Re: [PATCH v2 3/3] bpf: eliminate the allocation of an intermediate struct bpf_key

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

Hi James,

kernel test robot noticed the following build warnings:

[auto build test WARNING on bpf-next/master]
[also build test WARNING on bpf/master linus/master v6.16 next-20250731]
[cannot apply to bpf-next/net]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/James-Bottomley/bpf-make-bpf_key-an-opaque-type/20250731-013040
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20250730172745.8480-4-James.Bottomley%40HansenPartnership.com
patch subject: [PATCH v2 3/3] bpf: eliminate the allocation of an intermediate struct bpf_key
config: i386-randconfig-141-20250731 (https://download.01.org/0day-ci/archive/20250801/202508010803.nlVVIZ7G-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0

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/202508010803.nlVVIZ7G-lkp@intel.com/

smatch warnings:
kernel/trace/bpf_trace.c:1337 bpf_key_put() warn: always true condition '(key != BUILTIN_KEY) => (0-u32max != u64max)'

vim +1337 kernel/trace/bpf_trace.c

  1324	
  1325	/**
  1326	 * bpf_key_put - decrement key reference count if key is valid and free bpf_key
  1327	 * @bkey: bpf_key structure
  1328	 *
  1329	 * Decrement the reference count of the key inside *bkey*, if the pointer
  1330	 * is valid, and free *bkey*.
  1331	 */
  1332	__bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
  1333	{
  1334		struct key *key = (struct key *)bkey;
  1335	
  1336		if (system_keyring_id_check((unsigned long)key) < 0 &&
> 1337		    (unsigned long)key != BUILTIN_KEY)
  1338			key_put(key);
  1339	}
  1340	

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