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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34733C54EAA for ; Thu, 26 Jan 2023 20:48:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B4CB06B0074; Thu, 26 Jan 2023 15:48:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AD4F46B0075; Thu, 26 Jan 2023 15:48:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 975DC8E0001; Thu, 26 Jan 2023 15:48:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 7F1BA6B0074 for ; Thu, 26 Jan 2023 15:48:18 -0500 (EST) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 31BA9407DE for ; Thu, 26 Jan 2023 20:48:18 +0000 (UTC) X-FDA: 80398137876.18.4E18FF6 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf24.hostedemail.com (Postfix) with ESMTP id 93EFB18000E for ; Thu, 26 Jan 2023 20:48:14 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=C79SkTkU; spf=none (imf24.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1674766095; a=rsa-sha256; cv=none; b=neiLsSkpL3etoQVuTYZHpSWIL3Se4V86tpjW5MZ9DYTAwDwgcJOG+jUuymV+CGJeTBygaO Bw/3ptQ//qjg90d9bdzf4N9PYeVBhp8lyfdh2z89DImXARnpVw5g6R3EpQp2LwJXdZ9a71 wk0k5Iu9RwcaBsdU2b3cxMzf2swjpqs= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=C79SkTkU; spf=none (imf24.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1674766095; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=xYyn6gE7F+Ay1oJHev/ISGq5X5rN9LDnA4hf9TFZmgs=; b=48XkCMwWg9OGXnQct82fXGnXjZdj1DLNnJrB+aVKTqXm2rHWc4uDLeIPdMhq+eviuwS1+P tKBWl6BpONrus81dDqQFTfQOdb2piGWr3IvGaYrdrMc7FfqXZuLt4Qqq2U8u0UeUBEQlLt BRNs/CwN5T2XTKMFR1gB6U96XXBNwN8= 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=xYyn6gE7F+Ay1oJHev/ISGq5X5rN9LDnA4hf9TFZmgs=; b=C79SkTkUXPHdY1rqmNll246qpm BcZ9KxjPV6sjmvUDLBIB2PCuHKi6e70JMG5bU/DY0o8KZKFsEczGwkoqEvPn/wDajtV0GS8FQJUpt TSg9FVIbJh82hHe3RKQhuIWAIO2jq4CSf5Ixcgl0Tj7f08tplSbFSCdmilzJZ3rcwAEEzZUfWFRFj y+or7Xbh6k9W10ac2Y+sHXZmOffE7BnFb/peBUVwtEK8QQnogKQroWYHb5aOSHXtUsfxU8FQtjig0 mBMvtH7AjprYmdoq50OoqLKC9ezBgz+hHVJW0sNvX7HkaA+6A9JwlkQFURfoL12p0zR556EilTHvH iEKJlKdA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pL9AB-0074fm-Ky; Thu, 26 Jan 2023 20:48:03 +0000 Date: Thu, 26 Jan 2023 20:48:03 +0000 From: Matthew Wilcox To: Andrew Morton Cc: "Fabio M. De Francesco" , Ira Weiny , Sebastian Andrzej Siewior , Alexander Potapenko , Andrey Konovalov , Tony Luck , Bagas Sanjaya , David Sterba , Kees Cook , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Thomas Gleixner , Al Viro , Helge Deller Subject: Re: [PATCH] mm/highmem: Align-down to page the address for kunmap_flush_on_unmap() Message-ID: References: <20230126143346.12086-1-fmdefrancesco@gmail.com> <20230126123858.42d9377ad6e352a58c81668b@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230126123858.42d9377ad6e352a58c81668b@linux-foundation.org> X-Rspam-User: X-Rspamd-Queue-Id: 93EFB18000E X-Rspamd-Server: rspam01 X-Stat-Signature: jhcsqbso65yhaz9d1i4dr84bw5m7oa11 X-HE-Tag: 1674766094-767455 X-HE-Meta: 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 zbzVW+Y5 QQK/ZU/7STFUIaf+V8WqMJVgy70OHSFdWZc8G4bcDVRPOmthcVNgTp2G/KaPvSvQq+urT6VrwVn404rtPTeT3uPbdJwLsYB0HhdKaq4p1kXGIV9zFiVXoQ26odqo7ZhrgFPUuvaRHj94guXPWqxhQVdP2ahG0Wgf7CbzV74OoRu95HVbg7f5y8tqRnvuTVoVu8r2+8gcEUUI6vc0oRhZNIR9ZPbwpG3DsJQib 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 Thu, Jan 26, 2023 at 12:38:58PM -0800, Andrew Morton wrote: > On Thu, 26 Jan 2023 15:33:46 +0100 "Fabio M. De Francesco" wrote: > > > If ARCH_HAS_FLUSH_ON_KUNMAP is defined (PA-RISC case), __kunmap_local() > > calls kunmap_flush_on_unmap(). The latter currently flushes the wrong > > address (as confirmed by Matthew Wilcox and Helge Deller). Al Viro > > proposed to call kunmap_flush_on_unmap() on an aligned-down to page > > address in order to fix this issue. Consensus has been reached on this > > solution. > > What are the user-visible runtime effects of this flaw? The version of this patch I sent out includes this information, as well as the missed alignment for kunmap_atomic().