[PULL 05/20] hw/net/can/flexcan: Use mbs[] array for FIFO pop

From: Bernhard Beschow <[email protected]>

Implement FIFO entry shifting using the underlying `mbs[]` array instead
of the overlapping `fifo` union view. This makes it explicit that the
operation copies within a contiguous mailbox array and avoids Coverity
CID 1662971.

Reported-by: Peter Maydell <[email protected]>
Signed-off-by: Bernhard Beschow <[email protected]>
Tested-by: Pavel Pisa <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
---
 hw/net/can/flexcan.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/hw/net/can/flexcan.c b/hw/net/can/flexcan.c
index da36d10bd33..3a97edf7a4d 100644
--- a/hw/net/can/flexcan.c
+++ b/hw/net/can/flexcan.c
@@ -879,22 +879,22 @@ static bool flexcan_can_receive(CanBusClientState *client)
  */
 static void flexcan_fifo_pop(FlexcanState *s)
 {
-    if (s->regs.fifo.mb_back.can_ctrl != 0) {
+    if (s->regs.mbs[0].can_ctrl != 0) {
         /* move queue elements forward */
-        memmove(&s->regs.fifo.mb_back, &s->regs.fifo.mbs_queue[0],
-                sizeof(s->regs.fifo.mbs_queue));
+        memmove(&s->regs.mbs[0], &s->regs.mbs[1],
+                sizeof(s->regs.mbs[0]) * (FLEXCAN_FIFO_DEPTH - 1));
 
         /* clear the first-in slot */
         memset(&s->regs.mbs[FLEXCAN_FIFO_DEPTH - 1], 0,
                sizeof(FlexcanRegsMessageBuffer));
 
         trace_flexcan_fifo_pop(DEVICE(s)->canonical_path, 1,
-                               s->regs.fifo.mb_back.can_ctrl != 0);
+                               s->regs.mbs[0].can_ctrl != 0);
     } else {
         trace_flexcan_fifo_pop(DEVICE(s)->canonical_path, 0, 0);
     }
 
-    if (s->regs.fifo.mb_back.can_ctrl != 0) {
+    if (s->regs.mbs[0].can_ctrl != 0) {
         flexcan_irq_iflag_set(s, I_FIFO_AVAILABLE);
     } else {
         flexcan_irq_iflag_clear(s, I_FIFO_AVAILABLE);
-- 
2.43.0