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=-8.3 required=3.0 tests=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_SANE_2 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 8D05AC3A5A5 for ; Thu, 5 Sep 2019 12:26:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5980522CF6 for ; Thu, 5 Sep 2019 12:26:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="Rf1Dy9DJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387501AbfIEM0L (ORCPT ); Thu, 5 Sep 2019 08:26:11 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:37726 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731294AbfIEM0L (ORCPT ); Thu, 5 Sep 2019 08:26:11 -0400 Received: by mail-qk1-f193.google.com with SMTP id s14so1887197qkm.4 for ; Thu, 05 Sep 2019 05:26:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=message-id:subject:from:to:cc:date:in-reply-to:references :mime-version:content-transfer-encoding; bh=bo/kDWZp3bZZn3zakUhkg0ajor/kZS2pwWQ9iXAnPOc=; b=Rf1Dy9DJhqJAwIS4qIRCwfL+woHUrzX2/AEYlsJMpQHsESybDA8+/WuEII9w3/yWFM 27tnkefv9zimlG9bX/5TCZp4wtsJtvSJdV+g1nShVSEHze/4n0XCrtxc/riMwcAbkoio vpMZcjlpm60NZ13BUk3DmefkQQ1E24qr80aMrocI6brskeHTBsHCv5B9hytfGOTmsLTy hld14RW3fYlT2OYsXtRVUCbUXrsRpFZdHVQ+LMCcfOlHFxLLPu7OsgW0RbdUCwuF4C7h pS1/u4TSWZ0H9jFTGSkSRaVsNQOqPIavsHAr+Udo6UM22UB+pt/c5K+7ADt4pa3K0xOu rZIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=bo/kDWZp3bZZn3zakUhkg0ajor/kZS2pwWQ9iXAnPOc=; b=XXuA++kTbsekjYfWMYN5XOhyZPyVULqHBunubTk0fD8LVdnFiEs7mXUIZp3UUZc8Tq 305hHqq4pAXl1LfJqOXS7zVr02UVmjW05fnyUAruwtqJYH5ykycbLvMh9VCX78xMiif9 pX2hEPkOmxCVC3O6EhjOnbEWUJ+wosSnVNkQMScglX+fl4WwV63IoPPoFTj/rCIUc9fO GgdFsFwOcdP2EUCMRRtZv2ApmpHAe7HWYn5oFdqY6ridTr3o8n8a8m/NSnOLsTY+I4DT LIpcxvL4ewLHfihO51XRHtAcXplpehFqPFTxEyaM4RUQghJvRjfoYG57lt6JuWDl/Yp6 JBrA== X-Gm-Message-State: APjAAAUPUnzYbxXOcOkOYOGuXI5Ud8S2dvjd28UPltp9Ag7m7WPaCVxA M7o/LoH3WYyRx4cp9JsJ+FtosA== X-Google-Smtp-Source: APXvYqzrQ9dpro1Q2JB+WgiKIba61kIkoKO9xg2/x0erj1XWRalJyAP9GSJkxkeepAlE1qgNXbCb7Q== X-Received: by 2002:a37:9f93:: with SMTP id i141mr2284503qke.304.1567686369652; Thu, 05 Sep 2019 05:26:09 -0700 (PDT) Received: from dhcp-41-57.bos.redhat.com (nat-pool-bos-t.redhat.com. [66.187.233.206]) by smtp.gmail.com with ESMTPSA id z123sm1019144qke.96.2019.09.05.05.26.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Sep 2019 05:26:08 -0700 (PDT) Message-ID: <1567686367.5576.89.camel@lca.pw> Subject: Re: [PATCH] x86/kaslr: simplify the code in mem_avoid_memmap() From: Qian Cai To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, Borislav Petkov Cc: bhe@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org Date: Thu, 05 Sep 2019 08:26:07 -0400 In-Reply-To: <1566483962-10046-1-git-send-email-cai@lca.pw> References: <1566483962-10046-1-git-send-email-cai@lca.pw> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 (3.22.6-10.el7) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ping. Please take a look at this trivial patch. On Thu, 2019-08-22 at 10:26 -0400, Qian Cai wrote: > If "i >= MAX_MEMMAP_REGIONS" already when entering mem_avoid_memmap(), > even without the return statement the loop will not run anyway. The only > time it needs to set "memmap_too_large = true" in this situation is > "memmap_too_large" is "false" currently. Hence, the code could be > simplified. > > Signed-off-by: Qian Cai > --- >  arch/x86/boot/compressed/kaslr.c | 5 +---- >  1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/arch/x86/boot/compressed/kaslr.c > b/arch/x86/boot/compressed/kaslr.c > index 2e53c056ba20..35c6942fb95b 100644 > --- a/arch/x86/boot/compressed/kaslr.c > +++ b/arch/x86/boot/compressed/kaslr.c > @@ -176,9 +176,6 @@ static void mem_avoid_memmap(char *str) >  { >   static int i; >   > - if (i >= MAX_MEMMAP_REGIONS) > - return; > - >   while (str && (i < MAX_MEMMAP_REGIONS)) { >   int rc; >   unsigned long long start, size; > @@ -206,7 +203,7 @@ static void mem_avoid_memmap(char *str) >   } >   >   /* More than 4 memmaps, fail kaslr */ > - if ((i >= MAX_MEMMAP_REGIONS) && str) > + if (i >= MAX_MEMMAP_REGIONS && !memmap_too_large) >   memmap_too_large = true; >  } >