Re: [linux-next:master 10788/11220] include/linux/rcupdate.h:555:36: error: dereferencing pointer to incomplete type 'struct maple_enode'

["Liam R. Howlett" <Liam.Howlett@oracle.com>]

* kernel test robot <lkp@intel.com> [260202 13:31]:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   193579fe01389bc21aff0051d13f24e8ea95b47d
> commit: 60d8a8eb080e2f6927add49f47625574b39d3072 [10788/11220] maple_tree: add cp_is_new_root() helper
> config: parisc-randconfig-002-20260202 (https://download.01.org/0day-ci/archive/20260203/202602030233.gZQAuAMc-lkp@intel.com/config)
> compiler: hppa-linux-gcc (GCC) 8.5.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260203/202602030233.gZQAuAMc-lkp@intel.com/reproduce)

Thanks, as predicted by SK.

I will have to build the kernel with a lot more gcc versions, I guess.

> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202602030233.gZQAuAMc-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
>    In file included from ./arch/parisc/include/generated/asm/rwonce.h:1,
>                     from include/linux/compiler.h:380,
>                     from include/linux/array_size.h:5,
>                     from include/linux/kernel.h:16,
>                     from include/linux/maple_tree.h:11,
>                     from lib/maple_tree.c:56:
>    lib/maple_tree.c: In function 'cp_is_new_root':
> >> include/linux/rcupdate.h:555:36: error: dereferencing pointer to incomplete type 'struct maple_enode'
>     #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);    \
>                                     ^~~
>    include/linux/rcupdate.h:1046:3: note: in expansion of macro 'WRITE_ONCE'
>       WRITE_ONCE(p, RCU_INITIALIZER(v)); \
>       ^~~~~~~~~~
>    include/linux/rcupdate.h:1046:17: note: in expansion of macro 'RCU_INITIALIZER'
>       WRITE_ONCE(p, RCU_INITIALIZER(v)); \
>                     ^~~~~~~~~~~~~~~
>    lib/maple_tree.c:3364:3: note: in expansion of macro 'RCU_INIT_POINTER'
>       RCU_INIT_POINTER(cp->slot[0], mt_mk_node(cp->dst[0].node, mt));
>       ^~~~~~~~~~~~~~~~
> 
> 
> vim +555 include/linux/rcupdate.h
> 
> ca5ecddfa8fcbd Paul E. McKenney 2010-04-28  550  
> 462225ae47d717 Paul E. McKenney 2013-11-11  551  /**
> 462225ae47d717 Paul E. McKenney 2013-11-11  552   * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
> 462225ae47d717 Paul E. McKenney 2013-11-11  553   * @v: The value to statically initialize with.
> 462225ae47d717 Paul E. McKenney 2013-11-11  554   */
> 462225ae47d717 Paul E. McKenney 2013-11-11 @555  #define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
> 462225ae47d717 Paul E. McKenney 2013-11-11  556  
> 
> :::::: The code at line 555 was first introduced by commit
> :::::: 462225ae47d7175f886281d8a91708550cd5178c rcu: Add an RCU_INITIALIZER for global RCU-protected pointers
> 
> :::::: TO: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> :::::: CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki