Re: [PATCH 03/23] y2038: vdso: change timeval to __kernel_old_timeval

[Thomas Gleixner]

On Fri, 8 Nov 2019, Arnd Bergmann wrote:

> The gettimeofday() function in vdso uses the traditional 'timeval'
> structure layout, which will be incompatible with future versions of
> glibc on 32-bit architectures that use a 64-bit time_t.
> 
> This interface is problematic for y2038, when time_t overflows on 32-bit
> architectures, but the plan so far is that a libc with 64-bit time_t
> will not call into the gettimeofday() vdso helper at all, and only
> have a method for entering clock_gettime().  This means we don't have
> to fix it here, though we probably want to add a new clock_gettime()
> entry point using a 64-bit version of 'struct timespec' at some point.
> 
> Changing the vdso code to use __kernel_old_timeval helps isolate
> this usage from the other ones that still need to be fixed properly,
> and it gets us closer to removing the 'timeval' definition from the
> kernel sources.
> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>