From patchwork Tue Sep 12 09:01:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 724056 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7994BCA0EC3 for ; Tue, 12 Sep 2023 09:03:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233517AbjILJDI (ORCPT ); Tue, 12 Sep 2023 05:03:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233319AbjILJCC (ORCPT ); Tue, 12 Sep 2023 05:02:02 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D1C21727 for ; Tue, 12 Sep 2023 02:01:58 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-58d9e327d3aso58774377b3.3 for ; Tue, 12 Sep 2023 02:01:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1694509317; x=1695114117; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=0+YGLs65HuKDkoyCmUsNA1LK7hzYTmA6aBZzUDWZlAQ=; b=1ew42M7Y55Jzlomdu2tuD/2ewqPkwxAMNOoQpsOdPHJ1IAfI2IizCZ4MwNs65U0G0a euHdTFQVuZoknWTunmQTNqjNm1FyFzXfvq0gcCULp/KGbo5JXSTZzGLp8kimbLcPn3PO SdDas49TIxERE1IE+DSTBLUgJwcHvzWE9pu6XIPEGUv3CrejSVm4+/9ES+YL4YTTHynS oovGXadHuxb/6lEC6BRRGz9gNzWDGywPFwunNeNu1Q8r0eyCKgAB/YBpH4WZNwr+hFV4 rF400fXCZuRF+k3cfK6kMIXuJmrvpJnwBemjrGpsLD/VeyW+lZerYcONrhaZCi+PmSOg F0HA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694509317; x=1695114117; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=0+YGLs65HuKDkoyCmUsNA1LK7hzYTmA6aBZzUDWZlAQ=; b=Qci0FWhfyOVw5vCuGouJWoLZZ2C9Z02gki9lMe9IWK2i5kG3CBSPEtoFJdx2tg7l9Z uEYzvuidhKRKW7PErNJkkh0lGLA56SlZ4UGoR8WI8CAbuF8ialpsI7z/PSYmt7e6yvfh 52apKWPI1bWE6k8th7N58Ap3+okjS0kTPF+CxpOJgIpq4IHwLFUBJWcP6+SOf0A4fwo0 3j+Jz3CMfFA+JF4aLe2omyxlkAD7lC9MGslxnxX0tqpHyP8dfhW18XIkph7P8ITwp+R8 NmZ/FIou1eNDMico2bc4eDJ3g4blhGSyq1HdLismuiRsoBRK9hd+gCMSmEGjX5YEDpwp Alhg== X-Gm-Message-State: AOJu0YwQHSgB378FdJuNpodFFOmZWCbp0U6mhtVQ3Dgt21D07ynFHd5E JVFL6F2sE2DJ2QYkTK7DnXDwF2h3cF/MrlcfKa3UOhHGuMI5tIILW/CvyFdQ7gBH+InQLcP6a+l OKsqMHDquWGUQpEKKEytAJH+rTKHVFMcrr1LSeqJVsHBcDWWZzmL9lpbCHWRu X-Google-Smtp-Source: AGHT+IF4bojh0hjbNVDzV3nRBLrqzHwOlTccZruY0QAAQsm7RjDQhtfFTvdP590phB7L2bYQboFOgW+U X-Received: from palermo.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:118a]) (user=ardb job=sendgmr) by 2002:a05:6902:161a:b0:d74:93a1:70a2 with SMTP id bw26-20020a056902161a00b00d7493a170a2mr284754ybb.5.1694509317520; Tue, 12 Sep 2023 02:01:57 -0700 (PDT) Date: Tue, 12 Sep 2023 09:01:04 +0000 In-Reply-To: <20230912090051.4014114-17-ardb@google.com> Mime-Version: 1.0 References: <20230912090051.4014114-17-ardb@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=4623; i=ardb@kernel.org; h=from:subject; bh=F2Ts1gQ01OlqtgoyrXYKml6Q50qRYLzdjfB2PktVYD4=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIZVB4/JMvnNrVq0+eXDr4ZcGP7fv32BjycH+2Y4jrsq0s D5y35SLHaUsDGIcDLJiiiwCs/++23l6olSt8yxZmDmsTCBDGLg4BWAiYgyMDO+2tJknaVnHucjE 53/Se+hczvePt1UmeUJegf8j7V4ZdYb/mVJvjgR+cpcIf9e7bu6147U+miKnXl05YLHp4rP5O2d mMgAA X-Mailer: git-send-email 2.42.0.283.g2d96d420d3-goog Message-ID: <20230912090051.4014114-30-ardb@google.com> Subject: [PATCH v2 13/15] x86/boot: Drop PE/COFF .reloc section From: Ard Biesheuvel To: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , Evgeniy Baskov , Borislav Petkov , Dave Hansen , Ingo Molnar , Thomas Gleixner , Peter Jones , Matthew Garrett , Gerd Hoffmann , Kees Cook , "H. Peter Anvin" Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org From: Ard Biesheuvel Ancient buggy EFI loaders may have required a .reloc section to be present at some point in time, but this has not been true for a long time so the .reloc section can just be dropped. Signed-off-by: Ard Biesheuvel --- arch/x86/boot/header.S | 20 ------------ arch/x86/boot/setup.ld | 4 +-- arch/x86/boot/tools/build.c | 34 +++----------------- 3 files changed, 7 insertions(+), 51 deletions(-) diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S index 2b07bc596c39..9e9641e220a7 100644 --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -155,26 +155,6 @@ section_table: IMAGE_SCN_MEM_READ | \ IMAGE_SCN_MEM_EXECUTE # Characteristics - # - # The EFI application loader requires a relocation section - # because EFI applications must be relocatable. The .reloc - # offset & size fields are filled in by build.c. - # - .ascii ".reloc" - .byte 0 - .byte 0 - .long 0 - .long 0 - .long 0 # SizeOfRawData - .long 0 # PointerToRawData - .long 0 # PointerToRelocations - .long 0 # PointerToLineNumbers - .word 0 # NumberOfRelocations - .word 0 # NumberOfLineNumbers - .