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=-11.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9F571C432C3 for ; Sat, 16 Nov 2019 11:52:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 831F82072D for ; Sat, 16 Nov 2019 11:52:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727763AbfKPLv7 (ORCPT ); Sat, 16 Nov 2019 06:51:59 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:45292 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727659AbfKPLvf (ORCPT ); Sat, 16 Nov 2019 06:51:35 -0500 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iVwc0-0002AM-RX; Sat, 16 Nov 2019 12:51:32 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id B1CDE1C1901; Sat, 16 Nov 2019 12:51:23 +0100 (CET) Date: Sat, 16 Nov 2019 11:51:23 -0000 From: "tip-bot2 for Thomas Gleixner" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/iopl] x86/ioperm: Avoid bitmap allocation if no permissions are set Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org MIME-Version: 1.0 Message-ID: <157390508369.12247.423990236164065074.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/iopl branch of tip: Commit-ID: 32f3bf67ee78332f2caec0984cb9d412cd0a3c23 Gitweb: https://git.kernel.org/tip/32f3bf67ee78332f2caec0984cb9d412cd0a3c23 Author: Thomas Gleixner AuthorDate: Tue, 12 Nov 2019 19:56:19 +01:00 Committer: Thomas Gleixner CommitterDate: Sat, 16 Nov 2019 11:24:01 +01:00 x86/ioperm: Avoid bitmap allocation if no permissions are set If ioperm() is invoked the first time and the @turn_on argument is 0, then there is no point to allocate a bitmap just to clear permissions which are not set. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/ioport.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index ca6aa1e..80fa36b 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -36,6 +36,9 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) */ bitmap = t->io_bitmap_ptr; if (!bitmap) { + /* No point to allocate a bitmap just to clear permissions */ + if (!turn_on) + return 0; bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); if (!bitmap) return -ENOMEM;