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

[Christophe Leroy]

Le 28/02/2024 à 15:43, Eric Dumazet a écrit :
> On Wed, Feb 28, 2024 at 3:07 PM Vadim Fedorenko
> <vadim.fedorenko at linux.dev> 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 ?

Might be a circular header inclusion.

Christophe