Subject: Re: [mac80211] BUG_ON with current -git (4.8.0-11417-g24532f7)

From: Sergey Senozhatsky <[email-masked]>
Date: Fri, 14 Oct 2016 17:39:57 +0900

On (10/13/16 14:49), Andy Lutomirski wrote:
[..]
> > >  FAIL: 00004100002cba02 > ffffc900802cba02 || 1 -> (00004100002cba02
> > > >> 39) == 130
> >
> > Yeah, we already know that in this function the aad variable is on the
> > stack, it explicitly is.
> >
> > The question, though, is why precisely that fails in the crypto code.
> > Can you send the Oops report itself?
> >
> 
> It's failing before that.  With CONFIG_VMAP_STACK=y, the stack may not
> be physically contiguous and can't be used for DMA, so putting it in a
> scatterlist is bogus in general, and the crypto code mostly wants a
> scatterlist.
> 
> There are a couple (faster!) APIs for crypto that don't use
> scatterlists, but I don't think AEAD works with them.

given that we have a known issue shouldn't VMAP_STACK be
disabled for now, or would you rather prefer to mark MAC80211
as incompatible: "depends on CFG80211 && !VMAP_STACK"?

	-ss