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References: <20230724090044.2668064-1-ilia.lin@kernel.org> <20230724181105.GD11388@unreal>
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From:   Ilia Lin <ilia.lin@kernel.org>
Date:   Tue, 25 Jul 2023 07:41:49 +0300
Message-ID: <CA+5LGR3ifQbn4x9ncyjJLxsFU4NRs90rVcqECJ+-UC=pP35OjA@mail.gmail.com>
Subject: Re: [PATCH] xfrm: kconfig: Fix XFRM_OFFLOAD dependency on XFRM
To:     Leon Romanovsky <leon@kernel.org>
Cc:     Ilia Lin <ilia.lin@kernel.org>, steffen.klassert@secunet.com,
        herbert@gondor.apana.org.au, davem@davemloft.net,
        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        jeffrey.t.kirsher@intel.com
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Hi Leon,

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 mem=
ber.
* xfrm_dst_offload_ok() tries to access the dst->xfrm and that fails to com=
pile.


Thanks,
Ilia Lin

On Mon, Jul 24, 2023 at 9:11=E2=80=AFPM Leon Romanovsky <leon@kernel.org> w=
rote:
>
> 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:19=
32:30: error: no member named 'xfrm' in 'struct dst_entry'
> >  C 05:56:39         struct xfrm_state *x =3D 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 <ilia.lin@kernel.org>
> > Signed-off-by: Ilia Lin <ilia.lin@kernel.org>
> > ---
> >  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