lkml.org 
[lkml]   [2020]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL 5.5 510/542] bcache: explicity type cast in bset_bkey_last()
    Date
    From: Coly Li <colyli@suse.de>

    [ Upstream commit 7c02b0055f774ed9afb6e1c7724f33bf148ffdc0 ]

    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: kbuild test robot <lkp@intel.com>
    Signed-off-by: Coly Li <colyli@suse.de>
    Signed-off-by: Jens Axboe <axboe@kernel.dk>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/md/bcache/bset.h | 3 ++-
    1 file changed, 2 insertions(+), 1 deletion(-)

    diff --git a/drivers/md/bcache/bset.h b/drivers/md/bcache/bset.h
    index c71365e7c1fac..a50dcfda656f5 100644
    --- a/drivers/md/bcache/bset.h
    +++ b/drivers/md/bcache/bset.h
    @@ -397,7 +397,8 @@ void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *state);

    /* Bkey utility code */

    -#define bset_bkey_last(i) bkey_idx((struct bkey *) (i)->d, (i)->keys)
    +#define bset_bkey_last(i) bkey_idx((struct bkey *) (i)->d, \
    + (unsigned int)(i)->keys)

    static inline struct bkey *bset_bkey_idx(struct bset *i, unsigned int idx)
    {
    --
    2.20.1
    \
     
     \ /
      Last update: 2020-02-14 18:49    [W:4.041 / U:0.224 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site