From patchwork Tue Oct 25 14:12:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evgeniy Baskov X-Patchwork-Id: 13019337 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 DF478FA3744 for ; Tue, 25 Oct 2022 14:14:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233125AbiJYOOW (ORCPT ); Tue, 25 Oct 2022 10:14:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233052AbiJYONv (ORCPT ); Tue, 25 Oct 2022 10:13:51 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2D51A4853; Tue, 25 Oct 2022 07:13:49 -0700 (PDT) Received: from localhost.localdomain (unknown [83.149.199.65]) by mail.ispras.ru (Postfix) with ESMTPSA id 4832640737AC; Tue, 25 Oct 2022 14:13:48 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 4832640737AC DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1666707228; bh=DZTrbaBaHe77iGD0+HZCDY+dD1tpBzVWypKX0yhMApE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hSA4oTacdmboTGxjLXOr5oGkOsiMFnT3xJPfu/VNlPtW7JIOXZMeMgWWHF0EgbLVW D5UuKr7CK2Q4bYnegBpFEjz0ocLVEntGoQSj33IHkzhtpWZxhwb7DWXd69Xz/sPf7t 6n8NSPXbDeCVRIXbPDY2qQ2kgLdqTk2er3PdiL3E= From: Evgeniy Baskov To: Ard Biesheuvel Cc: Evgeniy Baskov , Borislav Petkov , Andy Lutomirski , Dave Hansen , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexey Khoroshilov , Peter Jones , lvc-project@linuxtesting.org, x86@kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v2 12/23] x86/boot: Make kernel_add_identity_map() a pointer Date: Tue, 25 Oct 2022 17:12:50 +0300 Message-Id: X-Mailer: git-send-email 2.37.4 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Convert kernel_add_identity_map() into a function pointer to be able to provide alternative implementations of this function. Required to enable calling the code using this function from EFI environment. Signed-off-by: Evgeniy Baskov --- arch/x86/boot/compressed/ident_map_64.c | 7 ++++--- arch/x86/boot/compressed/misc.c | 24 ++++++++++++++++++++++++ arch/x86/boot/compressed/misc.h | 15 +++------------ 3 files changed, 31 insertions(+), 15 deletions(-) diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c index ba5108c58a4e..1aee524d3c2b 100644 --- a/arch/x86/boot/compressed/ident_map_64.c +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -92,9 +92,9 @@ bool has_nx; /* set in head_64.S */ /* * Adds the specified range to the identity mappings. */ -unsigned long kernel_add_identity_map(unsigned long start, - unsigned long end, - unsigned int flags) +unsigned long kernel_add_identity_map_(unsigned long start, + unsigned long end, + unsigned int flags) { int ret; @@ -142,6 +142,7 @@ void initialize_identity_maps(void *rmode) struct setup_data *sd; boot_params = rmode; + kernel_add_identity_map = kernel_add_identity_map_; /* Exclude the encryption mask from __PHYSICAL_MASK */ physical_mask &= ~sme_me_mask; diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index aa4a22bc9cf9..c9c235d65d16 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -275,6 +275,22 @@ static void parse_elf(void *output, unsigned long output_len, free(phdrs); } +/* + * This points to actual implementation of mapping function + * for current environment: either EFI API wrapper, + * own implementation or dummy implementation below. + */ +unsigned long (*kernel_add_identity_map)(unsigned long start, + unsigned long end, + unsigned int flags); + +static inline unsigned long kernel_add_identity_map_dummy(unsigned long start, + unsigned long end, + unsigned int flags) +{ + return start; +} + /* * The compressed kernel image (ZO), has been moved so that its position * is against the end of the buffer used to hold the uncompressed kernel @@ -312,6 +328,14 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, init_default_io_ops(); + /* + * On 64-bit this pointer is set during page table uninitialization, + * but on 32-bit it remains uninitialized, since paging is disabled. + */ + if (IS_ENABLED(CONFIG_X86_32)) + kernel_add_identity_map = kernel_add_identity_map_dummy; + + /* * Detect TDX guest environment. * diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 38d31bec062d..0076b2845b4b 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -180,18 +180,9 @@ static inline int count_immovable_mem_regions(void) { return 0; } #ifdef CONFIG_X86_5LEVEL extern unsigned int __pgtable_l5_enabled, pgdir_shift, ptrs_per_p4d; #endif -#ifdef CONFIG_X86_64 -extern unsigned long kernel_add_identity_map(unsigned long start, - unsigned long end, - unsigned int flags); -#else -static inline unsigned long kernel_add_identity_map(unsigned long start, - unsigned long end, - unsigned int flags) -{ - return start; -} -#endif +extern unsigned long (*kernel_add_identity_map)(unsigned long start, + unsigned long end, + unsigned int flags); /* Used by PAGE_KERN* macros: */ extern pteval_t __default_kernel_pte_mask;