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=-15.7 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 8CE4AC433DB for ; Wed, 27 Jan 2021 15:41:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40877207D8 for ; Wed, 27 Jan 2021 15:41:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236035AbhA0Pkq (ORCPT ); Wed, 27 Jan 2021 10:40:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236226AbhA0Pea (ORCPT ); Wed, 27 Jan 2021 10:34:30 -0500 Received: from mail-pg1-x532.google.com (mail-pg1-x532.google.com [IPv6:2607:f8b0:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5F59C061756 for ; Wed, 27 Jan 2021 07:33:49 -0800 (PST) Received: by mail-pg1-x532.google.com with SMTP id z21so1819209pgj.4 for ; Wed, 27 Jan 2021 07:33:49 -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=o/Abzz1MNa7Fco9CCxROMcrjIASvEPo3uvH/rl5fP8w=; b=lgvsSDlTubmyorSP8tcLtES6Ntf/cUa6NqNpz49HlFQkH4MNDgh/1tTLdAU6RHudFn SU2TeG0549Bzqgh/hzEoUgUf8EiXs426sVOq7D7Nxhg2/gIJj8W6ZZ/k69Icv+riCY9y XKyrh0pks9XS8LRJpStHa/x40sGpsOsYgk9Od2ezRX83vFvr2+13qU3/mEPhAmcd5fZ+ fSL5o8+616UIWi6KLKgdwi3qJTj4iQaZXaKhm7rPIThE07cMAdlZaQQX9l1nLR6I4rU1 pU6l5vaZscF10VfCR4p2GUpszjDX0k8tMFSwSNSJ/LvRjKe3k6+TXT/lGdxp/iammv3z 2YKg== 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=o/Abzz1MNa7Fco9CCxROMcrjIASvEPo3uvH/rl5fP8w=; b=dVm13F5+q8RkwzDABFCBvSTbo6cI92t+6dvD5adGOZxNn/I6DHzhWFzuZEleff0kA4 OwTgrVR2g0N4lBTQ6KBur/eLH1pNkwzTH4YUpvgv/t2mnAZpH6q5j1insVzruKaX+m63 K0+i2iL1wEJBaouY1IOEeE6EK4bjKdmOyv/3E60ZDRlAcmBlCm4q8cDkqvK2f/Q02LLI bRlkpCxUCvz7lDm8Xqwar4SGchnyHn6xoFcc0k4fnJXFMXjIkB00Fl/cBT/my2weXeji eipFq/3CKlddF5IfsLxTIec7NUJUd1qtsxeNG+xgoWP8K+vsYxQ39/mCk7swP/LV+v3z QQ5Q== X-Gm-Message-State: AOAM530NjlfldeTuPiyOlbMAU8RaAUhIFl31eG1vMjkNrG24YyIdSuyn ac1ezJa6h221Zo9rcMUQIcl+/x1T5kUVVg== X-Google-Smtp-Source: ABdhPJzgRH4brtZujhvF+IU29JCCHe2KpHNDkBDPiafDtrAPFfac37zeU9JwHmtkItEUAlvXZF1fjQ== X-Received: by 2002:a62:a204:0:b029:1c3:fb27:16f3 with SMTP id m4-20020a62a2040000b02901c3fb2716f3mr9466063pff.61.1611761629253; Wed, 27 Jan 2021 07:33:49 -0800 (PST) Received: from localhost ([47.251.4.198]) by smtp.gmail.com with ESMTPSA id c19sm2727152pfc.122.2021.01.27.07.33.48 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Jan 2021 07:33:48 -0800 (PST) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Dave Hansen , Peter Zijlstra , Al Viro , Vincenzo Frascino , Joerg Roedel , Ricardo Neri , Reinette Chatre , 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 V3 5/6] x86_32/sysenter: use percpu to get thread.sp0 when sysenter Date: Thu, 28 Jan 2021 00:32:21 +0800 Message-Id: <20210127163231.12709-6-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20210127163231.12709-1-jiangshanlai@gmail.com> References: <20210127163231.12709-1-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 stored the value of thread.sp0. At the code where TSS_entry2task_stack is used in sysenter, the CR3 is already kernel CR3 and kernel segments is loaded. So that we can directly use percpu for it instead of offset-calculation. And we remove the unused TSS_entry2task_stack. Signed-off-by: Lai Jiangshan --- arch/x86/entry/entry_32.S | 2 +- arch/x86/kernel/asm-offsets_32.c | 10 ---------- 2 files changed, 1 insertion(+), 11 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 01f098c5b017..d5b5b43fd0c0 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -916,7 +916,7 @@ SYM_FUNC_START(entry_SYSENTER_32) /* Switch to task stack */ movl %esp, %eax - movl (3*4+TSS_entry2task_stack)(%esp), %esp + movl PER_CPU_VAR(cpu_tss_rw + TSS_sp1), %esp .Lsysenter_past_esp: pushl $__USER_DS /* pt_regs->ss */ diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c index 6e043f295a60..6d4143cfbf03 100644 --- a/arch/x86/kernel/asm-offsets_32.c +++ b/arch/x86/kernel/asm-offsets_32.c @@ -43,16 +43,6 @@ void foo(void) OFFSET(saved_context_gdt_desc, saved_context, gdt_desc); BLANK(); - /* - * Offset from the entry stack to task stack stored in TSS. Kernel entry - * happens on the per-cpu entry-stack, and the asm code switches to the - * task-stack pointer stored in x86_tss.sp1, which is a copy of - * task->thread.sp0 where entry code can find it. - */ - DEFINE(TSS_entry2task_stack, - offsetof(struct cpu_entry_area, tss.x86_tss.sp1) - - offsetofend(struct cpu_entry_area, entry_stack_page.stack)); - #ifdef CONFIG_STACKPROTECTOR BLANK(); OFFSET(stack_canary_offset, stack_canary, canary); -- 2.19.1.6.gb485710b