Fourth draft of the Y2038 design document

[Joseph Myers]

On Wed, 22 Jun 2016, Arnd Bergmann wrote:

> Regarding the "Support for non-Y2038-safe kernels" section, I'm not
> sure if that can work at all: A kernel that does not have the appropriate
> system calls will also not have the handlers for a lot of the ioctl
> commands and possibly other interfaces that rely on a specific
> structure layout. If we can instead enforce that __USE_TIME_BITS64

Maybe it's hard for ioctls, but I see no reason it shouldn't work for 
applications using normal non-ioctl glibc interfaces, with runtime 
fallbacks in glibc such as have been used for plenty of previous kernel 
features.

Of course eventually we remove support for the older kernels - when they 
are no longer on the list at https://www.kernel.org/category/releases.html 
unless something comes up like the issue with people expecting to use new 
glibc on old virtualization solutions only supporting 2.6.32 kernels - but 
it would be good for people and distributions to be using / testing 
_TIME_BITS=64 before they reach the point of ceasing to support any older 
kernels.

-- 
Joseph S. Myers
joseph@codesourcery.com