Re: [Y2038] [PATCH 01/23] y2038: remove CONFIG_64BIT_TIME

From: Dmitry Safonov
Date: Wed Nov 20 2019 - 17:58:35 EST


On 11/20/19 10:28 PM, Ben Hutchings wrote:
> On Fri, 2019-11-08 at 22:07 +0100, Arnd Bergmann wrote:
> [...]
>> --- a/kernel/time/time.c
>> +++ b/kernel/time/time.c
>> @@ -267,7 +267,7 @@ COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
>> }
>> #endif
>>
>> -#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
>> +#ifdef CONFIG_64BIT
>> SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p)
>> {
>> struct __kernel_timex txc; /* Local copy of parameter */
>> @@ -884,7 +884,7 @@ int get_timespec64(struct timespec64 *ts,
>> ts->tv_sec = kts.tv_sec;
>>
>> /* Zero out the padding for 32 bit systems or in compat mode */
>> - if (IS_ENABLED(CONFIG_64BIT_TIME) && in_compat_syscall())
>> + if (in_compat_syscall())
>> kts.tv_nsec &= 0xFFFFFFFFUL;
>>
>> ts->tv_nsec = kts.tv_nsec;
> [...]
>
> It's not a problem with this patch, but I noticed that this condition
> doesn't match what the comment says. It looks like it was broken by:
>
> commit 98f76206b33504b934209d16196477dfa519a807
> Author: Dmitry Safonov <dima@xxxxxxxxxx>
> Date: Fri Oct 12 14:42:53 2018 +0100
>
> compat: Cleanup in_compat_syscall() callers
>

Ugh, you right. I've failed to read the condition and thought it's
related to CONFIG_COMPAT :(
I'll send a fix shortly, thanks for spotting this!

--
Dmitry