From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753490Ab3KKLWA (ORCPT ); Mon, 11 Nov 2013 06:22:00 -0500 Received: from mail-ee0-f48.google.com ([74.125.83.48]:62502 "EHLO mail-ee0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753197Ab3KKLVx (ORCPT ); Mon, 11 Nov 2013 06:21:53 -0500 From: Michal Nazarewicz To: David Cohen Cc: Alan Stern , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCHv2 2/2] check quirk to pad epout buf size when not aligned to maxpacketsize In-Reply-To: <5280567C.2060004@linux.intel.com> Organization: http://mina86.com/ References: <1384102237-19784-1-git-send-email-mpn@google.com> <1384102237-19784-2-git-send-email-mpn@google.com> <5280567C.2060004@linux.intel.com> User-Agent: Notmuch/0.15.2+55~geb6e9d8 (http://notmuchmail.org) Emacs/24.3.50.1 (x86_64-unknown-linux-gnu) X-Face: PbkBB1w#)bOqd`iCe"Ds{e+!C7`pkC9a|f)Qo^BMQvy\q5x3?vDQJeN(DS?|-^$uMti[3D*#^_Ts"pU$jBQLq~Ud6iNwAw_r_o_4]|JO?]}P_}Nc&"p#D(ZgUb4uCNPe7~a[DbPG0T~!&c.y$Ur,=N4RT>]dNpd;KFrfMCylc}gc??'U2j,!8%xdD Face: 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 X-PGP: 50751FF4 X-PGP-FP: AC1F 5F5C D418 88F8 CC84 5858 2060 4012 5075 1FF4 X-Hashcash: 1:20:131111:linux-usb@vger.kernel.org::Z+4xjiXFSAF8HhfK:0000000000000000000000000000000000000FX6 X-Hashcash: 1:20:131111:david.a.cohen@linux.intel.com::HwIfexCwUGkUO1il:000000000000000000000000000000000CIz X-Hashcash: 1:20:131111:stern@rowland.harvard.edu::hFwt3u73VSLMbGzo:00000000000000000000000000000000000011O6 X-Hashcash: 1:20:131111:linux-kernel@vger.kernel.org::Dxnl2ffYeU6/clMk:0000000000000000000000000000000001NTs Date: Mon, 11 Nov 2013 12:21:49 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/usb/gadget/f_fs.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) > On 11/10/2013 08:50 AM, Michal Nazarewicz wrote: >> @@ -787,6 +788,13 @@ static ssize_t ffs_epfile_io(struct file *file, >> >> /* Allocate & copy */ >> if (!halt) { >> + /* >> + * 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(len, GFP_KERNEL); On Mon, Nov 11 2013, David Cohen wrote: > Shouldn't this kmalloc() allocate 'data_len' bytes, instead of 'len'? Yes, of coures. diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c index e496b72..fd769a8 100644 --- a/drivers/usb/gadget/f_fs.c +++ b/drivers/usb/gadget/f_fs.c @@ -753,8 +753,9 @@ 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; @@ -787,7 +788,14 @@ 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; @@ -824,7 +832,7 @@ 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); @@ -836,9 +844,16 @@ 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; } } -- 1.8.4.1