lib: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

Alter the prototype of qsort_r(3) to match POSIX, which adopted the
glibc-based interface.

Unfortunately, the glibc maintainers, despite knowing the existence
of the FreeBSD qsort_r(3) interface in 2004 and refused to add the
same interface to glibc based on grounds of the lack of standardization
and portability concerns, has decided it was a good idea to introduce
their own qsort_r(3) interface in 2007 as a GNU extension with a
slightly different and incompatible interface.

With the adoption of their interface as POSIX standard, let's switch
to the same prototype, there is no need to remain incompatible.

C++ and C applications written for the historical FreeBSD interface
get source level compatibility when building in C++ mode, or when
building with a C compiler with C11 generics support, provided that
the caller passes a fifth parameter of qsort_r() that exactly matches
the historical FreeBSD comparator function pointer type and does not
redefine the historical qsort_r(3) prototype in their source code.

Symbol versioning is used to keep old binaries working.

MFC: never
Relnotes: yes
Reviewed by: cem, imp, hps, pauamma
Differential revision: https://reviews.freebsd.org/D17083

libproc: replace home grown crc32 with zlib implementation.

MFC after: 2 weeks
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D35766

Merge OpenZFS support in to HEAD.

The primary benefit is maintaining a completely shared
code base with the community allowing FreeBSD to receive
new features sooner and with less effort.

I would advise against doing 'zpool upgrade'
or creating indispensable pools using new
features until this change has had a month+
to soak.

Work on merging FreeBSD support in to what was
at the time "ZFS on Linux" began in August 2018.
I first publicly proposed transitioning FreeBSD
to (new) OpenZFS on December 18th, 2018. FreeBSD
support in OpenZFS was finally completed in December
2019. A CFT for downstreaming OpenZFS support in
to FreeBSD was first issued on July 8th. All issues
that were reported have been addressed or, for
a couple of less critical matters there are
pull requests in progress with OpenZFS. iXsystems
has tested and dogfooded extensively internally.
The TrueNAS 12 release is based on OpenZFS with
some additional features that have not yet made
it upstream.

Improvements include:
project quotas, encrypted datasets,
allocation classes, vectorized raidz,
vectorized checksums, various command line
improvements, zstd compression.

Thanks to those who have helped along the way:
Ryan Moeller, Allan Jude, Zack Welch, and many
others.

Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D25872

Be consistent about temporary variable use in adjacent loops.

Obtained from: CheriBSD
MFC after: 1 week
Sponsored by: DARPA, AFRL

Take the mapping's segment offset into account when resolving symbols.

Reported by: Jenkins, via asomers
MFC after: 2 weeks

lib: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified 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.

Refine symtab sorting in libproc.

Add some rules to more closely match what illumos does when an address
resolves to multiple symbols:
- prefer non-local symbols
- prefer symbols with fewer leading underscores and no leading '$'

Add some regression tests to verify these rules.

Avoid keeping a dangling pointer when the mappings array is resized.

Sponsored by: Dell EMC Isilon

Ensure that the mappings table is populated in proc_objname().

MFC after: 1 week
Sponsored by: Dell EMC Isilon

Add a reasonable bound on the symbol table index size.

libproc: Cache symbol tables for mapped objects upon access.

Extend the file handle cache entries to include symbol tables as well. An
index is used to implement binary search by symbol value. Lookups by
name are comparatively rare and are thus still implemented with a linear
search, but support for a binary search by name would be straightforward
to add if needed.

libproc: Match prefixes when looking up mapped object by name.

When looking up an object by name, allow prefix matches if no direct match
is found. This allows one to, for example, match libc entry probes with:

# dtrace -n 'pid$target:libc.so::entry' -c ./foo

instead of requiring "libc.so.7" or a glob.

Also remove proc_obj2map() as it currently just duplicates the
functionality of proc_name2map(). It's supposed to take a Solaris
link-map ID as a paramter, but support for this isn't implemented and
isn't required to support DTrace's pid provider.

libproc: Cache ELF handles for loaded objects.

libproc previously created a new handle for each symbol lookup, which
gives rather egregious performance for DTrace's ustack() action. With
this change libproc will cache the libelf descriptor upon access, making
lookups much faster in the common case.

libproc: Improve .gnu_debuglink support.

As of r278658 libproc looks for debug files under /usr/lib/debug and will
use them if available. This change fleshes out that support a bit further:
- Check for a .gnu_debuglink section and use the file name specified
there if one is present.
- Validate external debug files with the CRC in the .gnu_debuglink
section so as to avoid using stale or corrupt debug files.
- Search for debug files in the directory containing the referencing
object or in the .debug subdirectory, as GDB does.

libproc: Make proc_getpid() an accessor for struct proc_handle.

