Re: [PATCH bpf-next v5 5/7] bpf: Implement bpf_local_storage for inodes

From: kernel test robot
Date: Wed Jul 22 2020 - 20:27:03 EST


Hi KP,

I love your patch! Perhaps something to improve:

[auto build test WARNING on bpf-next/master]

url: https://github.com/0day-ci/linux/commits/KP-Singh/Generalizing-bpf_local_storage/20200723-011814
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: sparc-allmodconfig (attached as .config)
compiler: sparc64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=sparc

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

kernel/bpf/bpf_inode_storage.c: In function 'unlink_inode_storage':
>> kernel/bpf/bpf_inode_storage.c:34:32: warning: variable 'smap' set but not used [-Wunused-but-set-variable]
34 | struct bpf_local_storage_map *smap;
| ^~~~

vim +/smap +34 kernel/bpf/bpf_inode_storage.c

29
30 static bool unlink_inode_storage(struct bpf_local_storage *local_storage,
31 struct bpf_local_storage_elem *selem,
32 bool uncharge_omem)
33 {
> 34 struct bpf_local_storage_map *smap;
35 struct bpf_storage_blob *bsb;
36 bool free_local_storage;
37 struct inode *inode;
38
39 inode = local_storage->owner;
40 bsb = bpf_inode(inode);
41 if (!bsb)
42 return false;
43
44 smap = rcu_dereference(SDATA(selem)->smap);
45 /* All uncharging on sk->sk_omem_alloc must be done first.
46 * sk may be freed once the last selem is unlinked from sk_storage.
47 */
48
49 free_local_storage = hlist_is_singular_node(&selem->snode,
50 &local_storage->list);
51
52 if (free_local_storage) {
53 /* After this RCU_INIT, sk may be freed and cannot be used */
54 RCU_INIT_POINTER(bsb->storage, NULL);
55 local_storage->owner = NULL;
56 }
57
58 return free_local_storage;
59

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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