MFC r258903,r264487,r271699,r288415:

r258903 (by markj):

Enable some previously-disabled DTrace tests for umod, ufunc and usym. They
expect the installed ksh binary to be named "ksh", which is not the case
when it's installed on FreeBSD via the shells/ksh93 port. Allow for it to be
"ksh93" as well so that the tests can actually pass.

r264487 (by markj):

Replace a few Solarisisms with their corresponding FreeBSDisms to make a few
printf tests pass.

r271699 (by markj):

Implement a workaround to allow this test program to be compiled with clang.
It seems that if a pragma is used to define a weak alias for a local
function, the pragma must appear after the function is defined.

PR: 193056

r288415 (by markj):

MFV r288408:
6266 harden dtrace_difo_chunksize() with respect to malicious DIF

illumos/illumos-gate@395c7a3dcfc66b8b671dc4b3c4a2f0ca26449922

Author: Bryan Cantrill <bryan@joyent.com>

MFC r277300 (by smh): Mechanically convert cddl sun #ifdef's to illumos

Since the upstream for cddl code is now illumos not sun, mechanically
convert all sun #ifdef's to illumos #ifdef's which have been used in all
newer code for some time.

Also do a manual pass to correct the use if #ifdef comments as per style(9)
as well as few uses of #if defined(__FreeBSD__) vs #ifndef illumos.

MFC r267759, r267761

r267759:
Fix a couple of bugs on amd64 when fetching probe arguments beyond the
first five for probes entered through a UD fault (i.e. FBT probes).

Specifically, handle the fact that dtrace_invop_callsite must be
16 byte-aligned and thus may not immediately follow the call to
dtrace_invop() in dtrace_invop_start(). Also fetch register arguments and
the stack pointer through a struct trapframe instead of a struct reg.

r267761:
Fix some bugs when fetching probe arguments in i386. Firstly ensure that
the 4 byte-aligned dtrace_invop_callsite can be found and that it
immediately follows the call to dtrace_invop(). Secondly, fix some pointer
arithmetic to account for differences between struct i386_frame and illumos'
struct frame. Finally, ensure that dtrace_getarg() isn't inlined. It works
by following a fixed number of frame pointers to the probe site, so inlining
breaks it.

PR: 191260

MFC 267929, 267937, 267939, 267940, 267941, 267942, 267987, 268006:

2915 DTrace in a zone should see "cpu", "curpsinfo", et al
2916 DTrace in a zone should be able to access fds[]
2917 DTrace in a zone should have limited provider access
4477 DTrace should speak JSON
Add stubs for CTF functions which are not yet implemented.
4474 DTrace Userland CTF Support
4475 DTrace userland Keyword
4476 DTrace tests should be better citizens
4479 pid provider types
4480 dof emulation is missing checks
4471 DTrace count() with histogram
4472 DTrace full width distribution histograms
4473 DTrace frequency trails

MFC r267759, r267761

r267759:
Fix a couple of bugs on amd64 when fetching probe arguments beyond the
first five for probes entered through a UD fault (i.e. FBT probes).

Specifically, handle the fact that dtrace_invop_callsite must be
16 byte-aligned and thus may not immediately follow the call to
dtrace_invop() in dtrace_invop_start(). Also fetch register arguments and
the stack pointer through a struct trapframe instead of a struct reg.

r267761:
Fix some bugs when fetching probe arguments in i386. Firstly ensure that
the 4 byte-aligned dtrace_invop_callsite can be found and that it
immediately follows the call to dtrace_invop(). Secondly, fix some pointer
arithmetic to account for differences between struct i386_frame and illumos'
struct frame. Finally, ensure that dtrace_getarg() isn't inlined. It works
by following a fixed number of frame pointers to the probe site, so inlining
breaks it.

PR: 191260

MFC 267929, 267937, 267939, 267940, 267941, 267942, 267987, 268006:

2915 DTrace in a zone should see "cpu", "curpsinfo", et al
2916 DTrace in a zone should be able to access fds[]
2917 DTrace in a zone should have limited provider access
4477 DTrace should speak JSON
Add stubs for CTF functions which are not yet implemented.
4474 DTrace Userland CTF Support
4475 DTrace userland Keyword
4476 DTrace tests should be better citizens
4479 pid provider types
4480 dof emulation is missing checks
4471 DTrace count() with histogram
4472 DTrace full width distribution histograms
4473 DTrace frequency trails