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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AACFE7AD77 for ; Tue, 3 Oct 2023 16:58:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240453AbjJCQ6E (ORCPT ); Tue, 3 Oct 2023 12:58:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231590AbjJCQ6D (ORCPT ); Tue, 3 Oct 2023 12:58:03 -0400 Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7ACD5A7 for ; Tue, 3 Oct 2023 09:57:59 -0700 (PDT) Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.west.internal (Postfix) with ESMTP id 702E13200B0B; Tue, 3 Oct 2023 12:57:58 -0400 (EDT) Received: from imap51 ([10.202.2.101]) by compute5.internal (MEProxy); Tue, 03 Oct 2023 12:57:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm1; t=1696352277; x=1696438677; bh=V2 FQ7Cu/afkL6EriG0Uiq965GFYkq5JFljrsPV+qIn8=; b=LOvNGpJORUwJ+gnnJ3 SQOqcVf8X1032fc2EgB7r2YcuiMQitNDg/0tJ9vb9FZBtuovzUkmIig9fTzQQnLH EwmFn7MTsgDpooNLbNlUB6b5xLgQ6eS0/VJezsWQiB0uhMIk0lWGP+5d0R4dDQRF GC2zvsBPjKmHAwz1nruBxHRb6wUETQXUUPEujhrRIc3HP19+ApeS0XRxnwgpWUBK 8Htx4DX0lq3xo8oSakrxxbsNXOAhQDyvoKMXt4F1hDOrnXLPakmDqkLqzvj2eZGd cBW3dtKGFlpuvZTf15nffXAIr2Jk8t/tdihnr0PBRC/ZHhGy8J83kyFNK99ZFczu 8dtw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm2; t=1696352277; x=1696438677; bh=V2FQ7Cu/afkL6 EriG0Uiq965GFYkq5JFljrsPV+qIn8=; b=B+M5wR9XKOQzUfvOYQDdsd7u+Lsm1 qcE6NqAKlY3Snkcg6MI7WrfVsZ4ME+H2OA49Jl6Bjt338iBImrBYA/6RppClxSbn 3RPGjXc2UC2Gisegg27LE4R+wTF/SjZPi0/943A+0q7FwB1GQw9Ab/pMf/cJ40wY Icpby1udhs/unsXxL2fR1iCc+z03Vdyet82SpMC0H9XLYfZ5+x3Ec1TITQR1YSCW 8RWIn3vxuYC8GYtaQaV85+bJiqNYapiaYGGx7l+lvZdFNBF41H5gfYXfhOjrbtZV VRzdhzbR8fWw0vvF2ktA9kFj5LgTXVKyJ+PdTouubvl7CMmwQ3djPEi9w== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvkedrfeejgdduiecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefofgggkfgjfhffhffvvefutgesthdtredtreertdenucfhrhhomhepfdetrhhn ugcuuegvrhhgmhgrnhhnfdcuoegrrhhnugesrghrnhgusgdruggvqeenucggtffrrghtth gvrhhnpeffheeugeetiefhgeethfejgfdtuefggeejleehjeeutefhfeeggefhkedtkeet ffenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegrrh hnugesrghrnhgusgdruggv X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id B5DCCB60089; Tue, 3 Oct 2023 12:57:57 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.9.0-alpha0-958-g1b1b911df8-fm-20230927.002-g1b1b911d MIME-Version: 1.0 Message-Id: <325de88f-1237-4910-aa2a-97707bedae26@app.fastmail.com> In-Reply-To: <20231003094912.08cf57998135446ef475dd19@linux-foundation.org> References: <20231003144857.752952-1-gregory.price@memverge.com> <20231003094912.08cf57998135446ef475dd19@linux-foundation.org> Date: Tue, 03 Oct 2023 18:57:37 +0200 From: "Arnd Bergmann" To: "Andrew Morton" , "Gregory Price" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Gregory Price" Subject: Re: [PATCH] mm/migrate: fix do_pages_move for compat pointers Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 3, 2023, at 18:49, Andrew Morton wrote: > On Tue, 3 Oct 2023 10:48:56 -0400 Gregory Price > wrote: > >> do_pages_move does not handle compat pointers for the page list. >> correctly. Add in_compat_syscall check and appropriate get_user >> fetch when iterating the page list. > > What are the userspace visible effects of this change? It makes the syscall in compat mode (32-bit userspace, 64-bit kernel) work the same way as the native 32-bit syscall again, restoring the behavior before my broken commit 5b1b561ba73c ("mm: simplify compat_sys_move_pages"). Arnd