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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E90F5C433DB for ; Wed, 10 Feb 2021 12:42:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1E2264E25 for ; Wed, 10 Feb 2021 12:42:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230231AbhBJMmO (ORCPT ); Wed, 10 Feb 2021 07:42:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231782AbhBJMjj (ORCPT ); Wed, 10 Feb 2021 07:39:39 -0500 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECB48C061756 for ; Wed, 10 Feb 2021 04:38:58 -0800 (PST) Received: by mail-pg1-x536.google.com with SMTP id t26so1156650pgv.3 for ; Wed, 10 Feb 2021 04:38:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=mU2mc5ad6GePbH4sYA1Nh2eY3tg5115KkQxePABseE0=; b=WwhsfLIz9PglgmOP6ZXqxDFtIOqPCvju1rxZQIZhbX4bnHRaXwW40TeGoYMQtH2mPM JZvAkR+2Dc3wbb5QZ4dnRA2SSHRmUolaV9ln2KLHYcsMt6eEaJfGEojKhQmnyHRwAHd/ ZemwPfr110fHRKS1i4tAEdN1IrB8J4RrWCDls72LjvrVxoh9G+Prt4HUTjjXfUjs3jrC adL72JteV9a8YQ67xUkvbjJfcGDYI6TuZTj8T3fu3AUF3eTOrBGXRhayThOVnogKEikd OZXAtfFKon7w+z78vkBIImmIFm6bARp+indkJJ4Jrtj3gj6Yb365T7fnoJ2Mrv0TNnwT CYfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=mU2mc5ad6GePbH4sYA1Nh2eY3tg5115KkQxePABseE0=; b=TqaWXs1x2GK00ZCTHMsC+7PgOvx0REatD0DYnDE9HIdpySVhhp+uI+l2Vzl53pwhYj +GOcL+lkaLXaRXsnUYxnmfbsqFRGDkDtTFN2Jz2rRWQwEfMm27sTAgAeEaKS7vA+F38l mPYoArvsT0eBH/kX+bk38wZ2tfpNANOY3+qxoBuzEIsPMGNYMvo5CnlexU3hd9PIuMr0 OTthfhcGIivnYvH5PiuJX64TjHzLErhM/seS7Gu/a7enFFjGLvcsLadIOE4WiDZjMmKC oIdCtEpJC+Af3jVzc8x9YBDG2gQOQzRzNOxBvtk8vcXSlKY1HpirURGD9Z8k4g9dqhJZ MFBQ== X-Gm-Message-State: AOAM531J3QTlvb3H87uPmqYeZg+gOkl6ugTqTZ9Mbl2iEfW4R2xg31VQ H4OiqDBLenQ31pv2BikN5+y05Ez3tRQ= X-Google-Smtp-Source: ABdhPJxDOWKKqsKC2198l56Yq+8ZDM5pQy6yb7jXIQYFpFxd4tL5QdtSUC4jcRlX4Vs+y1PDGYmGPw== X-Received: by 2002:a65:67cf:: with SMTP id b15mr2975277pgs.320.1612960738291; Wed, 10 Feb 2021 04:38:58 -0800 (PST) Received: from localhost ([47.251.3.230]) by smtp.gmail.com with ESMTPSA id r4sm2218196pgp.16.2021.02.10.04.38.57 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 10 Feb 2021 04:38:57 -0800 (PST) From: Lai Jiangshan To: linux-kernel@vger.kernel.org, Borislav Petkov Cc: Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Dave Hansen , Peter Zijlstra , Al Viro , Vincenzo Frascino , Joerg Roedel , Ricardo Neri , Reinette Chatre , Balbir Singh , Andrew Morton , Gabriel Krisman Bertazi , Kees Cook , Frederic Weisbecker , Jens Axboe , Arvind Sankar , Brian Gerst , Ard Biesheuvel , Andi Kleen , Mike Rapoport , Mike Hommey , Mark Gross , Fenghua Yu , Tony Luck , Anthony Steinhauser , Jay Lang , "Chang S. Bae" Subject: [PATCH V4 2/6] x86/entry/32: Use percpu instead of offset-calculation to get thread.sp0 in SWITCH_TO_KERNEL_STACK Date: Wed, 10 Feb 2021 21:39:13 +0800 Message-Id: <20210210133917.2414-3-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20210210133917.2414-1-jiangshanlai@gmail.com> References: <20210210133917.2414-1-jiangshanlai@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lai Jiangshan TSS_entry2task_stack is used to refer to tss.sp1 which is a copy of thread.sp0. When TSS_entry2task_stack is used in SWITCH_TO_KERNEL_STACK, the CR3 is already kernel CR3 and the kernel segments are loaded. So it directly uses percpu to get tss.sp1(thread.sp0) instead of the complicated offset-calculation via TSS_entry2task_stack. Signed-off-by: Lai Jiangshan --- arch/x86/entry/entry_32.S | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index df8c017e6161..3b4d1a63d1f0 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -465,16 +465,11 @@ cmpl $SIZEOF_entry_stack, %ecx jae .Lend_\@ - /* Load stack pointer into %esi and %edi */ + /* Load stack pointer into %esi */ movl %esp, %esi - movl %esi, %edi - - /* Move %edi to the top of the entry stack */ - andl $(MASK_entry_stack), %edi - addl $(SIZEOF_entry_stack), %edi /* Load top of task-stack into %edi */ - movl TSS_entry2task_stack(%edi), %edi + movl PER_CPU_VAR(cpu_tss_rw + TSS_sp1), %edi /* Special case - entry from kernel mode via entry stack */ #ifdef CONFIG_VM86 -- 2.19.1.6.gb485710b