This allows librtld_db to fetch the PID from a handle without calling into
libproc. Together with r303531, this means that librtld_db no longer
references symbols from libproc.

Fix debug symbols loading in libproc: 0 is a valid file descriptor.

Reported by: Chris Torek <chris.torek@gmail.com>

Teach libproc how to find debugging symbols in /usr/lib/debug.

MFC after: 1 week

Stop iterating and return if the caller-supplied callback function returns
a non-zero value.

MFC after: 1 week

Ensure that we don't try to demangle a symbol name if we failed to look
up the symbol. Add a test to exercise this code path.

Reviewed by: adrian

Fix a memory leak that occured when looking up CTF info for a symbol.

Remove an incorrect and useless debug print.

X-MFC-With: r272488

Hook up support for userland CTF support in DTrace. This required some
modifications to libproc to support fetching the CTF info for a given file.

With this change, dtrace(1) is able to resolve type info for function and
USDT probe arguments, and function return values. In particular, the args[n]
syntax should now work for referencing arguments of userland probes,
provided that the requisite CTF info is available.

The uctf tests pass if the test programs are compiled with CTF info. The
current infrastructure around the DTrace test suite doesn't support this
yet.

Differential Revision: https://reviews.freebsd.org/D891
MFC after: 1 month
Relnotes: yes
Sponsored by: EMC / Isilon Storage Division

Factor out some of the duplicated code in the symbol lookup functions, in
preparation for adding userland CTF support to DTrace.

MFC after: 1 month
Sponsored by: EMC / Isilon Storage Division

Fix a bug in r265255: only return NULL if the requested map wasn't found.

Submitted by: Luke Chang-Hsien Tsai <luke.tw@gmail.com>
MFC after: 1 week

In r268463, I misplaced a return in demangle(), causing the function to
erroneously skip symbols that were not mangled at all. Fix this by
moving the return into the preceding if block.

While here, simplify the code by letting __cxa_demangle() allocate the
needed space for the demangled symbol. This also fixes a memory leak,
which would occur whenever __cxa_demangle() failed.

Reported by: pgj
MFC after: 3 days

In libproc, avoid calling __cxa_demangle(), and thus depending on either
libcxxrt or libsupc++, if WITHOUT_CXX is defined.

Noticed by: sbruno
MFC after: 1 week

Allow "a.out" as an alias for the executable if no other matching entries
are found. This improves compatibility with Solaris' libproc and fixes a
number of failing DTrace tests that rely on this feature.

MFC after: 3 weeks

Fix some off-by-one errors. The kve_end and rdl_eaddr fields contain the
first address after the end of the map entry and should therefore be
excluded.

MFC after: 2 weeks

Consistently add the relocation offset only when the ELF type is not
ET_EXEC. This fixes several problems with the DTrace pid provider not
being able to match probes.

Reviewed by: rpaulo
MFC after: 2 weeks

Fix an off-by-one error when checking whether a given address is within
the extent of a symbol.

Submitted by: Prashanth Kumar <pra_udupi@yahoo.co.in>
Reviewed by: rpaulo
MFC after: 1 week

Remove an incorrect debug printf.

Clean up the debug printing in libproc a bit. In particular:

* Don't print any error messages to stderr unless DEBUG is defined.
* Add a DPRINTFX macro for use when errno isn't set.
* Print the error string from libelf when appropriate.

Fix the return value when we found a symbol in .dynstr. This nasty bug was
preventing a lot of symbol lookups in dtruss -s, for example.

When calling the C++ demangler, make sure to free the returned buffer,
which might have been reallocated.

Pointed out by: stefanf

Add support for demangling C++ symbols. This requires linking libproc with
libc++rt/libsupc++.

Discussed with: theraven

Make sure we visit both symbol sections even if one of them doesn't
exist. This makes it possible to dtrace some C++ programs like devd.

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

Several fixes for libproc:
o return the correct status in proc_wstatus()
o proc_read takes a void *
o correctly allocate the objs structure array

Sponsored by: The FreeBSD Foundation

New version of libproc. Changes are:
* breakpoint setup support
* register query
* symbol to address mapping and vice-versa
* more misc utility functions based on their Solaris counterpart

Also, I've written some test cases.

Sponsored by: The FreeBSD Foundation

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

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

Add a process library with some stubs that the DTrace client needs.
These will be fleshed out as part of the DTrace userland tracing
development.

For now, the kernel tracing part of DTrace requires minimal functionality
for this library.

The API for this library is deliberately different from the libproc in
OpenSolaris due to licensing restrictions.