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=-11.8 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 BF6BAC43215 for ; Fri, 15 Nov 2019 21:13:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E9D92073C for ; Fri, 15 Nov 2019 21:13:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727468AbfKOVNl (ORCPT ); Fri, 15 Nov 2019 16:13:41 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:44608 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726809AbfKOVMi (ORCPT ); Fri, 15 Nov 2019 16:12:38 -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 1iVitN-0007Qq-SH; Fri, 15 Nov 2019 22:12:34 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 2528B1C18D3; Fri, 15 Nov 2019 22:12:30 +0100 (CET) Date: Fri, 15 Nov 2019 21:12:30 -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 , "Peter Zijlstra (Intel)" , Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org In-Reply-To: <20191113210104.404509322@linutronix.de> References: <20191113210104.404509322@linutronix.de> MIME-Version: 1.0 Message-ID: <157385235012.12247.1247139198046995586.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: 5487da6bf0775d996352442b89a8defbd671b4ae Gitweb: https://git.kernel.org/tip/5487da6bf0775d996352442b89a8defbd671b4ae Author: Thomas Gleixner AuthorDate: Wed, 13 Nov 2019 21:42:47 +01:00 Committer: Thomas Gleixner CommitterDate: Thu, 14 Nov 2019 20:15:02 +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 Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20191113210104.404509322@linutronix.de --- 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;