diff --git a/cddl/lib/libdtrace/Makefile b/cddl/lib/libdtrace/Makefile
index 651609409a3a..84258169e44a 100644
--- a/cddl/lib/libdtrace/Makefile
+++ b/cddl/lib/libdtrace/Makefile
@@ -1,141 +1,145 @@
 # $FreeBSD$
 
 .PATH: ${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/common
 .PATH: ${SRCTOP}/cddl/contrib/opensolaris/lib/libgen/common
 
 PACKAGE=	dtrace
 LIB=		dtrace
 SRCS=		dt_aggregate.c \
 		dt_as.c \
 		dt_buf.c \
 		dt_cc.c \
 		dt_cg.c \
 		dt_consume.c \
 		dt_decl.c \
 		dt_dis.c \
 		dt_dof.c \
 		dt_error.c \
 		dt_errtags.c \
 		dt_grammar.y \
 		dt_handle.c \
 		dt_ident.c \
 		dt_isadep.c \
 		dt_inttab.c \
 		dt_lex.l \
 		dt_link.c \
 		dt_list.c \
 		dt_map.c \
 		dt_module.c \
 		dt_names.c \
 		dt_open.c \
 		dt_options.c \
 		dt_parser.c \
 		dt_pcb.c \
 		dt_pid.c \
 		dt_pq.c \
 		dt_pragma.c \
 		dt_print.c \
 		dt_printf.c \
 		dt_proc.c \
 		dt_program.c \
 		dt_provider.c \
 		dt_regset.c \
 		dt_string.c \
 		dt_strtab.c \
 		dt_subr.c \
 		dt_sugar.c \
 		dt_work.c \
 		dt_xlator.c \
 		gmatch.c
 
 DSRCS=		errno.d			\
 		io.d			\
 		ip.d			\
 		psinfo.d		\
 		sctp.d			\
 		siftr.d			\
 		signal.d		\
 		tcp.d			\
 		socket.d		\
 		udp.d			\
 		udplite.d		\
 		unistd.d
 
 FILES=		${DSRCS}
 FILESDIR=	/usr/lib/dtrace
 FILESMODE=	${NOBINMODE}
 
 INCSGROUPS=	INCS SYSINCS
 SYSINCSDIR=	${INCLUDEDIR}/sys
 INCS+=		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/common/dtrace.h
 SYSINCS+=	${SRCTOP}/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h
 SYSINCS+=	${SRCTOP}/sys/cddl/contrib/opensolaris/uts/common/sys/ctf_api.h
 
 WARNS?=		1
 
 CFLAGS+= -DIN_BASE
 CFLAGS+= -I${SRCTOP}/sys/contrib/openzfs/include
 CFLAGS+= -I${SRCTOP}/sys/contrib/openzfs/lib/libspl/include/
 CFLAGS+= -I${SRCTOP}/sys/contrib/openzfs/lib/libspl/include/os/freebsd
 CFLAGS+= -I${SRCTOP}/sys
 CFLAGS+= -include ${SRCTOP}/sys/contrib/openzfs/include/os/freebsd/spl/sys/ccompile.h
 CFLAGS+= -DHAVE_ISSETUGID
 
 
 CFLAGS+=	-I${.OBJDIR} -I${.CURDIR} \
 		-I${SRCTOP}/sys/cddl/dev/dtrace/${MACHINE_ARCH} \
 		-I${SRCTOP}/sys/cddl/dev/kinst \
 		-I${SRCTOP}/sys/cddl/compat/opensolaris \
 		-I${SRCTOP}/cddl/compat/opensolaris/include \
 		-I${OPENSOLARIS_USR_DISTDIR}/head \
 		-I${OPENSOLARIS_USR_DISTDIR}/lib/libctf/common \
 		-I${OPENSOLARIS_USR_DISTDIR}/lib/libdtrace/common \
 		-I${OPENSOLARIS_SYS_DISTDIR}/uts/common
 
 #CFLAGS+=	-DYYDEBUG
 
 .if ${MACHINE_CPUARCH} == "aarch64"
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/aarch64
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/aarch64
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/aarch64
 .elif ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"
 CFLAGS+=	-I${SRCTOP}/sys/cddl/dev/dtrace/x86
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/intel -DDIS_MEM
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/i386
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/${MACHINE_ARCH}
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/x86
 .elif ${MACHINE_CPUARCH} == "arm"
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/arm
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/arm
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/arm
 .elif ${MACHINE_CPUARCH} == "powerpc"
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/powerpc
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/powerpc
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/powerpc
 .elif ${MACHINE_CPUARCH} == "riscv"
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/riscv
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/riscv
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/riscv
 .else
 # temporary hack
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/intel
 .endif
 
 .if ${MACHINE_ARCH} == "i386" || ${MACHINE_ARCH} == "amd64"
-SRCS+=		dis_tables.c
+SRCS+=		dis_tables.c instr_size.c
 DSRCS+=		regs_x86.d
 .endif
 
+.if ${MACHINE_CPUARCH} == "riscv"
+SRCS+=		instr_size.c
+.endif
+
 YFLAGS+=-d
 
 LIBADD=	ctf elf proc pthread rtld_db
 
 CLEANFILES=	dt_errtags.c dt_names.c
 
 .include <bsd.lib.mk>
 
 dt_errtags.c: ${OPENSOLARIS_USR_DISTDIR}/lib/libdtrace/common/dt_errtags.h
 	sh ${OPENSOLARIS_USR_DISTDIR}/lib/libdtrace/common/mkerrtags.sh < ${.ALLSRC} > ${.TARGET}
 
 dt_names.c: ${OPENSOLARIS_SYS_DISTDIR}/uts/common/sys/dtrace.h
 	sh ${OPENSOLARIS_USR_DISTDIR}/lib/libdtrace/common/mknames.sh < ${.ALLSRC} > ${.TARGET}
diff --git a/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h b/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h
index d3d8fbca6164..7b8da08e9ae9 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h
+++ b/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h
@@ -1,2537 +1,2540 @@
 /*
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
  * Common Development and Distribution License (the "License").
  * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
  * See the License for the specific language governing permissions
  * and limitations under the License.
  *
  * When distributing Covered Code, include this CDDL HEADER in each
  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  * If applicable, add the following below this CDDL HEADER, with the
  * fields enclosed by brackets "[]" replaced with your own identifying
  * information: Portions Copyright [yyyy] [name of copyright owner]
  *
  * CDDL HEADER END
  */
 
 /*
  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
 /*
  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  * Copyright (c) 2013 by Delphix. All rights reserved.
  */
 
 #ifndef _SYS_DTRACE_H
 #define	_SYS_DTRACE_H
 
 #ifdef	__cplusplus
 extern "C" {
 #endif
 
 /*
  * DTrace Dynamic Tracing Software: Kernel Interfaces
  *
  * Note: The contents of this file are private to the implementation of the
  * Solaris system and DTrace subsystem and are subject to change at any time
  * without notice.  Applications and drivers using these interfaces will fail
  * to run on future releases.  These interfaces should not be used for any
  * purpose except those expressly outlined in dtrace(7D) and libdtrace(3LIB).
  * Please refer to the "Solaris Dynamic Tracing Guide" for more information.
  */
 
 #ifndef _ASM
 
 #include <sys/param.h>
 #include <sys/stdint.h>
 #ifdef _KERNEL
 #include <sys/endian.h>
 #endif
 #if !defined(IN_BASE) && !defined(_KERNEL)
 /* Compatibility types to allow including the CTF API */
 typedef unsigned int zoneid_t;
 typedef unsigned char uchar_t;
 typedef unsigned short ushort_t;
 typedef unsigned int uint_t;
 typedef unsigned long ulong_t;
 typedef int processorid_t;
 #else
 #include <sys/modctl.h>
 #include <sys/processor.h>
 #include <sys/cpuvar.h>
 #include <sys/param.h>
 #include <sys/linker.h>
 #include <sys/ioccom.h>
 #include <sys/cred.h>
 #include <sys/proc.h>
 #include <sys/types.h>
 #include <sys/ucred.h>
 #endif
 typedef int model_t;
 #include <sys/ctf_api.h>
 
 /*
  * DTrace Universal Constants and Typedefs
  */
 #define	DTRACE_CPUALL		-1	/* all CPUs */
 #define	DTRACE_IDNONE		0	/* invalid probe identifier */
 #define	DTRACE_EPIDNONE		0	/* invalid enabled probe identifier */
 #define	DTRACE_AGGIDNONE	0	/* invalid aggregation identifier */
 #define	DTRACE_AGGVARIDNONE	0	/* invalid aggregation variable ID */
 #define	DTRACE_CACHEIDNONE	0	/* invalid predicate cache */
 #define	DTRACE_PROVNONE		0	/* invalid provider identifier */
 #define	DTRACE_METAPROVNONE	0	/* invalid meta-provider identifier */
 #define	DTRACE_ARGNONE		-1	/* invalid argument index */
 
 #define	DTRACE_PROVNAMELEN	64
 #define	DTRACE_MODNAMELEN	64
 #define	DTRACE_FUNCNAMELEN	192
 #define	DTRACE_NAMELEN		64
 #define	DTRACE_FULLNAMELEN	(DTRACE_PROVNAMELEN + DTRACE_MODNAMELEN + \
 				DTRACE_FUNCNAMELEN + DTRACE_NAMELEN + 4)
 #define	DTRACE_ARGTYPELEN	128
 
 typedef uint32_t dtrace_id_t;		/* probe identifier */
 typedef uint32_t dtrace_epid_t;		/* enabled probe identifier */
 typedef uint32_t dtrace_aggid_t;	/* aggregation identifier */
 typedef int64_t dtrace_aggvarid_t;	/* aggregation variable identifier */
 typedef uint16_t dtrace_actkind_t;	/* action kind */
 typedef int64_t dtrace_optval_t;	/* option value */
 typedef uint32_t dtrace_cacheid_t;	/* predicate cache identifier */
 
 typedef enum dtrace_probespec {
 	DTRACE_PROBESPEC_NONE = -1,
 	DTRACE_PROBESPEC_PROVIDER = 0,
 	DTRACE_PROBESPEC_MOD,
 	DTRACE_PROBESPEC_FUNC,
 	DTRACE_PROBESPEC_NAME
 } dtrace_probespec_t;
 
 /*
  * DTrace Intermediate Format (DIF)
  *
  * The following definitions describe the DTrace Intermediate Format (DIF), a
  * a RISC-like instruction set and program encoding used to represent
  * predicates and actions that can be bound to DTrace probes.  The constants
  * below defining the number of available registers are suggested minimums; the
  * compiler should use DTRACEIOC_CONF to dynamically obtain the number of
  * registers provided by the current DTrace implementation.
  */
 #define	DIF_VERSION_1	1		/* DIF version 1: Solaris 10 Beta */
 #define	DIF_VERSION_2	2		/* DIF version 2: Solaris 10 FCS */
 #define	DIF_VERSION	DIF_VERSION_2	/* latest DIF instruction set version */
 #define	DIF_DIR_NREGS	8		/* number of DIF integer registers */
 #define	DIF_DTR_NREGS	8		/* number of DIF tuple registers */
 
 #define	DIF_OP_OR	1		/* or	r1, r2, rd */
 #define	DIF_OP_XOR	2		/* xor	r1, r2, rd */
 #define	DIF_OP_AND	3		/* and	r1, r2, rd */
 #define	DIF_OP_SLL	4		/* sll	r1, r2, rd */
 #define	DIF_OP_SRL	5		/* srl	r1, r2, rd */
 #define	DIF_OP_SUB	6		/* sub	r1, r2, rd */
 #define	DIF_OP_ADD	7		/* add	r1, r2, rd */
 #define	DIF_OP_MUL	8		/* mul	r1, r2, rd */
 #define	DIF_OP_SDIV	9		/* sdiv	r1, r2, rd */
 #define	DIF_OP_UDIV	10		/* udiv r1, r2, rd */
 #define	DIF_OP_SREM	11		/* srem r1, r2, rd */
 #define	DIF_OP_UREM	12		/* urem r1, r2, rd */
 #define	DIF_OP_NOT	13		/* not	r1, rd */
 #define	DIF_OP_MOV	14		/* mov	r1, rd */
 #define	DIF_OP_CMP	15		/* cmp	r1, r2 */
 #define	DIF_OP_TST	16		/* tst  r1 */
 #define	DIF_OP_BA	17		/* ba	label */
 #define	DIF_OP_BE	18		/* be	label */
 #define	DIF_OP_BNE	19		/* bne	label */
 #define	DIF_OP_BG	20		/* bg	label */
 #define	DIF_OP_BGU	21		/* bgu	label */
 #define	DIF_OP_BGE	22		/* bge	label */
 #define	DIF_OP_BGEU	23		/* bgeu	label */
 #define	DIF_OP_BL	24		/* bl	label */
 #define	DIF_OP_BLU	25		/* blu	label */
 #define	DIF_OP_BLE	26		/* ble	label */
 #define	DIF_OP_BLEU	27		/* bleu	label */
 #define	DIF_OP_LDSB	28		/* ldsb	[r1], rd */
 #define	DIF_OP_LDSH	29		/* ldsh	[r1], rd */
 #define	DIF_OP_LDSW	30		/* ldsw [r1], rd */
 #define	DIF_OP_LDUB	31		/* ldub	[r1], rd */
 #define	DIF_OP_LDUH	32		/* lduh	[r1], rd */
 #define	DIF_OP_LDUW	33		/* lduw	[r1], rd */
 #define	DIF_OP_LDX	34		/* ldx	[r1], rd */
 #define	DIF_OP_RET	35		/* ret	rd */
 #define	DIF_OP_NOP	36		/* nop */
 #define	DIF_OP_SETX	37		/* setx	intindex, rd */
 #define	DIF_OP_SETS	38		/* sets strindex, rd */
 #define	DIF_OP_SCMP	39		/* scmp	r1, r2 */
 #define	DIF_OP_LDGA	40		/* ldga	var, ri, rd */
 #define	DIF_OP_LDGS	41		/* ldgs var, rd */
 #define	DIF_OP_STGS	42		/* stgs var, rs */
 #define	DIF_OP_LDTA	43		/* ldta var, ri, rd */
 #define	DIF_OP_LDTS	44		/* ldts var, rd */
 #define	DIF_OP_STTS	45		/* stts var, rs */
 #define	DIF_OP_SRA	46		/* sra	r1, r2, rd */
 #define	DIF_OP_CALL	47		/* call	subr, rd */
 #define	DIF_OP_PUSHTR	48		/* pushtr type, rs, rr */
 #define	DIF_OP_PUSHTV	49		/* pushtv type, rs, rv */
 #define	DIF_OP_POPTS	50		/* popts */
 #define	DIF_OP_FLUSHTS	51		/* flushts */
 #define	DIF_OP_LDGAA	52		/* ldgaa var, rd */
 #define	DIF_OP_LDTAA	53		/* ldtaa var, rd */
 #define	DIF_OP_STGAA	54		/* stgaa var, rs */
 #define	DIF_OP_STTAA	55		/* sttaa var, rs */
 #define	DIF_OP_LDLS	56		/* ldls	var, rd */
 #define	DIF_OP_STLS	57		/* stls	var, rs */
 #define	DIF_OP_ALLOCS	58		/* allocs r1, rd */
 #define	DIF_OP_COPYS	59		/* copys  r1, r2, rd */
 #define	DIF_OP_STB	60		/* stb	r1, [rd] */
 #define	DIF_OP_STH	61		/* sth	r1, [rd] */
 #define	DIF_OP_STW	62		/* stw	r1, [rd] */
 #define	DIF_OP_STX	63		/* stx	r1, [rd] */
 #define	DIF_OP_ULDSB	64		/* uldsb [r1], rd */
 #define	DIF_OP_ULDSH	65		/* uldsh [r1], rd */
 #define	DIF_OP_ULDSW	66		/* uldsw [r1], rd */
 #define	DIF_OP_ULDUB	67		/* uldub [r1], rd */
 #define	DIF_OP_ULDUH	68		/* ulduh [r1], rd */
 #define	DIF_OP_ULDUW	69		/* ulduw [r1], rd */
 #define	DIF_OP_ULDX	70		/* uldx  [r1], rd */
 #define	DIF_OP_RLDSB	71		/* rldsb [r1], rd */
 #define	DIF_OP_RLDSH	72		/* rldsh [r1], rd */
 #define	DIF_OP_RLDSW	73		/* rldsw [r1], rd */
 #define	DIF_OP_RLDUB	74		/* rldub [r1], rd */
 #define	DIF_OP_RLDUH	75		/* rlduh [r1], rd */
 #define	DIF_OP_RLDUW	76		/* rlduw [r1], rd */
 #define	DIF_OP_RLDX	77		/* rldx  [r1], rd */
 #define	DIF_OP_XLATE	78		/* xlate xlrindex, rd */
 #define	DIF_OP_XLARG	79		/* xlarg xlrindex, rd */
 
 #define	DIF_INTOFF_MAX		0xffff	/* highest integer table offset */
 #define	DIF_STROFF_MAX		0xffff	/* highest string table offset */
 #define	DIF_REGISTER_MAX	0xff	/* highest register number */
 #define	DIF_VARIABLE_MAX	0xffff	/* highest variable identifier */
 #define	DIF_SUBROUTINE_MAX	0xffff	/* highest subroutine code */
 
 #define	DIF_VAR_ARRAY_MIN	0x0000	/* lowest numbered array variable */
 #define	DIF_VAR_ARRAY_UBASE	0x0080	/* lowest user-defined array */
 #define	DIF_VAR_ARRAY_MAX	0x00ff	/* highest numbered array variable */
 
