From patchwork Wed Apr 15 22:15:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arvind Sankar X-Patchwork-Id: 206410 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=-9.8 required=3.0 tests=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 1F5A1C2BA19 for ; Wed, 15 Apr 2020 22:15:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 036B3206E9 for ; Wed, 15 Apr 2020 22:15:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731327AbgDOWP3 (ORCPT ); Wed, 15 Apr 2020 18:15:29 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:37966 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731102AbgDOWP0 (ORCPT ); Wed, 15 Apr 2020 18:15:26 -0400 Received: by mail-qt1-f193.google.com with SMTP id f13so14732828qti.5; Wed, 15 Apr 2020 15:15:25 -0700 (PDT) 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=/884Y4S8L6kS/iSrGalw7uxiGyhKVKiR3Ww6KT2GqZU=; b=saoxkQ4jJVC78vnE7dGC4IvxFpewAunuLSS1GBV2UU7+/aY8YP0ZUCxQSL9/NTjs3/ StK1LsgBQ//j6tdvfWfyiTtfUuXY1Alu0suw1PiJCmsOqweAn+ibUuF8tbJDZaOu/YJi DIOM4AkkB/fywG7oHS4ZRh/j5Utkg5svGRmF/ocr5W92Zs9WQjZRyn8NtjQ10KsRJNau 7sI0kNkPa1rYOeOWJKI/igqhCT6DEesKkiJItvAWGiyp6nOXgetrPwqMQLHtANmBBbbn 4YF+30VfvY1u0iTUGpSa1Ro1MbZ4wPitGixqaDgvSWF7WDk7k90JEJ5m92AO+X7F1GaE MjxA== X-Gm-Message-State: AGi0PubQkVoUDJ7TdHyqn55gCAR4+dko2Qe322/tCWI+Pix3b+gOMMD2 eAC3jbe8Nai9oG+XRUTZ3g4= X-Google-Smtp-Source: APiQypJlrUQQ2en4qUdzPOfXDNxDRWtBRRylqygI8Tcxmp3E2gsu+n70rOWANLLUxOh7H3FryRVBlg== X-Received: by 2002:ac8:7309:: with SMTP id x9mr21688226qto.68.1586988924230; Wed, 15 Apr 2020 15:15:24 -0700 (PDT) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id i20sm13264340qkl.135.2020.04.15.15.15.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Apr 2020 15:15:23 -0700 (PDT) From: Arvind Sankar To: Ard Biesheuvel Cc: linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org Subject: [PATCH 3/5] efi/x86: Remove __efistub_global annotation Date: Wed, 15 Apr 2020 18:15:18 -0400 Message-Id: <20200415221520.2692512-4-nivedita@alum.mit.edu> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200415221520.2692512-1-nivedita@alum.mit.edu> References: <20200415221520.2692512-1-nivedita@alum.mit.edu> MIME-Version: 1.0 Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Instead of using __efistub_global to force variables into the .data section, leave them in the .bss but pull the EFI stub's .bss section into .data in the linker script for the compressed kernel. Signed-off-by: Arvind Sankar --- arch/x86/boot/compressed/vmlinux.lds.S | 1 + drivers/firmware/efi/libstub/Makefile | 12 ++++++++++-- drivers/firmware/efi/libstub/efistub.h | 4 ---- 3 files changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index 508cfa6828c5..0dc5c2b9614b 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -52,6 +52,7 @@ SECTIONS _data = . ; *(.data) *(.data.*) + *(.bss.efistub) _edata = . ; } . = ALIGN(L1_CACHE_BYTES); diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index e5e76677f2da..0bb2916eb12b 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -73,8 +73,8 @@ CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) # a verification pass to see if any absolute relocations exist in any of the # object files. # -extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y) -lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y)) +extra-y := $(lib-y) +lib-y := $(patsubst %.o,%.stub.o,$(lib-y)) STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ --prefix-symbols=__efistub_ @@ -89,6 +89,14 @@ STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub \ --rename-section .bss=.bss.efistub,load,alloc STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS +# +# For x86, bootloaders like systemd-boot or grub-efi do not zero-initialize the +# .bss section, so the .bss section of the EFI stub needs to be included in the +# .data section of the compressed kernel to ensure initialization. Rename the +# .bss section here so it's easy to pick out in the linker script. +# +STUBCOPY_FLAGS-$(CONFIG_X86) += --rename-section .bss=.bss.efistub,load,alloc + $(obj)/%.stub.o: $(obj)/%.o FORCE $(call if_changed,stubcopy) diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index a92d42ffd9f7..49651e20bb9f 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -25,11 +25,7 @@ #define EFI_ALLOC_ALIGN EFI_PAGE_SIZE #endif -#if defined(CONFIG_X86) -#define __efistub_global __section(.data) -#else #define __efistub_global -#endif extern bool __pure nochunk(void); extern bool __pure nokaslr(void);