Re: [revert 0d60d8df6f49] [net/net-next] [6.8-rc5] Build Failure

From: Eric Dumazet
Date: Wed Feb 28 2024 - 09:44:56 EST

On Wed, Feb 28, 2024 at 3:07 PM Vadim Fedorenko
<vadim.fedorenko@xxxxxxxxx> wrote:
>
> On 28/02/2024 11:09, Tasmiya Nalatwad wrote:
> > Greetings,
> >
> > [revert 0d60d8df6f49] [net/net-next] [6.8-rc5] Build Failure
> >
> > Reverting below commit fixes the issue
> >
> > commit 0d60d8df6f493bb46bf5db40d39dd60a1bafdd4e
> > dpll: rely on rcu for netdev_dpll_pin()
> >
> > --- Traces ---
> >
> > ./include/linux/dpll.h: In function ‘netdev_dpll_pin’:
> > ./include/linux/rcupdate.h:439:9: error: dereferencing pointer to
> > incomplete type ‘struct dpll_pin’
> > typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \
> > ^
> > ./include/linux/rcupdate.h:587:2: note: in expansion of macro
> > ‘__rcu_dereference_check’
> > __rcu_dereference_check((p), __UNIQUE_ID(rcu), \
> > ^~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/rtnetlink.h:70:2: note: in expansion of macro
> > ‘rcu_dereference_check’
> > rcu_dereference_check(p, lockdep_rtnl_is_held())
> > ^~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/dpll.h:175:9: note: in expansion of macro
> > ‘rcu_dereference_rtnl’
> > return rcu_dereference_rtnl(dev->dpll_pin);
> > ^~~~~~~~~~~~~~~~~~~~
> > make[4]: *** [scripts/Makefile.build:243: drivers/dpll/dpll_core.o] Error 1
> > make[4]: *** Waiting for unfinished jobs....
> > AR net/mpls/built-in.a
> > AR net/l3mdev/built-in.a
> > In file included from ./include/linux/rbtree.h:24,
> > from ./include/linux/mm_types.h:11,
> > from ./include/linux/mmzone.h:22,
> > from ./include/linux/gfp.h:7,
> > from ./include/linux/umh.h:4,
> > from ./include/linux/kmod.h:9,
> > from ./include/linux/module.h:17,
> > from drivers/dpll/dpll_netlink.c:9:
> > ./include/linux/dpll.h: In function ‘netdev_dpll_pin’:
> > ./include/linux/rcupdate.h:439:9: error: dereferencing pointer to
> > incomplete type ‘struct dpll_pin’
> > typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \
> > ^
> > ./include/linux/rcupdate.h:587:2: note: in expansion of macro
> > ‘__rcu_dereference_check’
> > __rcu_dereference_check((p), __UNIQUE_ID(rcu), \
> > ^~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/rtnetlink.h:70:2: note: in expansion of macro
> > ‘rcu_dereference_check’
> > rcu_dereference_check(p, lockdep_rtnl_is_held())
> > ^~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/dpll.h:175:9: note: in expansion of macro
> > ‘rcu_dereference_rtnl’
> > return rcu_dereference_rtnl(dev->dpll_pin);
> > ^~~~~~~~~~~~~~~~~~~~
> > make[4]: *** [scripts/Makefile.build:243: drivers/dpll/dpll_netlink.o]
> > Error 1
> > make[3]: *** [scripts/Makefile.build:481: drivers/dpll] Error 2
> > make[3]: *** Waiting for unfinished jobs....
> > In file included from ./arch/powerpc/include/generated/asm/rwonce.h:1,
> > from ./include/linux/compiler.h:251,
> > from ./include/linux/instrumented.h:10,
> > from ./include/linux/uaccess.h:6,
> > from net/core/dev.c:71:
> > net/core/dev.c: In function ‘netdev_dpll_pin_assign’:
> > ./include/linux/rcupdate.h:462:36: error: dereferencing pointer to
> > incomplete type ‘struct dpll_pin’
> > #define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
> > ^~~~
> > ./include/asm-generic/rwonce.h:55:33: note: in definition of macro
> > ‘__WRITE_ONCE’
> > *(volatile typeof(x) *)&(x) = (val); \
> > ^~~
> > ./arch/powerpc/include/asm/barrier.h:76:2: note: in expansion of macro
> > ‘WRITE_ONCE’
> > WRITE_ONCE(*p, v); \
> > ^~~~~~~~~~
> > ./include/asm-generic/barrier.h:172:55: note: in expansion of macro
> > ‘__smp_store_release’
> > #define smp_store_release(p, v) do { kcsan_release();
> > __smp_store_release(p, v); } while (0)
> > ^~~~~~~~~~~~~~~~~~~
> > ./include/linux/rcupdate.h:503:3: note: in expansion of macro
> > ‘smp_store_release’
> > smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
> > ^~~~~~~~~~~~~~~~~
> > ./include/linux/rcupdate.h:503:25: note: in expansion of macro
> > ‘RCU_INITIALIZER’
> > smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
> > ^~~~~~~~~~~~~~~
> > net/core/dev.c:9081:2: note: in expansion of macro ‘rcu_assign_pointer’
> > rcu_assign_pointer(dev->dpll_pin, dpll_pin);
> > ^~~~~~~~~~~~~~~~~~
> > make[4]: *** [scripts/Makefile.build:243: net/core/dev.o] Error 1
> > make[4]: *** Waiting for unfinished jobs....
> > AR drivers/net/ethernet/built-in.a
> > AR drivers/net/built-in.a
> > AR net/dcb/built-in.a
> > AR net/netlabel/built-in.a
> > AR net/strparser/built-in.a
> > AR net/handshake/built-in.a
> > GEN lib/test_fortify.log
> > AR net/8021q/built-in.a
> > AR net/nsh/built-in.a
> > AR net/unix/built-in.a
> > CC lib/string.o
> > AR net/packet/built-in.a
> > AR net/switchdev/built-in.a
> > AR lib/lib.a
> > AR net/mptcp/built-in.a
> > AR net/devlink/built-in.a
> > In file included from ./include/linux/rbtree.h:24,
> > from ./include/linux/mm_types.h:11,
> > from ./include/linux/mmzone.h:22,
> > from ./include/linux/gfp.h:7,
> > from ./include/linux/umh.h:4,
> > from ./include/linux/kmod.h:9,
> > from ./include/linux/module.h:17,
> > from net/core/rtnetlink.c:17:
> > ./include/linux/dpll.h: In function ‘netdev_dpll_pin’:
> > ./include/linux/rcupdate.h:439:9: error: dereferencing pointer to
> > incomplete type ‘struct dpll_pin’
> > typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \
> > ^
> > ./include/linux/rcupdate.h:587:2: note: in expansion of macro
> > ‘__rcu_dereference_check’
> > __rcu_dereference_check((p), __UNIQUE_ID(rcu), \
> > ^~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/rtnetlink.h:70:2: note: in expansion of macro
> > ‘rcu_dereference_check’
> > rcu_dereference_check(p, lockdep_rtnl_is_held())
> > ^~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/dpll.h:175:9: note: in expansion of macro
> > ‘rcu_dereference_rtnl’
> > return rcu_dereference_rtnl(dev->dpll_pin);
> > ^~~~~~~~~~~~~~~~~~~~
> > In file included from net/core/rtnetlink.c:60:
> > ./include/linux/dpll.h:179:1: error: control reaches end of non-void
> > function [-Werror=return-type]
> > }
> >
>
> Hi, Eric!
>
> Looks like we have to move struct dpll_pin definition to
> include/linux/dpll.h to have this fixed, right?
>