 #define	DIF_VAR_OTHER_MIN	0x0100	/* lowest numbered scalar or assc */
 #define	DIF_VAR_OTHER_UBASE	0x0500	/* lowest user-defined scalar or assc */
 #define	DIF_VAR_OTHER_MAX	0xffff	/* highest numbered scalar or assc */
 
 #define	DIF_VAR_ARGS		0x0000	/* arguments array */
 #define	DIF_VAR_REGS		0x0001	/* registers array */
 #define	DIF_VAR_UREGS		0x0002	/* user registers array */
 #define	DIF_VAR_CURTHREAD	0x0100	/* thread pointer */
 #define	DIF_VAR_TIMESTAMP	0x0101	/* timestamp */
 #define	DIF_VAR_VTIMESTAMP	0x0102	/* virtual timestamp */
 #define	DIF_VAR_IPL		0x0103	/* interrupt priority level */
 #define	DIF_VAR_EPID		0x0104	/* enabled probe ID */
 #define	DIF_VAR_ID		0x0105	/* probe ID */
 #define	DIF_VAR_ARG0		0x0106	/* first argument */
 #define	DIF_VAR_ARG1		0x0107	/* second argument */
 #define	DIF_VAR_ARG2		0x0108	/* third argument */
 #define	DIF_VAR_ARG3		0x0109	/* fourth argument */
 #define	DIF_VAR_ARG4		0x010a	/* fifth argument */
 #define	DIF_VAR_ARG5		0x010b	/* sixth argument */
 #define	DIF_VAR_ARG6		0x010c	/* seventh argument */
 #define	DIF_VAR_ARG7		0x010d	/* eighth argument */
 #define	DIF_VAR_ARG8		0x010e	/* ninth argument */
 #define	DIF_VAR_ARG9		0x010f	/* tenth argument */
 #define	DIF_VAR_STACKDEPTH	0x0110	/* stack depth */
 #define	DIF_VAR_CALLER		0x0111	/* caller */
 #define	DIF_VAR_PROBEPROV	0x0112	/* probe provider */
 #define	DIF_VAR_PROBEMOD	0x0113	/* probe module */
 #define	DIF_VAR_PROBEFUNC	0x0114	/* probe function */
 #define	DIF_VAR_PROBENAME	0x0115	/* probe name */
 #define	DIF_VAR_PID		0x0116	/* process ID */
 #define	DIF_VAR_TID		0x0117	/* (per-process) thread ID */
 #define	DIF_VAR_EXECNAME	0x0118	/* name of executable */
 #define	DIF_VAR_ZONENAME	0x0119	/* zone name associated with process */
 #define	DIF_VAR_WALLTIMESTAMP	0x011a	/* wall-clock timestamp */
 #define	DIF_VAR_USTACKDEPTH	0x011b	/* user-land stack depth */
 #define	DIF_VAR_UCALLER		0x011c	/* user-level caller */
 #define	DIF_VAR_PPID		0x011d	/* parent process ID */
 #define	DIF_VAR_UID		0x011e	/* process user ID */
 #define	DIF_VAR_GID		0x011f	/* process group ID */
 #define	DIF_VAR_ERRNO		0x0120	/* thread errno */
 #define	DIF_VAR_EXECARGS	0x0121	/* process arguments */
 #define	DIF_VAR_JID		0x0122	/* process jail id */
 #define	DIF_VAR_JAILNAME	0x0123	/* process jail name */
 
 #ifndef illumos
 #define	DIF_VAR_CPU		0x0200
 #endif
 
 #define	DIF_SUBR_RAND			0
 #define	DIF_SUBR_MUTEX_OWNED		1
 #define	DIF_SUBR_MUTEX_OWNER		2
 #define	DIF_SUBR_MUTEX_TYPE_ADAPTIVE	3
 #define	DIF_SUBR_MUTEX_TYPE_SPIN	4
 #define	DIF_SUBR_RW_READ_HELD		5
 #define	DIF_SUBR_RW_WRITE_HELD		6
 #define	DIF_SUBR_RW_ISWRITER		7
 #define	DIF_SUBR_COPYIN			8
 #define	DIF_SUBR_COPYINSTR		9
 #define	DIF_SUBR_SPECULATION		10
 #define	DIF_SUBR_PROGENYOF		11
 #define	DIF_SUBR_STRLEN			12
 #define	DIF_SUBR_COPYOUT		13
 #define	DIF_SUBR_COPYOUTSTR		14
 #define	DIF_SUBR_ALLOCA			15
 #define	DIF_SUBR_BCOPY			16
 #define	DIF_SUBR_COPYINTO		17
 #define	DIF_SUBR_MSGDSIZE		18
 #define	DIF_SUBR_MSGSIZE		19
 #define	DIF_SUBR_GETMAJOR		20
 #define	DIF_SUBR_GETMINOR		21
 #define	DIF_SUBR_DDI_PATHNAME		22
 #define	DIF_SUBR_STRJOIN		23
 #define	DIF_SUBR_LLTOSTR		24
 #define	DIF_SUBR_BASENAME		25
 #define	DIF_SUBR_DIRNAME		26
 #define	DIF_SUBR_CLEANPATH		27
 #define	DIF_SUBR_STRCHR			28
 #define	DIF_SUBR_STRRCHR		29
 #define	DIF_SUBR_STRSTR			30
 #define	DIF_SUBR_STRTOK			31
 #define	DIF_SUBR_SUBSTR			32
 #define	DIF_SUBR_INDEX			33
 #define	DIF_SUBR_RINDEX			34
 #define	DIF_SUBR_HTONS			35
 #define	DIF_SUBR_HTONL			36
 #define	DIF_SUBR_HTONLL			37
 #define	DIF_SUBR_NTOHS			38
 #define	DIF_SUBR_NTOHL			39
 #define	DIF_SUBR_NTOHLL			40
 #define	DIF_SUBR_INET_NTOP		41
 #define	DIF_SUBR_INET_NTOA		42
 #define	DIF_SUBR_INET_NTOA6		43
 #define	DIF_SUBR_TOUPPER		44
 #define	DIF_SUBR_TOLOWER		45
 #define	DIF_SUBR_MEMREF			46
 #define	DIF_SUBR_SX_SHARED_HELD		47
 #define	DIF_SUBR_SX_EXCLUSIVE_HELD	48
 #define	DIF_SUBR_SX_ISEXCLUSIVE		49
 #define	DIF_SUBR_MEMSTR			50
 #define	DIF_SUBR_GETF			51
 #define	DIF_SUBR_JSON			52
 #define	DIF_SUBR_STRTOLL		53
 #define	DIF_SUBR_MAX			53	/* max subroutine value */
 
 typedef uint32_t dif_instr_t;
 
 #define	DIF_INSTR_OP(i)			(((i) >> 24) & 0xff)
 #define	DIF_INSTR_R1(i)			(((i) >> 16) & 0xff)
 #define	DIF_INSTR_R2(i)			(((i) >>  8) & 0xff)
 #define	DIF_INSTR_RD(i)			((i) & 0xff)
 #define	DIF_INSTR_RS(i)			((i) & 0xff)
 #define	DIF_INSTR_LABEL(i)		((i) & 0xffffff)
 #define	DIF_INSTR_VAR(i)		(((i) >>  8) & 0xffff)
 #define	DIF_INSTR_INTEGER(i)		(((i) >>  8) & 0xffff)
 #define	DIF_INSTR_STRING(i)		(((i) >>  8) & 0xffff)
 #define	DIF_INSTR_SUBR(i)		(((i) >>  8) & 0xffff)
 #define	DIF_INSTR_TYPE(i)		(((i) >> 16) & 0xff)
 #define	DIF_INSTR_XLREF(i)		(((i) >>  8) & 0xffff)
 
 #define	DIF_INSTR_FMT(op, r1, r2, d) \
 	(((op) << 24) | ((r1) << 16) | ((r2) << 8) | (d))
 
 #define	DIF_INSTR_NOT(r1, d)		(DIF_INSTR_FMT(DIF_OP_NOT, r1, 0, d))
 #define	DIF_INSTR_MOV(r1, d)		(DIF_INSTR_FMT(DIF_OP_MOV, r1, 0, d))
 #define	DIF_INSTR_CMP(op, r1, r2)	(DIF_INSTR_FMT(op, r1, r2, 0))
 #define	DIF_INSTR_TST(r1)		(DIF_INSTR_FMT(DIF_OP_TST, r1, 0, 0))
 #define	DIF_INSTR_BRANCH(op, label)	(((op) << 24) | (label))
 #define	DIF_INSTR_LOAD(op, r1, d)	(DIF_INSTR_FMT(op, r1, 0, d))
 #define	DIF_INSTR_STORE(op, r1, d)	(DIF_INSTR_FMT(op, r1, 0, d))
 #define	DIF_INSTR_SETX(i, d)		((DIF_OP_SETX << 24) | ((i) << 8) | (d))
 #define	DIF_INSTR_SETS(s, d)		((DIF_OP_SETS << 24) | ((s) << 8) | (d))
 #define	DIF_INSTR_RET(d)		(DIF_INSTR_FMT(DIF_OP_RET, 0, 0, d))
 #define	DIF_INSTR_NOP			(DIF_OP_NOP << 24)
 #define	DIF_INSTR_LDA(op, v, r, d)	(DIF_INSTR_FMT(op, v, r, d))
 #define	DIF_INSTR_LDV(op, v, d)		(((op) << 24) | ((v) << 8) | (d))
 #define	DIF_INSTR_STV(op, v, rs)	(((op) << 24) | ((v) << 8) | (rs))
 #define	DIF_INSTR_CALL(s, d)		((DIF_OP_CALL << 24) | ((s) << 8) | (d))
 #define	DIF_INSTR_PUSHTS(op, t, r2, rs)	(DIF_INSTR_FMT(op, t, r2, rs))
 #define	DIF_INSTR_POPTS			(DIF_OP_POPTS << 24)
 #define	DIF_INSTR_FLUSHTS		(DIF_OP_FLUSHTS << 24)
 #define	DIF_INSTR_ALLOCS(r1, d)		(DIF_INSTR_FMT(DIF_OP_ALLOCS, r1, 0, d))
 #define	DIF_INSTR_COPYS(r1, r2, d)	(DIF_INSTR_FMT(DIF_OP_COPYS, r1, r2, d))
 #define	DIF_INSTR_XLATE(op, r, d)	(((op) << 24) | ((r) << 8) | (d))
 
 #define	DIF_REG_R0	0		/* %r0 is always set to zero */
 
 /*
  * A DTrace Intermediate Format Type (DIF Type) is used to represent the types
  * of variables, function and associative array arguments, and the return type
  * for each DIF object (shown below).  It contains a description of the type,
  * its size in bytes, and a module identifier.
  */
 typedef struct dtrace_diftype {
 	uint8_t dtdt_kind;		/* type kind (see below) */
 	uint8_t dtdt_ckind;		/* type kind in CTF */
 	uint8_t dtdt_flags;		/* type flags (see below) */
 	uint8_t dtdt_pad;		/* reserved for future use */
 	uint32_t dtdt_size;		/* type size in bytes (unless string) */
 } dtrace_diftype_t;
 
 #define	DIF_TYPE_CTF		0	/* type is a CTF type */
 #define	DIF_TYPE_STRING		1	/* type is a D string */
 
 #define	DIF_TF_BYREF		0x1	/* type is passed by reference */
 #define	DIF_TF_BYUREF		0x2	/* user type is passed by reference */
 
 /*
  * A DTrace Intermediate Format variable record is used to describe each of the
  * variables referenced by a given DIF object.  It contains an integer variable
  * identifier along with variable scope and properties, as shown below.  The
  * size of this structure must be sizeof (int) aligned.
  */
 typedef struct dtrace_difv {
 	uint32_t dtdv_name;		/* variable name index in dtdo_strtab */
 	uint32_t dtdv_id;		/* variable reference identifier */
 	uint8_t dtdv_kind;		/* variable kind (see below) */
 	uint8_t dtdv_scope;		/* variable scope (see below) */
 	uint16_t dtdv_flags;		/* variable flags (see below) */
 	dtrace_diftype_t dtdv_type;	/* variable type (see above) */
 } dtrace_difv_t;
 
 #define	DIFV_KIND_ARRAY		0	/* variable is an array of quantities */
 #define	DIFV_KIND_SCALAR	1	/* variable is a scalar quantity */
 
 #define	DIFV_SCOPE_GLOBAL	0	/* variable has global scope */
 #define	DIFV_SCOPE_THREAD	1	/* variable has thread scope */
 #define	DIFV_SCOPE_LOCAL	2	/* variable has local scope */
 
 #define	DIFV_F_REF		0x1	/* variable is referenced by DIFO */
 #define	DIFV_F_MOD		0x2	/* variable is written by DIFO */
 
 /*
  * DTrace Actions
  *
  * The upper byte determines the class of the action; the low bytes determines
  * the specific action within that class.  The classes of actions are as
  * follows:
  *
  *   [ no class ]                  <= May record process- or kernel-related data
  *   DTRACEACT_PROC                <= Only records process-related data
  *   DTRACEACT_PROC_DESTRUCTIVE    <= Potentially destructive to processes
  *   DTRACEACT_KERNEL              <= Only records kernel-related data
  *   DTRACEACT_KERNEL_DESTRUCTIVE  <= Potentially destructive to the kernel
  *   DTRACEACT_SPECULATIVE         <= Speculation-related action
  *   DTRACEACT_AGGREGATION         <= Aggregating action
  */
 #define	DTRACEACT_NONE			0	/* no action */
 #define	DTRACEACT_DIFEXPR		1	/* action is DIF expression */
 #define	DTRACEACT_EXIT			2	/* exit() action */
 #define	DTRACEACT_PRINTF		3	/* printf() action */
 #define	DTRACEACT_PRINTA		4	/* printa() action */
 #define	DTRACEACT_LIBACT		5	/* library-controlled action */
 #define	DTRACEACT_TRACEMEM		6	/* tracemem() action */
 #define	DTRACEACT_TRACEMEM_DYNSIZE	7	/* dynamic tracemem() size */
 #define	DTRACEACT_PRINTM		8	/* printm() action (BSD) */
 
 #define	DTRACEACT_PROC			0x0100
 #define	DTRACEACT_USTACK		(DTRACEACT_PROC + 1)
 #define	DTRACEACT_JSTACK		(DTRACEACT_PROC + 2)
 #define	DTRACEACT_USYM			(DTRACEACT_PROC + 3)
 #define	DTRACEACT_UMOD			(DTRACEACT_PROC + 4)
 #define	DTRACEACT_UADDR			(DTRACEACT_PROC + 5)
 
 #define	DTRACEACT_PROC_DESTRUCTIVE	0x0200
 #define	DTRACEACT_STOP			(DTRACEACT_PROC_DESTRUCTIVE + 1)
 #define	DTRACEACT_RAISE			(DTRACEACT_PROC_DESTRUCTIVE + 2)
 #define	DTRACEACT_SYSTEM		(DTRACEACT_PROC_DESTRUCTIVE + 3)
 #define	DTRACEACT_FREOPEN		(DTRACEACT_PROC_DESTRUCTIVE + 4)
 
 #define	DTRACEACT_PROC_CONTROL		0x0300
 
 #define	DTRACEACT_KERNEL		0x0400
 #define	DTRACEACT_STACK			(DTRACEACT_KERNEL + 1)
 #define	DTRACEACT_SYM			(DTRACEACT_KERNEL + 2)
 #define	DTRACEACT_MOD			(DTRACEACT_KERNEL + 3)
 
 #define	DTRACEACT_KERNEL_DESTRUCTIVE	0x0500
 #define	DTRACEACT_BREAKPOINT		(DTRACEACT_KERNEL_DESTRUCTIVE + 1)
 #define	DTRACEACT_PANIC			(DTRACEACT_KERNEL_DESTRUCTIVE + 2)
 #define	DTRACEACT_CHILL			(DTRACEACT_KERNEL_DESTRUCTIVE + 3)
 
 #define	DTRACEACT_SPECULATIVE		0x0600
 #define	DTRACEACT_SPECULATE		(DTRACEACT_SPECULATIVE + 1)
 #define	DTRACEACT_COMMIT		(DTRACEACT_SPECULATIVE + 2)
 #define	DTRACEACT_DISCARD		(DTRACEACT_SPECULATIVE + 3)
 
 #define	DTRACEACT_CLASS(x)		((x) & 0xff00)
 
 #define	DTRACEACT_ISDESTRUCTIVE(x)	\
 	(DTRACEACT_CLASS(x) == DTRACEACT_PROC_DESTRUCTIVE || \
 	DTRACEACT_CLASS(x) == DTRACEACT_KERNEL_DESTRUCTIVE)
 
 #define	DTRACEACT_ISSPECULATIVE(x)	\
 	(DTRACEACT_CLASS(x) == DTRACEACT_SPECULATIVE)
 
 #define	DTRACEACT_ISPRINTFLIKE(x)	\
 	((x) == DTRACEACT_PRINTF || (x) == DTRACEACT_PRINTA || \
 	(x) == DTRACEACT_SYSTEM || (x) == DTRACEACT_FREOPEN)
 
