Requested by:	kib

Fixes:		bd7630ef ia32: Sync signal context type names with i386.

- Use ia32_freebsd4_* instead of ia32_*4.
- Use ia32_o* instead of ia32_*3.

Reviewed by:	brooks, imp, kib
Sponsored by:	The University of Cambridge, Google Inc.
Differential Revision:	https://reviews.freebsd.org/D33882

No functional change.

Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D33632

Reviewed by:	emaste
Discussed with:	jrtc27
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D32960

- Use ustringp for the location of the argv and environment strings
  and allow destp to travel further down the stack for the stackgap
  and auxv regions.
- Update the Linux copyout_strings variants to move destp down the
  stack as was done for the native ABIs in r263349.
- Stop allocating a space for a stack gap in the Linux ABIs.  This
  used to hold translated system call arguments, but hasn't been used
  since r159992.

Reviewed by:	kib
Tested on:	md64 (amd64, i386, linux64), i386 (i386, linux)
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D22501

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.

This header depends on sigaltstack32 being declared.

64bit and 32bit ABIs.  As a side-effect, it enables AVX on capable
CPUs.

In particular:

- Query the CPU support for XSAVE, list of the supported extensions
  and the required size of FPU save area. The hw.use_xsave tunable is
  provided for disabling XSAVE, and hw.xsave_mask may be used to
  select the enabled extensions.

- Remove the FPU save area from PCB and dynamically allocate the
  (run-time sized) user save area on the top of the kernel stack,
  right above the PCB. Reorganize the thread0 PCB initialization to
  postpone it after BSP is queried for save area size.

- The dumppcb, stoppcbs and susppcbs now do not carry the FPU state as
  well. FPU state is only useful for suspend, where it is saved in
  dynamically allocated suspfpusave area.

- Use XSAVE and XRSTOR to save/restore FPU state, if supported and
  enabled.

- Define new mcontext_t flag _MC_HASFPXSTATE, indicating that
  mcontext_t has a valid pointer to out-of-struct extended FPU
  state. Signal handlers are supplied with stack-allocated fpu
  state. The sigreturn(2) and setcontext(2) syscall honour the flag,
  allowing the signal handlers to inspect and manipilate extended
  state in the interrupted context.

- The getcontext(2) never returns extended state, since there is no
  place in the fixed-sized mcontext_t to place variable-sized save
  area. And, since mcontext_t is embedded into ucontext_t, makes it
  impossible to fix in a reasonable way.  Instead of extending
  getcontext(2) syscall, provide a sysarch(2) facility to query
  extended FPU state.

- Add ptrace(2) support for getting and setting extended state; while
  there, implement missed PT_I386_{GET,SET}XMMREGS for 32bit binaries.

- Change fpu_kern KPI to not expose struct fpu_kern_ctx layout to
  consumers, making it opaque. Internally, struct fpu_kern_ctx now
  contains a space for the extended state. Convert in-kernel consumers
  of fpu_kern KPI both on i386 and amd64.

First version of the support for AVX was submitted by Tim Bird
<tim.bird am sony com> on behalf of Sony. This version was written
from scratch.

Tested by:	pho (previous version), Yamagi Burmeister <lists yamagi org>
MFC after:	1 month

In particular:
- implement compat shims for old stat(2) variants and ogetdirentries(2);
- implement delivery of signals with ancient stack frame layout and
  corresponding sigreturn(2);
- implement old getpagesize(2);
- provide a user-mode trampoline and LDT call gate for lcall $7,$0;
- port a.out image activator and connect it to the build as a module
  on amd64.

The changes are hidden under COMPAT_43.

MFC after:   1 month

MFC after:	3 days

by /etc/rc.d/jail.

Reviewed by:	kib
MFC after:	3 days

to the image_params struct instead of several members of that struct
individually. This makes it easier to expand its arguments in the future
without touching all platforms.

Reviewed by:	jhb

To keep these structures ABI-compatible, half the size of r_trapno,
r_err, mc_trapno, mc_flags.

Add fsbase and gsbase to mcontext on both amd64 and i386.
Add flags to amd64 mcontext to indicate that it contains valid segments
or bases.

In collaboration with:	pho
Discussed with:	peter
Reviewed by:	jhb

freebsd32-signal.h, implement sigtimedwait and sigwaitinfo system calls.

of siginfo just like the system one.  There are now two fields to copy
instead of one.

   changes in MD code are trivial, before this change, trapsignal and
   sendsig use discrete parameters, now they uses member fields of
   ksiginfo_t structure. For sendsig, this change allows us to pass
   POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
   generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
   blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
   thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
   be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
   an extra siginfo list holds additional siginfo_t data for signals.
   kernel code uses psignal() still behavior as before, it won't be failed
   even under memory pressure, only exception is when deleting a signal,
   we should call sigqueue_delete to remove signal from sigqueue but
   not SIGDELSET. Current there is no kernel code will deliver a signal
   with additional data, so kernel should be as stable as before,
   a ksiginfo can carry more information, for example, allow signal to
   be delivered but throw away siginfo data if memory is not enough.
   SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
   not be caught or masked.
   The sigqueue() syscall allows user code to queue a signal to target
   process, if resource is unavailable, EAGAIN will be returned as
   specification said.
   Just before thread exits, signal queue memory will be freed by
   sigqueue_flush.
   Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64

the register values coming back from sigreturn(2).  Normally this wouldn't
matter because the 32 bit environment would truncate the upper 32 bits
and re-save the truncated values at the next trap.  However, if we got
a fast second signal and it was pending while we were returning from
sigreturn(2) in the signal trampoline, we'd never have had a chance to
truncate the bogus values in 32 bit mode, and the new sendsig would get
an EFAULT when trying to write to the bogus user stack address.

Nothing uses these yet, but I dont want to lose them.

is highly MD in an emulation environment since it operates on the host
environment.  Although the setregs functions are really for exec support
rather than signals, they deal with the same sorts of context and include
files.  So I put it there rather than create yet another file.

i386/include/npx.h instead of the host's machine/npx.h (which might not
exist)

structures come out the right size.

Fix the ones that broke.  stat32 had some missing fields from the end
and statfs32 was broken due to the strange definition of MNAMELEN
(which is dependent on sizeof(long))

I'm not sure if this fixes any actual problems or not.

stolen from the ia64/ia32 code (indeed there was a repocopy), but I've
redone the MD parts and added and fixed a few essential syscalls.  It
is sufficient to run i386 binaries like /bin/ls, /usr/bin/id (dynamic)
and p4.  The ia64 code has not implemented signal delivery, so I had
to do that.

Before you say it, yes, this does need to go in a common place.  But
we're in a freeze at the moment and I didn't want to risk breaking ia64.
I will sort this out after the freeze so that the common code is in a
common place.

On the AMD64 side, this required adding segment selector context switch
support and some other support infrastructure.  The %fs/%gs etc code
is hairy because loading %gs will clobber the kernel's current MSR_GSBASE
setting.  The segment selectors are not used by the kernel, so they're only
changed at context switch time or when changing modes.  This still needs
to be optimized.

Approved by:	re (amd64/* blanket)