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ - IMAGE_SCN_MEM_READ | \ - IMAGE_SCN_MEM_DISCARDABLE # Characteristics - #ifdef CONFIG_EFI_MIXED # # The offset & size fields are filled in by build.c. diff --git a/arch/x86/boot/setup.ld b/arch/x86/boot/setup.ld index ae2b5046a0db..9b551eacffa8 100644 --- a/arch/x86/boot/setup.ld +++ b/arch/x86/boot/setup.ld @@ -40,8 +40,8 @@ SECTIONS setup_sig = .; LONG(0x5a5aaa55) - /* reserve some extra space for the reloc and compat sections */ - setup_size = ABSOLUTE(ALIGN(. + 64, 512)); + /* reserve some extra space for the compat section */ + setup_size = ABSOLUTE(ALIGN(. + 32, 512)); setup_sects = ABSOLUTE(setup_size / 512); } diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c index 9712f27e32c1..faccff9743a3 100644 --- a/arch/x86/boot/tools/build.c +++ b/arch/x86/boot/tools/build.c @@ -47,7 +47,6 @@ typedef unsigned int u32; /* This must be large enough to hold the entire setup */ u8 buf[SETUP_SECT_MAX*512]; -#define PECOFF_RELOC_RESERVE 0x20 #define PECOFF_COMPAT_RESERVE 0x20 static unsigned long efi32_pe_entry; @@ -180,24 +179,13 @@ static void update_pecoff_section_header(char *section_name, u32 offset, u32 siz update_pecoff_section_header_fields(section_name, offset, size, size, offset); } -static void update_pecoff_setup_and_reloc(unsigned int size) +static void update_pecoff_setup(unsigned int size) { u32 setup_offset = 0x200; - u32 reloc_offset = size - PECOFF_RELOC_RESERVE - PECOFF_COMPAT_RESERVE; -#ifdef CONFIG_EFI_MIXED - u32 compat_offset = reloc_offset + PECOFF_RELOC_RESERVE; -#endif - u32 setup_size = reloc_offset - setup_offset; + u32 compat_offset = size - PECOFF_COMPAT_RESERVE; + u32 setup_size = compat_offset - setup_offset; update_pecoff_section_header(".setup", setup_offset, setup_size); - update_pecoff_section_header(".reloc", reloc_offset, PECOFF_RELOC_RESERVE); - - /* - * Modify .reloc section contents with a single entry. The - * relocation is applied to offset 10 of the relocation section. - */ - put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]); - put_unaligned_le32(10, &buf[reloc_offset + 4]); #ifdef CONFIG_EFI_MIXED update_pecoff_section_header(".compat", compat_offset, PECOFF_COMPAT_RESERVE); @@ -214,21 +202,10 @@ static void update_pecoff_setup_and_reloc(unsigned int size) #endif } -static int reserve_pecoff_reloc_section(int c) -{ - /* Reserve 0x20 bytes for .reloc section */ - memset(buf+c, 0, PECOFF_RELOC_RESERVE); - return PECOFF_RELOC_RESERVE; -} - #else -static inline void update_pecoff_setup_and_reloc(unsigned int size) {} +static inline void update_pecoff_setup(unsigned int size) {} -static inline int reserve_pecoff_reloc_section(int c) -{ - return 0; -} #endif /* CONFIG_EFI_STUB */ static int reserve_pecoff_compat_section(int c) @@ -307,7 +284,6 @@ int main(int argc, char ** argv) fclose(file); c += reserve_pecoff_compat_section(c); - c += reserve_pecoff_reloc_section(c); /* Pad unused space with zeros */ setup_sectors = (c + 511) / 512; @@ -316,7 +292,7 @@ int main(int argc, char ** argv) i = setup_sectors*512; memset(buf+c, 0, i-c); - update_pecoff_setup_and_reloc(i); + update_pecoff_setup(i); /* Open and stat the kernel file */ fd = open(argv[2], O_RDONLY);