For 82599, QBRC is a 36-bit clear-on-read counter, while
QPRC is a 32-bit clear-on-read counter. ixgbe_read_stats_registers()
accumulates QBRC in a 64-bit software counter and, when CRC stripping
is disabled, subtracts the CRC bytes accounted for each received packet.
The CRC adjustment is computed as:
delta_qprc * RTE_ETHER_CRC_LEN
Since delta_qprc is 32-bit, the multiplication is performed in 32 bits
and may wrap before the result is subtracted from the 64-bit QBRC
accumulator. A full 32-bit packet delta needs more than 32 bits to
represent the CRC-byte adjustment.
Cast delta_qprc to uint64_t before the multiplication so the adjustment
is computed with the same effective width as the byte counter.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: c03fcee9abbd ("ixgbe: remove CRC size from byte counters")
Cc: [email protected]
Signed-off-by: Daniil Iskhakov <[email protected]>
---
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
drivers/net/intel/ixgbe/ixgbe_ethdev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/intel/ixgbe/ixgbe_ethdev.c
b/drivers/net/intel/ixgbe/ixgbe_ethdev.c
index 57d929cf2c..c17ce70810 100644
--- a/drivers/net/intel/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/intel/ixgbe/ixgbe_ethdev.c
@@ -3237,7 +3237,7 @@ ixgbe_read_stats_registers(struct ixgbe_hw *hw,
hw_stats->qbrc[i] +=
((uint64_t)IXGBE_READ_REG(hw, IXGBE_QBRC_H(i)) << 32);
if (crc_strip == 0)
- hw_stats->qbrc[i] -= delta_qprc * RTE_ETHER_CRC_LEN;
+ hw_stats->qbrc[i] -= (uint64_t)delta_qprc *
RTE_ETHER_CRC_LEN;
hw_stats->qbtc[i] += IXGBE_READ_REG(hw, IXGBE_QBTC_L(i));
hw_stats->qbtc[i] +=
--
2.43.0
