net/netfilter/nft_set_pipapo_avx2.c:1052:17: warning: variable 'lt' set but not used

From: kernel test robot
Date: Tue Nov 16 2021 - 20:27:34 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 8ab774587903771821b59471cc723bba6d893942
commit: 7400b063969bdca4a06cd97f1294d765c8eecbe1 nft_set_pipapo: Introduce AVX2-based lookup implementation
date: 1 year, 8 months ago
config: x86_64-randconfig-r006-20211116 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project fbe72e41b99dc7994daac300d208a955be3e4a0a)
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
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7400b063969bdca4a06cd97f1294d765c8eecbe1
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 7400b063969bdca4a06cd97f1294d765c8eecbe1
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=x86_64

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

All warnings (new ones prefixed by >>):

>> net/netfilter/nft_set_pipapo_avx2.c:1052:17: warning: variable 'lt' set but not used [-Wunused-but-set-variable]
unsigned long *lt = f->lt, bsize = f->bsize;
^
1 warning generated.


vim +/lt +1052 net/netfilter/nft_set_pipapo_avx2.c

1030
1031 /**
1032 * nft_pipapo_avx2_lookup_slow() - Fallback function for uncommon field sizes
1033 * @map: Previous match result, used as initial bitmap
1034 * @fill: Destination bitmap to be filled with current match result
1035 * @f: Field, containing lookup and mapping tables
1036 * @offset: Ignore buckets before the given index, no bits are filled there
1037 * @pkt: Packet data, pointer to input nftables register
1038 * @first: If this is the first field, don't source previous result
1039 * @last: Last field: stop at the first match and return bit index
1040 *
1041 * This function should never be called, but is provided for the case the field
1042 * size doesn't match any of the known data types. Matching rate is
1043 * substantially lower than AVX2 routines.
1044 *
1045 * Return: -1 on no match, rule index of match if @last, otherwise first long
1046 * word index to be checked next (i.e. first filled word).
1047 */
1048 static int nft_pipapo_avx2_lookup_slow(unsigned long *map, unsigned long *fill,
1049 struct nft_pipapo_field *f, int offset,
1050 const u8 *pkt, bool first, bool last)
1051 {
> 1052 unsigned long *lt = f->lt, bsize = f->bsize;
1053 int i, ret = -1, b;
1054
1055 lt += offset * NFT_PIPAPO_LONGS_PER_M256;
1056
1057 if (first)
1058 memset(map, 0xff, bsize * sizeof(*map));
1059
1060 for (i = offset; i < bsize; i++) {
1061 if (f->bb == 8)
1062 pipapo_and_field_buckets_8bit(f, map, pkt);
1063 else
1064 pipapo_and_field_buckets_4bit(f, map, pkt);
1065 NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4;
1066
1067 b = pipapo_refill(map, bsize, f->rules, fill, f->mt, last);
1068
1069 if (last)
1070 return b;
1071
1072 if (ret == -1)
1073 ret = b / XSAVE_YMM_SIZE;
1074 }
1075
1076 return ret;
1077 }
1078

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

Attachment: .config.gz
Description: application/gzip