Messages in this thread Patch in this message | | | Date | Fri, 08 Nov 2019 15:33:24 +0800 | Subject | [PATCH] psi:fix divide by zero in psi_update_stats | From | tim <> |
| |
In psi_update_stats, it is possible that period has value like 0xXXXXXXXX00000000 where the lower 32 bit is 0, then it calls div_u64 which truncates u64 period to u32, results in zero divisor. Use div64_u64() instead of div_u64() if the divisor is u64 to avoid truncation to 32-bit on 64-bit platforms.
Signed-off-by: xiejingfeng <xiejingfeng@linux.alibaba.com> --- kernel/sched/psi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 517e3719027e..399d6f106de5 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -291,7 +291,7 @@ static void calc_avgs(unsigned long avg[3], int missed_periods, } /* Sample the most recent active period */ - pct = div_u64(time * 100, period); + pct = div64_u64(time * 100, period); pct *= FIXED_1; avg[0] = calc_load(avg[0], EXP_10s, pct); avg[1] = calc_load(avg[1], EXP_60s, pct); -- 2.14.4.44.g2045bb
| |