 /*
  * DTrace Aggregating Actions
  *
  * These are functions f(x) for which the following is true:
  *
  *    f(f(x_0) U f(x_1) U ... U f(x_n)) = f(x_0 U x_1 U ... U x_n)
  *
  * where x_n is a set of arbitrary data.  Aggregating actions are in their own
  * DTrace action class, DTTRACEACT_AGGREGATION.  The macros provided here allow
  * for easier processing of the aggregation argument and data payload for a few
  * aggregating actions (notably:  quantize(), lquantize(), and ustack()).
  */
 #define	DTRACEACT_AGGREGATION		0x0700
 #define	DTRACEAGG_COUNT			(DTRACEACT_AGGREGATION + 1)
 #define	DTRACEAGG_MIN			(DTRACEACT_AGGREGATION + 2)
 #define	DTRACEAGG_MAX			(DTRACEACT_AGGREGATION + 3)
 #define	DTRACEAGG_AVG			(DTRACEACT_AGGREGATION + 4)
 #define	DTRACEAGG_SUM			(DTRACEACT_AGGREGATION + 5)
 #define	DTRACEAGG_STDDEV		(DTRACEACT_AGGREGATION + 6)
 #define	DTRACEAGG_QUANTIZE		(DTRACEACT_AGGREGATION + 7)
 #define	DTRACEAGG_LQUANTIZE		(DTRACEACT_AGGREGATION + 8)
 #define	DTRACEAGG_LLQUANTIZE		(DTRACEACT_AGGREGATION + 9)
 
 #define	DTRACEACT_ISAGG(x)		\
 	(DTRACEACT_CLASS(x) == DTRACEACT_AGGREGATION)
 
 #define	DTRACE_QUANTIZE_NBUCKETS	\
 	(((sizeof (uint64_t) * NBBY) - 1) * 2 + 1)
 
 #define	DTRACE_QUANTIZE_ZEROBUCKET	((sizeof (uint64_t) * NBBY) - 1)
 
 #define	DTRACE_QUANTIZE_BUCKETVAL(buck)					\
 	(int64_t)((buck) < DTRACE_QUANTIZE_ZEROBUCKET ?			\
 	-(1LL << (DTRACE_QUANTIZE_ZEROBUCKET - 1 - (buck))) :		\
 	(buck) == DTRACE_QUANTIZE_ZEROBUCKET ? 0 :			\
 	1LL << ((buck) - DTRACE_QUANTIZE_ZEROBUCKET - 1))
 
 #define	DTRACE_LQUANTIZE_STEPSHIFT		48
 #define	DTRACE_LQUANTIZE_STEPMASK		((uint64_t)UINT16_MAX << 48)
 #define	DTRACE_LQUANTIZE_LEVELSHIFT		32
 #define	DTRACE_LQUANTIZE_LEVELMASK		((uint64_t)UINT16_MAX << 32)
 #define	DTRACE_LQUANTIZE_BASESHIFT		0
 #define	DTRACE_LQUANTIZE_BASEMASK		UINT32_MAX
 
 #define	DTRACE_LQUANTIZE_STEP(x)		\
 	(uint16_t)(((x) & DTRACE_LQUANTIZE_STEPMASK) >> \
 	DTRACE_LQUANTIZE_STEPSHIFT)
 
 #define	DTRACE_LQUANTIZE_LEVELS(x)		\
 	(uint16_t)(((x) & DTRACE_LQUANTIZE_LEVELMASK) >> \
 	DTRACE_LQUANTIZE_LEVELSHIFT)
 
 #define	DTRACE_LQUANTIZE_BASE(x)		\
 	(int32_t)(((x) & DTRACE_LQUANTIZE_BASEMASK) >> \
 	DTRACE_LQUANTIZE_BASESHIFT)
 
 #define	DTRACE_LLQUANTIZE_FACTORSHIFT		48
 #define	DTRACE_LLQUANTIZE_FACTORMASK		((uint64_t)UINT16_MAX << 48)
 #define	DTRACE_LLQUANTIZE_LOWSHIFT		32
 #define	DTRACE_LLQUANTIZE_LOWMASK		((uint64_t)UINT16_MAX << 32)
 #define	DTRACE_LLQUANTIZE_HIGHSHIFT		16
 #define	DTRACE_LLQUANTIZE_HIGHMASK		((uint64_t)UINT16_MAX << 16)
 #define	DTRACE_LLQUANTIZE_NSTEPSHIFT		0
 #define	DTRACE_LLQUANTIZE_NSTEPMASK		UINT16_MAX
 
 #define	DTRACE_LLQUANTIZE_FACTOR(x)		\
 	(uint16_t)(((x) & DTRACE_LLQUANTIZE_FACTORMASK) >> \
 	DTRACE_LLQUANTIZE_FACTORSHIFT)
 
 #define	DTRACE_LLQUANTIZE_LOW(x)		\
 	(uint16_t)(((x) & DTRACE_LLQUANTIZE_LOWMASK) >> \
 	DTRACE_LLQUANTIZE_LOWSHIFT)
 
 #define	DTRACE_LLQUANTIZE_HIGH(x)		\
 	(uint16_t)(((x) & DTRACE_LLQUANTIZE_HIGHMASK) >> \
 	DTRACE_LLQUANTIZE_HIGHSHIFT)
 
 #define	DTRACE_LLQUANTIZE_NSTEP(x)		\
 	(uint16_t)(((x) & DTRACE_LLQUANTIZE_NSTEPMASK) >> \
 	DTRACE_LLQUANTIZE_NSTEPSHIFT)
 
 #define	DTRACE_USTACK_NFRAMES(x)	(uint32_t)((x) & UINT32_MAX)
 #define	DTRACE_USTACK_STRSIZE(x)	(uint32_t)((x) >> 32)
 #define	DTRACE_USTACK_ARG(x, y)		\
 	((((uint64_t)(y)) << 32) | ((x) & UINT32_MAX))
 
 #ifndef _LP64
 #if BYTE_ORDER == _BIG_ENDIAN
 #define	DTRACE_PTR(type, name)	uint32_t name##pad; type *name
 #else
 #define	DTRACE_PTR(type, name)	type *name; uint32_t name##pad
 #endif
 #else
 #define	DTRACE_PTR(type, name)	type *name
 #endif
 
 /*
  * DTrace Object Format (DOF)
  *
  * DTrace programs can be persistently encoded in the DOF format so that they
  * may be embedded in other programs (for example, in an ELF file) or in the
  * dtrace driver configuration file for use in anonymous tracing.  The DOF
  * format is versioned and extensible so that it can be revised and so that
  * internal data structures can be modified or extended compatibly.  All DOF
  * structures use fixed-size types, so the 32-bit and 64-bit representations
  * are identical and consumers can use either data model transparently.
  *
  * The file layout is structured as follows:
  *
  * +---------------+-------------------+----- ... ----+---- ... ------+
  * |   dof_hdr_t   |  dof_sec_t[ ... ] |   loadable   | non-loadable  |
  * | (file header) | (section headers) | section data | section data  |
  * +---------------+-------------------+----- ... ----+---- ... ------+
  * |<------------ dof_hdr.dofh_loadsz --------------->|               |
  * |<------------ dof_hdr.dofh_filesz ------------------------------->|
  *
  * The file header stores meta-data including a magic number, data model for
  * the instrumentation, data encoding, and properties of the DIF code within.
  * The header describes its own size and the size of the section headers.  By
  * convention, an array of section headers follows the file header, and then
  * the data for all loadable sections and unloadable sections.  This permits
  * consumer code to easily download the headers and all loadable data into the
  * DTrace driver in one contiguous chunk, omitting other extraneous sections.
  *
  * The section headers describe the size, offset, alignment, and section type
  * for each section.  Sections are described using a set of #defines that tell
  * the consumer what kind of data is expected.  Sections can contain links to
  * other sections by storing a dof_secidx_t, an index into the section header
  * array, inside of the section data structures.  The section header includes
  * an entry size so that sections with data arrays can grow their structures.
  *
  * The DOF data itself can contain many snippets of DIF (i.e. >1 DIFOs), which
  * are represented themselves as a collection of related DOF sections.  This
  * permits us to change the set of sections associated with a DIFO over time,
  * and also permits us to encode DIFOs that contain different sets of sections.
  * When a DOF section wants to refer to a DIFO, it stores the dof_secidx_t of a
  * section of type DOF_SECT_DIFOHDR.  This section's data is then an array of
  * dof_secidx_t's which in turn denote the sections associated with this DIFO.
  *
  * This loose coupling of the file structure (header and sections) to the
  * structure of the DTrace program itself (ECB descriptions, action
  * descriptions, and DIFOs) permits activities such as relocation processing
  * to occur in a single pass without having to understand D program structure.
  *
  * Finally, strings are always stored in ELF-style string tables along with a
  * string table section index and string table offset.  Therefore strings in
  * DOF are always arbitrary-length and not bound to the current implementation.
  */
 
 #define	DOF_ID_SIZE	16	/* total size of dofh_ident[] in bytes */
 
 typedef struct dof_hdr {
 	uint8_t dofh_ident[DOF_ID_SIZE]; /* identification bytes (see below) */
 	uint32_t dofh_flags;		/* file attribute flags (if any) */
 	uint32_t dofh_hdrsize;		/* size of file header in bytes */
 	uint32_t dofh_secsize;		/* size of section header in bytes */
 	uint32_t dofh_secnum;		/* number of section headers */
 	uint64_t dofh_secoff;		/* file offset of section headers */
 	uint64_t dofh_loadsz;		/* file size of loadable portion */
 	uint64_t dofh_filesz;		/* file size of entire DOF file */
 	uint64_t dofh_pad;		/* reserved for future use */
 } dof_hdr_t;
 
 #define	DOF_ID_MAG0	0	/* first byte of magic number */
 #define	DOF_ID_MAG1	1	/* second byte of magic number */
 #define	DOF_ID_MAG2	2	/* third byte of magic number */
 #define	DOF_ID_MAG3	3	/* fourth byte of magic number */
 #define	DOF_ID_MODEL	4	/* DOF data model (see below) */
 #define	DOF_ID_ENCODING	5	/* DOF data encoding (see below) */
 #define	DOF_ID_VERSION	6	/* DOF file format major version (see below) */
 #define	DOF_ID_DIFVERS	7	/* DIF instruction set version */
 #define	DOF_ID_DIFIREG	8	/* DIF integer registers used by compiler */
 #define	DOF_ID_DIFTREG	9	/* DIF tuple registers used by compiler */
 #define	DOF_ID_PAD	10	/* start of padding bytes (all zeroes) */
 
 #define	DOF_MAG_MAG0	0x7F	/* DOF_ID_MAG[0-3] */
 #define	DOF_MAG_MAG1	'D'
 #define	DOF_MAG_MAG2	'O'
 #define	DOF_MAG_MAG3	'F'
 
 #define	DOF_MAG_STRING	"\177DOF"
 #define	DOF_MAG_STRLEN	4
 
 #define	DOF_MODEL_NONE	0	/* DOF_ID_MODEL */
 #define	DOF_MODEL_ILP32	1
 #define	DOF_MODEL_LP64	2
 
 #ifdef _LP64
 #define	DOF_MODEL_NATIVE	DOF_MODEL_LP64
 #else
 #define	DOF_MODEL_NATIVE	DOF_MODEL_ILP32
 #endif
 
 #define	DOF_ENCODE_NONE	0	/* DOF_ID_ENCODING */
 #define	DOF_ENCODE_LSB	1
 #define	DOF_ENCODE_MSB	2
 
 #if BYTE_ORDER == _BIG_ENDIAN
 #define	DOF_ENCODE_NATIVE	DOF_ENCODE_MSB
 #else
 #define	DOF_ENCODE_NATIVE	DOF_ENCODE_LSB
 #endif
 
 #define	DOF_VERSION_1	1	/* DOF version 1: Solaris 10 FCS */
 #define	DOF_VERSION_2	2	/* DOF version 2: Solaris Express 6/06 */
 #define	DOF_VERSION	DOF_VERSION_2	/* Latest DOF version */
 
 #define	DOF_FL_VALID	0	/* mask of all valid dofh_flags bits */
 
 typedef uint32_t dof_secidx_t;	/* section header table index type */
 typedef uint32_t dof_stridx_t;	/* string table index type */
 
 #define	DOF_SECIDX_NONE	(-1U)	/* null value for section indices */
 #define	DOF_STRIDX_NONE	(-1U)	/* null value for string indices */
 
 typedef struct dof_sec {
 	uint32_t dofs_type;	/* section type (see below) */
 	uint32_t dofs_align;	/* section data memory alignment */
 	uint32_t dofs_flags;	/* section flags (if any) */
 	uint32_t dofs_entsize;	/* size of section entry (if table) */
 	uint64_t dofs_offset;	/* offset of section data within file */
 	uint64_t dofs_size;	/* size of section data in bytes */
 } dof_sec_t;
 
 #define	DOF_SECT_NONE		0	/* null section */
 #define	DOF_SECT_COMMENTS	1	/* compiler comments */
 #define	DOF_SECT_SOURCE		2	/* D program source code */
 #define	DOF_SECT_ECBDESC	3	/* dof_ecbdesc_t */
 #define	DOF_SECT_PROBEDESC	4	/* dof_probedesc_t */
 #define	DOF_SECT_ACTDESC	5	/* dof_actdesc_t array */
 #define	DOF_SECT_DIFOHDR	6	/* dof_difohdr_t (variable length) */
 #define	DOF_SECT_DIF		7	/* uint32_t array of byte code */
 #define	DOF_SECT_STRTAB		8	/* string table */
 #define	DOF_SECT_VARTAB		9	/* dtrace_difv_t array */
 #define	DOF_SECT_RELTAB		10	/* dof_relodesc_t array */
 #define	DOF_SECT_TYPTAB		11	/* dtrace_diftype_t array */
 #define	DOF_SECT_URELHDR	12	/* dof_relohdr_t (user relocations) */
 #define	DOF_SECT_KRELHDR	13	/* dof_relohdr_t (kernel relocations) */
 #define	DOF_SECT_OPTDESC	14	/* dof_optdesc_t array */
 #define	DOF_SECT_PROVIDER	15	/* dof_provider_t */
 #define	DOF_SECT_PROBES		16	/* dof_probe_t array */
 #define	DOF_SECT_PRARGS		17	/* uint8_t array (probe arg mappings) */
 #define	DOF_SECT_PROFFS		18	/* uint32_t array (probe arg offsets) */
 #define	DOF_SECT_INTTAB		19	/* uint64_t array */
 #define	DOF_SECT_UTSNAME	20	/* struct utsname */
 #define	DOF_SECT_XLTAB		21	/* dof_xlref_t array */
 #define	DOF_SECT_XLMEMBERS	22	/* dof_xlmember_t array */
 #define	DOF_SECT_XLIMPORT	23	/* dof_xlator_t */
 #define	DOF_SECT_XLEXPORT	24	/* dof_xlator_t */
 #define	DOF_SECT_PREXPORT	25	/* dof_secidx_t array (exported objs) */
 #define	DOF_SECT_PRENOFFS	26	/* uint32_t array (enabled offsets) */
 
 #define	DOF_SECF_LOAD		1	/* section should be loaded */
 
 #define	DOF_SEC_ISLOADABLE(x)						\
 	(((x) == DOF_SECT_ECBDESC) || ((x) == DOF_SECT_PROBEDESC) ||	\
 	((x) == DOF_SECT_ACTDESC) || ((x) == DOF_SECT_DIFOHDR) ||	\
 	((x) == DOF_SECT_DIF) || ((x) == DOF_SECT_STRTAB) ||		\
 	((x) == DOF_SECT_VARTAB) || ((x) == DOF_SECT_RELTAB) ||		\
 	((x) == DOF_SECT_TYPTAB) || ((x) == DOF_SECT_URELHDR) ||	\
 	((x) == DOF_SECT_KRELHDR) || ((x) == DOF_SECT_OPTDESC) ||	\
 	((x) == DOF_SECT_PROVIDER) || ((x) == DOF_SECT_PROBES) ||	\
 	((x) == DOF_SECT_PRARGS) || ((x) == DOF_SECT_PROFFS) ||		\
 	((x) == DOF_SECT_INTTAB) || ((x) == DOF_SECT_XLTAB) ||		\
 	((x) == DOF_SECT_XLMEMBERS) || ((x) == DOF_SECT_XLIMPORT) ||	\
 	((x) == DOF_SECT_XLEXPORT) ||  ((x) == DOF_SECT_PREXPORT) || 	\
 	((x) == DOF_SECT_PRENOFFS))
 
 typedef struct dof_ecbdesc {
 	dof_secidx_t dofe_probes;	/* link to DOF_SECT_PROBEDESC */
 	dof_secidx_t dofe_pred;		/* link to DOF_SECT_DIFOHDR */
 	dof_secidx_t dofe_actions;	/* link to DOF_SECT_ACTDESC */
 	uint32_t dofe_pad;		/* reserved for future use */
 	uint64_t dofe_uarg;		/* user-supplied library argument */
 } dof_ecbdesc_t;
 
 typedef struct dof_probedesc {
 	dof_secidx_t dofp_strtab;	/* link to DOF_SECT_STRTAB section */
 	dof_stridx_t dofp_provider;	/* provider string */
 	dof_stridx_t dofp_mod;		/* module string */
 	dof_stridx_t dofp_func;		/* function string */
 	dof_stridx_t dofp_name;		/* name string */
 	uint32_t dofp_id;		/* probe identifier (or zero) */
 } dof_probedesc_t;
 
 typedef struct dof_actdesc {
 	dof_secidx_t dofa_difo;		/* link to DOF_SECT_DIFOHDR */
 	dof_secidx_t dofa_strtab;	/* link to DOF_SECT_STRTAB section */
 	uint32_t dofa_kind;		/* action kind (DTRACEACT_* constant) */
 	uint32_t dofa_ntuple;		/* number of subsequent tuple actions */
 	uint64_t dofa_arg;		/* kind-specific argument */
 	uint64_t dofa_uarg;		/* user-supplied argument */
 } dof_actdesc_t;
 
 typedef struct dof_difohdr {
 	dtrace_diftype_t dofd_rtype;	/* return type for this fragment */
 	dof_secidx_t dofd_links[1];	/* variable length array of indices */
 } dof_difohdr_t;
 
 typedef struct dof_relohdr {
 	dof_secidx_t dofr_strtab;	/* link to DOF_SECT_STRTAB for names */
 	dof_secidx_t dofr_relsec;	/* link to DOF_SECT_RELTAB for relos */
 	dof_secidx_t dofr_tgtsec;	/* link to section we are relocating */
 } dof_relohdr_t;
 
 typedef struct dof_relodesc {
 	dof_stridx_t dofr_name;		/* string name of relocation symbol */
 	uint32_t dofr_type;		/* relo type (DOF_RELO_* constant) */
 	uint64_t dofr_offset;		/* byte offset for relocation */
 	uint64_t dofr_data;		/* additional type-specific data */
 } dof_relodesc_t;
 
