Re: [PATCH] ntp: fix bug in adjtimex reading time offset
From: Thomas Gleixner
Date: Wed Nov 27 2024 - 12:39:38 EST
On Wed, Nov 27 2024 at 18:35, Thomas Gleixner wrote:
> On Wed, Nov 27 2024 at 08:05, Richard Cochran wrote:
>> On Wed, Nov 27, 2024 at 03:10:30PM +0100, Thomas Gleixner wrote:
>> The patch was generated by the following coccinelle script:
>>
>> ...
>>
>> So I guess combining random other manual fixes into a patch that
>> claims to be generated is a bad idea?
>
> Indeed. I just figured out why the cast is there. txc::time_offset is of
> type 'long long', so the division triggers a build fail on 32-bit.
>
> It want's to be:
>
> txc->time_offset = div_s64(txc->time_offset, NSEC_PER_USEC);
Or simpler by using a (s32) cast instead, which is sufficient as
time_offset must be in the range of [INT_MIN ... INT_MAX] because
NTP_SCALE_SHIFT is 32.