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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 65313C433EF for ; Tue, 21 Sep 2021 11:51:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B985D60EDF for ; Tue, 21 Sep 2021 11:51:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B985D60EDF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 33A976B0071; Tue, 21 Sep 2021 07:51:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2EA426B0073; Tue, 21 Sep 2021 07:51:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1D83C6B0074; Tue, 21 Sep 2021 07:51:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0138.hostedemail.com [216.40.44.138]) by kanga.kvack.org (Postfix) with ESMTP id 0F3D26B0071 for ; Tue, 21 Sep 2021 07:51:39 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id BF64329DFC for ; Tue, 21 Sep 2021 11:51:38 +0000 (UTC) X-FDA: 78611415876.22.0831B19 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf01.hostedemail.com (Postfix) with ESMTP id 2394654D51A3 for ; Tue, 21 Sep 2021 11:51:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=bTA3D3ZAeT7t+Im754RVqVdxXjn1LBS3rDLE+oGefd4=; b=PaNJb5VXYlg6n2WGJ9by624FaJ 8/gELtvHwTX94WKL0K5/5SExzkZr8xf45N8/gvLxHoR52XbFnTgVhKdYBHCPa0poUaGULyswc4yOl NLQ49f9EQggYsZX+Knw9nehwkBNUxuIZM0f5GG4dQKS7NC21FWnIhkmLEO3BLavlRVoFkX/9XVGAQ oCQhvPnH8OxHHmSIY5oFiftreWiz/PEY5L6rxtRMZ+gKpjDA2njgfemCiD0Oyor8mKexp2tsnrdQ2 QxjXYf7lFvQS8bfawv2OBMRKM/EhhPwZqAvsC/WZLpx1iBX3Q3xs21gLrb3g3AJ2UufG8vBu7fZEI 6G1oqoaw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mSeHs-003llX-Qh; Tue, 21 Sep 2021 11:50:41 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 539703000A9; Tue, 21 Sep 2021 13:50:11 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 3C65A20303900; Tue, 21 Sep 2021 13:50:11 +0200 (CEST) Date: Tue, 21 Sep 2021 13:50:11 +0200 From: Peter Zijlstra To: sxwjean@me.com Cc: x86@kernel.org, linux-mm@kvack.org, Xiongwei Song Subject: Re: [PATCH 1/2] x86: Rename TIF_ADDR32 to TIF_32BIT Message-ID: References: <20210921110252.2593542-1-sxwjean@me.com> <20210921110252.2593542-2-sxwjean@me.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210921110252.2593542-2-sxwjean@me.com> Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=PaNJb5VX; spf=none (imf01.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org; dmarc=none X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 2394654D51A3 X-Stat-Signature: mhghtfc7dz3snyfsjpe757ky5gi7gk3z X-HE-Tag: 1632225098-338485 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Sep 21, 2021 at 07:02:51PM +0800, sxwjean@me.com wrote: > From: Xiongwei Song > > In arm64 or powerpc or sparc, the 32 bits process in 64 bits kernel is set > flag TIF_32BIT. However in x86, that flag name is TIF_ADDR32. This patch > makes the flag name in x86 same as other archs. x86 is fundamentally different here, the TIF flag does not say (nor can it) anything about the bitness of the code running. On x86_64 a 64bit process can run 32bit code without the kernel necessarily knowing anything about it. The only thing it does it limit the address range, and as such the name is correct.