Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Systems with lots of geom providers can end up with a kern.geom.confxml
value too large for the buffer allocated. Work around this by retrying
a few times with larger buffer sizes.

Submitted by: Scott Ferris <scott.ferris@isilon.com>
Reviewed by: mlaier, ngie
Sponsored by: EMC Isilon Storage Division

Add missing `void' keyword.

- Simplify the procedure of retrieving XML-data from the kernel.
- Fix a number of potential memory leaks in libgeom related to doing realloc
without freeing old pointer if things go wrong.
- Fix a number of places in libgeom where malloc and calloc return values
were not checked.
- Check malloc return value and provide sufficient warning messages when XML
parsing fails.

PR: kern/83464
Submitted by: Dan Lukes <dan - at - obluda.cz>
Approved by: kib (mentor)

Second call of sysctl() is used to gather a proper size of a memory chunk
needed to hold the GEOM tree. At this point, pointer 'p' has an improper
value (as it was used previously), and we're getting EFAULT. Fix this
functionality by passing NULL instead of 'p'.

This fixes mdconfig(8) -l output with high number of md(4) devices.

Found by: kris
Reviewed by: phk

Leak more stuff into libgeom.