On Wed, Feb 28, 2024 at 3:07 PM Vadim Fedorenko
[off-list ref] wrote:

quoted

On 28/02/2024 11:09, Tasmiya Nalatwad wrote:

quoted

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 */