 #define	DOF_RELO_NONE	0		/* empty relocation entry */
 #define	DOF_RELO_SETX	1		/* relocate setx value */
 #define	DOF_RELO_DOFREL	2		/* relocate DOF-relative value */
 
 typedef struct dof_optdesc {
 	uint32_t dofo_option;		/* option identifier */
 	dof_secidx_t dofo_strtab;	/* string table, if string option */
 	uint64_t dofo_value;		/* option value or string index */
 } dof_optdesc_t;
 
 typedef uint32_t dof_attr_t;		/* encoded stability attributes */
 
 #define	DOF_ATTR(n, d, c)	(((n) << 24) | ((d) << 16) | ((c) << 8))
 #define	DOF_ATTR_NAME(a)	(((a) >> 24) & 0xff)
 #define	DOF_ATTR_DATA(a)	(((a) >> 16) & 0xff)
 #define	DOF_ATTR_CLASS(a)	(((a) >>  8) & 0xff)
 
 typedef struct dof_provider {
 	dof_secidx_t dofpv_strtab;	/* link to DOF_SECT_STRTAB section */
 	dof_secidx_t dofpv_probes;	/* link to DOF_SECT_PROBES section */
 	dof_secidx_t dofpv_prargs;	/* link to DOF_SECT_PRARGS section */
 	dof_secidx_t dofpv_proffs;	/* link to DOF_SECT_PROFFS section */
 	dof_stridx_t dofpv_name;	/* provider name string */
 	dof_attr_t dofpv_provattr;	/* provider attributes */
 	dof_attr_t dofpv_modattr;	/* module attributes */
 	dof_attr_t dofpv_funcattr;	/* function attributes */
 	dof_attr_t dofpv_nameattr;	/* name attributes */
 	dof_attr_t dofpv_argsattr;	/* args attributes */
 	dof_secidx_t dofpv_prenoffs;	/* link to DOF_SECT_PRENOFFS section */
 } dof_provider_t;
 
 typedef struct dof_probe {
 	uint64_t dofpr_addr;		/* probe base address or offset */
 	dof_stridx_t dofpr_func;	/* probe function string */
 	dof_stridx_t dofpr_name;	/* probe name string */
 	dof_stridx_t dofpr_nargv;	/* native argument type strings */
 	dof_stridx_t dofpr_xargv;	/* translated argument type strings */
 	uint32_t dofpr_argidx;		/* index of first argument mapping */
 	uint32_t dofpr_offidx;		/* index of first offset entry */
 	uint8_t dofpr_nargc;		/* native argument count */
 	uint8_t dofpr_xargc;		/* translated argument count */
 	uint16_t dofpr_noffs;		/* number of offset entries for probe */
 	uint32_t dofpr_enoffidx;	/* index of first is-enabled offset */
 	uint16_t dofpr_nenoffs;		/* number of is-enabled offsets */
 	uint16_t dofpr_pad1;		/* reserved for future use */
 	uint32_t dofpr_pad2;		/* reserved for future use */
 } dof_probe_t;
 
 typedef struct dof_xlator {
 	dof_secidx_t dofxl_members;	/* link to DOF_SECT_XLMEMBERS section */
 	dof_secidx_t dofxl_strtab;	/* link to DOF_SECT_STRTAB section */
 	dof_stridx_t dofxl_argv;	/* input parameter type strings */
 	uint32_t dofxl_argc;		/* input parameter list length */
 	dof_stridx_t dofxl_type;	/* output type string name */
 	dof_attr_t dofxl_attr;		/* output stability attributes */
 } dof_xlator_t;
 
 typedef struct dof_xlmember {
 	dof_secidx_t dofxm_difo;	/* member link to DOF_SECT_DIFOHDR */
 	dof_stridx_t dofxm_name;	/* member name */
 	dtrace_diftype_t dofxm_type;	/* member type */
 } dof_xlmember_t;
 
 typedef struct dof_xlref {
 	dof_secidx_t dofxr_xlator;	/* link to DOF_SECT_XLATORS section */
 	uint32_t dofxr_member;		/* index of referenced dof_xlmember */
 	uint32_t dofxr_argn;		/* index of argument for DIF_OP_XLARG */
 } dof_xlref_t;
 
 /*
  * DTrace Intermediate Format Object (DIFO)
  *
  * A DIFO is used to store the compiled DIF for a D expression, its return
  * type, and its string and variable tables.  The string table is a single
  * buffer of character data into which sets instructions and variable
  * references can reference strings using a byte offset.  The variable table
  * is an array of dtrace_difv_t structures that describe the name and type of
  * each variable and the id used in the DIF code.  This structure is described
  * above in the DIF section of this header file.  The DIFO is used at both
  * user-level (in the library) and in the kernel, but the structure is never
  * passed between the two: the DOF structures form the only interface.  As a
  * result, the definition can change depending on the presence of _KERNEL.
  */
 typedef struct dtrace_difo {
 	dif_instr_t *dtdo_buf;		/* instruction buffer */
 	uint64_t *dtdo_inttab;		/* integer table (optional) */
 	char *dtdo_strtab;		/* string table (optional) */
 	dtrace_difv_t *dtdo_vartab;	/* variable table (optional) */
 	uint_t dtdo_len;		/* length of instruction buffer */
 	uint_t dtdo_intlen;		/* length of integer table */
 	uint_t dtdo_strlen;		/* length of string table */
 	uint_t dtdo_varlen;		/* length of variable table */
 	dtrace_diftype_t dtdo_rtype;	/* return type */
 	uint_t dtdo_refcnt;		/* owner reference count */
 	uint_t dtdo_destructive;	/* invokes destructive subroutines */
 #ifndef _KERNEL
 	dof_relodesc_t *dtdo_kreltab;	/* kernel relocations */
 	dof_relodesc_t *dtdo_ureltab;	/* user relocations */
 	struct dt_node **dtdo_xlmtab;	/* translator references */
 	uint_t dtdo_krelen;		/* length of krelo table */
 	uint_t dtdo_urelen;		/* length of urelo table */
 	uint_t dtdo_xlmlen;		/* length of translator table */
 #endif
 } dtrace_difo_t;
 
 /*
  * DTrace Enabling Description Structures
  *
  * When DTrace is tracking the description of a DTrace enabling entity (probe,
  * predicate, action, ECB, record, etc.), it does so in a description
  * structure.  These structures all end in "desc", and are used at both
  * user-level and in the kernel -- but (with the exception of
  * dtrace_probedesc_t) they are never passed between them.  Typically,
  * user-level will use the description structures when assembling an enabling.
  * It will then distill those description structures into a DOF object (see
  * above), and send it into the kernel.  The kernel will again use the
  * description structures to create a description of the enabling as it reads
  * the DOF.  When the description is complete, the enabling will be actually
  * created -- turning it into the structures that represent the enabling
  * instead of merely describing it.  Not surprisingly, the description
  * structures bear a strong resemblance to the DOF structures that act as their
  * conduit.
  */
 struct dtrace_predicate;
 
 typedef struct dtrace_probedesc {
 	dtrace_id_t dtpd_id;			/* probe identifier */
 	char dtpd_provider[DTRACE_PROVNAMELEN]; /* probe provider name */
 	char dtpd_mod[DTRACE_MODNAMELEN];	/* probe module name */
 	char dtpd_func[DTRACE_FUNCNAMELEN];	/* probe function name */
 	char dtpd_name[DTRACE_NAMELEN];		/* probe name */
 } dtrace_probedesc_t;
 
 typedef struct dtrace_repldesc {
 	dtrace_probedesc_t dtrpd_match;		/* probe descr. to match */
 	dtrace_probedesc_t dtrpd_create;	/* probe descr. to create */
 } dtrace_repldesc_t;
 
 typedef struct dtrace_preddesc {
 	dtrace_difo_t *dtpdd_difo;		/* pointer to DIF object */
 	struct dtrace_predicate *dtpdd_predicate; /* pointer to predicate */
 } dtrace_preddesc_t;
 
 typedef struct dtrace_actdesc {
 	dtrace_difo_t *dtad_difo;		/* pointer to DIF object */
 	struct dtrace_actdesc *dtad_next;	/* next action */
 	dtrace_actkind_t dtad_kind;		/* kind of action */
 	uint32_t dtad_ntuple;			/* number in tuple */
 	uint64_t dtad_arg;			/* action argument */
 	uint64_t dtad_uarg;			/* user argument */
 	int dtad_refcnt;			/* reference count */
 } dtrace_actdesc_t;
 
 typedef struct dtrace_ecbdesc {
 	dtrace_actdesc_t *dted_action;		/* action description(s) */
 	dtrace_preddesc_t dted_pred;		/* predicate description */
 	dtrace_probedesc_t dted_probe;		/* probe description */
 	uint64_t dted_uarg;			/* library argument */
 	int dted_refcnt;			/* reference count */
 } dtrace_ecbdesc_t;
 
 /*
  * DTrace Metadata Description Structures
  *
  * DTrace separates the trace data stream from the metadata stream.  The only
  * metadata tokens placed in the data stream are the dtrace_rechdr_t (EPID +
  * timestamp) or (in the case of aggregations) aggregation identifiers.  To
  * determine the structure of the data, DTrace consumers pass the token to the
  * kernel, and receive in return a corresponding description of the enabled
  * probe (via the dtrace_eprobedesc structure) or the aggregation (via the
  * dtrace_aggdesc structure).  Both of these structures are expressed in terms
  * of record descriptions (via the dtrace_recdesc structure) that describe the
  * exact structure of the data.  Some record descriptions may also contain a
  * format identifier; this additional bit of metadata can be retrieved from the
  * kernel, for which a format description is returned via the dtrace_fmtdesc
  * structure.  Note that all four of these structures must be bitness-neutral
  * to allow for a 32-bit DTrace consumer on a 64-bit kernel.
  */
 typedef struct dtrace_recdesc {
 	dtrace_actkind_t dtrd_action;		/* kind of action */
 	uint32_t dtrd_size;			/* size of record */
 	uint32_t dtrd_offset;			/* offset in ECB's data */
 	uint16_t dtrd_alignment;		/* required alignment */
 	uint16_t dtrd_format;			/* format, if any */
 	uint64_t dtrd_arg;			/* action argument */
 	uint64_t dtrd_uarg;			/* user argument */
 } dtrace_recdesc_t;
 
 typedef struct dtrace_eprobedesc {
 	dtrace_epid_t dtepd_epid;		/* enabled probe ID */
 	dtrace_id_t dtepd_probeid;		/* probe ID */
 	uint64_t dtepd_uarg;			/* library argument */
 	uint32_t dtepd_size;			/* total size */
 	int dtepd_nrecs;			/* number of records */
 	dtrace_recdesc_t dtepd_rec[1];		/* records themselves */
 } dtrace_eprobedesc_t;
 
 typedef struct dtrace_aggdesc {
 	DTRACE_PTR(char, dtagd_name);		/* not filled in by kernel */
 	dtrace_aggvarid_t dtagd_varid;		/* not filled in by kernel */
 	int dtagd_flags;			/* not filled in by kernel */
 	dtrace_aggid_t dtagd_id;		/* aggregation ID */
 	dtrace_epid_t dtagd_epid;		/* enabled probe ID */
 	uint32_t dtagd_size;			/* size in bytes */
 	int dtagd_nrecs;			/* number of records */
 	uint32_t dtagd_pad;			/* explicit padding */
 	dtrace_recdesc_t dtagd_rec[1];		/* record descriptions */
 } dtrace_aggdesc_t;
 
 typedef struct dtrace_fmtdesc {
 	DTRACE_PTR(char, dtfd_string);		/* format string */
 	int dtfd_length;			/* length of format string */
 	uint16_t dtfd_format;			/* format identifier */
 } dtrace_fmtdesc_t;
 
 #define	DTRACE_SIZEOF_EPROBEDESC(desc)				\
 	(sizeof (dtrace_eprobedesc_t) + ((desc)->dtepd_nrecs ?	\
 	(((desc)->dtepd_nrecs - 1) * sizeof (dtrace_recdesc_t)) : 0))
 
 #define	DTRACE_SIZEOF_AGGDESC(desc)				\
 	(sizeof (dtrace_aggdesc_t) + ((desc)->dtagd_nrecs ?	\
 	(((desc)->dtagd_nrecs - 1) * sizeof (dtrace_recdesc_t)) : 0))
 
 /*
  * DTrace Option Interface
  *
  * Run-time DTrace options are set and retrieved via DOF_SECT_OPTDESC sections
  * in a DOF image.  The dof_optdesc structure contains an option identifier and
  * an option value.  The valid option identifiers are found below; the mapping
  * between option identifiers and option identifying strings is maintained at
  * user-level.  Note that the value of DTRACEOPT_UNSET is such that all of the
  * following are potentially valid option values:  all positive integers, zero
  * and negative one.  Some options (notably "bufpolicy" and "bufresize") take
  * predefined tokens as their values; these are defined with
  * DTRACEOPT_{option}_{token}.
  */
 #define	DTRACEOPT_BUFSIZE	0	/* buffer size */
 #define	DTRACEOPT_BUFPOLICY	1	/* buffer policy */
 #define	DTRACEOPT_DYNVARSIZE	2	/* dynamic variable size */
 #define	DTRACEOPT_AGGSIZE	3	/* aggregation size */
 #define	DTRACEOPT_SPECSIZE	4	/* speculation size */
 #define	DTRACEOPT_NSPEC		5	/* number of speculations */
 #define	DTRACEOPT_STRSIZE	6	/* string size */
 #define	DTRACEOPT_CLEANRATE	7	/* dynvar cleaning rate */
 #define	DTRACEOPT_CPU		8	/* CPU to trace */
 #define	DTRACEOPT_BUFRESIZE	9	/* buffer resizing policy */
 #define	DTRACEOPT_GRABANON	10	/* grab anonymous state, if any */
 #define	DTRACEOPT_FLOWINDENT	11	/* indent function entry/return */
 #define	DTRACEOPT_QUIET		12	/* only output explicitly traced data */
 #define	DTRACEOPT_STACKFRAMES	13	/* number of stack frames */
 #define	DTRACEOPT_USTACKFRAMES	14	/* number of user stack frames */
 #define	DTRACEOPT_AGGRATE	15	/* aggregation snapshot rate */
 #define	DTRACEOPT_SWITCHRATE	16	/* buffer switching rate */
 #define	DTRACEOPT_STATUSRATE	17	/* status rate */
 #define	DTRACEOPT_DESTRUCTIVE	18	/* destructive actions allowed */
 #define	DTRACEOPT_STACKINDENT	19	/* output indent for stack traces */
 #define	DTRACEOPT_RAWBYTES	20	/* always print bytes in raw form */
 #define	DTRACEOPT_JSTACKFRAMES	21	/* number of jstack() frames */
 #define	DTRACEOPT_JSTACKSTRSIZE	22	/* size of jstack() string table */
 #define	DTRACEOPT_AGGSORTKEY	23	/* sort aggregations by key */
 #define	DTRACEOPT_AGGSORTREV	24	/* reverse-sort aggregations */
 #define	DTRACEOPT_AGGSORTPOS	25	/* agg. position to sort on */
 #define	DTRACEOPT_AGGSORTKEYPOS	26	/* agg. key position to sort on */
 #define	DTRACEOPT_TEMPORAL	27	/* temporally ordered output */
 #define	DTRACEOPT_AGGHIST	28	/* histogram aggregation output */
 #define	DTRACEOPT_AGGPACK	29	/* packed aggregation output */
 #define	DTRACEOPT_AGGZOOM	30	/* zoomed aggregation scaling */
 #define	DTRACEOPT_ZONE		31	/* zone in which to enable probes */
 #define	DTRACEOPT_MAX		32	/* number of options */
 
 #define	DTRACEOPT_UNSET		(dtrace_optval_t)-2	/* unset option */
 
 #define	DTRACEOPT_BUFPOLICY_RING	0	/* ring buffer */
 #define	DTRACEOPT_BUFPOLICY_FILL	1	/* fill buffer, then stop */
 #define	DTRACEOPT_BUFPOLICY_SWITCH	2	/* switch buffers */
 
 #define	DTRACEOPT_BUFRESIZE_AUTO	0	/* automatic resizing */
 #define	DTRACEOPT_BUFRESIZE_MANUAL	1	/* manual resizing */
 
