From patchwork Fri Jul 28 09:09:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 707707 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 5CFDFC04FDF for ; Fri, 28 Jul 2023 09:13:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235322AbjG1JNh (ORCPT ); Fri, 28 Jul 2023 05:13:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235388AbjG1JMv (ORCPT ); Fri, 28 Jul 2023 05:12:51 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0DE53C1F; Fri, 28 Jul 2023 02:11:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 55ADA62088; Fri, 28 Jul 2023 09:11:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04494C433CA; Fri, 28 Jul 2023 09:11:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690535501; bh=RyCASInDFX0BjQq753LAcm+uf0XadKvOwO74Z3uQu1s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IDPKqf9tA4kK7YqfOEkF8A+1EnTCYOJiqVXGQWKC/PU58CtpPjuZfrM1k7A4jAvDr Iy/wdlijulaBlO/7MwWe51t02H70L2lR1hLTIKG6RPBYoTtTltXt90tbpmfIKdu8Fp AAxais+23HtgDrXlwdAPIq/DEh3fEyXpDDFFWmeLb8sQfojmar7YjZaPSxP1C7NPLW ElthDNmLfXkK93+1MN01+WMZmqyft+1zAlkcTaA7zO5UezMo9jkkXsqZIp4slajbeu Thbq5RYHR8XIe6enMNVaTXNmco7/qbpqs7mVyBUqt3BFft+Hx0k+XgXncnhRr5rSlX Fx71/sivGAyqg== From: Ard Biesheuvel To: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , Evgeniy Baskov , Borislav Petkov , Andy Lutomirski , Dave Hansen , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexey Khoroshilov , Peter Jones , Gerd Hoffmann , Dave Young , Mario Limonciello , Kees Cook , Tom Lendacky , "Kirill A . Shutemov" , Linus Torvalds , Joerg Roedel Subject: [PATCH v7 14/22] x86/decompressor: Merge trampoline cleanup with switching code Date: Fri, 28 Jul 2023 11:09:08 +0200 Message-Id: <20230728090916.1538550-15-ardb@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230728090916.1538550-1-ardb@kernel.org> References: <20230728090916.1538550-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4143; i=ardb@kernel.org; h=from:subject; bh=RyCASInDFX0BjQq753LAcm+uf0XadKvOwO74Z3uQu1s=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIeVw66ZDvs7vb1cv2Seu0SHxW69t8fvGzGdL/rA+VD3to dQyuSCvo5SFQYyDQVZMkUVg9t93O09PlKp1niULM4eVCWQIAxenAEzkwEdGhrXH2J4Y1yTf637y xtFphkCj09VdMcffvbL+vCTup/9DlzOMDD1tClc/LOp3fs/WYfVE++ryO5oTZC9nPPnIodv9r+/ edyYA X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Now that the trampoline setup code and the actual invocation of it are all done from the C routine, the trampoline cleanup can be merged into it as well, instead of returning to asm just to call another C function. Acked-by: Kirill A. Shutemov Signed-off-by: Ard Biesheuvel --- arch/x86/boot/compressed/head_64.S | 13 +++------ arch/x86/boot/compressed/pgtable_64.c | 28 ++++++++------------ 2 files changed, 15 insertions(+), 26 deletions(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 88b5e45b8ecb490b..eb33edf1e75d4b02 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -429,19 +429,14 @@ SYM_CODE_START(startup_64) * set_paging_levels() updates the number of paging levels using a * trampoline in 32-bit addressable memory if the current number does * not match the desired number. + * + * RSI is the relocated address of the page table to use instead of + * page table in trampoline memory (if required). */ movq %r15, %rdi /* pass struct boot_params pointer */ + leaq rva(top_pgtable)(%rbx), %rsi call set_paging_levels - /* - * cleanup_trampoline() would restore trampoline memory. - * - * RDI is address of the page table to use instead of page table - * in trampoline memory (if required). - */ - leaq rva(top_pgtable)(%rbx), %rdi - call cleanup_trampoline - /* Zero EFLAGS */ pushq $0 popfq diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c index 4016444e6788304f..4f50af23a0854f18 100644 --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -101,9 +101,10 @@ static unsigned long find_trampoline_placement(void) return bios_start - TRAMPOLINE_32BIT_SIZE; } -asmlinkage void set_paging_levels(void *rmode) +asmlinkage void set_paging_levels(void *rmode, void *pgtable) { void (*toggle_la57)(void *trampoline, bool enable_5lvl); + void *trampoline_pgtable; bool l5_required = false; /* Initialize boot_params. Required for cmdline_find_option_bool(). */ @@ -133,7 +134,7 @@ asmlinkage void set_paging_levels(void *rmode) * the desired one. */ if (l5_required == !!(native_read_cr4() & X86_CR4_LA57)) - return; + goto out; trampoline_32bit = (unsigned long *)find_trampoline_placement(); @@ -163,6 +164,8 @@ asmlinkage void set_paging_levels(void *rmode) * The new page table will be used by trampoline code for switching * from 4- to 5-level paging or vice versa. */ + trampoline_pgtable = trampoline_32bit + + TRAMPOLINE_32BIT_PGTABLE_OFFSET / sizeof(unsigned long); if (l5_required) { /* @@ -182,31 +185,21 @@ asmlinkage void set_paging_levels(void *rmode) * may be above 4G. */ src = *(unsigned long *)__native_read_cr3() & PAGE_MASK; - memcpy(trampoline_32bit + TRAMPOLINE_32BIT_PGTABLE_OFFSET / sizeof(unsigned long), - (void *)src, PAGE_SIZE); + memcpy(trampoline_pgtable, (void *)src, PAGE_SIZE); } toggle_la57(trampoline_32bit, l5_required); -} - -void cleanup_trampoline(void *pgtable) -{ - void *trampoline_pgtable; - - trampoline_pgtable = trampoline_32bit + TRAMPOLINE_32BIT_PGTABLE_OFFSET / sizeof(unsigned long); /* - * Move the top level page table out of trampoline memory, - * if it's there. + * Move the top level page table out of trampoline memory. */ - if ((void *)__native_read_cr3() == trampoline_pgtable) { - memcpy(pgtable, trampoline_pgtable, PAGE_SIZE); - native_write_cr3((unsigned long)pgtable); - } + memcpy(pgtable, trampoline_pgtable, PAGE_SIZE); + native_write_cr3((unsigned long)pgtable); /* Restore trampoline memory */ memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE); +out: /* Initialize variables for 5-level paging */ #ifdef CONFIG_X86_5LEVEL if (__read_cr4() & X86_CR4_LA57) { @@ -215,4 +208,5 @@ void cleanup_trampoline(void *pgtable) ptrs_per_p4d = 512; } #endif + return; }