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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 81989C742D2 for ; Fri, 12 Jul 2019 22:42:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E31020651 for ; Fri, 12 Jul 2019 22:42:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Uvull8Js" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728166AbfGLWmg (ORCPT ); Fri, 12 Jul 2019 18:42:36 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:43716 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727994AbfGLWmf (ORCPT ); Fri, 12 Jul 2019 18:42:35 -0400 Received: by mail-qt1-f201.google.com with SMTP id e14so8390151qtq.10 for ; Fri, 12 Jul 2019 15:42:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=GPlldc1uUCaMqKOlqd707RfJFmN0vdU2ggLjnOu2mQQ=; b=Uvull8JsmAlDemDoFeLo0l6LKR9FI9L6JGngRgKyRPvHsDs77REgPEHGJVhR7epI3+ vm1KXehBkmrPa2LG3Yd5SlHjnZ4bY1nXgoj1C07P8j2MJtPOKX+gfQnqO9tqwyN7n71/ vHrqzKjVZRVy9zhIGHYo1Hjo/l5xY1ws6FKUAJoZ8x3hxkwAINDVgUf/oYF8d86EDMwv d71nKBNpdZRP5EDJ3CBPRaO5n4ygyG+0a3KX5hPap0QuZqFIfjA0EXIbQ7KCiC/Lh2R8 bpS4K29r+e4qow1a9R14IOzU+YZet83p4gP3NyVVL0Y1kWAzHWgZ0pVlg3DC+OKSS/Vb z/nw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=GPlldc1uUCaMqKOlqd707RfJFmN0vdU2ggLjnOu2mQQ=; b=bIzzFkArVzBwLmuLRdBw9452wAA3HaXIdDqqgq33HcTk+yCmvP2iYtDetJZ5D3wmsK lF1K0xauEJDZSb41WyDvYAnnhjOU6tcO1J2XCoDqFP3Uw9hYg/Qui9jFq0l0inLHWf6B Rea312KkdvKQ7PsrH89+oHv7mNiwsFrS5eid1jp1qGpN29R1sC7/kN/buZTED0fgZ7LM 0oMuZIBQ5FgnSPvzQ1JX7VKYPDlkDGKENKgjtw4z/y2Uy8FqkWn5KC3Tqf6ZpjizaF6K ih1Pes6Ql0mdvlFhmocoLBm6QIbdfdZifqaqXHp6t6lGMjDFCzMqTtc1FHj1QmKS2A35 YRUw== X-Gm-Message-State: APjAAAWEz1bh0TBloklu3WvQiv1p1fAQqMSalrhbJockr/KoaHieQmH7 NSjLBSgXzlYlQGiEzSLT4qXYQbVoAw== X-Google-Smtp-Source: APXvYqx29k+eyzx3OqMKqjQWf0f4JOSEoTZz20Pa8EdvWRvAEPlpyUcqBPDVKy3YURgXPlZlKgTsuLPZmg== X-Received: by 2002:ae9:f016:: with SMTP id l22mr8313268qkg.51.1562971354608; Fri, 12 Jul 2019 15:42:34 -0700 (PDT) Date: Sat, 13 Jul 2019 00:41:52 +0200 Message-Id: <20190712224152.13129-1-jannh@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.510.g264f2c817a-goog Subject: [PATCH] x86/process: Delete useless check for dead process with LDT From: Jann Horn To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , jannh@google.com Cc: "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At release_thread(), ->mm is NULL; and it is fine for the former mm to still have an LDT. Delete this check in process_64.c, similar to commit 2684927c6b93 ("[PATCH] x86: Deprecate useless bug"), which did the same in process_32.c. Signed-off-by: Jann Horn --- arch/x86/kernel/process_64.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 250e4c4ac6d9..af64519b2695 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -143,17 +143,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode) void release_thread(struct task_struct *dead_task) { - if (dead_task->mm) { -#ifdef CONFIG_MODIFY_LDT_SYSCALL - if (dead_task->mm->context.ldt) { - pr_warn("WARNING: dead process %s still has LDT? <%p/%d>\n", - dead_task->comm, - dead_task->mm->context.ldt->entries, - dead_task->mm->context.ldt->nr_entries); - BUG(); - } -#endif - } + WARN_ON(dead_task->mm); } enum which_selector { -- 2.22.0.510.g264f2c817a-goog