 /*
  * DTrace Buffer Interface
  *
  * In order to get a snapshot of the principal or aggregation buffer,
  * user-level passes a buffer description to the kernel with the dtrace_bufdesc
  * structure.  This describes which CPU user-level is interested in, and
  * where user-level wishes the kernel to snapshot the buffer to (the
  * dtbd_data field).  The kernel uses the same structure to pass back some
  * information regarding the buffer:  the size of data actually copied out, the
  * number of drops, the number of errors, the offset of the oldest record,
  * and the time of the snapshot.
  *
  * If the buffer policy is a "switch" policy, taking a snapshot of the
  * principal buffer has the additional effect of switching the active and
  * inactive buffers.  Taking a snapshot of the aggregation buffer _always_ has
  * the additional effect of switching the active and inactive buffers.
  */
 typedef struct dtrace_bufdesc {
 	uint64_t dtbd_size;			/* size of buffer */
 	uint32_t dtbd_cpu;			/* CPU or DTRACE_CPUALL */
 	uint32_t dtbd_errors;			/* number of errors */
 	uint64_t dtbd_drops;			/* number of drops */
 	DTRACE_PTR(char, dtbd_data);		/* data */
 	uint64_t dtbd_oldest;			/* offset of oldest record */
 	uint64_t dtbd_timestamp;		/* hrtime of snapshot */
 } dtrace_bufdesc_t;
 
 /*
  * Each record in the buffer (dtbd_data) begins with a header that includes
  * the epid and a timestamp.  The timestamp is split into two 4-byte parts
  * so that we do not require 8-byte alignment.
  */
 typedef struct dtrace_rechdr {
 	dtrace_epid_t dtrh_epid;		/* enabled probe id */
 	uint32_t dtrh_timestamp_hi;		/* high bits of hrtime_t */
 	uint32_t dtrh_timestamp_lo;		/* low bits of hrtime_t */
 } dtrace_rechdr_t;
 
 #define	DTRACE_RECORD_LOAD_TIMESTAMP(dtrh)			\
 	((dtrh)->dtrh_timestamp_lo +				\
 	((uint64_t)(dtrh)->dtrh_timestamp_hi << 32))
 
 #define	DTRACE_RECORD_STORE_TIMESTAMP(dtrh, hrtime) {		\
 	(dtrh)->dtrh_timestamp_lo = (uint32_t)hrtime;		\
 	(dtrh)->dtrh_timestamp_hi = hrtime >> 32;		\
 }
 
 /*
  * DTrace Status
  *
  * The status of DTrace is relayed via the dtrace_status structure.  This
  * structure contains members to count drops other than the capacity drops
  * available via the buffer interface (see above).  This consists of dynamic
  * drops (including capacity dynamic drops, rinsing drops and dirty drops), and
  * speculative drops (including capacity speculative drops, drops due to busy
  * speculative buffers and drops due to unavailable speculative buffers).
  * Additionally, the status structure contains a field to indicate the number
  * of "fill"-policy buffers have been filled and a boolean field to indicate
  * that exit() has been called.  If the dtst_exiting field is non-zero, no
  * further data will be generated until tracing is stopped (at which time any
  * enablings of the END action will be processed); if user-level sees that
  * this field is non-zero, tracing should be stopped as soon as possible.
  */
 typedef struct dtrace_status {
 	uint64_t dtst_dyndrops;			/* dynamic drops */
 	uint64_t dtst_dyndrops_rinsing;		/* dyn drops due to rinsing */
 	uint64_t dtst_dyndrops_dirty;		/* dyn drops due to dirty */
 	uint64_t dtst_specdrops;		/* speculative drops */
 	uint64_t dtst_specdrops_busy;		/* spec drops due to busy */
 	uint64_t dtst_specdrops_unavail;	/* spec drops due to unavail */
 	uint64_t dtst_errors;			/* total errors */
 	uint64_t dtst_filled;			/* number of filled bufs */
 	uint64_t dtst_stkstroverflows;		/* stack string tab overflows */
 	uint64_t dtst_dblerrors;		/* errors in ERROR probes */
 	char dtst_killed;			/* non-zero if killed */
 	char dtst_exiting;			/* non-zero if exit() called */
 	char dtst_pad[6];			/* pad out to 64-bit align */
 } dtrace_status_t;
 
 /*
  * DTrace Configuration
  *
  * User-level may need to understand some elements of the kernel DTrace
  * configuration in order to generate correct DIF.  This information is
  * conveyed via the dtrace_conf structure.
  */
 typedef struct dtrace_conf {
 	uint_t dtc_difversion;			/* supported DIF version */
 	uint_t dtc_difintregs;			/* # of DIF integer registers */
 	uint_t dtc_diftupregs;			/* # of DIF tuple registers */
 	uint_t dtc_ctfmodel;			/* CTF data model */
 	uint_t dtc_pad[8];			/* reserved for future use */
 } dtrace_conf_t;
 
 /*
  * DTrace Faults
  *
  * The constants below DTRACEFLT_LIBRARY indicate probe processing faults;
  * constants at or above DTRACEFLT_LIBRARY indicate faults in probe
  * postprocessing at user-level.  Probe processing faults induce an ERROR
  * probe and are replicated in unistd.d to allow users' ERROR probes to decode
  * the error condition using thse symbolic labels.
  */
 #define	DTRACEFLT_UNKNOWN		0	/* Unknown fault */
 #define	DTRACEFLT_BADADDR		1	/* Bad address */
 #define	DTRACEFLT_BADALIGN		2	/* Bad alignment */
 #define	DTRACEFLT_ILLOP			3	/* Illegal operation */
 #define	DTRACEFLT_DIVZERO		4	/* Divide-by-zero */
 #define	DTRACEFLT_NOSCRATCH		5	/* Out of scratch space */
 #define	DTRACEFLT_KPRIV			6	/* Illegal kernel access */
 #define	DTRACEFLT_UPRIV			7	/* Illegal user access */
 #define	DTRACEFLT_TUPOFLOW		8	/* Tuple stack overflow */
 #define	DTRACEFLT_BADSTACK		9	/* Bad stack */
 
 #define	DTRACEFLT_LIBRARY		1000	/* Library-level fault */
 
 /*
  * DTrace Argument Types
  *
  * Because it would waste both space and time, argument types do not reside
  * with the probe.  In order to determine argument types for args[X]
  * variables, the D compiler queries for argument types on a probe-by-probe
  * basis.  (This optimizes for the common case that arguments are either not
  * used or used in an untyped fashion.)  Typed arguments are specified with a
  * string of the type name in the dtragd_native member of the argument
  * description structure.  Typed arguments may be further translated to types
  * of greater stability; the provider indicates such a translated argument by
  * filling in the dtargd_xlate member with the string of the translated type.
  * Finally, the provider may indicate which argument value a given argument
  * maps to by setting the dtargd_mapping member -- allowing a single argument
  * to map to multiple args[X] variables.
  */
 typedef struct dtrace_argdesc {
 	dtrace_id_t dtargd_id;			/* probe identifier */
 	int dtargd_ndx;				/* arg number (-1 iff none) */
 	int dtargd_mapping;			/* value mapping */
 	char dtargd_native[DTRACE_ARGTYPELEN];	/* native type name */
 	char dtargd_xlate[DTRACE_ARGTYPELEN];	/* translated type name */
 } dtrace_argdesc_t;
 
 /*
  * DTrace Stability Attributes
  *
  * Each DTrace provider advertises the name and data stability of each of its
  * probe description components, as well as its architectural dependencies.
  * The D compiler can query the provider attributes (dtrace_pattr_t below) in
  * order to compute the properties of an input program and report them.
  */
 typedef uint8_t dtrace_stability_t;	/* stability code (see attributes(5)) */
 typedef uint8_t dtrace_class_t;		/* architectural dependency class */
 
 #define	DTRACE_STABILITY_INTERNAL	0	/* private to DTrace itself */
 #define	DTRACE_STABILITY_PRIVATE	1	/* private to Sun (see docs) */
 #define	DTRACE_STABILITY_OBSOLETE	2	/* scheduled for removal */
 #define	DTRACE_STABILITY_EXTERNAL	3	/* not controlled by Sun */
 #define	DTRACE_STABILITY_UNSTABLE	4	/* new or rapidly changing */
 #define	DTRACE_STABILITY_EVOLVING	5	/* less rapidly changing */
 #define	DTRACE_STABILITY_STABLE		6	/* mature interface from Sun */
 #define	DTRACE_STABILITY_STANDARD	7	/* industry standard */
 #define	DTRACE_STABILITY_MAX		7	/* maximum valid stability */
 
 #define	DTRACE_CLASS_UNKNOWN	0	/* unknown architectural dependency */
 #define	DTRACE_CLASS_CPU	1	/* CPU-module-specific */
 #define	DTRACE_CLASS_PLATFORM	2	/* platform-specific (uname -i) */
 #define	DTRACE_CLASS_GROUP	3	/* hardware-group-specific (uname -m) */
 #define	DTRACE_CLASS_ISA	4	/* ISA-specific (uname -p) */
 #define	DTRACE_CLASS_COMMON	5	/* common to all systems */
 #define	DTRACE_CLASS_MAX	5	/* maximum valid class */
 
 #define	DTRACE_PRIV_NONE	0x0000
 #define	DTRACE_PRIV_KERNEL	0x0001
 #define	DTRACE_PRIV_USER	0x0002
 #define	DTRACE_PRIV_PROC	0x0004
 #define	DTRACE_PRIV_OWNER	0x0008
 #define	DTRACE_PRIV_ZONEOWNER	0x0010
 
 #define	DTRACE_PRIV_ALL	\
 	(DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER | \
 	DTRACE_PRIV_PROC | DTRACE_PRIV_OWNER | DTRACE_PRIV_ZONEOWNER)
 
 typedef struct dtrace_ppriv {
 	uint32_t dtpp_flags;			/* privilege flags */
 	uid_t dtpp_uid;				/* user ID */
 	zoneid_t dtpp_zoneid;			/* zone ID */
 } dtrace_ppriv_t;
 
 typedef struct dtrace_attribute {
 	dtrace_stability_t dtat_name;		/* entity name stability */
 	dtrace_stability_t dtat_data;		/* entity data stability */
 	dtrace_class_t dtat_class;		/* entity data dependency */
 } dtrace_attribute_t;
 
 typedef struct dtrace_pattr {
 	dtrace_attribute_t dtpa_provider;	/* provider attributes */
 	dtrace_attribute_t dtpa_mod;		/* module attributes */
 	dtrace_attribute_t dtpa_func;		/* function attributes */
 	dtrace_attribute_t dtpa_name;		/* name attributes */
 	dtrace_attribute_t dtpa_args;		/* args[] attributes */
 } dtrace_pattr_t;
 
 typedef struct dtrace_providerdesc {
 	char dtvd_name[DTRACE_PROVNAMELEN];	/* provider name */
 	dtrace_pattr_t dtvd_attr;		/* stability attributes */
 	dtrace_ppriv_t dtvd_priv;		/* privileges required */
 } dtrace_providerdesc_t;
 
 /*
  * DTrace Pseudodevice Interface
  *
  * DTrace is controlled through ioctl(2)'s to the in-kernel dtrace:dtrace
  * pseudodevice driver.  These ioctls comprise the user-kernel interface to
  * DTrace.
  */
 #ifdef illumos
 #define	DTRACEIOC		(('d' << 24) | ('t' << 16) | ('r' << 8))
 #define	DTRACEIOC_PROVIDER	(DTRACEIOC | 1)		/* provider query */
 #define	DTRACEIOC_PROBES	(DTRACEIOC | 2)		/* probe query */
 #define	DTRACEIOC_BUFSNAP	(DTRACEIOC | 4)		/* snapshot buffer */
 #define	DTRACEIOC_PROBEMATCH	(DTRACEIOC | 5)		/* match probes */
 #define	DTRACEIOC_ENABLE	(DTRACEIOC | 6)		/* enable probes */
 #define	DTRACEIOC_AGGSNAP	(DTRACEIOC | 7)		/* snapshot agg. */
 #define	DTRACEIOC_EPROBE	(DTRACEIOC | 8)		/* get eprobe desc. */
 #define	DTRACEIOC_PROBEARG	(DTRACEIOC | 9)		/* get probe arg */
 #define	DTRACEIOC_CONF		(DTRACEIOC | 10)	/* get config. */
 #define	DTRACEIOC_STATUS	(DTRACEIOC | 11)	/* get status */
 #define	DTRACEIOC_GO		(DTRACEIOC | 12)	/* start tracing */
 #define	DTRACEIOC_STOP		(DTRACEIOC | 13)	/* stop tracing */
 #define	DTRACEIOC_AGGDESC	(DTRACEIOC | 15)	/* get agg. desc. */
 #define	DTRACEIOC_FORMAT	(DTRACEIOC | 16)	/* get format str */
 #define	DTRACEIOC_DOFGET	(DTRACEIOC | 17)	/* get DOF */
 #define	DTRACEIOC_REPLICATE	(DTRACEIOC | 18)	/* replicate enab */
 #else
 #define	DTRACEIOC_PROVIDER	_IOWR('x',1,dtrace_providerdesc_t)
 							/* provider query */
 #define	DTRACEIOC_PROBES	_IOWR('x',2,dtrace_probedesc_t)
 							/* probe query */
 #define	DTRACEIOC_BUFSNAP	_IOW('x',4,dtrace_bufdesc_t *)	
 							/* snapshot buffer */
 #define	DTRACEIOC_PROBEMATCH	_IOWR('x',5,dtrace_probedesc_t)
 							/* match probes */
 typedef struct {
 	void	*dof;		/* DOF userland address written to driver. */
 	int	n_matched;	/* # matches returned by driver. */
 } dtrace_enable_io_t;
 #define	DTRACEIOC_ENABLE	_IOWR('x',6,dtrace_enable_io_t)
 							/* enable probes */
 #define	DTRACEIOC_AGGSNAP	_IOW('x',7,dtrace_bufdesc_t *)
 							/* snapshot agg. */
 #define	DTRACEIOC_EPROBE	_IOW('x',8,dtrace_eprobedesc_t)
 							/* get eprobe desc. */
 #define	DTRACEIOC_PROBEARG	_IOWR('x',9,dtrace_argdesc_t)
 							/* get probe arg */
 #define	DTRACEIOC_CONF		_IOR('x',10,dtrace_conf_t)
 							/* get config. */
 #define	DTRACEIOC_STATUS	_IOR('x',11,dtrace_status_t)
 							/* get status */
 #define	DTRACEIOC_GO		_IOR('x',12,processorid_t)
 							/* start tracing */
 #define	DTRACEIOC_STOP		_IOWR('x',13,processorid_t)
 							/* stop tracing */
 #define	DTRACEIOC_AGGDESC	_IOW('x',15,dtrace_aggdesc_t *)	
 							/* get agg. desc. */
 #define	DTRACEIOC_FORMAT	_IOWR('x',16,dtrace_fmtdesc_t)	
 							/* get format str */
 #define	DTRACEIOC_DOFGET	_IOW('x',17,dof_hdr_t *)
 							/* get DOF */
 #define	DTRACEIOC_REPLICATE	_IOW('x',18,dtrace_repldesc_t)	
 							/* replicate enab */
 #endif
 
 /*
  * DTrace Helpers
  *
  * In general, DTrace establishes probes in processes and takes actions on
  * processes without knowing their specific user-level structures.  Instead of
  * existing in the framework, process-specific knowledge is contained by the
  * enabling D program -- which can apply process-specific knowledge by making
  * appropriate use of DTrace primitives like copyin() and copyinstr() to
  * operate on user-level data.  However, there may exist some specific probes
  * of particular semantic relevance that the application developer may wish to
  * explicitly export.  For example, an application may wish to export a probe
  * at the point that it begins and ends certain well-defined transactions.  In
  * addition to providing probes, programs may wish to offer assistance for
  * certain actions.  For example, in highly dynamic environments (e.g., Java),
  * it may be difficult to obtain a stack trace in terms of meaningful symbol
  * names (the translation from instruction addresses to corresponding symbol
  * names may only be possible in situ); these environments may wish to define
  * a series of actions to be applied in situ to obtain a meaningful stack
  * trace.
  *
  * These two mechanisms -- user-level statically defined tracing and assisting
  * DTrace actions -- are provided via DTrace _helpers_.  Helpers are specified
  * via DOF, but unlike enabling DOF, helper DOF may contain definitions of
  * providers, probes and their arguments.  If a helper wishes to provide
  * action assistance, probe descriptions and corresponding DIF actions may be
  * specified in the helper DOF.  For such helper actions, however, the probe
  * description describes the specific helper:  all DTrace helpers have the
  * provider name "dtrace" and the module name "helper", and the name of the
  * helper is contained in the function name (for example, the ustack() helper
  * is named "ustack").  Any helper-specific name may be contained in the name
  * (for example, if a helper were to have a constructor, it might be named
  * "dtrace:helper:<helper>:init").  Helper actions are only called when the
  * action that they are helping is taken.  Helper actions may only return DIF
  * expressions, and may only call the following subroutines:
  *
  *    alloca()      <= Allocates memory out of the consumer's scratch space
  *    bcopy()       <= Copies memory to scratch space
  *    copyin()      <= Copies memory from user-level into consumer's scratch
  *    copyinto()    <= Copies memory into a specific location in scratch
  *    copyinstr()   <= Copies a string into a specific location in scratch
  *
  * Helper actions may only access the following built-in variables:
  *
  *    curthread     <= Current kthread_t pointer
  *    tid           <= Current thread identifier
  *    pid           <= Current process identifier
  *    ppid          <= Parent process identifier
  *    uid           <= Current user ID
  *    gid           <= Current group ID
  *    execname      <= Current executable name
  *    zonename      <= Current zone name
  *
  * Helper actions may not manipulate or allocate dynamic variables, but they
  * may have clause-local and statically-allocated global variables.  The
  * helper action variable state is specific to the helper action -- variables
  * used by the helper action may not be accessed outside of the helper
  * action, and the helper action may not access variables that like outside
  * of it.  Helper actions may not load from kernel memory at-large; they are
  * restricting to loading current user state (via copyin() and variants) and
  * scratch space.  As with probe enablings, helper actions are executed in
  * program order.  The result of the helper action is the result of the last
  * executing helper expression.
  *
  * Helpers -- composed of either providers/probes or probes/actions (or both)
  * -- are added by opening the "helper" minor node, and issuing an ioctl(2)
  * (DTRACEHIOC_ADDDOF) that specifies the dof_helper_t structure. This
  * encapsulates the name and base address of the user-level library or
  * executable publishing the helpers and probes as well as the DOF that
  * contains the definitions of those helpers and probes.
  *
  * The DTRACEHIOC_ADD and DTRACEHIOC_REMOVE are left in place for legacy
  * helpers and should no longer be used.  No other ioctls are valid on the
  * helper minor node.
  */
 #ifdef illumos
 #define	DTRACEHIOC		(('d' << 24) | ('t' << 16) | ('h' << 8))
 #define	DTRACEHIOC_ADD		(DTRACEHIOC | 1)	/* add helper */
 #define	DTRACEHIOC_REMOVE	(DTRACEHIOC | 2)	/* remove helper */
 #define	DTRACEHIOC_ADDDOF	(DTRACEHIOC | 3)	/* add helper DOF */
 #else
 #define	DTRACEHIOC_REMOVE	_IOW('z', 2, int)	/* remove helper */
 #define	DTRACEHIOC_ADDDOF	_IOWR('z', 3, dof_helper_t)/* add helper DOF */
 #endif
 
 typedef struct dof_helper {
 	char dofhp_mod[DTRACE_MODNAMELEN];	/* executable or library name */
 	uint64_t dofhp_addr;			/* base address of object */
 	uint64_t dofhp_dof;			/* address of helper DOF */
 #ifdef __FreeBSD__
 	pid_t dofhp_pid;			/* target process ID */
 	int dofhp_gen;
 #endif
 } dof_helper_t;
 
