kernel/bpf/task_iter.c:707:27: warning: bitwise operation between different enumeration types ('enum bpf_reg_type' and 'enum bpf_type_flag')

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

CC: linux-kernel@vger.kernel.org
TO: Chuyi Zhou <zhouchuyi@bytedance.com>
CC: Martin KaFai Lau <martin.lau@kernel.org>

Hi Chuyi,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   9712d38c87087ae34f8cede6583092c272507c52
commit: 0de4f50de25af79c2a46db55d70cdbd8f985c6d1 bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg
date:   1 year, 4 months ago
config: x86_64-buildonly-randconfig-006-20250127 (https://download.01.org/0day-ci/archive/20250310/202503100632.ZO4IXUbn-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250310/202503100632.ZO4IXUbn-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/202503100632.ZO4IXUbn-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from kernel/bpf/task_iter.c:6:
   In file included from include/linux/pid_namespace.h:7:
   In file included from include/linux/mm.h:2166:
   include/linux/vmstat.h:522:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     522 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
>> kernel/bpf/task_iter.c:707:27: warning: bitwise operation between different enumeration types ('enum bpf_reg_type' and 'enum bpf_type_flag') [-Wenum-enum-conversion]
     707 |                   PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED },
         |                   ~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~
   2 warnings generated.


vim +707 kernel/bpf/task_iter.c

   699	
   700	static struct bpf_iter_reg task_reg_info = {
   701		.target			= "task",
   702		.attach_target		= bpf_iter_attach_task,
   703		.feature		= BPF_ITER_RESCHED,
   704		.ctx_arg_info_size	= 1,
   705		.ctx_arg_info		= {
   706			{ offsetof(struct bpf_iter__task, task),
 > 707			  PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED },
   708		},
   709		.seq_info		= &task_seq_info,
   710		.fill_link_info		= bpf_iter_fill_link_info,
   711		.show_fdinfo		= bpf_iter_task_show_fdinfo,
   712	};
   713	

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