On Sat, Apr 26, 2025 at 04:42:31PM +0300, Fedor Pchelkin wrote:
Currently the difference is computed on 32-bit unsigned values although eventually it is stored in a variable of int64_t type. This gives awkward results, e.g. when the diff _should_ be negative, it is represented as some large positive int64_t value.
Perform the calculations directly in int64_t as all other diff_two_keys routines actually do.
Found by Linux Verification Center (linuxtesting.org) with Svace static analysis tool.
Fixes: 08438b1e386b ("xfs: plumb in needed functions for range querying of the freespace btrees") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin pchelkin@ispras.ru
fs/xfs/libxfs/xfs_alloc_btree.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c index a4ac37ba5d51..b3c54ae90e25 100644 --- a/fs/xfs/libxfs/xfs_alloc_btree.c +++ b/fs/xfs/libxfs/xfs_alloc_btree.c @@ -238,13 +238,13 @@ xfs_cntbt_diff_two_keys( ASSERT(!mask || (mask->alloc.ar_blockcount && mask->alloc.ar_startblock));
- diff = be32_to_cpu(k1->alloc.ar_blockcount) -
be32_to_cpu(k2->alloc.ar_blockcount);
- diff = (int64_t)be32_to_cpu(k1->alloc.ar_blockcount) -
be32_to_cpu(k2->alloc.ar_blockcount);
Perhaps it's time to hoist cmp_int to include/ and refactor all these things to use it?
#define cmp_int(l, r) ((l > r) - (l < r))
--D
if (diff) return diff;
- return be32_to_cpu(k1->alloc.ar_startblock) -
be32_to_cpu(k2->alloc.ar_startblock);
- return (int64_t)be32_to_cpu(k1->alloc.ar_startblock) -
be32_to_cpu(k2->alloc.ar_startblock);} static xfs_failaddr_t -- 2.49.0