lkml.org 
[lkml]   [2021]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] staging: gdm724x: Fix DMA from stack
On Wed, Feb 10, 2021 at 02:28:11PM +0530, Amey Narkhede wrote:
> On 21/02/10 09:06AM, Greg KH wrote:
> > On Wed, Feb 10, 2021 at 01:31:34PM +0530, Amey Narkhede wrote:
> > > Stack allocated buffers cannot be used for DMA
> > > on all architectures so allocate hci_packet buffer
> > > using kzalloc().
> > >
> > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> > > ---
> > > Changes in v2:
> > > - Fixed build warning
> > > - Fixed memory leak using kfree
> > >
> > > drivers/staging/gdm724x/gdm_usb.c | 9 +++++++--
> > > 1 file changed, 7 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c
> > > index dc4da66c3..c4a9b90c5 100644
> > > --- a/drivers/staging/gdm724x/gdm_usb.c
> > > +++ b/drivers/staging/gdm724x/gdm_usb.c
> > > @@ -56,11 +56,15 @@ static int gdm_usb_recv(void *priv_dev,
> > >
> > > static int request_mac_address(struct lte_udev *udev)
> > > {
> > > - u8 buf[16] = {0,};
> > > - struct hci_packet *hci = (struct hci_packet *)buf;
> > > + u8 *buf;
> > > + struct hci_packet *hci;
> > > struct usb_device *usbdev = udev->usbdev;
> > > int actual;
> > > int ret = -1;
> > > + buf = kzalloc(16, GFP_KERNEL);
> >
> > checkpatch did not complain about this?
> No. checkpatch shows no errors and warnings.

Please add a blank line after variables and before logic.

> > And why do you need 'buf' anymore now? Why not just allocate hci and
> > pass that to the request instead? Saves you an extra cast and an extra
> > pointer.
> >
> > thanks,
> >
> > greg k-h
> Thanks. I'll send v3. I assume now we don't need kzalloc anymore as we initialize
> the hci_packet so kmalloc(sizeof(struct hci_packet),..) will do.

Why is it needed now? And why would that change?

thanks,

greg k-h

\
 
 \ /
  Last update: 2021-02-10 10:18    [W:0.094 / U:1.664 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site