xref: /illumos-gate/usr/src/uts/intel/dtrace/fasttrap_isa.c (revision ac448965596bc1c42f7accb3023f48d5fa9b8180)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*ac448965Sahl  * Common Development and Distribution License (the "License").
6*ac448965Sahl  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
21*ac448965Sahl 
227c478bd9Sstevel@tonic-gate /*
23*ac448965Sahl  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
277c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
287c478bd9Sstevel@tonic-gate 
297c478bd9Sstevel@tonic-gate #include <sys/fasttrap_isa.h>
307c478bd9Sstevel@tonic-gate #include <sys/fasttrap_impl.h>
317c478bd9Sstevel@tonic-gate #include <sys/dtrace.h>
327c478bd9Sstevel@tonic-gate #include <sys/dtrace_impl.h>
337c478bd9Sstevel@tonic-gate #include <sys/cmn_err.h>
347c478bd9Sstevel@tonic-gate #include <sys/regset.h>
357c478bd9Sstevel@tonic-gate #include <sys/privregs.h>
367c478bd9Sstevel@tonic-gate #include <sys/segments.h>
377c478bd9Sstevel@tonic-gate #include <sys/sysmacros.h>
387c478bd9Sstevel@tonic-gate #include <sys/trap.h>
397c478bd9Sstevel@tonic-gate 
407c478bd9Sstevel@tonic-gate /*
417c478bd9Sstevel@tonic-gate  * Lossless User-Land Tracing on x86
427c478bd9Sstevel@tonic-gate  * ---------------------------------
437c478bd9Sstevel@tonic-gate  *
44*ac448965Sahl  * The execution of most instructions is not dependent on the address; for
45*ac448965Sahl  * these instructions it is sufficient to copy them into the user process's
46*ac448965Sahl  * address space and execute them. To effectively single-step an instruction
47*ac448965Sahl  * in user-land, we copy out the following sequence of instructions to scratch
487c478bd9Sstevel@tonic-gate  * space in the user thread's ulwp_t structure.
497c478bd9Sstevel@tonic-gate  *
507c478bd9Sstevel@tonic-gate  * We then set the program counter (%eip or %rip) to point to this scratch
517c478bd9Sstevel@tonic-gate  * space. Once execution resumes, the original instruction is executed and
527c478bd9Sstevel@tonic-gate  * then control flow is redirected to what was originally the subsequent
537c478bd9Sstevel@tonic-gate  * instruction. If the kernel attemps to deliver a signal while single-
547c478bd9Sstevel@tonic-gate  * stepping, the signal is deferred and the program counter is moved into the
557c478bd9Sstevel@tonic-gate  * second sequence of instructions. The second sequence ends in a trap into
567c478bd9Sstevel@tonic-gate  * the kernel where the deferred signal is then properly handled and delivered.
577c478bd9Sstevel@tonic-gate  *
587c478bd9Sstevel@tonic-gate  * For instructions whose execute is position dependent, we perform simple
597c478bd9Sstevel@tonic-gate  * emulation. These instructions are limited to control transfer
607c478bd9Sstevel@tonic-gate  * instructions in 32-bit mode, but in 64-bit mode there's the added wrinkle
617c478bd9Sstevel@tonic-gate  * of %rip-relative addressing that means that almost any instruction can be
627c478bd9Sstevel@tonic-gate  * position dependent. For all the details on how we emulate generic
637c478bd9Sstevel@tonic-gate  * instructions included %rip-relative instructions, see the code in
647c478bd9Sstevel@tonic-gate  * fasttrap_pid_probe() below where we handle instructions of type
657c478bd9Sstevel@tonic-gate  * FASTTRAP_T_COMMON (under the header: Generic Instruction Tracing).
667c478bd9Sstevel@tonic-gate  */
677c478bd9Sstevel@tonic-gate 
687c478bd9Sstevel@tonic-gate #define	FASTTRAP_MODRM_MOD(modrm)	(((modrm) >> 6) & 0x3)
697c478bd9Sstevel@tonic-gate #define	FASTTRAP_MODRM_REG(modrm)	(((modrm) >> 3) & 0x7)
707c478bd9Sstevel@tonic-gate #define	FASTTRAP_MODRM_RM(modrm)	((modrm) & 0x7)
717c478bd9Sstevel@tonic-gate #define	FASTTRAP_MODRM(mod, reg, rm)	(((mod) << 6) | ((reg) << 3) | (rm))
727c478bd9Sstevel@tonic-gate 
737c478bd9Sstevel@tonic-gate #define	FASTTRAP_SIB_SCALE(sib)		(((sib) >> 6) & 0x3)
747c478bd9Sstevel@tonic-gate #define	FASTTRAP_SIB_INDEX(sib)		(((sib) >> 3) & 0x7)
757c478bd9Sstevel@tonic-gate #define	FASTTRAP_SIB_BASE(sib)		((sib) & 0x7)
767c478bd9Sstevel@tonic-gate 
777c478bd9Sstevel@tonic-gate #define	FASTTRAP_REX_W(rex)		(((rex) >> 3) & 1)
787c478bd9Sstevel@tonic-gate #define	FASTTRAP_REX_R(rex)		(((rex) >> 2) & 1)
797c478bd9Sstevel@tonic-gate #define	FASTTRAP_REX_X(rex)		(((rex) >> 1) & 1)
807c478bd9Sstevel@tonic-gate #define	FASTTRAP_REX_B(rex)		((rex) & 1)
817c478bd9Sstevel@tonic-gate #define	FASTTRAP_REX(w, r, x, b)	\
827c478bd9Sstevel@tonic-gate 	(0x40 | ((w) << 3) | ((r) << 2) | ((x) << 1) | (b))
837c478bd9Sstevel@tonic-gate 
847c478bd9Sstevel@tonic-gate /*
857c478bd9Sstevel@tonic-gate  * Single-byte op-codes.
