From: Sergey Temerkhanov ptp.cached_phc_time is a 64-bit value updated by a periodic work item on one CPU and read locklessly on another. On 32-bit or non-atomic architectures this can result in a torn read. Use READ_ONCE() to enforce a single atomic load. Fixes: 77a781155a65 ("ice: enable receive hardware timestamping") Cc: stable@vger.kernel.org Signed-off-by: Sergey Temerkhanov Signed-off-by: Aleksandr Loktionov Reviewed-by: Simon Horman Tested-by: Rinitha S (A Contingent worker at Intel) Signed-off-by: Tony Nguyen --- drivers/net/ethernet/intel/ice/ice_ptp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c index ec3d89d8d4d3..1469038bc895 100644 --- a/drivers/net/ethernet/intel/ice/ice_ptp.c +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c @@ -346,7 +346,7 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp) return 0; } - return ice_ptp_extend_32b_ts(pf->ptp.cached_phc_time, + return ice_ptp_extend_32b_ts(READ_ONCE(pf->ptp.cached_phc_time), (in_tstamp >> 8) & mask); } -- 2.47.1