task stack protector plugin is enabled, and we tweak the implementation of cc-option not to pipe the stderr output of GCC to /dev/null, the following output is generated when GCC is executed in the context of cc-option: cc1: error: plugin arm_ssp_per_task_plugin should be specified before \ -fplugin-arg-arm_ssp_per_task_plugin-tso=1 in the command line cc1: error: plugin arm_ssp_per_task_plugin should be specified before \ -fplugin-arg-arm_ssp_per_task_plugin-offset=24 in the command line These errors will cause any option passed to cc-option to be treated as unsupported, which is obviously incorrect. The cause of this issue is the fact that the -fplugin= argument is added to GCC_PLUGINS_CFLAGS, whereas the arguments above are added to KBUILD_CFLAGS, and the contents of the former get filtered out of the latter before being passed to the GCC running the cc-option test, and so the -fplugin= option does not appear at all on the GCC command line. Adding the arguments to GCC_PLUGINS_CFLAGS instead of KBUILD_CFLAGS would be the correct approach here, if it weren't for the fact that we are using $(eval) to defer the moment that they are added until after asm-offsets.h is generated, which is after the point where the contents of GCC_PLUGINS_CFLAGS are added to KBUILD_CFLAGS. So instead, we have to add our plugin arguments to both. For similar reasons, we cannot append DISABLE_ARM_SSP_PER_TASK_PLUGIN to KBUILD_CFLAGS, as it will be passed to GCC when executing in the context of cc-option, whereas the other plugin arguments will have been filtered out, resulting in a similar error and false negative result as above. So add it to ccflags-y instead. Fixes: 189af4657186da08 ("ARM: smp: add support for per-task stack canaries") Reported-by: Merlijn Wajer Tested-by: Tony Lindgren Acked-by: Kees Cook Reviewed-by: Masahiro Yamada Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/Makefile | 4 +++- arch/arm/boot/compressed/Makefile | 4 ++-- 2 files changed, 5 insertions(+), 3 deletions(-) --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -307,13 +307,15 @@ endif ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y) prepare: stack_protector_prepare stack_protector_prepare: prepare0 - $(eval KBUILD_CFLAGS += \ + $(eval SSP_PLUGIN_CFLAGS := \ -fplugin-arg-arm_ssp_per_task_plugin-tso=$(shell \ awk '{if ($$2 == "THREAD_SZ_ORDER") print $$3;}'\ include/generated/asm-offsets.h) \ -fplugin-arg-arm_ssp_per_task_plugin-offset=$(shell \ awk '{if ($$2 == "TI_STACK_CANARY") print $$3;}'\ include/generated/asm-offsets.h)) + $(eval KBUILD_CFLAGS += $(SSP_PLUGIN_CFLAGS)) + $(eval GCC_PLUGINS_CFLAGS += $(SSP_PLUGIN_CFLAGS)) endif all: $(notdir $(KBUILD_IMAGE)) --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -101,7 +101,6 @@ clean-files += piggy_data lib1funcs.S as $(libfdt) $(libfdt_hdrs) hyp-stub.S KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING -KBUILD_CFLAGS += $(DISABLE_ARM_SSP_PER_TASK_PLUGIN) ifeq ($(CONFIG_FUNCTION_TRACER),y) ORIG_CFLAGS := $(KBUILD_CFLAGS) @@ -117,7 +116,8 @@ CFLAGS_fdt_ro.o := $(nossp_flags) CFLAGS_fdt_rw.o := $(nossp_flags) CFLAGS_fdt_wip.o := $(nossp_flags) -ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin -I$(obj) +ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin \ + -I$(obj) $(DISABLE_ARM_SSP_PER_TASK_PLUGIN) asflags-y := -DZIMAGE # Supply kernel BSS size to the decompressor via a linker symbol.