From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763076AbXHFGph (ORCPT ); Mon, 6 Aug 2007 02:45:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754795AbXHFGpK (ORCPT ); Mon, 6 Aug 2007 02:45:10 -0400 Received: from mail.cs.umn.edu ([128.101.34.202]:47812 "EHLO mail.cs.umn.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754282AbXHFGpI (ORCPT ); Mon, 6 Aug 2007 02:45:08 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18102.49994.250514.93818@gargle.gargle.HOWL> Date: Mon, 6 Aug 2007 01:44:26 -0500 To: Matt Mackall CC: linux-kernel@vger.kernel.org, Dave Hansen , Andrew Morton Subject: [PATCH 1/3] Fix /proc/pid/pagemap return length calculation X-Mailer: VM 7.19 under Emacs 21.4.1 In-Reply-To: References: From: boutcher@cs.umn.edu (Dave Boutcher) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org /proc/pid/pagemap has a header (usually 8 bytes) the length of which needs to be compensated for when converting from proc file offset to page number. The calculation of the starting page number (svpfn) compensates for this, but the calculation of the ending page number (evpfn) does not, resulting in reads returning 8 bytes more than were asked for. Signed-off-by: Dave Boutcher --- fs/proc/task_mmu.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 4594f15..b2baeab 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -627,7 +627,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, addr = PAGE_SIZE * svpfn; if ((svpfn + 1) * sizeof(unsigned long) != src) goto out; - evpfn = min((src + count) / sizeof(unsigned long), + evpfn = min((src + count) / sizeof(unsigned long) - 1, ((~0UL) >> PAGE_SHIFT) + 1); count = (evpfn - svpfn) * sizeof(unsigned long); end = PAGE_SIZE * evpfn; -- 1.4.4.2