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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 748B8C433E1 for ; Fri, 31 Jul 2020 23:08:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FB6022B3F for ; Fri, 31 Jul 2020 23:08:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="MLXUvi1E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727786AbgGaXIk (ORCPT ); Fri, 31 Jul 2020 19:08:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727095AbgGaXIj (ORCPT ); Fri, 31 Jul 2020 19:08:39 -0400 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47441C061756 for ; Fri, 31 Jul 2020 16:08:39 -0700 (PDT) Received: by mail-pg1-x52c.google.com with SMTP id w2so16769241pgg.10 for ; Fri, 31 Jul 2020 16:08:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=wOq+Y00LQi/3deraAM6kBuaQbRKnLYOHk6N+NuQVWdA=; b=MLXUvi1EuKG0FE+rIsbID9rRvyHhHP/bC/1H8WYBKVP5ZSFhWYwP+lP5XZpTQ06Bf0 wv4BfOauML6dkzya4CuKy7gALZ+W+9xqlhpjxWQqkL5+umqTPynzx2CVlkxuPT6WpFPO j+sa9r0Kjrijgwt3APFSfc7Wq1KUkGc2Bq+kU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=wOq+Y00LQi/3deraAM6kBuaQbRKnLYOHk6N+NuQVWdA=; b=q7adtHJc1nmhmp1tZ9RerBTxoVg1peVxDRwu+9JRVqXMsZ7HYaepYmCWtO4aUsdaew rlcc6eMFoxBDfzirQLZarguxqUsO5lxMJyZSeSmMQefgCGU3lIYBifpN6It+8E4IGQIi 0XsEtiLumfqFQRjEwbS1ngNBKGi1uA975lez+jqfMWVlkvOvtcjRsJ7pqEpTVTc749rQ XdQloFZqsqXpDFZH/FxiSd4/YM3I2zGi8jpjifcalaIxQQwKPGNTePDWcPnUQ4gddnbx 5XHVnZWrE3DjzO7GHDhiIpOx8V/PMHiY+fj70Fhz1ulSl8Aoi5UatQ11FFtfZemqky3U uZaw== X-Gm-Message-State: AOAM533+ILchL/8OzOFEyiLmMzfJ6OpCSUsxWWRNcI3SgKMoDsYZQDfb fYMo6O+Qrgrd9a1/N+aHu62n6w== X-Google-Smtp-Source: ABdhPJxilVrjiuHEI9OJNGFNpHOWI1BRRuP7pZ9ogDRckvVa3npz7ZCMJpdwxdsXaIoH3Zh78zy0uA== X-Received: by 2002:a65:620f:: with SMTP id d15mr5623976pgv.270.1596236918800; Fri, 31 Jul 2020 16:08:38 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id m190sm9732049pfm.89.2020.07.31.16.08.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 31 Jul 2020 16:08:35 -0700 (PDT) From: Kees Cook To: Thomas Gleixner , Will Deacon Cc: Kees Cook , Arvind Sankar , Nick Desaulniers , Ard Biesheuvel , Fangrui Song , Sedat Dilek , Catalin Marinas , Mark Rutland , Peter Collingbourne , James Morse , Borislav Petkov , Ingo Molnar , Russell King , Masahiro Yamada , Nathan Chancellor , Arnd Bergmann , x86@kernel.org, clang-built-linux@googlegroups.com, linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 07/36] x86/boot: Check that there are no run-time relocations Date: Fri, 31 Jul 2020 16:07:51 -0700 Message-Id: <20200731230820.1742553-8-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200731230820.1742553-1-keescook@chromium.org> References: <20200731230820.1742553-1-keescook@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org From: Arvind Sankar Add a linker script check that there are no run-time relocations, and remove the old one that tries to check via looking for specially-named sections in the object files. Drop the tests for -fPIE compiler option and -pie linker option, as they are available in all supported gcc and binutils versions (as well as clang and lld). Tested-by: Nick Desaulniers Reviewed-by: Kees Cook Reviewed-by: Ard Biesheuvel Reviewed-by: Fangrui Song Reviewed-by: Sedat Dilek Tested-by: Sedat Dilek Signed-off-by: Arvind Sankar Signed-off-by: Kees Cook --- arch/x86/boot/compressed/Makefile | 28 +++----------------------- arch/x86/boot/compressed/vmlinux.lds.S | 8 ++++++++ 2 files changed, 11 insertions(+), 25 deletions(-) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 7db0102a573d..96d53e300ab6 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -29,7 +29,7 @@ targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 KBUILD_CFLAGS := -m$(BITS) -O2 -KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC) +KBUILD_CFLAGS += -fno-strict-aliasing -fPIE KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING cflags-$(CONFIG_X86_32) := -march=i386 cflags-$(CONFIG_X86_64) := -mcmodel=small @@ -51,7 +51,7 @@ UBSAN_SANITIZE :=n KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE) # Compressed kernel should be built as PIE since it may be loaded at any # address by the bootloader. -LDFLAGS_vmlinux := $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker) +LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker) LDFLAGS_vmlinux += -T hostprogs := mkpiggy @@ -86,30 +86,8 @@ vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a -# The compressed kernel is built with -fPIC/-fPIE so that a boot loader -# can place it anywhere in memory and it will still run. However, since -# it is executed as-is without any ELF relocation processing performed -# (and has already had all relocation sections stripped from the binary), -# none of the code can use data relocations (e.g. static assignments of -# pointer values), since they will be meaningless at runtime. This check -# will refuse to link the vmlinux if any of these relocations are found. -quiet_cmd_check_data_rel = DATAREL $@ -define cmd_check_data_rel - for obj in $(filter %.o,$^); do \ - $(READELF) -S $$obj | grep -qF .rel.local && { \ - echo "error: $$obj has data relocations!" >&2; \ - exit 1; \ - } || true; \ - done -endef - -# We need to run two commands under "if_changed", so merge them into a -# single invocation. -quiet_cmd_check-and-link-vmlinux = LD $@ - cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld) - $(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE - $(call if_changed,check-and-link-vmlinux) + $(call if_changed,ld) OBJCOPYFLAGS_vmlinux.bin := -R .comment -S $(obj)/vmlinux.bin: vmlinux FORCE diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index a4a4a59a2628..29df99b6cc64 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -42,6 +42,12 @@ SECTIONS *(.rodata.*) _erodata = . ; } + .rel.dyn : { + *(.rel.*) + } + .rela.dyn : { + *(.rela.*) + } .got : { *(.got) } @@ -85,3 +91,5 @@ ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18, "Unexpected GOT/PLT en #else ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0xc, "Unexpected GOT/PLT entries detected!") #endif + +ASSERT(SIZEOF(.rel.dyn) == 0 && SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations detected!") -- 2.25.1