On 30/11/2022 09:07:50+0100, Alexander Kanavin wrote:

On Tue, 29 Nov 2022 at 16:45, Stephen Jolley <sjolley.yp.pm@...> wrote:

We’d welcome a proposal/series on how to move forward with the Y2038 work for 32 bit platforms.

I have the following proposal:

1. A branch is made where:
a. "-D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64" is enabled globally.
b. qemu is always started with "-rtc base=2040-01-01", simulating
Y2038 actually occurring.
c. an additional runtime test verifies that both RTC clock and system
clock report 2040.

2. This branch is run through a-full on the autobuilder. Any uncovered
issues are filed as bugs.

I ran a-full with "-D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64" last week, it
didn't go too well gcc-sanitizer and pulseaudio being the main offenders
but buildtools needs to be investigated.

3. Once *all* of the bugs are addressed, repeat point 2.

4. Once there are no more open bugs, 1a is merged into master.

Any fatal flaws in the plan?

It's not hard to see that Y2038 problem is real and serious, e.g. on
qemux86 core-image-full-cmdline built from master:

root@qemux86:~# ls /
bin boot dev etc home lib lost+found media mnt proc
run sbin sys tmp usr var
root@qemux86:~# date -s "2040-01-01"
Sun Jan 1 00:00:00 UTC 2040
root@qemux86:~# ls /
bin boot dev etc home lib lost+found media mnt proc
run sbin sys tmp usr var
root@qemux86:~# ls /
-sh: ls: command not found

On qemux86_64 the same sequence works as expected, of course.

The main issue with the plan is that we are not running tests on 32
qemu anymore.


--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com