867c478bd9Sstevel@tonic-gate  */
877c478bd9Sstevel@tonic-gate #define	FASTTRAP_PUSHL_EBP	0x55
887c478bd9Sstevel@tonic-gate 
897c478bd9Sstevel@tonic-gate #define	FASTTRAP_JO		0x70
907c478bd9Sstevel@tonic-gate #define	FASTTRAP_JNO		0x71
917c478bd9Sstevel@tonic-gate #define	FASTTRAP_JB		0x72
927c478bd9Sstevel@tonic-gate #define	FASTTRAP_JAE		0x73
937c478bd9Sstevel@tonic-gate #define	FASTTRAP_JE		0x74
947c478bd9Sstevel@tonic-gate #define	FASTTRAP_JNE		0x75
957c478bd9Sstevel@tonic-gate #define	FASTTRAP_JBE		0x76
967c478bd9Sstevel@tonic-gate #define	FASTTRAP_JA		0x77
977c478bd9Sstevel@tonic-gate #define	FASTTRAP_JS		0x78
987c478bd9Sstevel@tonic-gate #define	FASTTRAP_JNS		0x79
997c478bd9Sstevel@tonic-gate #define	FASTTRAP_JP		0x7a
1007c478bd9Sstevel@tonic-gate #define	FASTTRAP_JNP		0x7b
1017c478bd9Sstevel@tonic-gate #define	FASTTRAP_JL		0x7c
1027c478bd9Sstevel@tonic-gate #define	FASTTRAP_JGE		0x7d
1037c478bd9Sstevel@tonic-gate #define	FASTTRAP_JLE		0x7e
1047c478bd9Sstevel@tonic-gate #define	FASTTRAP_JG		0x7f
1057c478bd9Sstevel@tonic-gate 
1067c478bd9Sstevel@tonic-gate #define	FASTTRAP_MOV_EAX	0xb8
1077c478bd9Sstevel@tonic-gate #define	FASTTRAP_MOV_ECX	0xb9
1087c478bd9Sstevel@tonic-gate 
1097c478bd9Sstevel@tonic-gate #define	FASTTRAP_RET16		0xc2
1107c478bd9Sstevel@tonic-gate #define	FASTTRAP_RET		0xc3
1117c478bd9Sstevel@tonic-gate 
1127c478bd9Sstevel@tonic-gate #define	FASTTRAP_LOOPNZ		0xe0
1137c478bd9Sstevel@tonic-gate #define	FASTTRAP_LOOPZ		0xe1
1147c478bd9Sstevel@tonic-gate #define	FASTTRAP_LOOP		0xe2
1157c478bd9Sstevel@tonic-gate #define	FASTTRAP_JCXZ		0xe3
1167c478bd9Sstevel@tonic-gate 
1177c478bd9Sstevel@tonic-gate #define	FASTTRAP_CALL		0xe8
1187c478bd9Sstevel@tonic-gate #define	FASTTRAP_JMP32		0xe9
1197c478bd9Sstevel@tonic-gate #define	FASTTRAP_JMP8		0xeb
1207c478bd9Sstevel@tonic-gate 
1217c478bd9Sstevel@tonic-gate #define	FASTTRAP_INT3		0xcc
1227c478bd9Sstevel@tonic-gate #define	FASTTRAP_INT		0xcd
1237c478bd9Sstevel@tonic-gate 
1247c478bd9Sstevel@tonic-gate #define	FASTTRAP_2_BYTE_OP	0x0f
1257c478bd9Sstevel@tonic-gate #define	FASTTRAP_GROUP5_OP	0xff
1267c478bd9Sstevel@tonic-gate 
1277c478bd9Sstevel@tonic-gate /*
1287c478bd9Sstevel@tonic-gate  * Two-byte op-codes (second byte only).
