From c0d31b3c3d9a025b8d5a57c35671e60c5f388bf7 Mon Sep 17 00:00:00 2001 From: David Cohen Date: Mon, 13 Oct 2014 11:15:54 -0700 Subject: [PATCH] usb: ffs: fix regression when quirk_ep_out_aligned_size flag is set The commit '2e4c7553cd usb: gadget: f_fs: add aio support' broke the quirk implemented to align buffer size to maxpacketsize on out endpoint. As result, functionfs does not work on Intel platforms using dwc3 driver (i.e. Bay Trail and Merrifield). This patch fixes the issue. This code is based on a previous Qiuxu's patch. Fixes: 2e4c7553cd (usb: gadget: f_fs: add aio support) Cc: # v3.16+ Signed-off-by: David Cohen Signed-off-by: Qiuxu Zhuo Acked-by: Michal Nazarewicz Signed-off-by: Felipe Balbi --- drivers/usb/gadget/function/f_fs.c | 40 +++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 6 deletions(-) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 12dbdafd78a8..63314ede7ba6 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -647,15 +647,26 @@ static void ffs_user_copy_worker(struct work_struct *work) if (io_data->read && ret > 0) { int i; size_t pos = 0; + + /* + * Since req->length may be bigger than io_data->len (after + * being rounded up to maxpacketsize), we may end up with more + * data then user space has space for. + */ + ret = min_t(int, ret, io_data->len); + use_mm(io_data->mm); for (i = 0; i < io_data->nr_segs; i++) { + size_t len = min_t(size_t, ret - pos, + io_data->iovec[i].iov_len); + if (!len) + break; if (unlikely(copy_to_user(io_data->iovec[i].iov_base, - &io_data->buf[pos], - io_data->iovec[i].iov_len))) { + &io_data->buf[pos], len))) { ret = -EFAULT; break; } - pos += io_data->iovec[i].iov_len; + pos += len; } unuse_mm(io_data->mm); } @@ -687,7 +698,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) struct ffs_epfile *epfile = file->private_data; struct ffs_ep *ep; char *data = NULL; - ssize_t ret, data_len; + ssize_t ret, data_len = -EINVAL; int halt; /* Are we still active? */ @@ -787,13 +798,30 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) /* Fire the request */ struct usb_request *req; + /* + * Sanity Check: even though data_len can't be used + * uninitialized at the time I write this comment, some + * compilers complain about this situation. + * In order to keep the code clean from warnings, data_len is + * being initialized to -EINVAL during its declaration, which + * means we can't rely on compiler anymore to warn no future + * changes won't result in data_len being used uninitialized. + * For such reason, we're adding this redundant sanity check + * here. + */ + if (unlikely(data_len == -EINVAL)) { + WARN(1, "%s: data_len == -EINVAL\n", __func__); + ret = -EINVAL; + goto error_lock; + } + if (io_data->aio) { req = usb_ep_alloc_request(ep->ep, GFP_KERNEL); if (unlikely(!req)) goto error_lock; req->buf = data; - req->length = io_data->len; + req->length = data_len; io_data->buf = data; io_data->ep = ep->ep; @@ -815,7 +843,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) req = ep->req; req->buf = data; - req->length = io_data->len; + req->length = data_len; req->context = &done; req->complete = ffs_epfile_io_complete;