From patchwork Tue Nov 22 11:12:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evgeniy Baskov X-Patchwork-Id: 13052209 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 8DB84C4332F for ; Tue, 22 Nov 2022 11:13:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233064AbiKVLNG (ORCPT ); Tue, 22 Nov 2022 06:13:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233042AbiKVLMu (ORCPT ); Tue, 22 Nov 2022 06:12:50 -0500 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F23FD2BD2; Tue, 22 Nov 2022 03:12:48 -0800 (PST) Received: from localhost.localdomain (unknown [83.149.199.65]) by mail.ispras.ru (Postfix) with ESMTPSA id 7B3A340737DC; Tue, 22 Nov 2022 11:12:43 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 7B3A340737DC DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1669115563; bh=PQtsrCYU1PKgl/tUvA5tLuxewf/SvD2lWTLiW0J0hPU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aoR9o6GCQktf0NJUvawuKROyXeRphTzk4l2u/3i189V58z4DVD61ktH5HW92MSIrk ohC0y4cHtZYMLLJVe/K/zZIfQ2MYcuyfqlcjjq0Tu2rP3nERn4wRC19etwywnbR9SP wq32Lt78Hns8pUov/+JGW3NfR/aeb0gAkg6qF/3U= 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 , "Limonciello, Mario" , joeyli , lvc-project@linuxtesting.org, x86@kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v3 13/24] x86/boot: Split trampoline and pt init code Date: Tue, 22 Nov 2022 14:12:22 +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 When allocating trampoline from libstub trampoline allocation is performed separately, so it needs to be skipped. Split trampoline initialization and allocation code into two functions to make them invokable separately. Tested-by: Mario Limonciello Signed-off-by: Evgeniy Baskov --- arch/x86/boot/compressed/pgtable_64.c | 73 +++++++++++++++++---------- 1 file changed, 46 insertions(+), 27 deletions(-) diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c index c7cf5a1059a8..1f7169248612 100644 --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -106,12 +106,8 @@ static unsigned long find_trampoline_placement(void) return bios_start - TRAMPOLINE_32BIT_SIZE; } -struct paging_config paging_prepare(void *rmode) +bool trampoline_pgtable_init(struct boot_params *boot_params) { - struct paging_config paging_config = {}; - - /* Initialize boot_params. Required for cmdline_find_option_bool(). */ - boot_params = rmode; /* * Check if LA57 is desired and supported. @@ -125,26 +121,10 @@ struct paging_config paging_prepare(void *rmode) * * That's substitute for boot_cpu_has() in early boot code. */ - if (IS_ENABLED(CONFIG_X86_5LEVEL) && - !cmdline_find_option_bool("no5lvl") && - native_cpuid_eax(0) >= 7 && - (native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31)))) { - paging_config.l5_required = 1; - } - - paging_config.trampoline_start = find_trampoline_placement(); - - trampoline_32bit = (unsigned long *)paging_config.trampoline_start; - - /* Preserve trampoline memory */ - memcpy(trampoline_save, trampoline_32bit, TRAMPOLINE_32BIT_SIZE); - - /* Clear trampoline memory first */ - memset(trampoline_32bit, 0, TRAMPOLINE_32BIT_SIZE); - - /* Copy trampoline code in place */ - memcpy(trampoline_32bit + TRAMPOLINE_32BIT_CODE_OFFSET / sizeof(unsigned long), - &trampoline_32bit_src, TRAMPOLINE_32BIT_CODE_SIZE); + bool l5_required = IS_ENABLED(CONFIG_X86_5LEVEL) && + !cmdline_find_option_bool("no5lvl") && + native_cpuid_eax(0) >= 7 && + (native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))); /* * The code below prepares page table in trampoline memory. @@ -160,10 +140,10 @@ struct paging_config paging_prepare(void *rmode) * We are not going to use the page table in trampoline memory if we * are already in the desired paging mode. */ - if (paging_config.l5_required == !!(native_read_cr4() & X86_CR4_LA57)) + if (l5_required == !!(native_read_cr4() & X86_CR4_LA57)) goto out; - if (paging_config.l5_required) { + if (l5_required) { /* * For 4- to 5-level paging transition, set up current CR3 as * the first and the only entry in a new top-level page table. @@ -185,6 +165,45 @@ struct paging_config paging_prepare(void *rmode) (void *)src, PAGE_SIZE); } +out: + return l5_required; +} + +struct paging_config paging_prepare(void *rmode) +{ + struct paging_config paging_config = {}; + bool early_trampoline_alloc = 0; + + /* Initialize boot_params. Required for cmdline_find_option_bool(). */ + boot_params = rmode; + + /* + * We only need to find trampoline placement, if we have + * not already done it from libstub. + */ + + paging_config.trampoline_start = find_trampoline_placement(); + trampoline_32bit = (unsigned long *)paging_config.trampoline_start; + early_trampoline_alloc = 0; + + /* + * Preserve trampoline memory. + * When trampoline is located in memory + * owned by us, i.e. allocated in EFISTUB, + * we don't care about previous contents + * of this memory so copying can also be skipped. + */ + memcpy(trampoline_save, trampoline_32bit, TRAMPOLINE_32BIT_SIZE); + + /* Clear trampoline memory first */ + memset(trampoline_32bit, 0, TRAMPOLINE_32BIT_SIZE); + + /* Copy trampoline code in place */ + memcpy(trampoline_32bit + TRAMPOLINE_32BIT_CODE_OFFSET / sizeof(unsigned long), + &trampoline_32bit_src, TRAMPOLINE_32BIT_CODE_SIZE); + + paging_config.l5_required = trampoline_pgtable_init(boot_params); + out: return paging_config; }