Hi Kangjie, Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master] [also build test WARNING on v5.0 next-20190306] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Kangjie-Lu/fs-affs-fix-a-NULL-pointer-dereference/20190314-170334 reproduce: # apt-get install sparse make ARCH=x86_64 allmodconfig make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' sparse warnings: (new ones prefixed by >>) fs/affs/file.c:525:23: sparse: expression using sizeof(void) fs/affs/file.c:525:23: sparse: expression using sizeof(void) fs/affs/file.c:558:23: sparse: expression using sizeof(void) fs/affs/file.c:558:23: sparse: expression using sizeof(void) fs/affs/file.c:577:23: sparse: expression using sizeof(void) fs/affs/file.c:577:23: sparse: expression using sizeof(void) fs/affs/file.c:706:23: sparse: expression using sizeof(void) fs/affs/file.c:706:23: sparse: expression using sizeof(void) fs/affs/file.c:759:23: sparse: expression using sizeof(void) fs/affs/file.c:759:23: sparse: expression using sizeof(void) >> fs/affs/file.c:946:40: sparse: incorrect type in assignment (different base >> types) @@ expected unsigned int [unsigned] [usertype] ext_bk @@ got >> igned] [usertype] ext_bk @@ fs/affs/file.c:946:40: expected unsigned int [unsigned] [usertype] ext_bk fs/affs/file.c:946:40: got restricted __be32 <noident> >> fs/affs/file.c:947:53: sparse: cast to restricted __be32 >> fs/affs/file.c:947:53: sparse: cast to restricted __be32 >> fs/affs/file.c:947:53: sparse: cast to restricted __be32 >> fs/affs/file.c:947:53: sparse: cast to restricted __be32 >> fs/affs/file.c:947:53: sparse: cast to restricted __be32 >> fs/affs/file.c:947:53: sparse: cast to restricted __be32 vim +946 fs/affs/file.c 833 834 void 835 affs_truncate(struct inode *inode) 836 { 837 struct super_block *sb = inode->i_sb; 838 u32 ext, ext_key, ext_bk; 839 u32 last_blk, blkcnt, blk; 840 u32 size; 841 struct buffer_head *ext_bh; 842 int i; 843 844 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n", 845 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size); 846 847 last_blk = 0; 848 ext = 0; 849 if (inode->i_size) { 850 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize; 851 ext = last_blk / AFFS_SB(sb)->s_hashsize; 852 } 853 854 if (inode->i_size > AFFS_I(inode)->mmu_private) { 855 struct address_space *mapping = inode->i_mapping; 856 struct page *page; 857 void *fsdata; 858 loff_t isize = inode->i_size; 859 int res; 860 861 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata); 862 if (!res) 863 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata); 864 else 865 inode->i_size = AFFS_I(inode)->mmu_private; 866 mark_inode_dirty(inode); 867 return; 868 } else if (inode->i_size == AFFS_I(inode)->mmu_private) 869 return; 870 871 // lock cache 872 ext_bh = affs_get_extblock(inode, ext); 873 if (IS_ERR(ext_bh)) { 874 affs_warning(sb, "truncate", 875 "unexpected read error for ext block %u (%ld)", 876 ext, PTR_ERR(ext_bh)); 877 return; 878 } 879 if (AFFS_I(inode)->i_lc) { 880 /* clear linear cache */ 881 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift; 882 if (AFFS_I(inode)->i_lc_size > i) { 883 AFFS_I(inode)->i_lc_size = i; 884 for (; i < AFFS_LC_SIZE; i++) 885 AFFS_I(inode)->i_lc[i] = 0; 886 } 887 /* clear associative cache */ 888 for (i = 0; i < AFFS_AC_SIZE; i++) 889 if (AFFS_I(inode)->i_ac[i].ext >= ext) 890 AFFS_I(inode)->i_ac[i].ext = 0; 891 } 892 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 893 894 blkcnt = AFFS_I(inode)->i_blkcnt; 895 i = 0; 896 blk = last_blk; 897 if (inode->i_size) { 898 i = last_blk % AFFS_SB(sb)->s_hashsize + 1; 899 blk++; 900 } else 901 AFFS_HEAD(ext_bh)->first_data = 0; 902 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i); 903 size = AFFS_SB(sb)->s_hashsize; 904 if (size > blkcnt - blk + i) 905 size = blkcnt - blk + i; 906 for (; i < size; i++, blk++) { 907 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i))); 908 AFFS_BLOCK(sb, ext_bh, i) = 0; 909 } 910 AFFS_TAIL(sb, ext_bh)->extension = 0; 911 affs_fix_checksum(sb, ext_bh); 912 mark_buffer_dirty_inode(ext_bh, inode); 913 affs_brelse(ext_bh); 914 915 if (inode->i_size) { 916 AFFS_I(inode)->i_blkcnt = last_blk + 1; 917 AFFS_I(inode)->i_extcnt = ext + 1; 918 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) { 919 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0); 920 u32 tmp; 921 if (IS_ERR(bh)) { 922 affs_warning(sb, "truncate", 923 "unexpected read error for last block %u (%ld)", 924 ext, PTR_ERR(bh)); 925 return; 926 } 927 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next); 928 AFFS_DATA_HEAD(bh)->next = 0; 929 affs_adjust_checksum(bh, -tmp); 930 affs_brelse(bh); 931 } 932 } else { 933 AFFS_I(inode)->i_blkcnt = 0; 934 AFFS_I(inode)->i_extcnt = 1; 935 } 936 AFFS_I(inode)->mmu_private = inode->i_size; 937 // unlock cache 938 939 while (ext_key) { 940 ext_bh = affs_bread(sb, ext_key); 941 size = AFFS_SB(sb)->s_hashsize; 942 if (size > blkcnt - blk) 943 size = blkcnt - blk; 944 if (ext_bh) { 945 for (i = 0; i < size; i++, blk++) { > 946 ext_bk = AFFS_BLOCK(sb, ext_bh, i); > 947 affs_free_block(sb, > be32_to_cpu(ext_bk)); 948 } 949 } 950 affs_free_block(sb, ext_key); 951 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension); 952 affs_brelse(ext_bh); 953 } 954 affs_free_prealloc(inode); 955 } 956 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