No idea what is wrong. Is it powerpc specific ? Some compiler version ?

netdev_dpll_pin() could be moved to net/core/rtnetlink.c, this is the only user.

diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index 4ec2fe9caf5a3f284afd0cfe4fc7c2bf42cbbc60..72d21e710d7f201d2fc57bb3a32b4bc0ff2b1749
100644
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -169,13 +169,4 @@ int dpll_device_change_ntf(struct dpll_device *dpll);

int dpll_pin_change_ntf(struct dpll_pin *pin);

-static inline struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
-{
-#if IS_ENABLED(CONFIG_DPLL)
- return rcu_dereference_rtnl(dev->dpll_pin);
-#else
- return NULL;
-#endif
-}
-
#endif
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 9c4f427f3a5057b52ec05405e8b15b8ca2246b4b..32dc601fd8ca66dfcd3cb8f38b533314de02d1d2
100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1053,6 +1053,15 @@ static size_t rtnl_devlink_port_size(const
struct net_device *dev)
return size;
}

+static struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
+{
+#if IS_ENABLED(CONFIG_DPLL)
+ return rcu_dereference_rtnl(dev->dpll_pin);
+#else
+ return NULL;
+#endif
+}
+
static size_t rtnl_dpll_pin_size(const struct net_device *dev)
{
size_t size = nla_total_size(0); /* nest IFLA_DPLL_PIN */