From: Lukasz Czapnik In ice_sched_bw_to_rl_profile(), the loop over 64 bits computes the scheduler timestamp rate as: ts_rate = div64_long((s64)hw->psm_clk_freq, pow_result * ICE_RL_PROF_TS_MULTIPLIER); where pow_result = BIT_ULL(i). For large values of i, the product pow_result * ICE_RL_PROF_TS_MULTIPLIER overflows u64 before being used as the divisor, producing incorrect ts_rate values and potentially undefined behaviour. Fix this by pre-computing ts_freq = hw->psm_clk_freq / ICE_RL_PROF_TS_MULTIPLIER once before the loop and then dividing only by pow_result inside the loop. The division order avoids the overflow while preserving the same mathematical result. Declare ts_freq as s64 to match the type domain of the surrounding arithmetic and avoid a redundant cast at the use site. While at it, scope the loop variable i to the for statement itself. Fixes: 1ddef455f4a8 ("ice: Add NDO callback to set the maximum per-queue bitrate") Signed-off-by: Lukasz Czapnik Signed-off-by: Aleksandr Loktionov --- drivers/net/ethernet/intel/ice/ice_sched.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_sched.c b/drivers/net/ethernet/intel/ice/ice_sched.c index fff0c1a..edea262c 100644 --- a/drivers/net/ethernet/intel/ice/ice_sched.c +++ b/drivers/net/ethernet/intel/ice/ice_sched.c @@ -3237,12 +3237,12 @@ static int ice_sched_bw_to_rl_profile(struct ice_hw *hw, u32 bw, struct ice_aqc_rl_profile_elem *profile) { + s64 ts_freq = hw->psm_clk_freq / ICE_RL_PROF_TS_MULTIPLIER; s64 bytes_per_sec, ts_rate, mv_tmp; int status = -EINVAL; bool found = false; s32 encode = 0; s64 mv = 0; - s32 i; /* Bw settings range is from 0.5Mb/sec to 100Gb/sec */ if (bw < ICE_SCHED_MIN_BW || bw > ICE_SCHED_MAX_BW) @@ -3255,8 +3255,7 @@ ice_sched_bw_to_rl_profile(struct ice_hw *hw, u32 bw, - for (i = 0; i < 64; i++) { + for (int i = 0; i < 64; i++) { u64 pow_result = BIT_ULL(i); - ts_rate = div64_long((s64)hw->psm_clk_freq, - pow_result * ICE_RL_PROF_TS_MULTIPLIER); + ts_rate = div64_long(ts_freq, pow_result); if (ts_rate <= 0) continue; -- 2.52.0