1297c478bd9Sstevel@tonic-gate  */
1307c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JO		0x80
1317c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JNO		0x81
1327c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JB		0x82
1337c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JAE		0x83
1347c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JE		0x84
1357c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JNE		0x85
1367c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JBE		0x86
1377c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JA		0x87
1387c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JS		0x88
1397c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JNS		0x89
1407c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JP		0x8a
1417c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JNP		0x8b
1427c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JL		0x8c
1437c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JGE		0x8d
1447c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JLE		0x8e
1457c478bd9Sstevel@tonic-gate #define	FASTTRAP_0F_JG		0x8f
1467c478bd9Sstevel@tonic-gate 
1477c478bd9Sstevel@tonic-gate #define	FASTTRAP_EFLAGS_OF	0x800
1487c478bd9Sstevel@tonic-gate #define	FASTTRAP_EFLAGS_DF	0x400
1497c478bd9Sstevel@tonic-gate #define	FASTTRAP_EFLAGS_SF	0x080
1507c478bd9Sstevel@tonic-gate #define	FASTTRAP_EFLAGS_ZF	0x040
1517c478bd9Sstevel@tonic-gate #define	FASTTRAP_EFLAGS_AF	0x010
1527c478bd9Sstevel@tonic-gate #define	FASTTRAP_EFLAGS_PF	0x004
1537c478bd9Sstevel@tonic-gate #define	FASTTRAP_EFLAGS_CF	0x001
1547c478bd9Sstevel@tonic-gate 
1557c478bd9Sstevel@tonic-gate /*
1567c478bd9Sstevel@tonic-gate  * Instruction prefixes.
1577c478bd9Sstevel@tonic-gate  */
1587c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_OPERAND	0x66
1597c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_ADDRESS	0x67
1607c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_CS	0x2E
1617c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_DS	0x3E
1627c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_ES	0x26
1637c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_FS	0x64
1647c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_GS	0x65
1657c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_SS	0x36
1667c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_LOCK	0xF0
1677c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_REP	0xF3
1687c478bd9Sstevel@tonic-gate #define	FASTTRAP_PREFIX_REPNE	0xF2
1697c478bd9Sstevel@tonic-gate 
1707c478bd9Sstevel@tonic-gate #define	FASTTRAP_NOREG	0xff
1717c478bd9Sstevel@tonic-gate 
1727c478bd9Sstevel@tonic-gate /*
1737c478bd9Sstevel@tonic-gate  * Map between instruction register encodings and the kernel constants which
1747c478bd9Sstevel@tonic-gate  * correspond to indicies into struct regs.
1757c478bd9Sstevel@tonic-gate  */
1767c478bd9Sstevel@tonic-gate #ifdef __amd64
1777c478bd9Sstevel@tonic-gate static const uint8_t regmap[16] = {
1787c478bd9Sstevel@tonic-gate 	REG_RAX, REG_RCX, REG_RDX, REG_RBX, REG_RSP, REG_RBP, REG_RSI, REG_RDI,
1797c478bd9Sstevel@tonic-gate 	REG_R8, REG_R9, REG_R10, REG_R11, REG_R12, REG_R13, REG_R14, REG_R15,
1807c478bd9Sstevel@tonic-gate };
1817c478bd9Sstevel@tonic-gate #else
1827c478bd9Sstevel@tonic-gate static const uint8_t regmap[8] = {
1837c478bd9Sstevel@tonic-gate 	EAX, ECX, EDX, EBX, UESP, EBP, ESI, EDI
1847c478bd9Sstevel@tonic-gate };
1857c478bd9Sstevel@tonic-gate #endif
1867c478bd9Sstevel@tonic-gate 
1877c478bd9Sstevel@tonic-gate static ulong_t fasttrap_getreg(struct regs *, uint_t);
1887c478bd9Sstevel@tonic-gate 
1897c478bd9Sstevel@tonic-gate static uint64_t
1907c478bd9Sstevel@tonic-gate fasttrap_anarg(struct regs *rp, int function_entry, int argno)
1917c478bd9Sstevel@tonic-gate {
1927c478bd9Sstevel@tonic-gate 	uint64_t value;
1937c478bd9Sstevel@tonic-gate 	int shift = function_entry ? 1 : 0;
1947c478bd9Sstevel@tonic-gate 
1957c478bd9Sstevel@tonic-gate #ifdef __amd64
1967c478bd9Sstevel@tonic-gate 	if (curproc->p_model == DATAMODEL_LP64) {
1977c478bd9Sstevel@tonic-gate 		uintptr_t *stack;
1987c478bd9Sstevel@tonic-gate 
1997c478bd9Sstevel@tonic-gate 		/*
2007c478bd9Sstevel@tonic-gate 		 * In 64-bit mode, the first six arguments are stored in
2017c478bd9Sstevel@tonic-gate 		 * registers.
