Subject: Re: [PATCH] xfrm: kconfig: Fix XFRM_OFFLOAD dependency on XFRM

From: Leon Romanovsky <[email-masked]>
Date: Tue, 25 Jul 2023 08:19:17 +0300

On Tue, Jul 25, 2023 at 07:41:49AM +0300, Ilia Lin wrote:
> Hi Leon,

You was already asked do not top-post.
https://lore.kernel.org/netdev/20230718105446.GD8808@unreal/
Please stop it.

> 
> This is exactly like I described:
> * xfrm.h is included from the net/core/sock.c unconditionally.
> * If CONFIG_XFRM_OFFLOAD is set, then the xfrm_dst_offload_ok() is
> being compiled.
> * If CONFIG_XFRM is not set, the struct dst_entry doesn't have the xfrm member.
> * xfrm_dst_offload_ok() tries to access the dst->xfrm and that fails to compile.

I asked two questions. First one was "How did you set XFRM_OFFLOAD
without XFRM?".

Thanks

> 
> 
> Thanks,
> Ilia Lin
> 
> On Mon, Jul 24, 2023 at 9:11 PM Leon Romanovsky <[email-masked]> wrote:
> >
> > On Mon, Jul 24, 2023 at 12:00:44PM +0300, Ilia Lin wrote:
> > > If XFRM_OFFLOAD is configured, but XFRM is not
> >
> > How did you do it?
> >
> > >, it will cause
> > > compilation error on include xfrm.h:
> > >  C 05:56:39 In file included from /src/linux/kernel_platform/msm-kernel/net/core/sock.c:127:
> > >  C 05:56:39 /src/linux/kernel_platform/msm-kernel/include/net/xfrm.h:1932:30: error: no member named 'xfrm' in 'struct dst_entry'
> > >  C 05:56:39         struct xfrm_state *x = dst->xfrm;
> > >  C 05:56:39                                ~~~  ^
> > >
> > > Making the XFRM_OFFLOAD select the XFRM.
> > >
> > > Fixes: 48e01e001da31 ("ixgbe/ixgbevf: fix XFRM_ALGO dependency")
> > > Reported-by: Ilia Lin <[email-masked]>
> > > Signed-off-by: Ilia Lin <[email-masked]>
> > > ---
> > >  net/xfrm/Kconfig | 1 +
> > >  1 file changed, 1 insertion(+)
> > >
> > > diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
> > > index 3adf31a83a79a..3fc2c1bcb5bbe 100644
> > > --- a/net/xfrm/Kconfig
> > > +++ b/net/xfrm/Kconfig
> > > @@ -10,6 +10,7 @@ config XFRM
> > >
> > >  config XFRM_OFFLOAD
> > >       bool
> > > +     select XFRM
> >
> > struct dst_entry depends on CONFIG_XFRM and not on CONFIG_XFRM_OFFLOAD,
> > so it is unclear to me why do you need to add new "select XFRM" line.
> >
> >    26 struct dst_entry {
> >    27         struct net_device       *dev;
> >    28         struct  dst_ops         *ops;
> >    29         unsigned long           _metrics;
> >    30         unsigned long           expires;
> >    31 #ifdef CONFIG_XFRM
> >    32         struct xfrm_state       *xfrm;
> >    33 #else
> >    34         void                    *__pad1;
> >    35 #endif
> >    36         int
> >
> > Thanks