When we use BLK_MIG_BLOCK_SIZE in expressions like block_mig_state.submitted * BLK_MIG_BLOCK_SIZE, this multiplication is done as 32 bits, because both operands are 32 bits. Coverity complains about possible overflows because we then accumulate that into a 64 bit variable.
Define BLK_MIG_BLOCK_SIZE as unsigned long long using the ULL suffix. The only two current uses of it with this problem are both in block_save_pending(), so we could just cast to uint64_t there, but using the ULL suffix is simpler and ensures that we don't accidentally introduce new variants of the same issue in future. Resolves: Coverity CID 1487136, 1487175 Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> --- I haven't tried to analyse the code to see if the multiplications could ever actually end up overflowing, but I would assume probably not. migration/block.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/migration/block.c b/migration/block.c index 9e5aae58982..3577c815a94 100644 --- a/migration/block.c +++ b/migration/block.c @@ -28,7 +28,7 @@ #include "sysemu/block-backend.h" #include "trace.h" -#define BLK_MIG_BLOCK_SIZE (1 << 20) +#define BLK_MIG_BLOCK_SIZE (1ULL << 20) #define BDRV_SECTORS_PER_DIRTY_CHUNK (BLK_MIG_BLOCK_SIZE >> BDRV_SECTOR_BITS) #define BLK_MIG_FLAG_DEVICE_BLOCK 0x01 -- 2.25.1