Received: by 2002:a05:6a10:f347:0:0:0:0 with SMTP id d7csp2288030pxu; Mon, 7 Dec 2020 02:36:48 -0800 (PST) X-Google-Smtp-Source: ABdhPJxoG550WLwDlFMwaTosaDRHd7W6PTCRUlC6ExhxqZpge+K2m3YcfiLfQbVGxVGU7GUzmbTX X-Received: by 2002:aa7:d64d:: with SMTP id v13mr17478922edr.196.1607337408286; Mon, 07 Dec 2020 02:36:48 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1607337408; cv=none; d=google.com; s=arc-20160816; b=AB9C5Aq/6V/r3j4j3pSAqn43Dxh3ahUQKWuzT3Pkwy6h7u9DT+xqDRSYumL6KL02bp PlKiMB2JjPuMrL3hOE7B0a/Gsw6nArkpE2dBgpv9YzUmttcWdbLZyeHp8HmT00Xsa2nK HkBy6oBiXfAuQcsGpzqbDeKZLbcV0GV+U2IrZT+LNCyS+p/JrTqvw9XLBiQ4c0BA/k1J 6vJwHC4dHzDiZBRKJN3l76FLyRfc05XpzK2jX7nD/XbUfxmP632L6aBs9jWIjsKELY0C 0h/pipkxU/8jkH6TJCB1kghSR9Kfu/nPpSSF3Wn3hsY8ZN8flW6v+9ex8mFeoBdJsMMy r4zA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=p1DaA8ThftQi94yLWkz32HaxD9dmULyV2whH1bFZQig=; b=aOQl9z7wHjEbjX6L0LbzA87ChFLSJ5yEULKsXHyMogNV3wnDAcLNeRocl+G5Bi4jUr gI3XYL7rhGrYOZHiEPnOJ01MJyfDX3yoTXqJqta8PHpGcfvGQxQqPdEQSoZisohQ9+p3 YDR7w035UjVWC03Z0/s5Uqi/0nE+cj0qmZvxZukExqqEHwuuwNn+eCtt9C5pObl+vC3V daLDALHaRej0be+H9DRsfvjFvKZtyncU39tmVlSKnwxTLLA4TWMZzRq8JWwSbARJ4rg1 RZCY6rInjlGiSORg9UW3aYxW9Ci08unNnSmn6p1IJyStQ+xrKmp1KA8SgEEKgcAQFgO1 96bQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id j14si6397406ejy.327.2020.12.07.02.36.25; Mon, 07 Dec 2020 02:36:48 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726733AbgLGKeA (ORCPT + 99 others); Mon, 7 Dec 2020 05:34:00 -0500 Received: from elvis.franken.de ([193.175.24.41]:54217 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726567AbgLGKeA (ORCPT ); Mon, 7 Dec 2020 05:34:00 -0500 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1kmDpT-00058D-01; Mon, 07 Dec 2020 11:33:15 +0100 Received: by alpha.franken.de (Postfix, from userid 1000) id 93FFDC031F; Mon, 7 Dec 2020 11:32:51 +0100 (CET) Date: Mon, 7 Dec 2020 11:32:51 +0100 From: Thomas Bogendoerfer To: Jinyang He Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] MIPS: KASLR: Avoid endless loop in sync_icache when synci_step is zero Message-ID: <20201207103251.GA15719@alpha.franken.de> References: <1607044306-4800-1-git-send-email-hejinyang@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1607044306-4800-1-git-send-email-hejinyang@loongson.cn> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 04, 2020 at 09:11:46AM +0800, Jinyang He wrote: > Avoid endless loop if synci_step was zero read by rdhwr instruction. > > Most platforms do not need to do synci instruction operations when > synci_step is 0. But for example, the synci implementation on Loongson64 > platform has some changes. On the one hand, it ensures that the memory > access instructions have been completed. On the other hand, it guarantees > that all prefetch instructions need to be fetched again. And its address > information is useless. Thus, only one synci operation is required when > synci_step is 0 on Loongson64 platform. I guess that some other platforms > have similar implementations on synci, so add judgment conditions in > `while` to ensure that at least all platforms perform synci operations > once. For those platforms that do not need synci, they just do one more > operation similar to nop. > > Signed-off-by: Jinyang He > --- > arch/mips/kernel/relocate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) applied to mips-next. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]