From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758593AbYJPRcD (ORCPT ); Thu, 16 Oct 2008 13:32:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755722AbYJPRPM (ORCPT ); Thu, 16 Oct 2008 13:15:12 -0400 Received: from kroah.org ([198.145.64.141]:47054 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753325AbYJPRPK (ORCPT ); Thu, 16 Oct 2008 13:15:10 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: "Andrew G. Harvey" , "Hans J. Koch" , Greg Kroah-Hartman Subject: [PATCH 46/46] UIO: Fix mapping of logical and virtual memory Date: Thu, 16 Oct 2008 10:10:47 -0700 Message-Id: <1224177047-11859-46-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: <20081016170954.GA11824@kroah.com> References: <20081016170954.GA11824@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrew G. Harvey mmap() doesn't work as expected for UIO_MEM_LOGICAL or UIO_MEM_VIRTUAL mappings. The offset into the memory needs to be added, otherwise uio_vma_fault always returns the first page only. Note that for UIO userspace calls mmap() with offset = N * getpagesize() to access mapping N. This must be compensated when calculating the offset. A comment was added to explain this since it is not obvious. Signed-off-by: Andrew G. Harvey Signed-off-by: Hans J. Koch Signed-off-by: Greg Kroah-Hartman --- drivers/uio/uio.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 557e73e..5dccf05 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -490,15 +490,23 @@ static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct uio_device *idev = vma->vm_private_data; struct page *page; + unsigned long offset; int mi = uio_find_mem_index(vma); if (mi < 0) return VM_FAULT_SIGBUS; + /* + * We need to subtract mi because userspace uses offset = N*PAGE_SIZE + * to use mem[N]. + */ + offset = (vmf->pgoff - mi) << PAGE_SHIFT; + if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) - page = virt_to_page(idev->info->mem[mi].addr); + page = virt_to_page(idev->info->mem[mi].addr + offset); else - page = vmalloc_to_page((void*)idev->info->mem[mi].addr); + page = vmalloc_to_page((void *)idev->info->mem[mi].addr + + offset); get_page(page); vmf->page = page; return 0; -- 1.6.0.2