include/linux/rculist.h:524:9: sparse: sparse: incompatible types in comparison expression (different address spaces):

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   1b907d0507354b74a4f2c286380cd6059af79248
commit: 6b03d1304a32dc8450c7516000a0fe07bef7c446 proc: Ensure we see the exit of each process tid exactly once
date:   3 years, 7 months ago
config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20231113/202311130034.cLZT80OM-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/20231113/202311130034.cLZT80OM-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/202311130034.cLZT80OM-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
   kernel/pid.c:377:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/pid.c:377:9: sparse:    struct pid [noderef] <asn:4> *
   kernel/pid.c:377:9: sparse:    struct pid *
   kernel/pid.c:378:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/pid.c:378:9: sparse:    struct pid [noderef] <asn:4> *
   kernel/pid.c:378:9: sparse:    struct pid *
   kernel/pid.c:440:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/pid.c:440:23: sparse:    struct pid [noderef] <asn:4> *
   kernel/pid.c:440:23: sparse:    struct pid *
   kernel/pid.c:499:32: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/pid.c:499:32: sparse:    struct pid [noderef] <asn:4> *
   kernel/pid.c:499:32: sparse:    struct pid *
   kernel/pid.c: note: in included file (through include/linux/pid.h, include/linux/sched.h, include/linux/mm.h):
>> include/linux/rculist.h:524:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   include/linux/rculist.h:524:9: sparse:    struct hlist_node [noderef] <asn:4> *
>> include/linux/rculist.h:524:9: sparse:    struct hlist_node *
   include/linux/rculist.h:525:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   include/linux/rculist.h:525:9: sparse:    struct hlist_node [noderef] <asn:4> *
   include/linux/rculist.h:525:9: sparse:    struct hlist_node *

vim +524 include/linux/rculist.h

82524746c27fa4 Franck Bui-Huu    2008-05-12  508  
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  509  /**
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  510   * hlists_swap_heads_rcu - swap the lists the hlist heads point to
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  511   * @left:  The hlist head on the left
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  512   * @right: The hlist head on the right
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  513   *
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  514   * The lists start out as [@left  ][node1 ... ] and
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  515                            [@right ][node2 ... ]
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  516   * The lists end up as    [@left  ][node2 ... ]
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  517   *                        [@right ][node1 ... ]
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  518   */
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  519  static inline void hlists_swap_heads_rcu(struct hlist_head *left, struct hlist_head *right)
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  520  {
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  521  	struct hlist_node *node1 = left->first;
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  522  	struct hlist_node *node2 = right->first;
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  523  
35fc0e3b0bd5be Eric W. Biederman 2020-04-24 @524  	rcu_assign_pointer(left->first, node2);
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  525  	rcu_assign_pointer(right->first, node1);
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  526  	WRITE_ONCE(node2->pprev, &left->first);
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  527  	WRITE_ONCE(node1->pprev, &right->first);
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  528  }
35fc0e3b0bd5be Eric W. Biederman 2020-04-24  529  

:::::: The code at line 524 was first introduced by commit
:::::: 35fc0e3b0bd5be3b059e53ae90c4536ee4922330 rculist: Add hlists_swap_heads_rcu

:::::: TO: Eric W. Biederman <ebiederm@xmission.com>
:::::: CC: Eric W. Biederman <ebiederm@xmission.com>

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