[jarkko-tpmdd:tpm2key-v4 5/5] crypto/asymmetric_keys/tpm2_key_rsa.c:273:22: warning: unused variable 'offset'

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

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git tpm2key-v4
head:   8d6000fe712d525bf767a9fbe7028d809adaf79e
commit: 8d6000fe712d525bf767a9fbe7028d809adaf79e [5/5] keys: asymmetric: ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20240522/202405221925.Wje4IgfU-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240522/202405221925.Wje4IgfU-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/202405221925.Wje4IgfU-lkp@intel.com/

All warnings (new ones prefixed by >>):

   crypto/asymmetric_keys/tpm2_key_rsa.c: In function '__tpm2_key_rsa_decrypt':
>> crypto/asymmetric_keys/tpm2_key_rsa.c:273:22: warning: unused variable 'offset' [-Wunused-variable]
     273 |         unsigned int offset = 0;
         |                      ^~~~~~


vim +/offset +273 crypto/asymmetric_keys/tpm2_key_rsa.c

   267	
   268	static int __tpm2_key_rsa_decrypt(struct tpm_chip *chip,
   269					  struct tpm2_key_rsa *key,
   270					  struct kernel_pkey_params *params,
   271					  const void *in, int in_len, void *out)
   272	{
 > 273		unsigned int offset = 0;
   274		u32 key_handle = 0;
   275		struct tpm_buf buf;
   276		u16 decrypted_len;
   277		u32 parent;
   278		u8 *pos;
   279		int ret;
   280	
   281		ret = tpm_try_get_ops(chip);
   282		if (ret)
   283			return ret;
   284	
   285		ret = tpm2_start_auth_session(chip);
   286		if (ret)
   287			goto err_ops;
   288	
   289		parent = key->key.parent;
   290	
   291		ret = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
   292		if (ret < 0)
   293			goto err_auth;
   294	
   295		tpm_buf_append_name(chip, &buf, parent, NULL);
   296		tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_CONTINUE_SESSION |
   297					    TPM2_SA_ENCRYPT, NULL, 0);
   298		tpm_buf_append(&buf, key->key.blob, key->key.blob_len);
   299		if (buf.flags & TPM_BUF_OVERFLOW) {
   300			ret = -E2BIG;
   301			goto err_buf;
   302		}
   303		tpm_buf_fill_hmac_session(chip, &buf);
   304		ret = tpm_transmit_cmd(chip, &buf, 4, "RSA key loading");
   305		ret = tpm_buf_check_hmac_response(chip, &buf, ret);
   306		if (ret) {
   307			ret = -EIO;
   308			goto err_buf;
   309		}
   310		key_handle = be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE]);
   311	
   312		tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_RSA_DECRYPT);
   313		tpm_buf_append_name(chip, &buf, key_handle, NULL);
   314		tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT, NULL, 0);
   315		tpm_buf_append_u16(&buf, in_len);
   316		tpm_buf_append(&buf, in, in_len);
   317		tpm_buf_append_u16(&buf, TPM_ALG_NULL);
   318		tpm_buf_append_u16(&buf, 0);
   319		tpm_buf_fill_hmac_session(chip, &buf);
   320		ret = tpm_transmit_cmd(chip, &buf, 4, "RSA key decrypting");
   321		ret = tpm_buf_check_hmac_response(chip, &buf, ret);
   322		if (ret) {
   323			ret = -EIO;
   324			goto err_blob;
   325		}
   326	
   327		pos = buf.data + TPM_HEADER_SIZE + 4;
   328		decrypted_len = be16_to_cpup((__be16 *)pos);
   329		pos += 2;
   330	
   331		if (params->out_len < decrypted_len) {
   332			ret = -EMSGSIZE;
   333			goto err_blob;
   334		}
   335	
   336		memcpy(out, pos, decrypted_len);
   337		ret = decrypted_len;
   338	
   339	err_blob:
   340		tpm2_flush_context(chip, key_handle);
   341	
   342	err_buf:
   343		tpm_buf_destroy(&buf);
   344	
   345	err_auth:
   346		if (ret < 0)
   347			tpm2_end_auth_session(chip);
   348	
   349	err_ops:
   350		tpm_put_ops(chip);
   351		return ret;
   352	}
   353	

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