Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751434AbaBHXjQ (ORCPT ); Sat, 8 Feb 2014 18:39:16 -0500 Received: from smtp.gentoo.org ([140.211.166.183]:51225 "EHLO smtp.gentoo.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751170AbaBHXjP convert rfc822-to-8bit (ORCPT ); Sat, 8 Feb 2014 18:39:15 -0500 References: <1391886730-19667-1-git-send-email-ryao@gentoo.org> <1391886730-19667-2-git-send-email-ryao@gentoo.org> <52F68C67.6050606@gentoo.org> <52F6972C.2030307@gentoo.org> Mime-Version: 1.0 (1.0) In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Message-Id: Cc: Mel Gorman , Andrew Morton , Rik van Riel , Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , "David S. Miller" , V9FS Develooper Mailing List , Linux Netdev Mailing List , Linux Kernel Mailing List , "Aneesh Kumar K.V" , Will Deacon , Christopher Covington , Matthew Thode X-Mailer: iPad Mail (10B146) From: Richard Yao Subject: Re: [PATCH 1/2] mm/vmalloc: export is_vmalloc_or_module_addr Date: Sat, 8 Feb 2014 18:39:12 -0500 To: Linus Torvalds Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Feb 8, 2014, at 5:24 PM, Linus Torvalds wrote: > On Sat, Feb 8, 2014 at 12:44 PM, Richard Yao wrote: >> >> However, is_vmalloc_addr() only applies to the vmalloc region. While all >> architectures load kernel modules into virtual memory (to my knowledge), >> some architectures do not load them into the vmalloc region. > > So? > > People shouldn't do IO to module data, so who cares if something is a > module address or not? > > The thing is, even module *loading* doesn't do IO to the magic module > addresses - it loads the module data into regular vmalloc space, and > then copies it into the final location separately. > > And no module should ever do any IO on random static data (and > certainly not on code). > > So there is _zero_ reason for a driver or a filesystem to use > is_vmalloc_or_module_addr(). It's just not a valid question to ask. > > If somebody uses module data/code addresses, we're *better* off with a > oops or other nasty behavior than to try to make it "work". > > Linus I will modify this to use is_vmalloc_addr() and send it back to the appropriate subsystem maintainer(s). Thank-you for taking the time to write that explanation.-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/