Re: For snapshot builds: armv7 chroot on aarch64 has kyua test -k /usr/tests/Kyuafile sys/kern/kern_copyin hung up [in getpid?], unkillable, prevents reboot

From: Mike Karels <mike_at_karels.net>
Date: Fri, 07 Jul 2023 13:50:37 UTC 
On 7 Jul 2023, at 6:06, John F Carr wrote:

> On Jul 6, 2023, at 20:42, Mike Karels <mike@karels.net> wrote:
>>
>>
>> Thanks for isolating this.  Let me know when you have the bug number.
>> I just tested a fix (the compat code drops the reference on the current
>> address space an extra time, probably freeing it).
>>
>> Mike

The fix is in https://cgit.freebsd.org/src/commit/?id=be30fd3ab2e8418a696e69f54a91a7e2db5962de.

> The bug was introduced in January, 2022.   It allows 32 bit binaries to crash a 64 bit system when COMPAT_FREEBSD32 is on.  Test coverage of the buggy function (sysctl_kern_proc_vm_layout) was added at the same time.
>
> There should be routine runs of 32 bit test suites on 64 bit systems.  Although i386 and armv7 are tier 2 systems, the tier 1 COMPAT_FREEBSD32 kernel code needs to be exercised.  This bug was only discovered by manually running tests in the right environment, 17 months after automated testing could have discovered it.

That is not so simple currently, as the shared libraries for the
test environment are not part of 32-bit compatibility package.
The required bits could be extracted from the corresponding 32-bit
build, but that isn't easy to automate.  Fortunately, I think that
very few of the tests exercise any 32-bit-specific code paths.

		Mike