• Coly Li's avatar
    bcache: explicity type cast in bset_bkey_last() · 328c1eab
    Coly Li authored
    [ Upstream commit 7c02b005 ]
    
    In bset.h, macro bset_bkey_last() is defined as,
        bkey_idx((struct bkey *) (i)->d, (i)->keys)
    
    Parameter i can be variable type of data structure, the macro always
    works once the type of struct i has member 'd' and 'keys'.
    
    bset_bkey_last() is also used in macro csum_set() to calculate the
    checksum of a on-disk data structure. When csum_set() is used to
    calculate checksum of on-disk bcache super block, the parameter 'i'
    data type is struct cache_sb_disk. Inside struct cache_sb_disk (also in
    struct cache_sb) the member keys is __u16 type. But bkey_idx() expects
    unsigned int (a 32bit width), so there is problem when sending
    parameters via stack to call bkey_idx().
    
    Sparse tool from Intel 0day kbuild system reports this incompatible
    problem. bkey_idx() is part of user space API, so the simplest fix is
    to cast the (i)->keys to unsigned int type in macro bset_bkey_last().
    Reported-by: default avatarkbuild test robot <[email protected]>
    Signed-off-by: default avatarColy Li <[email protected]>
    Signed-off-by: default avatarJens Axboe <[email protected]>
    Signed-off-by: default avatarSasha Levin <[email protected]>
    328c1eab
bset.h 19.1 KB