tree: https://github.com/rgushchin/linux.git bpf_memcg.4 head: d45b914fe800e2a8ec174017a193fbc08ea30c32 commit: 4790e514d4cc4913da25fe2173cca11169506499 [4/31] bpf: memcg-based memory accounting for bpf maps config: i386-randconfig-m021-20200809 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; smatch warnings: kernel/bpf/helpers.c:64 __bpf_map_update_elem() error: uninitialized symbol 'old_memcg'. vim +/old_memcg +64 kernel/bpf/helpers.c 44 45 #ifdef CONFIG_MEMCG_KMEM 46 static __always_inline int __bpf_map_update_elem(struct bpf_map *map, void *key, 47 void *value, u64 flags) 48 { 49 struct mem_cgroup *old_memcg; 50 int ret; 51 52 /* 53 * If update from an interrupt context results in a memory allocation, 54 * the memory cgroup to charge can't be determined from the context 55 * of the current task. Instead, we charge the memory cgroup, which 56 * contained a process created the map. 57 */ 58 if (in_interrupt()) 59 old_memcg = memalloc_use_memcg(map->memcg); 60 61 ret = map->ops->map_update_elem(map, key, value, flags); 62 63 if (in_interrupt()) 65 66 return ret; 67 } 68 #else 69 static __always_inline int __bpf_map_update_elem(struct bpf_map *map, void *key, 70 void *value, u64 flags) 71 { 72 return map->ops->map_update_elem(map, key, value, flags); 73 } 74 #endif 75 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org