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[PULL,4/5] migration: Define BLK_MIG_BLOCK_SIZE as unsigned long long

Message ID 20220802155447.216018-5-dgilbert@redhat.com
State Accepted
Commit 4bcb7de072fd8ab9de40b24aac00c7b6659f7f7d
Headers show
Series None | expand

Commit Message

Dr. David Alan Gilbert Aug. 2, 2022, 3:54 p.m. UTC 
From: Peter Maydell <peter.maydell@linaro.org>

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.maydell@linaro.org>
Message-Id: <20220721115207.729615-3-peter.maydell@linaro.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/block.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/migration/block.c b/migration/block.c
index 9e5aae5898..3577c815a9 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