From patchwork Wed Sep 21 14:54:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 608053 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 E6AD9ECAAD8 for ; Wed, 21 Sep 2022 14:55:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230449AbiIUOzy (ORCPT ); Wed, 21 Sep 2022 10:55:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230335AbiIUOzJ (ORCPT ); Wed, 21 Sep 2022 10:55:09 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 919D92F38D; Wed, 21 Sep 2022 07:54:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 305FEB83016; Wed, 21 Sep 2022 14:54:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D1DFC433B5; Wed, 21 Sep 2022 14:54:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663772093; bh=XGOv1f+E6PQRclir8TXJx9cDwDQezaGlv4nQIiVk7vs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DoiETaFSwfGSaAXMxwffH9Xxis1cYu8jMM3VSD21rYwOLkhCRBMoYjSw2kp0yhmTQ UOAN0EvbOIyq1GEl7hhUal2Hh+a8ZsAWF05by41gbMyiMNZAiQqInwNVRFNnrLFXCA 8/7G93J73LxoZRLJg5JATSgGLp+FnGHYzI/9k6bfF0CXWzx78I3RcnoUUurEhlb9Me 4lL7QXASEZfIwX0TlSOCotK1NGVpiBLnyy4ujKyJXfZ/SAz1r0KrlszTGsidNux/4H CXa4q/lVPBnkH0AlIvPjGHyX0yslxu9apw6rCYtWhHPXK4MCmk8gs57asm3lSu+/FD 3fQy6FGrXKSxw== From: Ard Biesheuvel To: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Michael Roth Subject: [PATCH v2 11/16] x86/compressed: move startup32_load_idt() into .text section Date: Wed, 21 Sep 2022 16:54:17 +0200 Message-Id: <20220921145422.437618-12-ardb@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220921145422.437618-1-ardb@kernel.org> References: <20220921145422.437618-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2494; i=ardb@kernel.org; h=from:subject; bh=XGOv1f+E6PQRclir8TXJx9cDwDQezaGlv4nQIiVk7vs=; b=owEB7QES/pANAwAKAcNPIjmS2Y8kAcsmYgBjKyWVnp/7Hjms7eUQhcYnrLlxJDyZ+gJO3OZu8xtm WwvUe0CJAbMEAAEKAB0WIQT72WJ8QGnJQhU3VynDTyI5ktmPJAUCYysllQAKCRDDTyI5ktmPJLTvC/ 98A6Cxj06piaelMbbPTO924O3aPixByu15CpFLSTm7st2dVCjR6M+XbGBmbC5FhFk0q7WJqohOcn3B 3Kuv1sUyabIe/lXHlUHiIXa9bBwoH8JtoHPN/qlvpk+wKbr36pruah0bvNkSVz5632Ozd3y91qZay5 iQJ9UZ3h+KDlxpFfggar3TXgltclQmzZlSWnkDye7SglY0W5lVf2pnWuhSC5+XnylBnetQB4QQsf3S tnDYnIgVEFnLQ7pcyfmlJKffAJR7nGTNN3BdrN/gpTSuMP2AbIDDADLgrALU7aDRn4kj8QfiXZ98TV JsnMZMQvlm7v9F745bYlgnSPtyANaeQnbkiDG14XJqWt59runSYtM8BdsiVHG5tpy75zjztt966l+H kyuI18QVhXYXkj9fyzVC4FuKT1GQycCGHpLKm1wEglU75FhyKuv4n4UYehue15SSRCQL9ab0e0xf+L 9z7BtNYmaWy1TSnM0c64NQTtcAAk0MPUtgsAfkRMA+W0Y= X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Convert startup32_load_idt() into an ordinary function and move it into the .text section. This involves turning the rva() immediates into ones derived from a local label, and preserving/restoring the %ebp and %ebx as per the calling convention. Also move the #ifdef to the only existing call site. This makes it clear that the function call does nothing if support for memory encryption is not compiled in. Signed-off-by: Ard Biesheuvel --- arch/x86/boot/compressed/head_64.S | 29 ++++++++++++++------ 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index a1f893dd5bbf..b4b2b76ed1af 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -118,7 +118,9 @@ SYM_FUNC_START(startup_32) 1: /* Setup Exception handling for SEV-ES */ +#ifdef CONFIG_AMD_MEM_ENCRYPT call startup32_load_idt +#endif /* Make sure cpu supports long mode. */ call verify_cpu @@ -719,7 +721,7 @@ SYM_DATA_END_LABEL(boot32_idt, SYM_L_GLOBAL, boot32_idt_end) #endif #ifdef CONFIG_AMD_MEM_ENCRYPT - __HEAD + .text .code32 /* * Write an IDT entry into boot32_idt @@ -752,24 +754,32 @@ SYM_FUNC_START_LOCAL(startup32_set_idt_entry) RET SYM_FUNC_END(startup32_set_idt_entry) -#endif SYM_FUNC_START(startup32_load_idt) -#ifdef CONFIG_AMD_MEM_ENCRYPT - leal rva(boot32_idt)(%ebp), %ecx + push %ebp + push %ebx + + call 1f +1: pop %ebp + + leal (boot32_idt - 1b)(%ebp), %ebx /* #VC handler */ - leal rva(startup32_vc_handler)(%ebp), %eax + leal (startup32_vc_handler - 1b)(%ebp), %eax movl $X86_TRAP_VC, %edx + movl %ebx, %ecx call startup32_set_idt_entry /* Load IDT */ - leal rva(boot32_idt)(%ebp), %eax - movl %eax, rva(boot32_idt_desc+2)(%ebp) - lidt rva(boot32_idt_desc)(%ebp) -#endif + leal (boot32_idt_desc - 1b)(%ebp), %ecx + movl %ebx, 2(%ecx) + lidt (%ecx) + + pop %ebx + pop %ebp RET SYM_FUNC_END(startup32_load_idt) +#endif /* * Check for the correct C-bit position when the startup_32 boot-path is used. @@ -788,6 +798,7 @@ SYM_FUNC_END(startup32_load_idt) * succeed. An incorrect C-bit position will map all memory unencrypted, so that * the compare will use the encrypted random data and fail. */ + __HEAD SYM_FUNC_START(startup32_check_sev_cbit) #ifdef CONFIG_AMD_MEM_ENCRYPT pushl %eax