From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 140171B0104 for ; Wed, 14 Aug 2024 12:16:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723637804; cv=none; b=pYjgRAwHC6j8fTTzjxdpZLzbGTQePGJFr+QnTdWS7Jq9odE+Rrf3PgDsvaW0tix01O7ByhOv/WezAySJwWOOhEkujTI9VzHUQcTqmGOxMSnUbx8fyAp4tOpGIJtISW0VLrE0XgeBUDD8hsYrbIKSYeTsrfKTzsn7H/UCVzJ5jT8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723637804; c=relaxed/simple; bh=fwrrqi59D8+gyaVDxw+e4glai5gQB/boHoF93Oean/s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AqZ/+VnT3nBCDr/oaViqOXmJ08pjoC9eFyi2LH+2euizs4d0egFNiWzKc+q1gxYUk8GPnorWirvW600GdpZPCJw5KDmDFDMg9a0TzZv5LsHIBU8wdSx33RdyEv61GvYTWnae4inDxyd/iyQMZFEKgPPvm5iRJRRdOpAV1+JpeI8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=a5Vsb4nK; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="a5Vsb4nK" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=fwrrqi59D8+gyaVDxw+e4glai5gQB/boHoF93Oean/s=; b=a5Vsb4nKZCkCLSWJc4DKosJAcD fq1STNAyLp/GsplezQyiXkheoWHZivKw1ZWUbfKoDNk/SGDUV2pexYYBTKc815KiNmXFhs5k1Neno KD0DTgCfTUi4zh3dxcubMsfycGqVSv/gWbQBerZ8NcuEWQ1Xiz0Oxfd2kDBdiAv18auP0ml5v41PL 2dYAUcMfMTOigg5gPpPLfNDHk7Curhj/6YOxgESiLX3teiad4nALIpskfeFIau8j4SYhcW3WiNjSK UIY1HtnpVMvxzn6tW3YI1nmVlix4IgmHcVnQJ6JRK1SKIHVNks2DE6LszjcFzGGGm0MiUoyI0EIol W6HLIPLA==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1seCve-00000006tkh-0ev7; Wed, 14 Aug 2024 12:16:38 +0000 Date: Wed, 14 Aug 2024 05:16:38 -0700 From: Christoph Hellwig To: Alistair Popple Cc: Thomas Gleixner , Christoph Hellwig , Max Ramanouski , x86@kernel.org, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org, jniethe@nvidia.com, jhubbard@nvidia.com, linux-mm@kvack.org Subject: Re: [PATCH v2] x86/ioremap: Use is_ioremap_addr() in iounmap() Message-ID: References: <20240812203538.82548-1-max8rr8@gmail.com> <878qwzpfbi.ffs@tglx> <87le0zmhdp.fsf@nvdebian.thelocal> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87le0zmhdp.fsf@nvdebian.thelocal> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Aug 14, 2024 at 10:08:23PM +1000, Alistair Popple wrote: > I would tend to agree and had the same thought when we found this. At > least some kind of message (WARN_ON, WARN_ON_ONCE, printk, etc) would > have made the issue we were debugging much more obvious. FWIW I have > tested running with a WARN_ON() there and it never fired except in the > bug scenario. Various architectures had either an early ioremap variant that got silently ignored here, or magic carveout that don't get remapped at all. None of this should currently apply to x86, though.