From patchwork Thu May 18 23:14:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 683764 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 6265EC7EE2E for ; Thu, 18 May 2023 23:15:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230233AbjERXO7 (ORCPT ); Thu, 18 May 2023 19:14:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230373AbjERXOz (ORCPT ); Thu, 18 May 2023 19:14:55 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7C92E6E; Thu, 18 May 2023 16:14:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1684451693; x=1715987693; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=BuLaVtTf5RKQWpr3anFnaNnaMQK4KaotupS5o/iFyhQ=; b=IO5kue1Hkr9uJpm4HUiGHAZ9t4tixBmYNGVPHeIULKnrQaUD+2LN8WFm aclgC0/bgik8BMDc/R3aGAF19C57jJi1ZWUpnW2PuEjUruIDc56/IPykU 8keoZ5fz+WNvJceZ02tX1A8Blt+1ADBcBoeg8FU3u+U76hL+c1YFO5hQl SJjDGSXELXigapmhxnaRSw+x7i6dBVpjogU1ZFnM39Qcd1apfe3bdrf8b FVstrMe/meJxIkXMzz8oVxBdSB3ChYNRCwblr0JXyX41sCwBok9j6VnGx lI1EOlizZLyXk9/9Y6xYpCFp8exx+lV8dug//jFt0t4zY9sscC5MUodk8 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10714"; a="380431748" X-IronPort-AV: E=Sophos;i="6.00,175,1681196400"; d="scan'208";a="380431748" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 May 2023 16:14:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10714"; a="846669541" X-IronPort-AV: E=Sophos;i="6.00,175,1681196400"; d="scan'208";a="846669541" Received: from rkiyama-mobl1.amr.corp.intel.com (HELO box.shutemov.name) ([10.251.222.16]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 May 2023 16:14:42 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 3F46A10DFCF; Fri, 19 May 2023 02:14:40 +0300 (+03) From: "Kirill A. Shutemov" To: Borislav Petkov , Andy Lutomirski , Dave Hansen , Sean Christopherson , Andrew Morton , Joerg Roedel , Ard Biesheuvel Cc: Andi Kleen , Kuppuswamy Sathyanarayanan , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , Dario Faggioli , Mike Rapoport , David Hildenbrand , Mel Gorman , marcelo.cerri@canonical.com, tim.gardner@canonical.com, khalid.elmously@canonical.com, philip.cox@canonical.com, aarcange@redhat.com, peterx@redhat.com, x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Liam Merwick Subject: [PATCHv12 4/9] x86/boot/compressed: Handle unaccepted memory Date: Fri, 19 May 2023 02:14:29 +0300 Message-Id: <20230518231434.26080-5-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230518231434.26080-1-kirill.shutemov@linux.intel.com> References: <20230518231434.26080-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org The firmware will pre-accept the memory used to run the stub. But, the stub is responsible for accepting the memory into which it decompresses the main kernel. Accept memory just before decompression starts. The stub is also responsible for choosing a physical address in which to place the decompressed kernel image. The KASLR mechanism will randomize this physical address. Since the accepted memory region is relatively small, KASLR would be quite ineffective if it only used the pre-accepted area (EFI_CONVENTIONAL_MEMORY). Ensure that KASLR randomizes among the entire physical address space by also including EFI_UNACCEPTED_MEMORY. Signed-off-by: Kirill A. Shutemov Reviewed-by: Liam Merwick Reviewed-by: Tom Lendacky Reviewed-by: Ard Biesheuvel --- arch/x86/boot/compressed/efi.h | 10 +++++++++ arch/x86/boot/compressed/kaslr.c | 35 +++++++++++++++++++++----------- arch/x86/boot/compressed/mem.c | 23 +++++++++++++++++++++ arch/x86/boot/compressed/misc.c | 7 +++++++ arch/x86/boot/compressed/misc.h | 6 ++++++ 5 files changed, 69 insertions(+), 12 deletions(-) diff --git a/arch/x86/boot/compressed/efi.h b/arch/x86/boot/compressed/efi.h index 7db2f41b54cd..866c0af8b5b9 100644 --- a/arch/x86/boot/compressed/efi.h +++ b/arch/x86/boot/compressed/efi.h @@ -16,6 +16,7 @@ typedef guid_t efi_guid_t __aligned(__alignof__(u32)); #define ACPI_TABLE_GUID EFI_GUID(0xeb9d2d30, 0x2d88, 0x11d3, 0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d) #define ACPI_20_TABLE_GUID EFI_GUID(0x8868e871, 0xe4f1, 0x11d3, 0xbc, 0x22, 0x00, 0x80, 0xc7, 0x3c, 0x88, 0x81) #define EFI_CC_BLOB_GUID EFI_GUID(0x067b1f5f, 0xcf26, 0x44c5, 0x85, 0x54, 0x93, 0xd7, 0x77, 0x91, 0x2d, 0x42) +#define LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID EFI_GUID(0xd5d1de3c, 0x105c, 0x44f9, 0x9e, 0xa9, 0xbc, 0xef, 0x98, 0x12, 0x00, 