2027c478bd9Sstevel@tonic-gate 		 */
2037c478bd9Sstevel@tonic-gate 		if (argno < 6)
2047c478bd9Sstevel@tonic-gate 			return ((&rp->r_rdi)[argno]);
2057c478bd9Sstevel@tonic-gate 
2067c478bd9Sstevel@tonic-gate 		stack = (uintptr_t *)rp->r_sp;
2077c478bd9Sstevel@tonic-gate 		DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2087c478bd9Sstevel@tonic-gate 		value = dtrace_fulword(&stack[argno - 6 + shift]);
2097c478bd9Sstevel@tonic-gate 		DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
2107c478bd9Sstevel@tonic-gate 	} else {
2117c478bd9Sstevel@tonic-gate #endif
2127c478bd9Sstevel@tonic-gate 		uint32_t *stack = (uint32_t *)rp->r_sp;
2137c478bd9Sstevel@tonic-gate 		DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2147c478bd9Sstevel@tonic-gate 		value = dtrace_fuword32(&stack[argno + shift]);
2157c478bd9Sstevel@tonic-gate 		DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
2167c478bd9Sstevel@tonic-gate #ifdef __amd64
2177c478bd9Sstevel@tonic-gate 	}
2187c478bd9Sstevel@tonic-gate #endif
2197c478bd9Sstevel@tonic-gate 
2207c478bd9Sstevel@tonic-gate 	return (value);
2217c478bd9Sstevel@tonic-gate }
2227c478bd9Sstevel@tonic-gate 
2237c478bd9Sstevel@tonic-gate /*ARGSUSED*/
2247c478bd9Sstevel@tonic-gate int
225*ac448965Sahl fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, uintptr_t pc,
226*ac448965Sahl     fasttrap_probe_type_t type)
2277c478bd9Sstevel@tonic-gate {
2287c478bd9Sstevel@tonic-gate 	uint8_t instr[FASTTRAP_MAX_INSTR_SIZE + 10];
2297c478bd9Sstevel@tonic-gate 	size_t len = FASTTRAP_MAX_INSTR_SIZE;
2307c478bd9Sstevel@tonic-gate 	size_t first = MIN(len, PAGESIZE - (pc & PAGEOFFSET));
2317c478bd9Sstevel@tonic-gate 	uint_t start = 0;
2327c478bd9Sstevel@tonic-gate 	int rmindex;
2337c478bd9Sstevel@tonic-gate 	uint8_t rex = 0;
2347c478bd9Sstevel@tonic-gate 
2357c478bd9Sstevel@tonic-gate 	/*
2367c478bd9Sstevel@tonic-gate 	 * Read the instruction at the given address out of the process's
2377c478bd9Sstevel@tonic-gate 	 * address space. We don't have to worry about a debugger
2387c478bd9Sstevel@tonic-gate 	 * changing this instruction before we overwrite it with our trap
2397c478bd9Sstevel@tonic-gate 	 * instruction since P_PR_LOCK is set. Since instructions can span
2407c478bd9Sstevel@tonic-gate 	 * pages, we potentially read the instruction in two parts. If the
2417c478bd9Sstevel@tonic-gate 	 * second part fails, we just zero out that part of the instruction.
2427c478bd9Sstevel@tonic-gate 	 */
2437c478bd9Sstevel@tonic-gate 	if (uread(p, &instr[0], first, pc) != 0)
2447c478bd9Sstevel@tonic-gate 		return (-1);
2457c478bd9Sstevel@tonic-gate 	if (len > first &&
2467c478bd9Sstevel@tonic-gate 	    uread(p, &instr[first], len - first, pc + first) != 0) {
2477c478bd9Sstevel@tonic-gate 		bzero(&instr[first], len - first);
2487c478bd9Sstevel@tonic-gate 		len = first;
2497c478bd9Sstevel@tonic-gate 	}
2507c478bd9Sstevel@tonic-gate 
2517c478bd9Sstevel@tonic-gate 	/*
2527c478bd9Sstevel@tonic-gate 	 * If the disassembly fails, then we have a malformed instruction.
2537c478bd9Sstevel@tonic-gate 	 */
2547c478bd9Sstevel@tonic-gate 	if ((tp->ftt_size = dtrace_instr_size_isa(instr, p->p_model,
2557c478bd9Sstevel@tonic-gate 	    &rmindex)) <= 0)
2567c478bd9Sstevel@tonic-gate 		return (-1);
2577c478bd9Sstevel@tonic-gate 
2587c478bd9Sstevel@tonic-gate 	/*
2597c478bd9Sstevel@tonic-gate 	 * Make sure the disassembler isn't completely broken.
2607c478bd9Sstevel@tonic-gate 	 */
2617c478bd9Sstevel@tonic-gate 	ASSERT(-1 <= rmindex && rmindex < tp->ftt_size);
2627c478bd9Sstevel@tonic-gate 
2637c478bd9Sstevel@tonic-gate 	/*
2647c478bd9Sstevel@tonic-gate 	 * If the computed size is greater than the number of bytes read,
2657c478bd9Sstevel@tonic-gate 	 * then it was a malformed instruction possibly because it fell on a
2667c478bd9Sstevel@tonic-gate 	 * page boundary and the subsequent page was missing or because of
2677c478bd9Sstevel@tonic-gate 	 * some malicious user.