 #define	DTRACEMNR_DTRACE	"dtrace"	/* node for DTrace ops */
 #define	DTRACEMNR_HELPER	"helper"	/* node for helpers */
 #define	DTRACEMNRN_DTRACE	0		/* minor for DTrace ops */
 #define	DTRACEMNRN_HELPER	1		/* minor for helpers */
 #define	DTRACEMNRN_CLONE	2		/* first clone minor */
 
 #ifdef _KERNEL
 
 /*
  * DTrace Provider API
  *
  * The following functions are implemented by the DTrace framework and are
  * used to implement separate in-kernel DTrace providers.  Common functions
  * are provided in uts/common/os/dtrace.c.  ISA-dependent subroutines are
  * defined in uts/<isa>/dtrace/dtrace_asm.s or uts/<isa>/dtrace/dtrace_isa.c.
  *
  * The provider API has two halves:  the API that the providers consume from
  * DTrace, and the API that providers make available to DTrace.
  *
  * 1 Framework-to-Provider API
  *
  * 1.1  Overview
  *
  * The Framework-to-Provider API is represented by the dtrace_pops structure
  * that the provider passes to the framework when registering itself.  This
  * structure consists of the following members:
  *
  *   dtps_provide()          <-- Provide all probes, all modules
  *   dtps_provide_module()   <-- Provide all probes in specified module
  *   dtps_enable()           <-- Enable specified probe
  *   dtps_disable()          <-- Disable specified probe
  *   dtps_suspend()          <-- Suspend specified probe
  *   dtps_resume()           <-- Resume specified probe
  *   dtps_getargdesc()       <-- Get the argument description for args[X]
  *   dtps_getargval()        <-- Get the value for an argX or args[X] variable
  *   dtps_usermode()         <-- Find out if the probe was fired in user mode
  *   dtps_destroy()          <-- Destroy all state associated with this probe
  *
  * 1.2  void dtps_provide(void *arg, const dtrace_probedesc_t *spec)
  *
  * 1.2.1  Overview
  *
  *   Called to indicate that the provider should provide all probes.  If the
  *   specified description is non-NULL, dtps_provide() is being called because
  *   no probe matched a specified probe -- if the provider has the ability to
  *   create custom probes, it may wish to create a probe that matches the
  *   specified description.
  *
  * 1.2.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register().  The
  *   second argument is a pointer to a probe description that the provider may
  *   wish to consider when creating custom probes.  The provider is expected to
  *   call back into the DTrace framework via dtrace_probe_create() to create
  *   any necessary probes.  dtps_provide() may be called even if the provider
  *   has made available all probes; the provider should check the return value
  *   of dtrace_probe_create() to handle this case.  Note that the provider need
  *   not implement both dtps_provide() and dtps_provide_module(); see
  *   "Arguments and Notes" for dtrace_register(), below.
  *
  * 1.2.3  Return value
  *
  *   None.
  *
  * 1.2.4  Caller's context
  *
  *   dtps_provide() is typically called from open() or ioctl() context, but may
  *   be called from other contexts as well.  The DTrace framework is locked in
  *   such a way that providers may not register or unregister.  This means that
  *   the provider may not call any DTrace API that affects its registration with
  *   the framework, including dtrace_register(), dtrace_unregister(),
  *   dtrace_invalidate(), and dtrace_condense().  However, the context is such
  *   that the provider may (and indeed, is expected to) call probe-related
  *   DTrace routines, including dtrace_probe_create(), dtrace_probe_lookup(),
  *   and dtrace_probe_arg().
  *
  * 1.3  void dtps_provide_module(void *arg, modctl_t *mp)
  *
  * 1.3.1  Overview
  *
  *   Called to indicate that the provider should provide all probes in the
  *   specified module.
  *
  * 1.3.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register().  The
  *   second argument is a pointer to a modctl structure that indicates the
  *   module for which probes should be created.
  *
  * 1.3.3  Return value
  *
  *   None.
  *
  * 1.3.4  Caller's context
  *
  *   dtps_provide_module() may be called from open() or ioctl() context, but
  *   may also be called from a module loading context.  mod_lock is held, and
  *   the DTrace framework is locked in such a way that providers may not
  *   register or unregister.  This means that the provider may not call any
  *   DTrace API that affects its registration with the framework, including
  *   dtrace_register(), dtrace_unregister(), dtrace_invalidate(), and
  *   dtrace_condense().  However, the context is such that the provider may (and
  *   indeed, is expected to) call probe-related DTrace routines, including
  *   dtrace_probe_create(), dtrace_probe_lookup(), and dtrace_probe_arg().  Note
  *   that the provider need not implement both dtps_provide() and
  *   dtps_provide_module(); see "Arguments and Notes" for dtrace_register(),
  *   below.
  *
  * 1.4  void dtps_enable(void *arg, dtrace_id_t id, void *parg)
  *
  * 1.4.1  Overview
  *
  *   Called to enable the specified probe.
  *
  * 1.4.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register().  The
  *   second argument is the identifier of the probe to be enabled.  The third
  *   argument is the probe argument as passed to dtrace_probe_create().
  *   dtps_enable() will be called when a probe transitions from not being
  *   enabled at all to having one or more ECB.  The number of ECBs associated
  *   with the probe may change without subsequent calls into the provider.
  *   When the number of ECBs drops to zero, the provider will be explicitly
  *   told to disable the probe via dtps_disable().  dtrace_probe() should never
  *   be called for a probe identifier that hasn't been explicitly enabled via
  *   dtps_enable().
  *
  * 1.4.3  Return value
  *
  *   None.
  *
  * 1.4.4  Caller's context
  *
  *   The DTrace framework is locked in such a way that it may not be called
  *   back into at all.  cpu_lock is held.  mod_lock is not held and may not
  *   be acquired.
  *
  * 1.5  void dtps_disable(void *arg, dtrace_id_t id, void *parg)
  *
  * 1.5.1  Overview
  *
  *   Called to disable the specified probe.
  *
  * 1.5.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register().  The
  *   second argument is the identifier of the probe to be disabled.  The third
  *   argument is the probe argument as passed to dtrace_probe_create().
  *   dtps_disable() will be called when a probe transitions from being enabled
  *   to having zero ECBs.  dtrace_probe() should never be called for a probe
  *   identifier that has been explicitly enabled via dtps_disable().
  *
  * 1.5.3  Return value
  *
  *   None.
  *
  * 1.5.4  Caller's context
  *
  *   The DTrace framework is locked in such a way that it may not be called
  *   back into at all.  cpu_lock is held.  mod_lock is not held and may not
  *   be acquired.
  *
  * 1.6  void dtps_suspend(void *arg, dtrace_id_t id, void *parg)
  *
  * 1.6.1  Overview
  *
  *   Called to suspend the specified enabled probe.  This entry point is for
  *   providers that may need to suspend some or all of their probes when CPUs
  *   are being powered on or when the boot monitor is being entered for a
  *   prolonged period of time.
  *
  * 1.6.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register().  The
  *   second argument is the identifier of the probe to be suspended.  The
  *   third argument is the probe argument as passed to dtrace_probe_create().
  *   dtps_suspend will only be called on an enabled probe.  Providers that
  *   provide a dtps_suspend entry point will want to take roughly the action
  *   that it takes for dtps_disable.
  *
  * 1.6.3  Return value
  *
  *   None.
  *
  * 1.6.4  Caller's context
  *
  *   Interrupts are disabled.  The DTrace framework is in a state such that the
  *   specified probe cannot be disabled or destroyed for the duration of
  *   dtps_suspend().  As interrupts are disabled, the provider is afforded
  *   little latitude; the provider is expected to do no more than a store to
  *   memory.
  *
  * 1.7  void dtps_resume(void *arg, dtrace_id_t id, void *parg)
  *
  * 1.7.1  Overview
  *
  *   Called to resume the specified enabled probe.  This entry point is for
  *   providers that may need to resume some or all of their probes after the
  *   completion of an event that induced a call to dtps_suspend().
  *
  * 1.7.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register().  The
  *   second argument is the identifier of the probe to be resumed.  The
  *   third argument is the probe argument as passed to dtrace_probe_create().
  *   dtps_resume will only be called on an enabled probe.  Providers that
  *   provide a dtps_resume entry point will want to take roughly the action
  *   that it takes for dtps_enable.
  *
  * 1.7.3  Return value
  *
  *   None.
  *
  * 1.7.4  Caller's context
  *
  *   Interrupts are disabled.  The DTrace framework is in a state such that the
  *   specified probe cannot be disabled or destroyed for the duration of
  *   dtps_resume().  As interrupts are disabled, the provider is afforded
  *   little latitude; the provider is expected to do no more than a store to
  *   memory.
  *
  * 1.8  void dtps_getargdesc(void *arg, dtrace_id_t id, void *parg,
  *           dtrace_argdesc_t *desc)
  *
  * 1.8.1  Overview
  *
  *   Called to retrieve the argument description for an args[X] variable.
  *
  * 1.8.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register(). The
  *   second argument is the identifier of the current probe. The third
  *   argument is the probe argument as passed to dtrace_probe_create(). The
  *   fourth argument is a pointer to the argument description.  This
  *   description is both an input and output parameter:  it contains the
  *   index of the desired argument in the dtargd_ndx field, and expects
  *   the other fields to be filled in upon return.  If there is no argument
  *   corresponding to the specified index, the dtargd_ndx field should be set
  *   to DTRACE_ARGNONE.
  *
  * 1.8.3  Return value
  *
  *   None.  The dtargd_ndx, dtargd_native, dtargd_xlate and dtargd_mapping
  *   members of the dtrace_argdesc_t structure are all output values.
  *
  * 1.8.4  Caller's context
  *
  *   dtps_getargdesc() is called from ioctl() context. mod_lock is held, and
  *   the DTrace framework is locked in such a way that providers may not
  *   register or unregister.  This means that the provider may not call any
  *   DTrace API that affects its registration with the framework, including
  *   dtrace_register(), dtrace_unregister(), dtrace_invalidate(), and
  *   dtrace_condense().
  *
  * 1.9  uint64_t dtps_getargval(void *arg, dtrace_id_t id, void *parg,
  *               int argno, int aframes)
  *
  * 1.9.1  Overview
  *
  *   Called to retrieve a value for an argX or args[X] variable.
  *
  * 1.9.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register(). The
  *   second argument is the identifier of the current probe. The third
  *   argument is the probe argument as passed to dtrace_probe_create(). The
  *   fourth argument is the number of the argument (the X in the example in
  *   1.9.1). The fifth argument is the number of stack frames that were used
  *   to get from the actual place in the code that fired the probe to
  *   dtrace_probe() itself, the so-called artificial frames. This argument may
  *   be used to descend an appropriate number of frames to find the correct
  *   values. If this entry point is left NULL, the dtrace_getarg() built-in
  *   function is used.
  *
  * 1.9.3  Return value
  *
  *   The value of the argument.
  *
  * 1.9.4  Caller's context
  *
  *   This is called from within dtrace_probe() meaning that interrupts
  *   are disabled. No locks should be taken within this entry point.
  *
  * 1.10  int dtps_usermode(void *arg, dtrace_id_t id, void *parg)
  *
  * 1.10.1  Overview
  *
  *   Called to determine if the probe was fired in a user context.
  *
  * 1.10.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register(). The
  *   second argument is the identifier of the current probe. The third
  *   argument is the probe argument as passed to dtrace_probe_create().  This
  *   entry point must not be left NULL for providers whose probes allow for
  *   mixed mode tracing, that is to say those probes that can fire during
  *   kernel- _or_ user-mode execution
  *
  * 1.10.3  Return value
  *
  *   A bitwise OR that encapsulates both the mode (either DTRACE_MODE_KERNEL
  *   or DTRACE_MODE_USER) and the policy when the privilege of the enabling
  *   is insufficient for that mode (a combination of DTRACE_MODE_NOPRIV_DROP,
  *   DTRACE_MODE_NOPRIV_RESTRICT, and DTRACE_MODE_LIMITEDPRIV_RESTRICT).  If
  *   DTRACE_MODE_NOPRIV_DROP bit is set, insufficient privilege will result
  *   in the probe firing being silently ignored for the enabling; if the
  *   DTRACE_NODE_NOPRIV_RESTRICT bit is set, insufficient privilege will not
  *   prevent probe processing for the enabling, but restrictions will be in
  *   place that induce a UPRIV fault upon attempt to examine probe arguments
  *   or current process state.  If the DTRACE_MODE_LIMITEDPRIV_RESTRICT bit
  *   is set, similar restrictions will be placed upon operation if the
  *   privilege is sufficient to process the enabling, but does not otherwise
  *   entitle the enabling to all zones.  The DTRACE_MODE_NOPRIV_DROP and
  *   DTRACE_MODE_NOPRIV_RESTRICT are mutually exclusive (and one of these
  *   two policies must be specified), but either may be combined (or not)
  *   with DTRACE_MODE_LIMITEDPRIV_RESTRICT.
  *
  * 1.10.4  Caller's context
  *
  *   This is called from within dtrace_probe() meaning that interrupts
  *   are disabled. No locks should be taken within this entry point.
  *
  * 1.11 void dtps_destroy(void *arg, dtrace_id_t id, void *parg)
  *
  * 1.11.1 Overview
  *
  *   Called to destroy the specified probe.
  *
  * 1.11.2 Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_register().  The
  *   second argument is the identifier of the probe to be destroyed.  The third
  *   argument is the probe argument as passed to dtrace_probe_create().  The
  *   provider should free all state associated with the probe.  The framework
  *   guarantees that dtps_destroy() is only called for probes that have either
  *   been disabled via dtps_disable() or were never enabled via dtps_enable().
  *   Once dtps_disable() has been called for a probe, no further call will be
  *   made specifying the probe.
  *
  * 1.11.3 Return value
  *
  *   None.
  *
  * 1.11.4 Caller's context
  *
  *   The DTrace framework is locked in such a way that it may not be called
  *   back into at all.  mod_lock is held.  cpu_lock is not held, and may not be
  *   acquired.
  *
  *
  * 2 Provider-to-Framework API
  *
  * 2.1  Overview
  *
  * The Provider-to-Framework API provides the mechanism for the provider to
  * register itself with the DTrace framework, to create probes, to lookup
  * probes and (most importantly) to fire probes.  The Provider-to-Framework
  * consists of:
  *
  *   dtrace_register()       <-- Register a provider with the DTrace framework
  *   dtrace_unregister()     <-- Remove a provider's DTrace registration
  *   dtrace_invalidate()     <-- Invalidate the specified provider
  *   dtrace_condense()       <-- Remove a provider's unenabled probes
  *   dtrace_attached()       <-- Indicates whether or not DTrace has attached
  *   dtrace_probe_create()   <-- Create a DTrace probe
