[linux-next:master 2209/2947] fs/proc/base.c:879:88: 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/next/linux-next.git master
head:   f524a5e4dfb75b277c9a5ad819ca5f035f490f14
commit: b2ae850c7a0b156ce991bb3d5e6090bf9174b161 [2209/2947] proc: add config & param to block forcing mem writes
config: x86_64-randconfig-121-20240803 (https://download.01.org/0day-ci/archive/20240803/202408032026.4HZU39Nb-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/20240803/202408032026.4HZU39Nb-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/202408032026.4HZU39Nb-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> fs/proc/base.c:879:88: sparse: sparse: incompatible types in comparison expression (different address spaces):
   fs/proc/base.c:879:88: sparse:    struct task_struct [noderef] __rcu *
   fs/proc/base.c:879:88: sparse:    struct task_struct *
   fs/proc/base.c:2315:25: sparse: sparse: cast to restricted fmode_t
   fs/proc/base.c:2372:42: sparse: sparse: cast from restricted fmode_t
   fs/proc/base.c:2472:48: sparse: sparse: cast from restricted fmode_t
   fs/proc/base.c: note: in included file (through include/linux/rcuwait.h, include/linux/percpu-rwsem.h, include/linux/fs.h, ...):
   include/linux/sched/signal.h:754:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   include/linux/sched/signal.h:754:37: sparse:     expected struct spinlock [usertype] *lock
   include/linux/sched/signal.h:754:37: sparse:     got struct spinlock [noderef] __rcu *
   fs/proc/base.c:1158:36: sparse: sparse: context imbalance in '__set_oom_adj' - unexpected unlock
   fs/proc/base.c:2162:36: sparse: sparse: self-comparison always evaluates to false
   fs/proc/base.c:2175:36: sparse: sparse: self-comparison always evaluates to false
   fs/proc/base.c:2499:13: sparse: sparse: context imbalance in 'timers_start' - wrong count at exit
   include/linux/sched/signal.h:754:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock @@     got struct spinlock [noderef] __rcu * @@
   include/linux/sched/signal.h:754:37: sparse:     expected struct spinlock [usertype] *lock
   include/linux/sched/signal.h:754:37: sparse:     got struct spinlock [noderef] __rcu *
   fs/proc/base.c:2525:36: sparse: sparse: context imbalance in 'timers_stop' - unexpected unlock
   fs/proc/base.c:3855:19: sparse: sparse: self-comparison always evaluates to false

vim +879 fs/proc/base.c

   867	
   868	static bool proc_mem_foll_force(struct file *file, struct mm_struct *mm)
   869	{
   870		struct task_struct *task;
   871		bool ptrace_active = false;
   872	
   873		switch (proc_mem_force_override) {
   874		case PROC_MEM_FORCE_NEVER:
   875			return false;
   876		case PROC_MEM_FORCE_PTRACE:
   877			task = get_proc_task(file_inode(file));
   878			if (task) {
 > 879				ptrace_active = task->ptrace && task->mm == mm && task->parent == current;
   880				put_task_struct(task);
   881			}
   882			return ptrace_active;
   883		default:
   884			return true;
   885		}
   886	}
   887	

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