drivers/crypto/sa2ul.c:1674:6: warning: variable 'auth_len' set but not used

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   231bc539066760aaa44d46818c85b14ca2f56d9f
commit: 00c9211f60db2dead16856f81a3e6ab86b31f275 crypto: sa2ul - Fix DMA mapping API usage
date:   8 months ago
config: arm64-randconfig-r005-20210601 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project d41cb6bb2607fa5c7a9df2b3dab361353657d225)
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
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=00c9211f60db2dead16856f81a3e6ab86b31f275
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 00c9211f60db2dead16856f81a3e6ab86b31f275
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

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

All warnings (new ones prefixed by >>):

>> drivers/crypto/sa2ul.c:1674:6: warning: variable 'auth_len' set but not used [-Wunused-but-set-variable]
           u16 auth_len;
               ^
   1 warning generated.


vim +/auth_len +1674 drivers/crypto/sa2ul.c

2dc53d0047458e2 Keerthy        2020-07-13  1662  
d2c8ac187fc922e Keerthy        2020-07-13  1663  static void sa_aead_dma_in_callback(void *data)
d2c8ac187fc922e Keerthy        2020-07-13  1664  {
d2c8ac187fc922e Keerthy        2020-07-13  1665  	struct sa_rx_data *rxd = (struct sa_rx_data *)data;
d2c8ac187fc922e Keerthy        2020-07-13  1666  	struct aead_request *req;
d2c8ac187fc922e Keerthy        2020-07-13  1667  	struct crypto_aead *tfm;
d2c8ac187fc922e Keerthy        2020-07-13  1668  	unsigned int start;
d2c8ac187fc922e Keerthy        2020-07-13  1669  	unsigned int authsize;
d2c8ac187fc922e Keerthy        2020-07-13  1670  	u8 auth_tag[SA_MAX_AUTH_TAG_SZ];
d2c8ac187fc922e Keerthy        2020-07-13  1671  	size_t pl, ml;
00c9211f60db2de Peter Ujfalusi 2020-09-23  1672  	int i;
d2c8ac187fc922e Keerthy        2020-07-13  1673  	int err = 0;
d2c8ac187fc922e Keerthy        2020-07-13 @1674  	u16 auth_len;
d2c8ac187fc922e Keerthy        2020-07-13  1675  	u32 *mdptr;
d2c8ac187fc922e Keerthy        2020-07-13  1676  
00c9211f60db2de Peter Ujfalusi 2020-09-23  1677  	sa_sync_from_device(rxd);
d2c8ac187fc922e Keerthy        2020-07-13  1678  	req = container_of(rxd->req, struct aead_request, base);
d2c8ac187fc922e Keerthy        2020-07-13  1679  	tfm = crypto_aead_reqtfm(req);
d2c8ac187fc922e Keerthy        2020-07-13  1680  	start = req->assoclen + req->cryptlen;
d2c8ac187fc922e Keerthy        2020-07-13  1681  	authsize = crypto_aead_authsize(tfm);
d2c8ac187fc922e Keerthy        2020-07-13  1682  
d2c8ac187fc922e Keerthy        2020-07-13  1683  	mdptr = (u32 *)dmaengine_desc_get_metadata_ptr(rxd->tx_in, &pl, &ml);
d2c8ac187fc922e Keerthy        2020-07-13  1684  	for (i = 0; i < (authsize / 4); i++)
d2c8ac187fc922e Keerthy        2020-07-13  1685  		mdptr[i + 4] = swab32(mdptr[i + 4]);
d2c8ac187fc922e Keerthy        2020-07-13  1686  
d2c8ac187fc922e Keerthy        2020-07-13  1687  	auth_len = req->assoclen + req->cryptlen;
d2c8ac187fc922e Keerthy        2020-07-13  1688  
d2c8ac187fc922e Keerthy        2020-07-13  1689  	if (rxd->enc) {
d2c8ac187fc922e Keerthy        2020-07-13  1690  		scatterwalk_map_and_copy(&mdptr[4], req->dst, start, authsize,
d2c8ac187fc922e Keerthy        2020-07-13  1691  					 1);
d2c8ac187fc922e Keerthy        2020-07-13  1692  	} else {
00c9211f60db2de Peter Ujfalusi 2020-09-23  1693  		auth_len -= authsize;
d2c8ac187fc922e Keerthy        2020-07-13  1694  		start -= authsize;
d2c8ac187fc922e Keerthy        2020-07-13  1695  		scatterwalk_map_and_copy(auth_tag, req->src, start, authsize,
d2c8ac187fc922e Keerthy        2020-07-13  1696  					 0);
d2c8ac187fc922e Keerthy        2020-07-13  1697  
d2c8ac187fc922e Keerthy        2020-07-13  1698  		err = memcmp(&mdptr[4], auth_tag, authsize) ? -EBADMSG : 0;
d2c8ac187fc922e Keerthy        2020-07-13  1699  	}
d2c8ac187fc922e Keerthy        2020-07-13  1700  
00c9211f60db2de Peter Ujfalusi 2020-09-23  1701  	sa_free_sa_rx_data(rxd);
d2c8ac187fc922e Keerthy        2020-07-13  1702  
d2c8ac187fc922e Keerthy        2020-07-13  1703  	aead_request_complete(req, err);
d2c8ac187fc922e Keerthy        2020-07-13  1704  }
d2c8ac187fc922e Keerthy        2020-07-13  1705  

:::::: The code at line 1674 was first introduced by commit
:::::: d2c8ac187fc922e73930a1b2f6a211e27f595d01 crypto: sa2ul - Add AEAD algorithm support

:::::: TO: Keerthy <j-keerthy@xxxxxx>
:::::: CC: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>

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

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