  *   dtrace_probe_lookup()   <-- Lookup a DTrace probe based on its name
  *   dtrace_probe_arg()      <-- Return the probe argument for a specific probe
  *   dtrace_probe()          <-- Fire the specified probe
  *
  * 2.2  int dtrace_register(const char *name, const dtrace_pattr_t *pap,
  *          uint32_t priv, cred_t *cr, const dtrace_pops_t *pops, void *arg,
  *          dtrace_provider_id_t *idp)
  *
  * 2.2.1  Overview
  *
  *   dtrace_register() registers the calling provider with the DTrace
  *   framework.  It should generally be called by DTrace providers in their
  *   attach(9E) entry point.
  *
  * 2.2.2  Arguments and Notes
  *
  *   The first argument is the name of the provider.  The second argument is a
  *   pointer to the stability attributes for the provider.  The third argument
  *   is the privilege flags for the provider, and must be some combination of:
  *
  *     DTRACE_PRIV_NONE     <= All users may enable probes from this provider
  *
  *     DTRACE_PRIV_PROC     <= Any user with privilege of PRIV_DTRACE_PROC may
  *                             enable probes from this provider
  *
  *     DTRACE_PRIV_USER     <= Any user with privilege of PRIV_DTRACE_USER may
  *                             enable probes from this provider
  *
  *     DTRACE_PRIV_KERNEL   <= Any user with privilege of PRIV_DTRACE_KERNEL
  *                             may enable probes from this provider
  *
  *     DTRACE_PRIV_OWNER    <= This flag places an additional constraint on
  *                             the privilege requirements above. These probes
  *                             require either (a) a user ID matching the user
  *                             ID of the cred passed in the fourth argument
  *                             or (b) the PRIV_PROC_OWNER privilege.
  *
  *     DTRACE_PRIV_ZONEOWNER<= This flag places an additional constraint on
  *                             the privilege requirements above. These probes
  *                             require either (a) a zone ID matching the zone
  *                             ID of the cred passed in the fourth argument
  *                             or (b) the PRIV_PROC_ZONE privilege.
  *
  *   Note that these flags designate the _visibility_ of the probes, not
  *   the conditions under which they may or may not fire.
  *
  *   The fourth argument is the credential that is associated with the
  *   provider.  This argument should be NULL if the privilege flags don't
  *   include DTRACE_PRIV_OWNER or DTRACE_PRIV_ZONEOWNER.  If non-NULL, the
  *   framework stashes the uid and zoneid represented by this credential
  *   for use at probe-time, in implicit predicates.  These limit visibility
  *   of the probes to users and/or zones which have sufficient privilege to
  *   access them.
  *
  *   The fifth argument is a DTrace provider operations vector, which provides
  *   the implementation for the Framework-to-Provider API.  (See Section 1,
  *   above.)  This must be non-NULL, and each member must be non-NULL.  The
  *   exceptions to this are (1) the dtps_provide() and dtps_provide_module()
  *   members (if the provider so desires, _one_ of these members may be left
  *   NULL -- denoting that the provider only implements the other) and (2)
  *   the dtps_suspend() and dtps_resume() members, which must either both be
  *   NULL or both be non-NULL.
  *
  *   The sixth argument is a cookie to be specified as the first argument for
  *   each function in the Framework-to-Provider API.  This argument may have
  *   any value.
  *
  *   The final argument is a pointer to dtrace_provider_id_t.  If
  *   dtrace_register() successfully completes, the provider identifier will be
  *   stored in the memory pointed to be this argument.  This argument must be
  *   non-NULL.
  *
  * 2.2.3  Return value
  *
  *   On success, dtrace_register() returns 0 and stores the new provider's
  *   identifier into the memory pointed to by the idp argument.  On failure,
  *   dtrace_register() returns an errno:
  *
  *     EINVAL   The arguments passed to dtrace_register() were somehow invalid.
  *              This may because a parameter that must be non-NULL was NULL,
  *              because the name was invalid (either empty or an illegal
  *              provider name) or because the attributes were invalid.
  *
  *   No other failure code is returned.
  *
  * 2.2.4  Caller's context
  *
  *   dtrace_register() may induce calls to dtrace_provide(); the provider must
  *   hold no locks across dtrace_register() that may also be acquired by
  *   dtrace_provide().  cpu_lock and mod_lock must not be held.
  *
  * 2.3  int dtrace_unregister(dtrace_provider_t id)
  *
  * 2.3.1  Overview
  *
  *   Unregisters the specified provider from the DTrace framework.  It should
  *   generally be called by DTrace providers in their detach(9E) entry point.
  *
  * 2.3.2  Arguments and Notes
  *
  *   The only argument is the provider identifier, as returned from a
  *   successful call to dtrace_register().  As a result of calling
  *   dtrace_unregister(), the DTrace framework will call back into the provider
  *   via the dtps_destroy() entry point.  Once dtrace_unregister() successfully
  *   completes, however, the DTrace framework will no longer make calls through
  *   the Framework-to-Provider API.
  *
  * 2.3.3  Return value
  *
  *   On success, dtrace_unregister returns 0.  On failure, dtrace_unregister()
  *   returns an errno:
  *
  *     EBUSY    There are currently processes that have the DTrace pseudodevice
  *              open, or there exists an anonymous enabling that hasn't yet
  *              been claimed.
  *
  *   No other failure code is returned.
  *
  * 2.3.4  Caller's context
  *
  *   Because a call to dtrace_unregister() may induce calls through the
  *   Framework-to-Provider API, the caller may not hold any lock across
  *   dtrace_register() that is also acquired in any of the Framework-to-
  *   Provider API functions.  Additionally, mod_lock may not be held.
  *
  * 2.4  void dtrace_invalidate(dtrace_provider_id_t id)
  *
  * 2.4.1  Overview
  *
  *   Invalidates the specified provider.  All subsequent probe lookups for the
  *   specified provider will fail, but its probes will not be removed.
  *
  * 2.4.2  Arguments and note
  *
  *   The only argument is the provider identifier, as returned from a
  *   successful call to dtrace_register().  In general, a provider's probes
  *   always remain valid; dtrace_invalidate() is a mechanism for invalidating
  *   an entire provider, regardless of whether or not probes are enabled or
  *   not.  Note that dtrace_invalidate() will _not_ prevent already enabled
  *   probes from firing -- it will merely prevent any new enablings of the
  *   provider's probes.
  *
  * 2.5 int dtrace_condense(dtrace_provider_id_t id)
  *
  * 2.5.1  Overview
  *
  *   Removes all the unenabled probes for the given provider. This function is
  *   not unlike dtrace_unregister(), except that it doesn't remove the
  *   provider just as many of its associated probes as it can.
  *
  * 2.5.2  Arguments and Notes
  *
  *   As with dtrace_unregister(), the sole argument is the provider identifier
  *   as returned from a successful call to dtrace_register().  As a result of
  *   calling dtrace_condense(), the DTrace framework will call back into the
  *   given provider's dtps_destroy() entry point for each of the provider's
  *   unenabled probes.
  *
  * 2.5.3  Return value
  *
  *   Currently, dtrace_condense() always returns 0.  However, consumers of this
  *   function should check the return value as appropriate; its behavior may
  *   change in the future.
  *
  * 2.5.4  Caller's context
  *
  *   As with dtrace_unregister(), the caller may not hold any lock across
  *   dtrace_condense() that is also acquired in the provider's entry points.
  *   Also, mod_lock may not be held.
  *
  * 2.6 int dtrace_attached()
  *
  * 2.6.1  Overview
  *
  *   Indicates whether or not DTrace has attached.
  *
  * 2.6.2  Arguments and Notes
  *
  *   For most providers, DTrace makes initial contact beyond registration.
  *   That is, once a provider has registered with DTrace, it waits to hear
  *   from DTrace to create probes.  However, some providers may wish to
  *   proactively create probes without first being told by DTrace to do so.
  *   If providers wish to do this, they must first call dtrace_attached() to
  *   determine if DTrace itself has attached.  If dtrace_attached() returns 0,
  *   the provider must not make any other Provider-to-Framework API call.
  *
  * 2.6.3  Return value
  *
  *   dtrace_attached() returns 1 if DTrace has attached, 0 otherwise.
  *
  * 2.7  int dtrace_probe_create(dtrace_provider_t id, const char *mod,
  *	    const char *func, const char *name, int aframes, void *arg)
  *
  * 2.7.1  Overview
  *
  *   Creates a probe with specified module name, function name, and name.
  *
  * 2.7.2  Arguments and Notes
  *
  *   The first argument is the provider identifier, as returned from a
  *   successful call to dtrace_register().  The second, third, and fourth
  *   arguments are the module name, function name, and probe name,
  *   respectively.  Of these, module name and function name may both be NULL
  *   (in which case the probe is considered to be unanchored), or they may both
  *   be non-NULL.  The name must be non-NULL, and must point to a non-empty
  *   string.
  *
  *   The fifth argument is the number of artificial stack frames that will be
  *   found on the stack when dtrace_probe() is called for the new probe.  These
  *   artificial frames will be automatically be pruned should the stack() or
  *   stackdepth() functions be called as part of one of the probe's ECBs.  If
  *   the parameter doesn't add an artificial frame, this parameter should be
  *   zero.
  *
  *   The final argument is a probe argument that will be passed back to the
  *   provider when a probe-specific operation is called.  (e.g., via
  *   dtps_enable(), dtps_disable(), etc.)
  *
  *   Note that it is up to the provider to be sure that the probe that it
  *   creates does not already exist -- if the provider is unsure of the probe's
  *   existence, it should assure its absence with dtrace_probe_lookup() before
  *   calling dtrace_probe_create().
  *
  * 2.7.3  Return value
  *
  *   dtrace_probe_create() always succeeds, and always returns the identifier
  *   of the newly-created probe.
  *
  * 2.7.4  Caller's context
  *
  *   While dtrace_probe_create() is generally expected to be called from
  *   dtps_provide() and/or dtps_provide_module(), it may be called from other
  *   non-DTrace contexts.  Neither cpu_lock nor mod_lock may be held.
  *
  * 2.8  dtrace_id_t dtrace_probe_lookup(dtrace_provider_t id, const char *mod,
  *	    const char *func, const char *name)
  *
  * 2.8.1  Overview
  *
  *   Looks up a probe based on provdider and one or more of module name,
  *   function name and probe name.
  *
  * 2.8.2  Arguments and Notes
  *
  *   The first argument is the provider identifier, as returned from a
  *   successful call to dtrace_register().  The second, third, and fourth
  *   arguments are the module name, function name, and probe name,
  *   respectively.  Any of these may be NULL; dtrace_probe_lookup() will return
  *   the identifier of the first probe that is provided by the specified
  *   provider and matches all of the non-NULL matching criteria.
  *   dtrace_probe_lookup() is generally used by a provider to be check the
  *   existence of a probe before creating it with dtrace_probe_create().
  *
  * 2.8.3  Return value
  *
  *   If the probe exists, returns its identifier.  If the probe does not exist,
  *   return DTRACE_IDNONE.
  *
  * 2.8.4  Caller's context
  *
  *   While dtrace_probe_lookup() is generally expected to be called from
  *   dtps_provide() and/or dtps_provide_module(), it may also be called from
  *   other non-DTrace contexts.  Neither cpu_lock nor mod_lock may be held.
  *
  * 2.9  void *dtrace_probe_arg(dtrace_provider_t id, dtrace_id_t probe)
  *
  * 2.9.1  Overview
  *
  *   Returns the probe argument associated with the specified probe.
  *
  * 2.9.2  Arguments and Notes
  *
  *   The first argument is the provider identifier, as returned from a
  *   successful call to dtrace_register().  The second argument is a probe
  *   identifier, as returned from dtrace_probe_lookup() or
  *   dtrace_probe_create().  This is useful if a probe has multiple
  *   provider-specific components to it:  the provider can create the probe
  *   once with provider-specific state, and then add to the state by looking
  *   up the probe based on probe identifier.
  *
  * 2.9.3  Return value
  *
  *   Returns the argument associated with the specified probe.  If the
  *   specified probe does not exist, or if the specified probe is not provided
  *   by the specified provider, NULL is returned.
  *
  * 2.9.4  Caller's context
  *
  *   While dtrace_probe_arg() is generally expected to be called from
  *   dtps_provide() and/or dtps_provide_module(), it may also be called from
  *   other non-DTrace contexts.  Neither cpu_lock nor mod_lock may be held.
  *
  * 2.10  void dtrace_probe(dtrace_id_t probe, uintptr_t arg0, uintptr_t arg1,
  *		uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
  *
  * 2.10.1  Overview
  *
  *   The epicenter of DTrace:  fires the specified probes with the specified
  *   arguments.
  *
  * 2.10.2  Arguments and Notes
  *
  *   The first argument is a probe identifier as returned by
  *   dtrace_probe_create() or dtrace_probe_lookup().  The second through sixth
  *   arguments are the values to which the D variables "arg0" through "arg4"
  *   will be mapped.
  *
  *   dtrace_probe() should be called whenever the specified probe has fired --
  *   however the provider defines it.
  *
  * 2.10.3  Return value
  *
  *   None.
  *
  * 2.10.4  Caller's context
  *
  *   dtrace_probe() may be called in virtually any context:  kernel, user,
  *   interrupt, high-level interrupt, with arbitrary adaptive locks held, with
  *   dispatcher locks held, with interrupts disabled, etc.  The only latitude
  *   that must be afforded to DTrace is the ability to make calls within
  *   itself (and to its in-kernel subroutines) and the ability to access
  *   arbitrary (but mapped) memory.  On some platforms, this constrains
  *   context.  For example, on UltraSPARC, dtrace_probe() cannot be called
  *   from any context in which TL is greater than zero.  dtrace_probe() may
  *   also not be called from any routine which may be called by dtrace_probe()
  *   -- which includes functions in the DTrace framework and some in-kernel
  *   DTrace subroutines.  All such functions "dtrace_"; providers that
  *   instrument the kernel arbitrarily should be sure to not instrument these
  *   routines.
  */
 typedef struct dtrace_pops {
 	void (*dtps_provide)(void *arg, dtrace_probedesc_t *spec);
 	void (*dtps_provide_module)(void *arg, modctl_t *mp);
 	void (*dtps_enable)(void *arg, dtrace_id_t id, void *parg);
 	void (*dtps_disable)(void *arg, dtrace_id_t id, void *parg);
 	void (*dtps_suspend)(void *arg, dtrace_id_t id, void *parg);
 	void (*dtps_resume)(void *arg, dtrace_id_t id, void *parg);
 	void (*dtps_getargdesc)(void *arg, dtrace_id_t id, void *parg,
 	    dtrace_argdesc_t *desc);
 	uint64_t (*dtps_getargval)(void *arg, dtrace_id_t id, void *parg,
 	    int argno, int aframes);
 	int (*dtps_usermode)(void *arg, dtrace_id_t id, void *parg);
 	void (*dtps_destroy)(void *arg, dtrace_id_t id, void *parg);
 } dtrace_pops_t;
 
