From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753371Ab3KKUNY (ORCPT ); Mon, 11 Nov 2013 15:13:24 -0500 Received: from mga09.intel.com ([134.134.136.24]:8575 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752876Ab3KKUMb (ORCPT ); Mon, 11 Nov 2013 15:12:31 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,535,1378882800"; d="scan'208";a="433422451" From: David Cohen To: balbi@ti.com, gregkh@linuxfoundation.org Cc: stern@rowland.harvard.edu, mina86@mina86.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 4/5] usb: f_fs: check quirk to pad epout buf size when not aligned to maxpacketsize Date: Mon, 11 Nov 2013 12:16:50 -0800 Message-Id: <1384201011-11114-5-git-send-email-david.a.cohen@linux.intel.com> X-Mailer: git-send-email 1.8.4.rc3 In-Reply-To: <1384201011-11114-1-git-send-email-david.a.cohen@linux.intel.com> References: <1384201011-11114-1-git-send-email-david.a.cohen@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michal Nazarewicz Check gadget.quirk_ep_out_aligned_size to decide if buffer size requires to be aligned to maxpacketsize of an out endpoint. ffs_epfile_io() needs to pad epout buffer to match above condition if quirk is found. Signed-off-by: Michal Nazarewicz Acked-by: David Cohen --- drivers/usb/gadget/f_fs.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c index f1563c47e0c2..c49288778fe0 100644 --- a/drivers/usb/gadget/f_fs.c +++ b/drivers/usb/gadget/f_fs.c @@ -755,8 +755,9 @@ static ssize_t ffs_epfile_io(struct file *file, char __user *buf, size_t len, int read) { struct ffs_epfile *epfile = file->private_data; + struct usb_gadget *gadget = epfile->ffs->gadget; struct ffs_ep *ep; - ssize_t ret; + ssize_t ret, data_len; char *data; int halt; @@ -789,7 +790,14 @@ static ssize_t ffs_epfile_io(struct file *file, /* Allocate & copy */ if (!halt) { - data = kmalloc(len, GFP_KERNEL); + /* + * Controller requires buffer size to be aligned to + * maxpacketsize of an out endpoint. + */ + data_len = read && gadget->quirk_ep_out_aligned_size ? + usb_ep_align_maxpacketsize(ep->ep, len) : len; + + data = kmalloc(data_len, GFP_KERNEL); if (unlikely(!data)) return -ENOMEM; @@ -826,7 +834,7 @@ static ssize_t ffs_epfile_io(struct file *file, req->context = &done; req->complete = ffs_epfile_io_complete; req->buf = data; - req->length = len; + req->length = data_len; ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); @@ -838,9 +846,16 @@ static ssize_t ffs_epfile_io(struct file *file, ret = -EINTR; usb_ep_dequeue(ep->ep, req); } else { + /* + * XXX We may end up silently droping data here. + * Since data_len (i.e. req->length) may be bigger + * than len (after being rounded up to maxpacketsize), + * we may end up with more data then user space has + * space for. + */ ret = ep->status; if (read && ret > 0 && - unlikely(copy_to_user(buf, data, ret))) + unlikely(copy_to_user(buf, data, min(ret, len)))) ret = -EFAULT; } } -- 1.8.4.rc3