2687c478bd9Sstevel@tonic-gate 	 */
2697c478bd9Sstevel@tonic-gate 	if (tp->ftt_size > len)
2707c478bd9Sstevel@tonic-gate 		return (-1);
2717c478bd9Sstevel@tonic-gate 
2727c478bd9Sstevel@tonic-gate 	/*
2737c478bd9Sstevel@tonic-gate 	 * Find the start of the instruction's opcode by processing any
2747c478bd9Sstevel@tonic-gate 	 * legacy prefixes.
2757c478bd9Sstevel@tonic-gate 	 */
2767c478bd9Sstevel@tonic-gate 	for (;;) {
2777c478bd9Sstevel@tonic-gate 		switch (instr[start]) {
2787c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_OPERAND:
2797c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_ADDRESS:
2807c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_CS:
2817c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_DS:
2827c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_ES:
2837c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_FS:
2847c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_GS:
2857c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_SS:
2867c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_LOCK:
2877c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_REP:
2887c478bd9Sstevel@tonic-gate 		case FASTTRAP_PREFIX_REPNE:
2897c478bd9Sstevel@tonic-gate 			start++;
2907c478bd9Sstevel@tonic-gate 			continue;
2917c478bd9Sstevel@tonic-gate 		}
2927c478bd9Sstevel@tonic-gate 		break;
2937c478bd9Sstevel@tonic-gate 	}
2947c478bd9Sstevel@tonic-gate 
2957c478bd9Sstevel@tonic-gate #ifdef __amd64
2967c478bd9Sstevel@tonic-gate 	/*
2977c478bd9Sstevel@tonic-gate 	 * Identify the REX prefix on 64-bit processes.
2987c478bd9Sstevel@tonic-gate 	 */
2997c478bd9Sstevel@tonic-gate 	if (p->p_model == DATAMODEL_LP64 && (instr[start] & 0xf0) == 0x40)
3007c478bd9Sstevel@tonic-gate 		rex = instr[start++];
3017c478bd9Sstevel@tonic-gate #endif
3027c478bd9Sstevel@tonic-gate 
3037c478bd9Sstevel@tonic-gate 	/*
3047c478bd9Sstevel@tonic-gate 	 * Now that we're pretty sure that the instruction is okay, copy the
3057c478bd9Sstevel@tonic-gate 	 * valid part to the tracepoint.
3067c478bd9Sstevel@tonic-gate 	 */
3077c478bd9Sstevel@tonic-gate 	bcopy(instr, tp->ftt_instr, FASTTRAP_MAX_INSTR_SIZE);
3087c478bd9Sstevel@tonic-gate 
3097c478bd9Sstevel@tonic-gate 	tp->ftt_type = FASTTRAP_T_COMMON;
3107c478bd9Sstevel@tonic-gate 	if (instr[start] == FASTTRAP_2_BYTE_OP) {
3117c478bd9Sstevel@tonic-gate 		switch (instr[start + 1]) {
3127c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JO:
3137c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JNO:
3147c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JB:
3157c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JAE:
3167c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JE:
3177c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JNE:
3187c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JBE:
3197c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JA:
3207c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JS:
3217c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JNS:
3227c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JP:
3237c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JNP:
3247c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JL:
3257c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JGE:
3267c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JLE:
3277c478bd9Sstevel@tonic-gate 		case FASTTRAP_0F_JG:
3287c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_JCC;
3297c478bd9Sstevel@tonic-gate 			tp->ftt_code = (instr[start + 1] & 0x0f) | FASTTRAP_JO;
3307c478bd9Sstevel@tonic-gate 			tp->ftt_dest = pc + tp->ftt_size +
3317c478bd9Sstevel@tonic-gate 			    *(int32_t *)&instr[start + 2];
3327c478bd9Sstevel@tonic-gate 			break;
3337c478bd9Sstevel@tonic-gate 		}
3347c478bd9Sstevel@tonic-gate 	} else if (instr[start] == FASTTRAP_GROUP5_OP) {
3357c478bd9Sstevel@tonic-gate 		uint_t mod = FASTTRAP_MODRM_MOD(instr[start + 1]);
3367c478bd9Sstevel@tonic-gate 		uint_t reg = FASTTRAP_MODRM_REG(instr[start + 1]);
3377c478bd9Sstevel@tonic-gate 		uint_t rm = FASTTRAP_MODRM_RM(instr[start + 1]);
3387c478bd9Sstevel@tonic-gate 
3397c478bd9Sstevel@tonic-gate 		if (reg == 2 || reg == 4) {
3407c478bd9Sstevel@tonic-gate 			uint_t i, sz;
3417c478bd9Sstevel@tonic-gate 
3427c478bd9Sstevel@tonic-gate 			if (reg == 2)
3437c478bd9Sstevel@tonic-gate 				tp->ftt_type = FASTTRAP_T_CALL;
3447c478bd9Sstevel@tonic-gate 			else
3457c478bd9Sstevel@tonic-gate 				tp->ftt_type = FASTTRAP_T_JMP;
3467c478bd9Sstevel@tonic-gate 
3477c478bd9Sstevel@tonic-gate 			if (mod == 3)
3487c478bd9Sstevel@tonic-gate 				tp->ftt_code = 2;
3497c478bd9Sstevel@tonic-gate 			else
3507c478bd9Sstevel@tonic-gate 				tp->ftt_code = 1;
3517c478bd9Sstevel@tonic-gate 
3527c478bd9Sstevel@tonic-gate 			ASSERT(p->p_model == DATAMODEL_LP64 || rex == 0);
3537c478bd9Sstevel@tonic-gate 
3547c478bd9Sstevel@tonic-gate 			/*
3557c478bd9Sstevel@tonic-gate 			 * See AMD x86-64 Architecture Programmer's Manual
3567c478bd9Sstevel@tonic-gate 			 * Volume 3, Section 1.2.7, Table 1-12, and
3577c478bd9Sstevel@tonic-gate 			 * Appendix A.3.1, Table A-15.
