mm/bpf_memcontrol.c:125:27: sparse: sparse: symbol 'bpf_mem_cgroup_memory_events' was not declared. Should it be static?

mm/bpf_memcontrol.c:125:27: sparse: sparse: symbol 'bpf_mem_cgroup_memory_events' was not declared. Should it be static?

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   8cd9520d35a6c38db6567e97dd93b1f11f185dc6
commit: 99430ab8b804c26b8a0dec93fcbfe75469f3edc7 mm: introduce BPF kfuncs to access memcg statistics and events
date:   6 months ago
config: powerpc-randconfig-r134-20260614 (https://download.01.org/0day-ci/archive/20260615/202606150332.Xy4Egd9s-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 305faf498a4e0b52b40742c927af63ab2082e1a9)
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260615/202606150332.Xy4Egd9s-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: 99430ab8b804 ("mm: introduce BPF kfuncs to access memcg statistics and events")
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202606150332.Xy4Egd9s-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> mm/bpf_memcontrol.c:125:27: sparse: sparse: symbol 'bpf_mem_cgroup_memory_events' was not declared. Should it be static?
   mm/bpf_memcontrol.c:68:9: sparse: sparse: context imbalance in 'bpf_get_mem_cgroup' - different lock contexts for basic block

vim +/bpf_mem_cgroup_memory_events +125 mm/bpf_memcontrol.c

   117	
   118	/**
   119	 * bpf_mem_cgroup_memory_events - Read memory cgroup's memory event value
   120	 * @memcg: memory cgroup
   121	 * @event: memory event id
   122	 *
   123	 * Return: The current value of the memory event counter.
   124	 */
 > 125	__bpf_kfunc unsigned long bpf_mem_cgroup_memory_events(struct mem_cgroup *memcg,
   126							       enum memcg_memory_event event)
   127	{
   128		if (unlikely(event >= MEMCG_NR_MEMORY_EVENTS))
   129			return (unsigned long)-1;
   130	
   131		return atomic_long_read(&memcg->memory_events[event]);
   132	}
   133	

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

Re: mm/bpf_memcontrol.c:125:27: sparse: sparse: symbol 'bpf_mem_cgroup_memory_events' was not declared. Should it be static?

[JP Kobryn]

On 6/14/26 12:07 PM, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   8cd9520d35a6c38db6567e97dd93b1f11f185dc6
> commit: 99430ab8b804c26b8a0dec93fcbfe75469f3edc7 mm: introduce BPF kfuncs to access memcg statistics and events
> date:   6 months ago
> config: powerpc-randconfig-r134-20260614 (https://download.01.org/0day-ci/archive/20260615/202606150332.Xy4Egd9s-lkp@intel.com/config)
> compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 305faf498a4e0b52b40742c927af63ab2082e1a9)
> sparse: v0.6.5-rc1
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260615/202606150332.Xy4Egd9s-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: 99430ab8b804 ("mm: introduce BPF kfuncs to access memcg statistics and events")
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202606150332.Xy4Egd9s-lkp@intel.com/
> 
> sparse warnings: (new ones prefixed by >>)
>>> mm/bpf_memcontrol.c:125:27: sparse: sparse: symbol 'bpf_mem_cgroup_memory_events' was not declared. Should it be static?
>    mm/bpf_memcontrol.c:68:9: sparse: sparse: context imbalance in 'bpf_get_mem_cgroup' - different lock contexts for basic block
> 
> vim +/bpf_mem_cgroup_memory_events +125 mm/bpf_memcontrol.c
> 
>    117	
>    118	/**
>    119	 * bpf_mem_cgroup_memory_events - Read memory cgroup's memory event value
>    120	 * @memcg: memory cgroup
>    121	 * @event: memory event id
>    122	 *
>    123	 * Return: The current value of the memory event counter.
>    124	 */
>  > 125	__bpf_kfunc unsigned long bpf_mem_cgroup_memory_events(struct mem_cgroup *memcg,
>    126							       enum memcg_memory_event event)

Roman, it looks like the kfuncs added for bpfoom can safely be made
static since they get resolved through BTF. I'll send a patch to update
where applicable.