From mboxrd@z Thu Jan 1 00:00:00 1970 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 ABEBFC433EF for ; Tue, 19 Jul 2022 12:51:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241928AbiGSMvE (ORCPT ); Tue, 19 Jul 2022 08:51:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241906AbiGSMtV (ORCPT ); Tue, 19 Jul 2022 08:49:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 190EF8E4F1; Tue, 19 Jul 2022 05:19:32 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 7FF13617B2; Tue, 19 Jul 2022 12:19:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FA1DC341CA; Tue, 19 Jul 2022 12:19:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658233170; bh=wt4k0BMHgTqMtsDUiI5OoAhxupig8hdc03zTNxLLy00=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xBbZJ2U++1hAKuOdpdt2gxPKlU1hujt/Im+NPNUKgwYYAWECie+Bfukz4muHXq6Q6 YN9ceJK1n5OTQdg94HRzFdkY7BJ1rnQhY3QwqbqwKM/swJZtKJu7W5X4SXieHQWLV1 gU/ipfiJOi46r2uXnZ9e++DkljU5bWdjsCCqnTlY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Juergen Gross , Borislav Petkov , Jan Beulich , Boris Ostrovsky Subject: [PATCH 5.18 006/231] x86/xen: Use clear_bss() for Xen PV guests Date: Tue, 19 Jul 2022 13:51:31 +0200 Message-Id: <20220719114714.704934047@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220719114714.247441733@linuxfoundation.org> References: <20220719114714.247441733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Juergen Gross commit 96e8fc5818686d4a1591bb6907e7fdb64ef29884 upstream. Instead of clearing the bss area in assembly code, use the clear_bss() function. This requires to pass the start_info address as parameter to xen_start_kernel() in order to avoid the xen_start_info being zeroed again. Signed-off-by: Juergen Gross Signed-off-by: Borislav Petkov Reviewed-by: Jan Beulich Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20220630071441.28576-2-jgross@suse.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/setup.h | 3 +++ arch/x86/kernel/head64.c | 2 +- arch/x86/xen/enlighten_pv.c | 8 ++++++-- arch/x86/xen/xen-head.S | 10 +--------- 4 files changed, 11 insertions(+), 12 deletions(-) --- a/arch/x86/include/asm/setup.h +++ b/arch/x86/include/asm/setup.h @@ -132,6 +132,9 @@ void *extend_brk(size_t size, size_t ali } extern void probe_roms(void); + +void clear_bss(void); + #ifdef __i386__ asmlinkage void __init i386_start_kernel(void); --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -421,7 +421,7 @@ void __init do_early_exception(struct pt /* Don't add a printk in there. printk relies on the PDA which is not initialized yet. */ -static void __init clear_bss(void) +void __init clear_bss(void) { memset(__bss_start, 0, (unsigned long) __bss_stop - (unsigned long) __bss_start); --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1183,15 +1183,19 @@ static void __init xen_domu_set_legacy_f extern void early_xen_iret_patch(void); /* First C function to be called on Xen boot */ -asmlinkage __visible void __init xen_start_kernel(void) +asmlinkage __visible void __init xen_start_kernel(struct start_info *si) { struct physdev_set_iopl set_iopl; unsigned long initrd_start = 0; int rc; - if (!xen_start_info) + if (!si) return; + clear_bss(); + + xen_start_info = si; + __text_gen_insn(&early_xen_iret_patch, JMP32_INSN_OPCODE, &early_xen_iret_patch, &xen_iret, JMP32_INSN_SIZE); --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -48,15 +48,6 @@ SYM_CODE_START(startup_xen) ANNOTATE_NOENDBR cld - /* Clear .bss */ - xor %eax,%eax - mov $__bss_start, %rdi - mov $__bss_stop, %rcx - sub %rdi, %rcx - shr $3, %rcx - rep stosq - - mov %rsi, xen_start_info mov initial_stack(%rip), %rsp /* Set up %gs. @@ -71,6 +62,7 @@ SYM_CODE_START(startup_xen) cdq wrmsr + mov %rsi, %rdi call xen_start_kernel SYM_CODE_END(startup_xen) __FINIT