Re: [PATCH] rds: synchronize info callbacks with connection teardown

Hi Chengfeng,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net/main]
[also build test WARNING on linus/master horms-ipvs/master v7.2-rc7]
[cannot apply to net-next/main next-20260812]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Chengfeng-Ye/rds-synchronize-info-callbacks-with-connection-teardown/20260812-225931
base:   net/main
patch link:    https://lore.kernel.org/r/20260720184955.3008978-1-nicoyip.dev%40gmail.com
patch subject: [PATCH] rds: synchronize info callbacks with connection teardown
config: mips-randconfig-r134-20260813 (https://download.01.org/0day-ci/archive/20260814/[email protected]/config)
compiler: mips-linux-gcc (GCC) 11.5.0
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260814/[email protected]/reproduce)

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 <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

sparse warnings: (new ones prefixed by >>)
>> net/rds/info.c:83:9: sparse: sparse: cast removes address space '__rcu' of expression
>> net/rds/info.c:83:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/rds/info.c:83:9: sparse:    void ( [noderef] __rcu * )( ... )
   net/rds/info.c:83:9: sparse:    void ( * )( ... )
   net/rds/info.c:84:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/rds/info.c:84:9: sparse:    void ( [noderef] __rcu * )( ... )
   net/rds/info.c:84:9: sparse:    void ( * )( ... )
   net/rds/info.c:96:9: sparse: sparse: cast removes address space '__rcu' of expression
   net/rds/info.c:96:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/rds/info.c:96:9: sparse:    void ( [noderef] __rcu * )( ... )
   net/rds/info.c:96:9: sparse:    void ( * )( ... )
   net/rds/info.c:97:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/rds/info.c:97:9: sparse:    void ( [noderef] __rcu * )( ... )
   net/rds/info.c:97:9: sparse:    void ( * )( ... )
   net/rds/info.c:222:16: sparse: sparse: cast removes address space '__rcu' of expression
   net/rds/info.c:222:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/rds/info.c:222:16: sparse:    void ( [noderef] __rcu * )( ... )
   net/rds/info.c:222:16: sparse:    void ( * )( ... )

vim +/__rcu +83 net/rds/info.c

    75	
    76	void rds_info_register_func(int optname, rds_info_func func)
    77	{
    78		int offset = optname - RDS_INFO_FIRST;
    79	
    80		BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);
    81	
    82		spin_lock(&rds_info_lock);
  > 83		BUG_ON(rcu_access_pointer(rds_info_funcs[offset]));
    84		rcu_assign_pointer(rds_info_funcs[offset], func);
    85		spin_unlock(&rds_info_lock);
    86	}
    87	EXPORT_SYMBOL_GPL(rds_info_register_func);
    88	

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