[balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))

[balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))

[Fengguang Wu]

Hi Felipe,

FYI, there are new smatch warnings show up in

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git merge-result-for-greg
head:   23953bde3e4d6aa8780dc054f6ad9882ac63f4f4
commit: e918fa161f510136fce45a524e934fe20e62c8b1 [66/99] Merge tag 'gadget-for-v3.7' into merge-result-for-greg

drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))
drivers/usb/core/hub.c:4733 store_port_power_control() info: why not propagate 'ret' from set_port_feature() instead of -5?
drivers/usb/core/hub.c:4744 store_port_power_control() info: why not propagate 'ret' from clear_port_feature() instead of -5?

vim +2654 drivers/usb/core/hub.c
  2644		return ret;
  2645	}
  2646	
  2647	static int usb_get_hub_port_power_state(struct usb_device *hdev, int port1)
  2648	{
  2649		struct usb_hub *hub = hdev_to_hub(hdev);
  2650		struct usb_port_status data;
  2651		u16 portstatus;
  2652		int ret;
  2653	
> 2654		ret = get_port_status(hub->hdev, port1, &data);
  2655		if (ret < 4) {
  2656			dev_err(hub->intfdev,
  2657				"%s failed (err = %d)\n", __func__, ret);
  2658			if (ret >= 0)
  2659				ret = -EIO;
  2660			return ret;
  2661		} else
  2662			portstatus = le16_to_cpu(data.wPortStatus);
  2663		return port_is_power_on(hub, portstatus);
  2664	}

---
0-DAY kernel build testing backend         Open Source Technology Centre
Fengguang Wu <wfg@linux.intel.com>                     Intel Corporation

Re: [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))

[Dan Carpenter]

On Wed, Sep 12, 2012 at 04:26:22PM +0800, Fengguang Wu wrote:
> Hi Felipe,
> 
> FYI, there are new smatch warnings show up in
> 
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git merge-result-for-greg
> head:   23953bde3e4d6aa8780dc054f6ad9882ac63f4f4
> commit: e918fa161f510136fce45a524e934fe20e62c8b1 [66/99] Merge tag 'gadget-for-v3.7' into merge-result-for-greg
> 
> drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))

Smatch prints out a lot of these warnings.  I haven't looked at the
rules in a while, so maybe there is a bounce buffer somewhere where
it detects stack memory and allocates a DMA'able buffer?

It would be better if the function documentation for
usb_control_msg() said that the *data pointer had to be kmalloc()ed.

Also I wonder if Documentation/DMA-API-HOWTO.txt is out of data.
Are we allowed to DMA to vmalloc()ed memory yet?

regards,
dan carpenter

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 712 bytes --]

Hi,

On Wed, Sep 12, 2012 at 11:50:57AM +0300, Dan Carpenter wrote:
> On Wed, Sep 12, 2012 at 04:26:22PM +0800, Fengguang Wu wrote:
> > Hi Felipe,
> > 
> > FYI, there are new smatch warnings show up in
> > 
> > tree:   git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git merge-result-for-greg
> > head:   23953bde3e4d6aa8780dc054f6ad9882ac63f4f4
> > commit: e918fa161f510136fce45a524e934fe20e62c8b1 [66/99] Merge tag 'gadget-for-v3.7' into merge-result-for-greg
> > 
> > drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))

that's not part of what I handle :-(

And merge-result-for-greg was really a temporary branch, btw :-)

-- 
balbi

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]

Re: [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))

[Fengguang Wu]

On Wed, Sep 12, 2012 at 03:02:13PM +0300, Felipe Balbi wrote:
> Hi,
> 
> On Wed, Sep 12, 2012 at 11:50:57AM +0300, Dan Carpenter wrote:
> > On Wed, Sep 12, 2012 at 04:26:22PM +0800, Fengguang Wu wrote:
> > > Hi Felipe,
> > > 
> > > FYI, there are new smatch warnings show up in
> > > 
> > > tree:   git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git merge-result-for-greg
> > > head:   23953bde3e4d6aa8780dc054f6ad9882ac63f4f4
> > > commit: e918fa161f510136fce45a524e934fe20e62c8b1 [66/99] Merge tag 'gadget-for-v3.7' into merge-result-for-greg
> > > 
> > > drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))
> 
> that's not part of what I handle :-(
> 
> And merge-result-for-greg was really a temporary branch, btw :-)

No problem. I'll stop testing this branch :)

Thanks,
Fengguang
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html