diff options
| author | Colin Ian King <colin.king@canonical.com> | 2019-06-07 19:19:20 +0100 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2019-06-28 15:59:38 -0700 |
| commit | b97c0b521ae05d40e6541858600088a30f6dbe3a (patch) | |
| tree | 09b7b457bf1287f84cf3965d985e37ba2843d759 /drivers/net/ethernet/intel/ixgbe | |
| parent | 92924064106e410cdc015f1dbfc0499309f9f5b1 (diff) | |
ixgbe: fix potential u32 overflow on shift
The u32 variable rem is being shifted using u32 arithmetic however
it is being passed to div_u64 that expects the expression to be a u64.
The 32 bit shift may potentially overflow, so cast rem to a u64 before
shifting to avoid this. Also remove comment about overflow.
Addresses-Coverity: ("Unintentional integer overflow")
Fixes: cd4583206990 ("ixgbe: implement support for SDP/PPS output on X550 hardware")
Fixes: 68d9676fc04e ("ixgbe: fix PTP SDP pin setup on X540 hardware")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/ixgbe')
| -rw-r--r-- | drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c index 2c4d327fcc2e..0be13a90ff79 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c @@ -205,11 +205,8 @@ static void ixgbe_ptp_setup_sdp_X540(struct ixgbe_adapter *adapter) */ rem = (NS_PER_SEC - rem); - /* Adjust the clock edge to align with the next full second. This - * assumes that the cycle counter shift is small enough to avoid - * overflowing when shifting the remainder. - */ - clock_edge += div_u64((rem << cc->shift), cc->mult); + /* Adjust the clock edge to align with the next full second. */ + clock_edge += div_u64(((u64)rem << cc->shift), cc->mult); trgttiml = (u32)clock_edge; trgttimh = (u32)(clock_edge >> 32); @@ -291,11 +288,8 @@ static void ixgbe_ptp_setup_sdp_X550(struct ixgbe_adapter *adapter) */ rem = (NS_PER_SEC - rem); - /* Adjust the clock edge to align with the next full second. This - * assumes that the cycle counter shift is small enough to avoid - * overflowing when shifting the remainder. - */ - clock_edge += div_u64((rem << cc->shift), cc->mult); + /* Adjust the clock edge to align with the next full second. */ + clock_edge += div_u64(((u64)rem << cc->shift), cc->mult); /* X550 hardware stores the time in 32bits of 'billions of cycles' and * 32bits of 'cycles'. There's no guarantee that cycles represents |