0x31) #define EFI32_LOADER_SIGNATURE "EL32" #define EFI64_LOADER_SIGNATURE "EL64" @@ -32,6 +33,7 @@ typedef struct { } efi_table_hdr_t; #define EFI_CONVENTIONAL_MEMORY 7 +#define EFI_UNACCEPTED_MEMORY 15 #define EFI_MEMORY_MORE_RELIABLE \ ((u64)0x0000000000010000ULL) /* higher reliability */ @@ -104,6 +106,14 @@ struct efi_setup_data { u64 reserved[8]; }; +struct efi_unaccepted_memory { + u32 version; + u32 unit_size; + u64 phys_base; + u64 size; + unsigned long bitmap[]; +}; + static inline int efi_guidcmp (efi_guid_t left, efi_guid_t right) { return memcmp(&left, &right, sizeof (efi_guid_t)); diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 454757fbdfe5..749f0fe7e446 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -672,6 +672,28 @@ static bool process_mem_region(struct mem_vector *region, } #ifdef CONFIG_EFI + +/* + * Only EFI_CONVENTIONAL_MEMORY and EFI_UNACCEPTED_MEMORY (if supported) are + * guaranteed to be free. + * + * It is more conservative in picking free memory than the EFI spec allows: + * + * According to the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also free memory + * and thus available to place the kernel image into, but in practice there's + * firmware where using that memory leads to crashes. + */ +static inline bool memory_type_is_free(efi_memory_desc_t *md) +{ + if (md->type == EFI_CONVENTIONAL_MEMORY) + return true; + + if (md->type == EFI_UNACCEPTED_MEMORY) + return IS_ENABLED(CONFIG_UNACCEPTED_MEMORY); + + return false; +} + /* * Returns true if we processed the EFI memmap, which we prefer over the E820 * table if it is available. @@ -716,18 +738,7 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) for (i = 0; i < nr_desc; i++) { md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i); - /* - * Here we are more conservative in picking free memory than - * the EFI spec allows: - * - * According to the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also - * free memory and thus available to place the kernel image into, - * but in practice there's firmware where using that memory leads - * to crashes. - * - * Only EFI_CONVENTIONAL_MEMORY is guaranteed to be free. - */ - if (md->type != EFI_CONVENTIONAL_MEMORY) + if (!memory_type_is_free(md)) continue; if (efi_soft_reserve_enabled() && diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c index 67594fcb11d9..87372b96d613 100644 --- a/arch/x86/boot/compressed/mem.c +++ b/arch/x86/boot/compressed/mem.c @@ -1,9 +1,32 @@ // SPDX-License-Identifier: GPL-2.0-only #include "error.h" +#include "misc.h" void arch_accept_memory(phys_addr_t start, phys_addr_t end) { /* Platform-specific memory-acceptance call goes here */ error("Cannot accept memory"); } + +void init_unaccepted_memory(void) +{ + guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID; + struct efi_unaccepted_memory *unaccepted_table; + unsigned long cfg_table_pa; + unsigned int cfg_table_len; + int ret; + + ret = efi_get_conf_table(boot_params, &cfg_table_pa, &cfg_table_len); + if (ret) + error("EFI config table not found."); + + unaccepted_table = (void *)efi_find_vendor_table(boot_params, + cfg_table_pa, + cfg_table_len, + guid); + if (unaccepted_table->version != 1) + error("Unknown version of unaccepted memory table\n"); + + set_unaccepted_table(unaccepted_table); +} diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 014ff222bf4b..36535a3753f5 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -455,6 +455,13 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, #endif debug_putstr("\nDecompressing Linux... "); + + if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) { + debug_putstr("Accepting memory... "); + init_unaccepted_memory(); + accept_memory(__pa(output), __pa(output) + needed_size); + } + __decompress(input_data, input_len, NULL, NULL, output, output_len, NULL, error); entry_offset = parse_elf(output); diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 2f155a0e3041..e1a0b49e0ed2 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -247,4 +247,10 @@ static inline unsigned long efi_find_vendor_table(struct boot_params *bp, } #endif /* CONFIG_EFI */ +void init_unaccepted_memory(void); + +/* Implemented in EFI stub */ +void set_unaccepted_table(struct efi_unaccepted_memory *table); +void accept_memory(phys_addr_t start, phys_addr_t end); + #endif /* BOOT_COMPRESSED_MISC_H */