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=-10.1 required=3.0 tests=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 3FB0DC433DF for ; Wed, 24 Jun 2020 01:50:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18F5F20786 for ; Wed, 24 Jun 2020 01:50:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="SfpOc2hU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388383AbgFXBuC (ORCPT ); Tue, 23 Jun 2020 21:50:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388580AbgFXBtz (ORCPT ); Tue, 23 Jun 2020 21:49:55 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0BEDC061797 for ; Tue, 23 Jun 2020 18:49:53 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id a45so1707902pje.1 for ; Tue, 23 Jun 2020 18:49:53 -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=pYQ7/UZeNlKUAAzd40PNMMjARn27pZcaavNwLjboXuY=; b=SfpOc2hUEIBZELMivwVdfPJYqCy5X8PdsjkdknZE3l8iQFROsv3i6chxLhftMku9Xb 6tsOXBb1e9JDRd5qFNA6lSfPVMaJO9wSUISKnlca3WIenGXCvUr0fPoXLMHEugtTAoOT NcS3jDEyvtoIgTcw9ADMPmRSLOVBJsa/GPcsE= 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=pYQ7/UZeNlKUAAzd40PNMMjARn27pZcaavNwLjboXuY=; b=bsD/8IePxY5e4BiNKmlNxvmml0aMkI0MvAw7s17Q4uq0rO8BBXNJ/uTjmsUw6F7TKv 4AAr0b8TlHaq5jYKzv8wT/n/UCxnyLRq/+h+h7Qy0s19v6kKGR0/2eb7h5+hmvWEukyz opUTjWoX1Mg+2EVQF86vOnKkjjzZtbqp4oWopyIbG2t8A8Q2MgcnuM9TaY+SGlk5eYZS vqEJ0nizMYYsS6A3eLdwO5QvENivOfoVWZnGhRii6XQBvHhviq8pBuu1K8RAfZmfjRV+ 4v/V3e/Q/A/rbLTqRlUfi0v3GERy+xtDfEUjOCPs8RqfLv6YwbFvPVQfFnKdDGbbd+yW qeLg== X-Gm-Message-State: AOAM533q3rJzkXQ/HTb38aUaIykAcqY3tf4fGLVrmLRKEUer/RekWSeL blvE0B7ksBKKG8+EE2LRYDBzXg== X-Google-Smtp-Source: ABdhPJxF401TyoczuI9y6Odtjb3HBshgiTglQEqL8Iaoe+oZuP7eR1/hBT5Q+j0SgAH4D3wZeHXfhg== X-Received: by 2002:a17:902:bd46:: with SMTP id b6mr4986763plx.287.1592963393344; Tue, 23 Jun 2020 18:49:53 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id n1sm2941055pjo.47.2020.06.23.18.49.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jun 2020 18:49:50 -0700 (PDT) From: Kees Cook To: Will Deacon Cc: Kees Cook , Catalin Marinas , Mark Rutland , Ard Biesheuvel , Peter Collingbourne , James Morse , Borislav Petkov , Thomas Gleixner , Ingo Molnar , Russell King , Masahiro Yamada , Arvind Sankar , Nick Desaulniers , 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 v3 5/9] x86/boot: Warn on orphan section placement Date: Tue, 23 Jun 2020 18:49:36 -0700 Message-Id: <20200624014940.1204448-6-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200624014940.1204448-1-keescook@chromium.org> References: <20200624014940.1204448-1-keescook@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We don't want to depend on the linker's orphan section placement heuristics as these can vary between linkers, and may change between versions. All sections need to be explicitly named in the linker script. Add the common debugging sections. Discard the unused note, rel, plt, dyn, and hash sections that are not needed in the compressed vmlinux. Disable .eh_frame generation in the linker and enable orphan section warnings. Signed-off-by: Kees Cook --- arch/x86/boot/compressed/Makefile | 3 ++- arch/x86/boot/compressed/vmlinux.lds.S | 11 +++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 7619742f91c9..646720a05f89 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -48,6 +48,7 @@ GCOV_PROFILE := n UBSAN_SANITIZE :=n KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE) +KBUILD_LDFLAGS += $(call ld-option,--no-ld-generated-unwind-info) # Compressed kernel should be built as PIE since it may be loaded at any # address by the bootloader. ifeq ($(CONFIG_X86_32),y) @@ -59,7 +60,7 @@ else KBUILD_LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \ && echo "-z noreloc-overflow -pie --no-dynamic-linker") endif -LDFLAGS_vmlinux := -T +LDFLAGS_vmlinux := --orphan-handling=warn -T hostprogs := mkpiggy HOST_EXTRACFLAGS += -I$(srctree)/tools/include diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index 8f1025d1f681..6fe3ecdfd685 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -75,5 +75,16 @@ SECTIONS . = ALIGN(PAGE_SIZE); /* keep ZO size page aligned */ _end = .; + STABS_DEBUG + DWARF_DEBUG + DISCARDS + /DISCARD/ : { + *(.note.*) + *(.rela.*) *(.rela_*) + *(.rel.*) *(.rel_*) + *(.plt) *(.plt.*) + *(.dyn*) + *(.hash) *(.gnu.hash) + } } -- 2.25.1