Re: [ipsec-next:testing 7/8] include/net/espintcp.h:36:20: sparse: sparse: incorrect type in return expression (different address spaces)

[Sabrina Dubroca <sd@queasysnail.net>]

2019-10-08, 07:55:09 +0200, Steffen Klassert wrote:
> On Sun, Oct 06, 2019 at 10:46:40AM +0800, kbuild test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next.git testing
> > head:   5374d99ba41893b4bb1ddbe35a88b1f08e860903
> > commit: 735de2631f8680ac714df1ecc8e052785e9f9f8e [7/8] xfrm: add espintcp (RFC 8229)
> > reproduce:
> >         # apt-get install sparse
> >         # sparse version: v0.6.1-rc1-42-g38eda53-dirty
> >         git checkout 735de2631f8680ac714df1ecc8e052785e9f9f8e
> >         make ARCH=x86_64 allmodconfig
> >         make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
> > 
> > If you fix the issue, kindly add following tag
> > Reported-by: kbuild test robot <lkp@intel.com>
> > 
> > 
> > >> include/net/espintcp.h:36:20: sparse:    expected struct espintcp_ctx *
> > >> include/net/espintcp.h:36:20: sparse:    got void [noderef] <asn:4> *icsk_ulp_data
> > >> include/net/espintcp.h:36:20: sparse: sparse: incorrect type in return expression (different address spaces) @@    expected struct espintcp_ctx * @@    got voistruct espintcp_ctx * @@
> > >> include/net/espintcp.h:36:20: sparse:    expected struct espintcp_ctx *
> > >> include/net/espintcp.h:36:20: sparse:    got void [noderef] <asn:4> *icsk_ulp_data
> > 
> > vim +36 include/net/espintcp.h
> > 
> >     31	
> >     32	static inline struct espintcp_ctx *espintcp_getctx(const struct sock *sk)
> >     33	{
> >     34		struct inet_connection_sock *icsk = inet_csk(sk);
> >     35	
> >   > 36		return icsk->icsk_ulp_data;
> 
> Sabrina, can you please fix this and resend the patchset?

Yep, will do.

> Also, icsk_ulp_data has a __rcu annotation, so maybe better
> using rcu primitives to access the pointer?

Apparently RCU protection of icsk_ulp_data is only needed for diag
(see commit 15a7dea750e0 ("net/tls: use RCU protection on
icsk->icsk_ulp_data")). I'll check this and update the patch.

> Another thing, where is espintcp_ctx that is assigned to
> icsk_ulp_data freed?

That's in espintcp_destruct:

static void espintcp_destruct(struct sock *sk)
{
	struct espintcp_ctx *ctx = espintcp_getctx(sk);

	kfree(ctx);
}


Thanks,

-- 
Sabrina