Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755190Ab0DUVK7 (ORCPT ); Wed, 21 Apr 2010 17:10:59 -0400 Received: from f0.cmpxchg.org ([85.214.51.133]:43716 "EHLO cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754344Ab0DUVK5 (ORCPT ); Wed, 21 Apr 2010 17:10:57 -0400 X-Greylist: delayed 1063 seconds by postgrey-1.27 at vger.kernel.org; Wed, 21 Apr 2010 17:10:57 EDT Date: Wed, 21 Apr 2010 23:10:52 +0200 From: Johannes Weiner To: Andrea Arcangeli Cc: Rik van Riel , Dan Carpenter , Izik Eidus , Hugh Dickins , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-janitors@vger.kernel.org, Andrew Morton Subject: Re: [patch] ksm: check for ERR_PTR from follow_page() Message-ID: <20100421211052.GE5336@cmpxchg.org> References: <20100421102759.GA29647@bicker> <4BCF18A8.8080809@redhat.com> <20100421174615.GO32034@random.random> <20100421205305.GO20640@cmpxchg.org> <20100421205807.GV32034@random.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100421205807.GV32034@random.random> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1058 Lines: 19 On Wed, Apr 21, 2010 at 10:58:07PM +0200, Andrea Arcangeli wrote: > On Wed, Apr 21, 2010 at 10:53:05PM +0200, Johannes Weiner wrote: > > + * Returns the mapped (struct page *), %NULL if no mapping exists, or > > + * an error pointer if there is a mapping to something not represented > > + * by a page descriptor (see also vm_normal_page()). > > where exactly in vm_normal_page? Note I already checked vm_normal_page > before sending the prev email and I didn't immediately see. I search > return and they all return NULL except the return pfn_to_page(pfn), so > is pfn_to_page that returns -EFAULT (the implementations I checked > don't but there are plenty that I didn't check...). It's not vm_normal_page() that returns -EFAULT. It is follow_page() that translates NULL from vm_normal_page() into -EFAULT. -- 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/