sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

sys: Add definitions for RELR relative relocation format

MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D32526

Add ElfW() macro for compatibility with Linux

Some Linux software using ELF headers assumes the existence of an
ElfW(type) macro, which concatenates 'Elf', the default ELF word size,
and the given type. This is identical to our __ElfN(x) macro in
<sys/elf_generic.h>. Add the macro for compatibility, with a comment
that we prefer the __ElfN() macro for FreeBSD.

Reviewed by: emaste, kib
Differential Revision: https://reviews.freebsd.org/D31427
MFC after: 1 week

sys/sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Define ELF_ST_VISIBILITY().

Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

style(9)

Verified with: svn diff -x -Bbw elf_generic.h elf64.h

- Import the HEAD csup code which is the basis for the cvsmode work.

Implement ELF symbol versioning using GNU semantics. This code aims
to be compatible with symbol versioning support as implemented by
GNU libc and documented by http://people.redhat.com/~drepper/symbol-versioning
and LSB 3.0.

Implement dlvsym() function to allow lookups for a specific version of
a given symbol.

Make our ELF64 type definitions match standards. In particular this
means:
o Remove Elf64_Quarter,
o Redefine Elf64_Half to be 16-bit,
o Redefine Elf64_Word to be 32-bit,
o Add Elf64_Xword and Elf64_Sxword for 64-bit entities,
o Use Elf_Size in MI code to abstract the difference between
Elf32_Word and Elf64_Word.
o Add Elf_Ssize as the signed counterpart of Elf_Size.

MFC after: 2 weeks

Infrastructure tweaks to allow having both an Elf32 and an Elf64 executable
handler in the kernel at the same time. Also, allow for the
exec_new_vmspace() code to build a different sized vmspace depending on
the executable environment. This is a big help for execing i386 binaries
on ia64. The ELF exec code grows the ability to map partial pages when
there is a page size difference, eg: emulating 4K pages on 8K or 16K
hardware pages.

Flesh out the i386 emulation support for ia64. At this point, the only
binary that I know of that fails is cvsup, because the cvsup runtime
tries to execute code in pages not marked executable.

Obtained from: dfr (mostly, many tweaks from me).

Move the definition of ElfN_Hashelt to common headers. The only platform
which has a different definition for this is alpha.

$Id$ -> $FreeBSD$

The structure Elf_Note does not have 32 and 64 bit variants but always
has 32bit fields. This change allows FreeBSD/alpha to generate well-formed
ELF corefiles.

Reviewed by: John Polstra <jdp@polstra.com>

Add generic defines ELF_ARCH, ELF_CLASS, and ELF_DATA. These give
the relevant characteristics of the native machine, for building
and checking Elf_Ehdr structures.

Add structures to represent ELF "note" headers. Add defines for the
note types used in ELF core files.

Revamp the ELF include files to better support architecture-independent
applications. Here's how it works.

The kernel should include <machine/elf.h> to get the definitions
for the native architecture. It can reference the various ELF
structures with generic names like Elf_Sym, Elf_Shdr, etc. A define
__ELF_WORD_SIZE is also available with the value 32 or 64 as
appropriate for the native architecture.

Generic applications should include <elf.h>, which is just a wrapper
for <machine/elf.h>.

Applications such as object file dumpers that need to deal with
foreign ELF files can include <sys/elf32.h> and/or <sys/elf64.h>.
Both can be included from the same source file if desired. The
structure names must be referenced using wordsize-specific names
like Elf32_Sym, Elf64_Shdr, etc.

I haven't change the alpha stuff, but I haven't broken it either.