Re: DMA debug trace pointing to rtl8187

[Greg KH <greg@kroah.com>]

On Wed, May 06, 2009 at 08:35:52AM +0200, Eric Valette wrote:
> FUJITA Tomonori wrote:
> > CC'ed linux-usb,
> > 
> > The ehci_hcd driver uses buffers on the stack for DMA?
> > 
> > On Sun, 03 May 2009 17:36:24 +0200
> > Eric Valette <eric.valette@free.fr> wrote:
> > 
> >> ------------[ cut here ]------------
> >>
> >> WARNING: at /usr/src/linux-2.6.22.9/lib/dma-debug.c:609
> > 
> > Hmm, the kernel version is wired. lib/dma-debug.c was added in
> > 2.6.30-rc.
> 
> No that's the file path.  I use ketchup to apply patches...
> 
> > 
> >> check_for_stack+0x6b/0x8b()
> >> Hardware name: P5W DH Deluxe
> >>
> >> ehci_hcd 0000:00:1d.7: DMA-API: device driver maps memory fromstack
> >> [addr=ffff88007fa79968]
> >> Modules linked in:
> >>
> >> Pid: 297, comm: khubd Not tainted 2.6.30-rc4-git1 #32
> 
> Here is the real version.

The problem is in the rtl8187 driver.

They are calling usb_control_msg and passing a pointer to a buffer on
the stack.  See drivers/net/wireless/rtl818x/rtl8187.h for where the
problem happens in numerous places.

Also it looks like rtl8225_write_8051() is incorrect.  You are passing a
pointer to a variable that was passed as an argument.  I don't know
where that is supposed to be on, somewhere on the stack I guess.

Larry, care to fix this up?

thanks,

greg k-h