From 7c02b0055f774ed9afb6e1c7724f33bf148ffdc0 Mon Sep 17 00:00:00 2001 From: Coly Li Date: Sat, 1 Feb 2020 22:42:32 +0800 Subject: [PATCH] bcache: explicity type cast in bset_bkey_last() 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 Signed-off-by: Coly Li Signed-off-by: Jens Axboe --- 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 c71365e7c1fa..a50dcfda656f 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) {