net/ipv4/ipmr.c:312:24: sparse: sparse: incompatible types in comparison expression (different address spaces):

net/ipv4/ipmr.c:312:24: sparse: sparse: incompatible types in comparison expression (different address spaces):

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   f1a5e78a55ebf2b05777fd5eb738038ddae609d6
commit: b3b6babf47517fde6b6de2493dea28e8831b9347 ipmr: Free mr_table after RCU grace period.
date:   5 days ago
config: nios2-randconfig-r132-20260502 (https://download.01.org/0day-ci/archive/20260503/202605030032.glNApko7-lkp@intel.com/config)
compiler: nios2-linux-gcc (GCC) 8.5.0
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260503/202605030032.glNApko7-lkp@intel.com/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
| Fixes: b3b6babf4751 ("ipmr: Free mr_table after RCU grace period.")
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202605030032.glNApko7-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
   net/ipv4/ipmr.c: note: in included file (through include/uapi/linux/swab.h, include/linux/swab.h, include/uapi/linux/byteorder/little_endian.h, ...):
   arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini
>> net/ipv4/ipmr.c:312:24: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/ipv4/ipmr.c:312:24: sparse:    struct mr_table [noderef] __rcu *
   net/ipv4/ipmr.c:312:24: sparse:    struct mr_table *
   net/ipv4/ipmr.c:318:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/ipv4/ipmr.c:318:16: sparse:    struct mr_table [noderef] __rcu *
   net/ipv4/ipmr.c:318:16: sparse:    struct mr_table *
   net/ipv4/ipmr.c:318:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/ipv4/ipmr.c:318:16: sparse:    struct mr_table [noderef] __rcu *
   net/ipv4/ipmr.c:318:16: sparse:    struct mr_table *
   net/ipv4/ipmr.c:329:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/ipv4/ipmr.c:329:16: sparse:    struct mr_table [noderef] __rcu *
   net/ipv4/ipmr.c:329:16: sparse:    struct mr_table *
   net/ipv4/ipmr.c:343:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/ipv4/ipmr.c:343:9: sparse:    struct mr_table [noderef] __rcu *
   net/ipv4/ipmr.c:343:9: sparse:    struct mr_table *
   net/ipv4/ipmr.c:354:32: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/ipv4/ipmr.c:354:32: sparse:    struct mr_table [noderef] __rcu *
   net/ipv4/ipmr.c:354:32: sparse:    struct mr_table *
   net/ipv4/ipmr.c:356:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/ipv4/ipmr.c:356:9: sparse:    struct mr_table [noderef] __rcu *
   net/ipv4/ipmr.c:356:9: sparse:    struct mr_table *
   arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini
   arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini
   arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini
   arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini
   arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini
   arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini
   arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini

vim +312 net/ipv4/ipmr.c

   301	
   302	bool ipmr_rule_default(const struct fib_rule *rule)
   303	{
   304		return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
   305	}
   306	EXPORT_SYMBOL(ipmr_rule_default);
   307	#else
   308	static struct mr_table *ipmr_mr_table_iter(struct net *net,
   309						   struct mr_table *mrt)
   310	{
   311		if (!mrt)
 > 312			return rcu_dereference(net->ipv4.mrt);
   313		return NULL;
   314	}
   315	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: net/ipv4/ipmr.c:312:24: sparse: sparse: incompatible types in comparison expression (different address spaces):

[Kuniyuki Iwashima]

On Sat, May 2, 2026 at 9:39 AM kernel test robot <lkp@intel.com> wrote:
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   f1a5e78a55ebf2b05777fd5eb738038ddae609d6
> commit: b3b6babf47517fde6b6de2493dea28e8831b9347 ipmr: Free mr_table after RCU grace period.
> date:   5 days ago
> config: nios2-randconfig-r132-20260502 (https://download.01.org/0day-ci/archive/20260503/202605030032.glNApko7-lkp@intel.com/config)
> compiler: nios2-linux-gcc (GCC) 8.5.0
> sparse: v0.6.5-rc1
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260503/202605030032.glNApko7-lkp@intel.com/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
> | Fixes: b3b6babf4751 ("ipmr: Free mr_table after RCU grace period.")
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202605030032.glNApko7-lkp@intel.com/
>
> sparse warnings: (new ones prefixed by >>)
>    net/ipv4/ipmr.c: note: in included file (through include/uapi/linux/swab.h, include/linux/swab.h, include/uapi/linux/byteorder/little_endian.h, ...):
>    arch/nios2/include/asm/swab.h:25:24: sparse: sparse: too many arguments for function __builtin_custom_ini
> >> net/ipv4/ipmr.c:312:24: sparse: sparse: incompatible types in comparison expression (different address spaces):
>    net/ipv4/ipmr.c:312:24: sparse:    struct mr_table [noderef] __rcu *
>    net/ipv4/ipmr.c:312:24: sparse:    struct mr_table *

Will add __rcu to struct mr_table in netns_ipv4.

Thanks