Re: port binary dumping core on recent head in poudriere [tmpfs corruptions involving blocks of zeros that should not be all zeros]

Mark Millard <marklmi@yahoo.com> writes:
> From inside a bulk -i where I did a manual make command
> after it built and installed libsass.so.1.0.0 . The
> manual make produced a /wrkdirs/ :
> [...]
> So the original creation looks okay. But . . .
> [...]
> So: The later, staged copy is a bad copy. Both are in the
> tmpfs. So copying to the staging area makes a corrupted
> copy inside the same tmpfs. After that, further copies of
> staging's bad copy can be expected to be messed up.

This and the fact that it happens on 14 and 15 but not on 13 strongly
suggests an issue wth `copy_file_range(2)`, since `install(1)` in 14 and
15 (but not in 13) now uses `copy_file_range(2)` if at all possible.

My educated guess is that hole detection doesn't work reliably for files
that have had holes filled while memory-mapped, so `copy_file_range(2)`
thinks there is a hole where there isn't one and skips some of the data
when `install(1)` uses it to copy the library from `${WRKSRC}` to
`${STAGEDIR}`.  This may or may not be specific to tmpfs.

You may want to try applying the attached patch to your FreeBSD 14 and
15 jails.  It prevents `cp(1)` and `install(1)` from trying to use
`copy_file_range(2)`.

DES
-- 
Dag-Erling Smørgrav - des@FreeBSD.org