linux-kernel - Re: [PATCH v2 2/3] USB: ehci-tegra: fix inefficient copy of unaligned buffers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20150423144508.GA22193@localhost>
Date:	Thu, 23 Apr 2015 16:45:08 +0200
From:	Johan Hovold <johan@...nel.org>
To:	Frans Klaver <fransklaver@...il.com>
Cc:	Johan Hovold <johan@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Felipe Balbi <balbi@...com>,
	Alan Stern <stern@...land.harvard.edu>,
	"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Stephen Warren <swarren@...dotorg.org>,
	Thierry Reding <thierry.reding@...il.com>,
	Alexandre Courbot <gnurou@...il.com>,
	linux-tegra@...r.kernel.org
Subject: Re: [PATCH v2 2/3] USB: ehci-tegra: fix inefficient copy of
 unaligned buffers

On Thu, Apr 23, 2015 at 04:31:51PM +0200, Frans Klaver wrote:
> On Thu, Apr 23, 2015 at 4:06 PM, Johan Hovold <johan@...nel.org> wrote:

> >  static void free_dma_aligned_buffer(struct urb *urb)
> >  {
> >         struct dma_aligned_buffer *temp;
> > +       size_t length;
> >
> >         if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
> >                 return;
> > @@ -311,9 +312,14 @@ static void free_dma_aligned_buffer(struct urb *urb)
> >         temp = container_of(urb->transfer_buffer,
> >                 struct dma_aligned_buffer, data);
> >
> > -       if (usb_urb_dir_in(urb))
> > -               memcpy(temp->old_xfer_buffer, temp->data,
> > -                      urb->transfer_buffer_length);
> > +       if (usb_urb_dir_in(urb)) {
> > +               if (usb_pipeisoc(urb->pipe))
> > +                       length = urb->transfer_buffer_length;
> > +               else
> > +                       length = urb->actual_length;
> > +
> > +               memcpy(temp->old_xfer_buffer, temp->data, length);
> > +       }
> >         urb->transfer_buffer = temp->old_xfer_buffer;
> >         kfree(temp->kmalloc_ptr);
> 
> Out of curiosity: any reason not to declare that length variable
> inside this new compound?

Just my style preference.

Johan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/