 #define	DTRACE_MODE_KERNEL			0x01
 #define	DTRACE_MODE_USER			0x02
 #define	DTRACE_MODE_NOPRIV_DROP			0x10
 #define	DTRACE_MODE_NOPRIV_RESTRICT		0x20
 #define	DTRACE_MODE_LIMITEDPRIV_RESTRICT	0x40
 
 typedef uintptr_t	dtrace_provider_id_t;
 
 extern int dtrace_register(const char *, const dtrace_pattr_t *, uint32_t,
     cred_t *, const dtrace_pops_t *, void *, dtrace_provider_id_t *);
 extern int dtrace_unregister(dtrace_provider_id_t);
 extern int dtrace_condense(dtrace_provider_id_t);
 extern void dtrace_invalidate(dtrace_provider_id_t);
 extern dtrace_id_t dtrace_probe_lookup(dtrace_provider_id_t, char *,
     char *, char *);
 extern dtrace_id_t dtrace_probe_create(dtrace_provider_id_t, const char *,
     const char *, const char *, int, void *);
 extern void *dtrace_probe_arg(dtrace_provider_id_t, dtrace_id_t);
 extern void dtrace_probe(dtrace_id_t, uintptr_t arg0, uintptr_t arg1,
     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4);
 
 /*
  * DTrace Meta Provider API
  *
  * The following functions are implemented by the DTrace framework and are
  * used to implement meta providers. Meta providers plug into the DTrace
  * framework and are used to instantiate new providers on the fly. At
  * present, there is only one type of meta provider and only one meta
  * provider may be registered with the DTrace framework at a time. The
  * sole meta provider type provides user-land static tracing facilities
  * by taking meta probe descriptions and adding a corresponding provider
  * into the DTrace framework.
  *
  * 1 Framework-to-Provider
  *
  * 1.1 Overview
  *
  * The Framework-to-Provider API is represented by the dtrace_mops structure
  * that the meta provider passes to the framework when registering itself as
  * a meta provider. This structure consists of the following members:
  *
  *   dtms_create_probe()	<-- Add a new probe to a created provider
  *   dtms_provide_pid()		<-- Create a new provider for a given process
  *   dtms_remove_pid()		<-- Remove a previously created provider
  *
  * 1.2  void dtms_create_probe(void *arg, void *parg,
  *           dtrace_helper_probedesc_t *probedesc);
  *
  * 1.2.1  Overview
  *
  *   Called by the DTrace framework to create a new probe in a provider
  *   created by this meta provider.
  *
  * 1.2.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_meta_register().
  *   The second argument is the provider cookie for the associated provider;
  *   this is obtained from the return value of dtms_provide_pid(). The third
  *   argument is the helper probe description.
  *
  * 1.2.3  Return value
  *
  *   None
  *
  * 1.2.4  Caller's context
  *
  *   dtms_create_probe() is called from either ioctl() or module load context
  *   in the context of a newly-created provider (that is, a provider that
  *   is a result of a call to dtms_provide_pid()). The DTrace framework is
  *   locked in such a way that meta providers may not register or unregister,
  *   such that no other thread can call into a meta provider operation and that
  *   atomicity is assured with respect to meta provider operations across
  *   dtms_provide_pid() and subsequent calls to dtms_create_probe().
  *   The context is thus effectively single-threaded with respect to the meta
  *   provider, and that the meta provider cannot call dtrace_meta_register()
  *   or dtrace_meta_unregister(). However, the context is such that the
  *   provider may (and is expected to) call provider-related DTrace provider
  *   APIs including dtrace_probe_create().
  *
  * 1.3  void *dtms_provide_pid(void *arg, dtrace_meta_provider_t *mprov,
  *	      pid_t pid)
  *
  * 1.3.1  Overview
  *
  *   Called by the DTrace framework to instantiate a new provider given the
  *   description of the provider and probes in the mprov argument. The
  *   meta provider should call dtrace_register() to insert the new provider
  *   into the DTrace framework.
  *
  * 1.3.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_meta_register().
  *   The second argument is a pointer to a structure describing the new
  *   helper provider. The third argument is the process identifier for
  *   process associated with this new provider. Note that the name of the
  *   provider as passed to dtrace_register() should be the contatenation of
  *   the dtmpb_provname member of the mprov argument and the processs
  *   identifier as a string.
  *
  * 1.3.3  Return value
  *
  *   The cookie for the provider that the meta provider creates. This is
  *   the same value that it passed to dtrace_register().
  *
  * 1.3.4  Caller's context
  *
  *   dtms_provide_pid() is called from either ioctl() or module load context.
  *   The DTrace framework is locked in such a way that meta providers may not
  *   register or unregister. This means that the meta provider cannot call
  *   dtrace_meta_register() or dtrace_meta_unregister(). However, the context
  *   is such that the provider may -- and is expected to --  call
  *   provider-related DTrace provider APIs including dtrace_register().
  *
  * 1.4  void dtms_remove_pid(void *arg, dtrace_meta_provider_t *mprov,
  *	     pid_t pid)
  *
  * 1.4.1  Overview
  *
  *   Called by the DTrace framework to remove a provider that had previously
  *   been instantiated via the dtms_provide_pid() entry point. The meta
  *   provider need not remove the provider immediately, but this entry
  *   point indicates that the provider should be removed as soon as possible
  *   using the dtrace_unregister() API.
  *
  * 1.4.2  Arguments and notes
  *
  *   The first argument is the cookie as passed to dtrace_meta_register().
  *   The second argument is a pointer to a structure describing the helper
  *   provider. The third argument is the process identifier for process
  *   associated with this new provider.
  *
  * 1.4.3  Return value
  *
  *   None
  *
  * 1.4.4  Caller's context
  *
  *   dtms_remove_pid() is called from either ioctl() or exit() context.
  *   The DTrace framework is locked in such a way that meta providers may not
  *   register or unregister. This means that the meta provider cannot call
  *   dtrace_meta_register() or dtrace_meta_unregister(). However, the context
  *   is such that the provider may -- and is expected to -- call
  *   provider-related DTrace provider APIs including dtrace_unregister().
  */
 typedef struct dtrace_helper_probedesc {
 	char *dthpb_mod;			/* probe module */
 	char *dthpb_func; 			/* probe function */
 	char *dthpb_name; 			/* probe name */
 	uint64_t dthpb_base;			/* base address */
 	uint32_t *dthpb_offs;			/* offsets array */
 	uint32_t *dthpb_enoffs;			/* is-enabled offsets array */
 	uint32_t dthpb_noffs;			/* offsets count */
 	uint32_t dthpb_nenoffs;			/* is-enabled offsets count */
 	uint8_t *dthpb_args;			/* argument mapping array */
 	uint8_t dthpb_xargc;			/* translated argument count */
 	uint8_t dthpb_nargc;			/* native argument count */
 	char *dthpb_xtypes;			/* translated types strings */
 	char *dthpb_ntypes;			/* native types strings */
 } dtrace_helper_probedesc_t;
 
 typedef struct dtrace_helper_provdesc {
 	char *dthpv_provname;			/* provider name */
 	dtrace_pattr_t dthpv_pattr;		/* stability attributes */
 } dtrace_helper_provdesc_t;
 
 typedef struct dtrace_mops {
 	void (*dtms_create_probe)(void *, void *, dtrace_helper_probedesc_t *);
 	void *(*dtms_provide_pid)(void *, dtrace_helper_provdesc_t *, pid_t);
 	void (*dtms_remove_pid)(void *, dtrace_helper_provdesc_t *, pid_t);
 } dtrace_mops_t;
 
 typedef uintptr_t	dtrace_meta_provider_id_t;
 
 extern int dtrace_meta_register(const char *, const dtrace_mops_t *, void *,
     dtrace_meta_provider_id_t *);
 extern int dtrace_meta_unregister(dtrace_meta_provider_id_t);
 
 /*
  * DTrace Kernel Hooks
  *
  * The following functions are implemented by the base kernel and form a set of
  * hooks used by the DTrace framework.  DTrace hooks are implemented in either
  * uts/common/os/dtrace_subr.c, an ISA-specific assembly file, or in a
  * uts/<platform>/os/dtrace_subr.c corresponding to each hardware platform.
  */
 
 typedef enum dtrace_vtime_state {
 	DTRACE_VTIME_INACTIVE = 0,	/* No DTrace, no TNF */
 	DTRACE_VTIME_ACTIVE,		/* DTrace virtual time, no TNF */
 	DTRACE_VTIME_INACTIVE_TNF,	/* No DTrace, TNF active */
 	DTRACE_VTIME_ACTIVE_TNF		/* DTrace virtual time _and_ TNF */
 } dtrace_vtime_state_t;
 
 #ifdef illumos
 extern dtrace_vtime_state_t dtrace_vtime_active;
 #endif
 extern void dtrace_vtime_switch(kthread_t *next);
 extern void dtrace_vtime_enable_tnf(void);
 extern void dtrace_vtime_disable_tnf(void);
 extern void dtrace_vtime_enable(void);
 extern void dtrace_vtime_disable(void);
 
 struct regs;
 struct reg;
 
 #ifdef illumos
 extern int (*dtrace_pid_probe_ptr)(struct reg *);
 extern int (*dtrace_return_probe_ptr)(struct reg *);
 extern void (*dtrace_fasttrap_fork_ptr)(proc_t *, proc_t *);
 extern void (*dtrace_fasttrap_exec_ptr)(proc_t *);
 extern void (*dtrace_fasttrap_exit_ptr)(proc_t *);
 extern void dtrace_fasttrap_fork(proc_t *, proc_t *);
 #endif
 
 typedef uintptr_t dtrace_icookie_t;
 typedef void (*dtrace_xcall_t)(void *);
 
 extern dtrace_icookie_t dtrace_interrupt_disable(void);
 extern void dtrace_interrupt_enable(dtrace_icookie_t);
 
 extern void dtrace_membar_producer(void);
 extern void dtrace_membar_consumer(void);
 
 extern void (*dtrace_cpu_init)(processorid_t);
 #ifdef illumos
 extern void (*dtrace_modload)(modctl_t *);
 extern void (*dtrace_modunload)(modctl_t *);
 #endif
 extern void (*dtrace_helpers_cleanup)(void);
 extern void (*dtrace_helpers_fork)(proc_t *parent, proc_t *child);
 extern void (*dtrace_cpustart_init)(void);
 extern void (*dtrace_cpustart_fini)(void);
 extern void (*dtrace_closef)(void);
 
 extern void (*dtrace_debugger_init)(void);
 extern void (*dtrace_debugger_fini)(void);
 extern dtrace_cacheid_t dtrace_predcache_id;
 
 #ifdef illumos
 extern hrtime_t dtrace_gethrtime(void);
 #else
 void dtrace_debug_printf(const char *, ...) __printflike(1, 2);
 #endif
 extern void dtrace_sync(void);
 extern void dtrace_toxic_ranges(void (*)(uintptr_t, uintptr_t));
 extern void dtrace_xcall(processorid_t, dtrace_xcall_t, void *);
 extern void dtrace_vpanic(const char *, __va_list);
 extern void dtrace_panic(const char *, ...);
 
 extern int dtrace_safe_defer_signal(void);
 extern void dtrace_safe_synchronous_signal(void);
 
 extern int dtrace_mach_aframes(void);
 
 #if defined(__i386) || defined(__amd64)
-extern int dtrace_instr_size(uint8_t *instr);
 extern int dtrace_instr_size_isa(uint8_t *, model_t, int *);
 extern void dtrace_invop_callsite(void);
 #endif
 extern void dtrace_invop_add(int (*)(uintptr_t, struct trapframe *, uintptr_t));
 extern void dtrace_invop_remove(int (*)(uintptr_t, struct trapframe *,
     uintptr_t));
 
 #ifdef __sparc
 extern int dtrace_blksuword32(uintptr_t, uint32_t *, int);
 extern void dtrace_getfsr(uint64_t *);
 #endif
 
 #ifndef illumos
 extern void dtrace_helpers_duplicate(proc_t *, proc_t *);
 extern void dtrace_helpers_destroy(proc_t *);
 #endif
 
 #define	DTRACE_CPUFLAG_ISSET(flag) \
 	(cpu_core[curcpu].cpuc_dtrace_flags & (flag))
 
 #define	DTRACE_CPUFLAG_SET(flag) \
 	(cpu_core[curcpu].cpuc_dtrace_flags |= (flag))
 
 #define	DTRACE_CPUFLAG_CLEAR(flag) \
 	(cpu_core[curcpu].cpuc_dtrace_flags &= ~(flag))
 
 #endif /* _KERNEL */
 
+#if defined(__i386) || defined(__amd64) || defined (__riscv)
+extern int dtrace_instr_size(uint8_t *instr);
+#endif
+
 #endif	/* _ASM */
 
 #if defined(__i386) || defined(__amd64)
 
 #define	DTRACE_INVOP_PUSHL_EBP		1
 #define	DTRACE_INVOP_PUSHQ_RBP		DTRACE_INVOP_PUSHL_EBP
 #define	DTRACE_INVOP_POPL_EBP		2
 #define	DTRACE_INVOP_POPQ_RBP		DTRACE_INVOP_POPL_EBP
 #define	DTRACE_INVOP_LEAVE		3
 #define	DTRACE_INVOP_NOP		4
 #define	DTRACE_INVOP_RET		5
 
 #if defined(__amd64)
 #define	DTRACE_INVOP_CALL		6
 #endif
 
 #elif defined(__powerpc__)
 
 #define DTRACE_INVOP_BCTR	1
 #define DTRACE_INVOP_BLR	2
 #define DTRACE_INVOP_JUMP	3
 #define DTRACE_INVOP_MFLR_R0	4
 #define DTRACE_INVOP_NOP	5
 
 #elif defined(__arm__)
 
 #define	DTRACE_INVOP_SHIFT	4
 #define	DTRACE_INVOP_MASK	((1 << DTRACE_INVOP_SHIFT) - 1)
 #define	DTRACE_INVOP_DATA(x)	((x) >> DTRACE_INVOP_SHIFT)
 
 #define DTRACE_INVOP_PUSHM	1
 #define DTRACE_INVOP_POPM	2
 #define DTRACE_INVOP_B		3
 
 #elif defined(__aarch64__)
 
 #define	INSN_SIZE	4
 
 #define	B_MASK		0xff000000
 #define	B_DATA_MASK	0x00ffffff
 #define	B_INSTR		0x14000000
 
 #define	BTI_MASK	0xffffff3f
 #define	BTI_INSTR	0xd503241f
 
 #define	NOP_INSTR	0xd503201f
 
 #define	RET_INSTR	0xd65f03c0
 
 #define	SUB_MASK	0xffc00000
 #define	SUB_INSTR	0xd1000000
 #define	SUB_RD_SHIFT	0
 #define	SUB_RN_SHIFT	5
 #define	SUB_R_MASK	0x1f
 #define	SUB_IMM_SHIFT	10
 #define	SUB_IMM_MASK	0xfff
 
 #define	LDP_STP_MASK	0xffc00000
 #define	STP_32		0x29800000
 #define	STP_64		0xa9800000
 #define	LDP_32		0x28c00000
 #define	LDP_64		0xa8c00000
 #define	LDP_STP_PREIND	(1 << 24)
 #define	LDP_STP_DIR	(1 << 22) /* Load instruction */
 #define	ARG1_SHIFT	0
 #define	ARG1_MASK	0x1f
 #define	ARG2_SHIFT	10
 #define	ARG2_MASK	0x1f
 #define	ADDR_SHIFT	5
 #define	ADDR_MASK	0x1f
 #define	OFFSET_SHIFT	15
 #define	OFFSET_SIZE	7
 #define	OFFSET_MASK	((1 << OFFSET_SIZE) - 1)
 
 #define	DTRACE_INVOP_STP	1
 #define	DTRACE_INVOP_RET	2
 #define	DTRACE_INVOP_B		3
 #define	DTRACE_INVOP_SUB	4
 
 #elif defined(__mips__)
 
 #define	INSN_SIZE		4
 
 /* Load/Store double RA to/from SP */
 #define	LDSD_RA_SP_MASK		0xffff0000
 #define	LDSD_DATA_MASK		0x0000ffff
 #define	SD_RA_SP		0xffbf0000
 #define	LD_RA_SP		0xdfbf0000
 
 #define	DTRACE_INVOP_SD		1
 #define	DTRACE_INVOP_LD		2
 
 #elif defined(__riscv)
 
 #define	DTRACE_INVOP_SD		1
 #define	DTRACE_INVOP_C_SDSP	2
 #define	DTRACE_INVOP_RET	3
 #define	DTRACE_INVOP_C_RET	4
 #define	DTRACE_INVOP_NOP	5
 
 #endif
 
 #ifdef	__cplusplus
 }
 #endif
 
 #endif	/* _SYS_DTRACE_H */
diff --git a/sys/cddl/dev/dtrace/riscv/instr_size.c b/sys/cddl/dev/dtrace/riscv/instr_size.c
new file mode 100644
index 000000000000..bfdc962f4aa9
--- /dev/null
+++ b/sys/cddl/dev/dtrace/riscv/instr_size.c
@@ -0,0 +1,22 @@
+/*
+ * SPDX-License-Identifier: CDDL 1.0
+ *
+ * Copyright 2023 Christos Margiolis <christos@FreeBSD.org>
+ */
+
+#include <sys/types.h>
+#include <sys/dtrace.h>
+
+#include <machine/riscvreg.h>
+
+#define RVC_MASK 0x03
+
+int
+dtrace_instr_size(uint8_t *instr)
+{
+	/* Detect compressed instructions. */
+	if ((~(*instr) & RVC_MASK) == 0)
+		return (INSN_SIZE);
+	else
+		return (INSN_C_SIZE);
+}
diff --git a/sys/modules/dtrace/dtrace/Makefile b/sys/modules/dtrace/dtrace/Makefile
index 0bd81bb39db0..1513418281ad 100644
--- a/sys/modules/dtrace/dtrace/Makefile
+++ b/sys/modules/dtrace/dtrace/Makefile
@@ -1,62 +1,66 @@
 # $FreeBSD$
 
 SYSDIR?=	${SRCTOP}/sys
 
 ARCHDIR=	${MACHINE_CPUARCH}
 
 .PATH: ${SYSDIR}/cddl/contrib/opensolaris/uts/common/dtrace
 .PATH: ${SYSDIR}/cddl/compat/opensolaris/kern
 .PATH: ${SYSDIR}/cddl/kern
 .PATH: ${SYSDIR}/cddl/dev/dtrace
 .PATH: ${SYSDIR}/cddl/dev/dtrace/${ARCHDIR}
 
 KMOD=		dtrace
 SRCS=		dtrace.c \
 		dtrace_xoroshiro128_plus.c \
 		dtrace_asm.S \
 		dtrace_subr.c
 
 .if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"
 .PATH: ${SYSDIR}/cddl/dev/dtrace/x86
 SRCS+=		dis_tables.c \
 		instr_size.c
 CFLAGS+=       -I${SYSDIR}/cddl/contrib/opensolaris/uts/intel \
                -I${SYSDIR}/cddl/dev/dtrace/x86
+.endif
 
+.if ${MACHINE_CPUARCH} == "riscv"
+SRCS+=		instr_size.c
 .endif
+
 CFLAGS+= ${OPENZFS_CFLAGS}
 
 SRCS+=		bus_if.h device_if.h vnode_if.h
 
 # Needed for dtrace_asm.S
 DPSRCS+=	assym.inc
 
 # These are needed for assym.inc
 SRCS+=		opt_kstack_pages.h opt_nfs.h opt_hwpmc_hooks.h
 
 #This is needed for dtrace.c
 SRCS += 	opensolaris_taskq.c
 
 .if ${MACHINE_CPUARCH} == "i386"
 SRCS+=		opt_apic.h
 .endif
 
 CFLAGS+=	-I${SYSDIR}/cddl/compat/opensolaris \
 		-I${SYSDIR}/cddl/dev/dtrace \
 		-I${SYSDIR}/cddl/dev/dtrace/${ARCHDIR} \
 		-I${SYSDIR}/cddl/contrib/opensolaris/uts/common \
 		-I${SYSDIR}/cddl/contrib/opensolaris/uts/common/dtrace \
 		-I${SYSDIR}/cddl/contrib/opensolaris/common/util \
 		-I${SYSDIR} -DDIS_MEM
 
 EXPORT_SYMS=	YES
 
 dtrace_asm.o:  assym.inc
 
 .include <bsd.kmod.mk>
 
 CFLAGS+=	-include ${SYSDIR}/cddl/compat/opensolaris/sys/debug_compat.h
 CFLAGS.dtrace_asm.S+= -D_SYS_ERRNO_H_ -D_SYS_PARAM_H_ -DLOCORE
 CWARNFLAGS+=	-Wno-parentheses
 CWARNFLAGS+=	-Wno-cast-qual
 CWARNFLAGS+=	-Wno-unused