Re: [PATCH bpf-next v2 1/2] bpf: add skcipher API support to TC/XDP programs

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

Hi Vadim,

kernel test robot noticed the following build warnings:

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

url:    https://github.com/intel-lab-lkp/linux/commits/Vadim-Fedorenko/selftests-bpf-crypto-skcipher-algo-selftests/20231028-020332
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20231027172039.1365917-1-vadfed%40meta.com
patch subject: [PATCH bpf-next v2 1/2] bpf: add skcipher API support to TC/XDP programs
config: mips-allyesconfig (https://download.01.org/0day-ci/archive/20231028/202310280854.tycUngCC-lkp@intel.com/config)
compiler: mips-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231028/202310280854.tycUngCC-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/202310280854.tycUngCC-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/bpf/crypto.c:74: warning: Function parameter or member 'palgo' not described in 'bpf_crypto_skcipher_ctx_create'
>> kernel/bpf/crypto.c:74: warning: Function parameter or member 'pkey' not described in 'bpf_crypto_skcipher_ctx_create'
>> kernel/bpf/crypto.c:74: warning: Function parameter or member 'err' not described in 'bpf_crypto_skcipher_ctx_create'
>> kernel/bpf/crypto.c:74: warning: Excess function parameter 'algo' description in 'bpf_crypto_skcipher_ctx_create'
>> kernel/bpf/crypto.c:74: warning: Excess function parameter 'key' description in 'bpf_crypto_skcipher_ctx_create'


vim +74 kernel/bpf/crypto.c

    58	
    59	/**
    60	 * bpf_crypto_skcipher_ctx_create() - Create a mutable BPF crypto context.
    61	 *
    62	 * Allocates a crypto context that can be used, acquired, and released by
    63	 * a BPF program. The crypto context returned by this function must either
    64	 * be embedded in a map as a kptr, or freed with bpf_crypto_skcipher_ctx_release().
    65	 *
    66	 * bpf_crypto_skcipher_ctx_create() allocates memory using the BPF memory
    67	 * allocator, and will not block. It may return NULL if no memory is available.
    68	 * @algo: bpf_dynptr which holds string representation of algorithm.
    69	 * @key:  bpf_dynptr which holds cipher key to do crypto.
    70	 */
    71	__bpf_kfunc struct bpf_crypto_skcipher_ctx *
    72	bpf_crypto_skcipher_ctx_create(const struct bpf_dynptr_kern *palgo,
    73				       const struct bpf_dynptr_kern *pkey, int *err)
  > 74	{
    75		struct bpf_crypto_skcipher_ctx *ctx;
    76		char *algo;
    77	
    78		if (__bpf_dynptr_size(palgo) > CRYPTO_MAX_ALG_NAME) {
    79			*err = -EINVAL;
    80			return NULL;
    81		}
    82	
    83		algo = __bpf_dynptr_data_ptr(palgo);
    84	
    85		if (!crypto_has_skcipher(algo, CRYPTO_ALG_TYPE_SKCIPHER, CRYPTO_ALG_TYPE_MASK)) {
    86			*err = -EOPNOTSUPP;
    87			return NULL;
    88		}
    89	
    90		ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
    91		if (!ctx) {
    92			*err = -ENOMEM;
    93			return NULL;
    94		}
    95	
    96		memset(ctx, 0, sizeof(*ctx));
    97	
    98		ctx->tfm = crypto_alloc_sync_skcipher(algo, 0, 0);
    99		if (IS_ERR(ctx->tfm)) {
   100			*err = PTR_ERR(ctx->tfm);
   101			ctx->tfm = NULL;
   102			goto err;
   103		}
   104	
   105		*err = crypto_sync_skcipher_setkey(ctx->tfm, __bpf_dynptr_data_ptr(pkey),
   106						   __bpf_dynptr_size(pkey));
   107		if (*err)
   108			goto err;
   109	
   110		refcount_set(&ctx->usage, 1);
   111	
   112		return ctx;
   113	err:
   114		if (ctx->tfm)
   115			crypto_free_sync_skcipher(ctx->tfm);
   116		kfree(ctx);
   117	
   118		return NULL;
   119	}
   120	

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