[paulmckrcu:dev.2025.01.07a 56/56] kernel/rcu/refscale.c:225:21: sparse: sparse: incorrect type in assignment (different address spaces)

[kernel test robot <lkp@intel.com>]

tree:   https://github.com/paulmckrcu/linux dev.2025.01.07a
head:   88e44a908bff076d1e7f47634f06a8a4560c19e9
commit: 88e44a908bff076d1e7f47634f06a8a4560c19e9 [56/56] refscale: Add srcu_read_lock_fast() support using "srcu-fast"
config: x86_64-randconfig-121-20250111 (https://download.01.org/0day-ci/archive/20250111/202501111020.ConYIOJC-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250111/202501111020.ConYIOJC-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
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501111020.ConYIOJC-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> kernel/rcu/refscale.c:225:21: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct srcu_ctr *scp @@     got struct srcu_ctr [noderef] __percpu * @@
   kernel/rcu/refscale.c:225:21: sparse:     expected struct srcu_ctr *scp
   kernel/rcu/refscale.c:225:21: sparse:     got struct srcu_ctr [noderef] __percpu *
>> kernel/rcu/refscale.c:226:50: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected struct srcu_ctr [noderef] __percpu *scp @@     got struct srcu_ctr *scp @@
   kernel/rcu/refscale.c:226:50: sparse:     expected struct srcu_ctr [noderef] __percpu *scp
   kernel/rcu/refscale.c:226:50: sparse:     got struct srcu_ctr *scp
   kernel/rcu/refscale.c:236:21: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct srcu_ctr *scp @@     got struct srcu_ctr [noderef] __percpu * @@
   kernel/rcu/refscale.c:236:21: sparse:     expected struct srcu_ctr *scp
   kernel/rcu/refscale.c:236:21: sparse:     got struct srcu_ctr [noderef] __percpu *
   kernel/rcu/refscale.c:238:50: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected struct srcu_ctr [noderef] __percpu *scp @@     got struct srcu_ctr *scp @@
   kernel/rcu/refscale.c:238:50: sparse:     expected struct srcu_ctr [noderef] __percpu *scp
   kernel/rcu/refscale.c:238:50: sparse:     got struct srcu_ctr *scp
   kernel/rcu/refscale.c:745:24: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/rcu/refscale.c:745:24: sparse:    struct refscale_typesafe [noderef] __rcu *
   kernel/rcu/refscale.c:745:24: sparse:    struct refscale_typesafe *
   kernel/rcu/refscale.c:195:37: sparse: sparse: context imbalance in 'srcu_ref_scale_read_section' - unexpected unlock
   kernel/rcu/refscale.c:206:37: sparse: sparse: context imbalance in 'srcu_ref_scale_delay_section' - unexpected unlock
   kernel/rcu/refscale.c: note: in included file (through include/linux/srcu.h, include/linux/notifier.h, arch/x86/include/asm/uprobes.h, ...):
   include/linux/srcutiny.h:93:39: sparse: sparse: cast removes address space '__percpu' of expression
   kernel/rcu/refscale.c:226:38: sparse: sparse: context imbalance in 'srcu_fast_ref_scale_read_section' - unexpected unlock
   include/linux/srcutiny.h:93:39: sparse: sparse: cast removes address space '__percpu' of expression
   kernel/rcu/refscale.c:237:17: sparse: sparse: context imbalance in 'srcu_fast_ref_scale_delay_section' - unexpected unlock
   kernel/rcu/refscale.c:255:42: sparse: sparse: context imbalance in 'srcu_lite_ref_scale_read_section' - unexpected unlock
   kernel/rcu/refscale.c:266:42: sparse: sparse: context imbalance in 'srcu_lite_ref_scale_delay_section' - unexpected unlock
   kernel/rcu/refscale.c:700:13: sparse: sparse: context imbalance in 'typesafe_lock_acquire' - wrong count at exit
   kernel/rcu/refscale.c:707:13: sparse: sparse: context imbalance in 'typesafe_lock_release' - unexpected unlock

vim +225 kernel/rcu/refscale.c

   218	
   219	static void srcu_fast_ref_scale_read_section(const int nloops)
   220	{
   221		int i;
   222		struct srcu_ctr *scp;
   223	
   224		for (i = nloops; i >= 0; i--) {
 > 225			scp = srcu_read_lock_fast(srcu_ctlp);
 > 226			srcu_read_unlock_fast(srcu_ctlp, scp);
   227		}
   228	}
   229	

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