3587c478bd9Sstevel@tonic-gate 			 */
3597c478bd9Sstevel@tonic-gate 			if (mod != 3 && rm == 4) {
3607c478bd9Sstevel@tonic-gate 				uint8_t sib = instr[start + 2];
3617c478bd9Sstevel@tonic-gate 				uint_t index = FASTTRAP_SIB_INDEX(sib);
3627c478bd9Sstevel@tonic-gate 				uint_t base = FASTTRAP_SIB_BASE(sib);
3637c478bd9Sstevel@tonic-gate 
3647c478bd9Sstevel@tonic-gate 				tp->ftt_scale = FASTTRAP_SIB_SCALE(sib);
3657c478bd9Sstevel@tonic-gate 
3667c478bd9Sstevel@tonic-gate 				tp->ftt_index = (index == 4) ?
3677c478bd9Sstevel@tonic-gate 				    FASTTRAP_NOREG :
3687c478bd9Sstevel@tonic-gate 				    regmap[index | (FASTTRAP_REX_X(rex) << 3)];
3697c478bd9Sstevel@tonic-gate 				tp->ftt_base = (mod == 0 && base == 5) ?
3707c478bd9Sstevel@tonic-gate 				    FASTTRAP_NOREG :
3717c478bd9Sstevel@tonic-gate 				    regmap[base | (FASTTRAP_REX_B(rex) << 3)];
3727c478bd9Sstevel@tonic-gate 
3737c478bd9Sstevel@tonic-gate 				i = 3;
3747c478bd9Sstevel@tonic-gate 				sz = mod == 1 ? 1 : 4;
3757c478bd9Sstevel@tonic-gate 			} else {
3767c478bd9Sstevel@tonic-gate 				/*
3777c478bd9Sstevel@tonic-gate 				 * In 64-bit mode, mod == 0 and r/m == 5
3787c478bd9Sstevel@tonic-gate 				 * denotes %rip-relative addressing; in 32-bit
3797c478bd9Sstevel@tonic-gate 				 * mode, the base register isn't used. In both
3807c478bd9Sstevel@tonic-gate 				 * modes, there is a 32-bit operand.
3817c478bd9Sstevel@tonic-gate 				 */
3827c478bd9Sstevel@tonic-gate 				if (mod == 0 && rm == 5) {
3837c478bd9Sstevel@tonic-gate #ifdef __amd64
3847c478bd9Sstevel@tonic-gate 					if (p->p_model == DATAMODEL_LP64)
3857c478bd9Sstevel@tonic-gate 						tp->ftt_base = REG_RIP;
3867c478bd9Sstevel@tonic-gate 					else
3877c478bd9Sstevel@tonic-gate #endif
3887c478bd9Sstevel@tonic-gate 						tp->ftt_base = FASTTRAP_NOREG;
3897c478bd9Sstevel@tonic-gate 					sz = 4;
3907c478bd9Sstevel@tonic-gate 				} else  {
3917c478bd9Sstevel@tonic-gate 					uint8_t base = rm |
3927c478bd9Sstevel@tonic-gate 					    (FASTTRAP_REX_B(rex) << 3);
3937c478bd9Sstevel@tonic-gate 
3947c478bd9Sstevel@tonic-gate 					tp->ftt_base = regmap[base];
3957c478bd9Sstevel@tonic-gate 					sz = mod == 1 ? 1 : mod == 2 ? 4 : 0;
3967c478bd9Sstevel@tonic-gate 				}
3977c478bd9Sstevel@tonic-gate 				tp->ftt_index = FASTTRAP_NOREG;
3987c478bd9Sstevel@tonic-gate 				i = 2;
3997c478bd9Sstevel@tonic-gate 			}
4007c478bd9Sstevel@tonic-gate 
4017c478bd9Sstevel@tonic-gate 			if (sz == 1)
4027c478bd9Sstevel@tonic-gate 				tp->ftt_dest = *(int8_t *)&instr[start + i];
4037c478bd9Sstevel@tonic-gate 			else if (sz == 4)
4047c478bd9Sstevel@tonic-gate 				tp->ftt_dest = *(int32_t *)&instr[start + i];
4057c478bd9Sstevel@tonic-gate 			else
4067c478bd9Sstevel@tonic-gate 				tp->ftt_dest = 0;
4077c478bd9Sstevel@tonic-gate 		}
4087c478bd9Sstevel@tonic-gate 	} else {
4097c478bd9Sstevel@tonic-gate 		switch (instr[start]) {
4107c478bd9Sstevel@tonic-gate 		case FASTTRAP_RET:
4117c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_RET;
4127c478bd9Sstevel@tonic-gate 			break;
4137c478bd9Sstevel@tonic-gate 
4147c478bd9Sstevel@tonic-gate 		case FASTTRAP_RET16:
4157c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_RET16;
4167c478bd9Sstevel@tonic-gate 			tp->ftt_dest = *(uint16_t *)&instr[start + 1];
4177c478bd9Sstevel@tonic-gate 			break;
4187c478bd9Sstevel@tonic-gate 
4197c478bd9Sstevel@tonic-gate 		case FASTTRAP_JO:
4207c478bd9Sstevel@tonic-gate 		case FASTTRAP_JNO:
4217c478bd9Sstevel@tonic-gate 		case FASTTRAP_JB:
4227c478bd9Sstevel@tonic-gate 		case FASTTRAP_JAE:
4237c478bd9Sstevel@tonic-gate 		case FASTTRAP_JE:
4247c478bd9Sstevel@tonic-gate 		case FASTTRAP_JNE:
4257c478bd9Sstevel@tonic-gate 		case FASTTRAP_JBE:
4267c478bd9Sstevel@tonic-gate 		case FASTTRAP_JA:
4277c478bd9Sstevel@tonic-gate 		case FASTTRAP_JS:
4287c478bd9Sstevel@tonic-gate 		case FASTTRAP_JNS:
4297c478bd9Sstevel@tonic-gate 		case FASTTRAP_JP:
4307c478bd9Sstevel@tonic-gate 		case FASTTRAP_JNP:
4317c478bd9Sstevel@tonic-gate 		case FASTTRAP_JL:
4327c478bd9Sstevel@tonic-gate 		case FASTTRAP_JGE:
4337c478bd9Sstevel@tonic-gate 		case FASTTRAP_JLE:
4347c478bd9Sstevel@tonic-gate 		case FASTTRAP_JG:
4357c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_JCC;
4367c478bd9Sstevel@tonic-gate 			tp->ftt_code = instr[start];
4377c478bd9Sstevel@tonic-gate 			tp->ftt_dest = pc + tp->ftt_size +
4387c478bd9Sstevel@tonic-gate 			    (int8_t)instr[start + 1];
4397c478bd9Sstevel@tonic-gate 			break;
4407c478bd9Sstevel@tonic-gate 
4417c478bd9Sstevel@tonic-gate 		case FASTTRAP_LOOPNZ:
4427c478bd9Sstevel@tonic-gate 		case FASTTRAP_LOOPZ:
4437c478bd9Sstevel@tonic-gate 		case FASTTRAP_LOOP:
4447c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_LOOP;
4457c478bd9Sstevel@tonic-gate 			tp->ftt_code = instr[start];
4467c478bd9Sstevel@tonic-gate 			tp->ftt_dest = pc + tp->ftt_size +
4477c478bd9Sstevel@tonic-gate 			    (int8_t)instr[start + 1];
4487c478bd9Sstevel@tonic-gate 			break;
4497c478bd9Sstevel@tonic-gate 
4507c478bd9Sstevel@tonic-gate 		case FASTTRAP_JCXZ:
4517c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_JCXZ;
4527c478bd9Sstevel@tonic-gate 			tp->ftt_dest = pc + tp->ftt_size +
4537c478bd9Sstevel@tonic-gate 			    (int8_t)instr[start + 1];
4547c478bd9Sstevel@tonic-gate 			break;
4557c478bd9Sstevel@tonic-gate 
4567c478bd9Sstevel@tonic-gate 		case FASTTRAP_CALL:
4577c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_CALL;
4587c478bd9Sstevel@tonic-gate 			tp->ftt_dest = pc + tp->ftt_size +
4597c478bd9Sstevel@tonic-gate 			    *(int32_t *)&instr[start + 1];
4607c478bd9Sstevel@tonic-gate 			tp->ftt_code = 0;
4617c478bd9Sstevel@tonic-gate 			break;
4627c478bd9Sstevel@tonic-gate 
4637c478bd9Sstevel@tonic-gate 		case FASTTRAP_JMP32:
4647c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_JMP;
4657c478bd9Sstevel@tonic-gate 			tp->ftt_dest = pc + tp->ftt_size +
4667c478bd9Sstevel@tonic-gate 			    *(int32_t *)&instr[start + 1];
4677c478bd9Sstevel@tonic-gate 			break;
4687c478bd9Sstevel@tonic-gate 		case FASTTRAP_JMP8:
4697c478bd9Sstevel@tonic-gate 			tp->ftt_type = FASTTRAP_T_JMP;
4707c478bd9Sstevel@tonic-gate 			tp->ftt_dest = pc + tp->ftt_size +
4717c478bd9Sstevel@tonic-gate 			    (int8_t)instr[start + 1];
4727c478bd9Sstevel@tonic-gate 			break;
4737c478bd9Sstevel@tonic-gate 
4747c478bd9Sstevel@tonic-gate 		case FASTTRAP_PUSHL_EBP:
4757c478bd9Sstevel@tonic-gate 			if (start == 0)
4767c478bd9Sstevel@tonic-gate 				tp->ftt_type = FASTTRAP_T_PUSHL_EBP;
4777c478bd9Sstevel@tonic-gate 			break;
4787c478bd9Sstevel@tonic-gate 
4797c478bd9Sstevel@tonic-gate 		case FASTTRAP_INT3:
4807c478bd9Sstevel@tonic-gate 			/*
4817c478bd9Sstevel@tonic-gate 			 * The pid provider shares the int3 trap with debugger
4827c478bd9Sstevel@tonic-gate 			 * breakpoints so we can't instrument them.
