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

MFC 303002: Include process IDs in core dumps.

When threads were added to the kernel, the pr_pid member of the
NT_PRSTATUS note was repurposed to store LWP IDs instead of process
IDs. However, the process ID was no longer recorded in core dumps.
This change adds a pr_pid field to prpsinfo (NT_PRSINFO). Rather than
bumping the prpsinfo version number, note parsers can use the note's
payload size to determine if pr_pid is present.

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

Remove THRMISC_VERSION. The thrmisc structure doesn't include a version
number, so this wasn't used (and can't easily be added). If at some point
we want to extend thrmisc, we will probably need to just add a new note
type and ensure that the new type includes a version number.

Discussed with: kib
MFC after: 2 weeks

Move the 32-bit compatible procfs types from freebsd32.h to <sys/procfs.h>
and export them to userland.
- Define __HAVE_REG32 on platforms that define a reg32 structure and check
for this in <sys/procfs.h> to control when to export prstatus32, etc.
- Add prstatus32_t and prpsinfo32_t typedefs for the 32-bit structures.
libbfd looks for these types, and having them fixes 'gcore' in gdb of a
32-bit process on a 64-bit platform.
- Use the structure definitions from <sys/procfs.h> in gcore's elf32 core
dump code instead of duplicating the definitions.

Differential Revision: https://reviews.freebsd.org/D2142
Reviewed by: kib, nathanw (powerpc bits)
MFC after: 1 week

Add the ability for GDB to printout the thread name along with other
thread specific informations.

In order to do that, and in order to avoid KBI breakage with existing
infrastructure the following semantic is implemented:
- For live programs, a new member to the PT_LWPINFO is added (pl_tdname)
- For cores, a new ELF note is added (NT_THRMISC) that can be used for
storing thread specific, miscellaneous, informations. Right now it is
just popluated with a thread name.

GDB, then, retrieves the correct informations from the corefile via the
BFD interface, as it groks the ELF notes and create appropriate
pseudo-sections.

Sponsored by: Sandvine Incorporated
Tested by: gianni
Discussed with: dim, kan, kib
MFC after: 2 weeks

Widen psaddr_t from uintptr_t to uint64_t. This results in an
ABI change on ILP32 platforms and relating to events. However
it's harmless on little-endian ILP32 platforms in the sense
that it doesn't cause breakages. Old ILP32 thread libraries
write a 32-bit th_p and new thread libraries write a 64-bit
th_p. But due to the fact that we have an unused 32-bit data
field right after th_p and that field is always initialized to
zero, little-endian ILP32 machines effectively have a valid
64-bit th_p by accident. Likewise for new thread libraries and
old libthread_db: little endian ILP32 is unaffected.

At this time we don't support big-endian threaded applications
in GDB, so the breakage for the ILP32 case goes unnoticed.

Change the type of psaddr_t from void* to uintptr_t. A pointer
type cannot be made wider to allow ILP32 platforms to target
LP64 platforms.

type prgregset_t really should be an array. this is odd, however, other
systems defined interfaces in thread_db.h use prgregset_t but not
prgregset_t * to be a output parameter, this is the only way to maintain
source code compatible with them.

Add type definitions for prgregset_t and psaddr_t. Both are used by
the proc services API. The prfpregset_t type already existed.

Use explicit sizes for the prpsinfo command length string so that
we dont have any more unexpected changes in core dumps. This gets us
back to the original core dump layout from a few days ago.

$Id$ -> $FreeBSD$

Viola! The kernel now generates standard ELF core dumps for ELF
executables.

Currently only data and stack are included in the core dumps. I am
looking into adding the other (mmapped) writable segments as well.