Re: [PATCH v3] Define in_int32_t_range to check if the 64 bit time_t syscall should be used

[Florian Weimer <fweimer@redhat.com>]

* Arnd Bergmann:

> On Tue, Nov 8, 2022, at 05:49, YunQiang Su wrote:
>> Currently glibc uses in_time_t_range to detects time_t overflow,
>> and if it occurs fallbacks to 64 bit syscall version.
>>
>> The function name is confusing because internally time_t might be
>> either 32 bits or 64 bits (depending on __TIMESIZE).
>>
>> This patch refactors the in_time_t_range by replacing it with
>> in_int32_t_range for the case to check if the 64 bit time_t syscall
>> should be used.
>>
>> The in_time_t range is used to detect overflow of the
>> syscall return value.
>
> It looks like the fallback logic has another flaw, I don't
> see how this works on kernels with COMPAT_32BIT_TIME disabled,
> as these only have the time64 syscalls available.

Isn't that an invalid kernel configuration?

Thanks,
Florian