4837c478bd9Sstevel@tonic-gate 			 */
4847c478bd9Sstevel@tonic-gate 			ASSERT(instr[start] == FASTTRAP_INSTR);
4857c478bd9Sstevel@tonic-gate 			return (-1);
4867c478bd9Sstevel@tonic-gate 		}
4877c478bd9Sstevel@tonic-gate 	}
4887c478bd9Sstevel@tonic-gate 
4897c478bd9Sstevel@tonic-gate #ifdef __amd64
4907c478bd9Sstevel@tonic-gate 	if (p->p_model == DATAMODEL_LP64 && tp->ftt_type == FASTTRAP_T_COMMON) {
4917c478bd9Sstevel@tonic-gate 		/*
4927c478bd9Sstevel@tonic-gate 		 * If the process is 64-bit and the instruction type is still
4937c478bd9Sstevel@tonic-gate 		 * FASTTRAP_T_COMMON -- meaning we're going to copy it out an
4947c478bd9Sstevel@tonic-gate 		 * execute it -- we need to watch for %rip-relative
4957c478bd9Sstevel@tonic-gate 		 * addressing mode. See the portion of fasttrap_pid_probe()
4967c478bd9Sstevel@tonic-gate 		 * below where we handle tracepoints with type
4977c478bd9Sstevel@tonic-gate 		 * FASTTRAP_T_COMMON for how we emulate instructions that
4987c478bd9Sstevel@tonic-gate 		 * employ %rip-relative addressing.
4997c478bd9Sstevel@tonic-gate 		 */
5007c478bd9Sstevel@tonic-gate 		if (rmindex != -1) {
5017c478bd9Sstevel@tonic-gate 			uint_t mod = FASTTRAP_MODRM_MOD(instr[rmindex]);
5027c478bd9Sstevel@tonic-gate 			uint_t reg = FASTTRAP_MODRM_REG(instr[rmindex]);
5037c478bd9Sstevel@tonic-gate 			uint_t rm = FASTTRAP_MODRM_RM(instr[rmindex]);
5047c478bd9Sstevel@tonic-gate 
5057c478bd9Sstevel@tonic-gate 			ASSERT(rmindex > start);
5067c478bd9Sstevel@tonic-gate 
5077c478bd9Sstevel@tonic-gate 			if (mod == 0 && rm == 5) {
5087c478bd9Sstevel@tonic-gate 				/*
5097c478bd9Sstevel@tonic-gate 				 * We need to be sure to avoid other
5107c478bd9Sstevel@tonic-gate 				 * registers used by this instruction. While
5117c478bd9Sstevel@tonic-gate 				 * the reg field may determine the op code
5127c478bd9Sstevel@tonic-gate 				 * rather than denoting a register, assuming
5137c478bd9Sstevel@tonic-gate 				 * that it denotes a register is always safe.
5147c478bd9Sstevel@tonic-gate 				 * We leave the REX field intact and use
5157c478bd9Sstevel@tonic-gate 				 * whatever value's there for simplicity.
5167c478bd9Sstevel@tonic-gate 				 */
5177c478bd9Sstevel@tonic-gate 				if (reg != 0) {
5187c478bd9Sstevel@tonic-gate 					tp->ftt_ripmode = FASTTRAP_RIP_1 |
5197c478bd9Sstevel@tonic-gate 					    (FASTTRAP_RIP_X *
5207c478bd9Sstevel@tonic-gate 					    FASTTRAP_REX_B(rex));
5217c478bd9Sstevel@tonic-gate 					rm = 0;
5227c478bd9Sstevel@tonic-gate 				} else {
5237c478bd9Sstevel@tonic-gate 					tp->ftt_ripmode = FASTTRAP_RIP_2 |
5247c478bd9Sstevel@tonic-gate 					    (FASTTRAP_RIP_X *
5257c478bd9Sstevel@tonic-gate 					    FASTTRAP_REX_B(rex));
5267c478bd9Sstevel@tonic-gate 					rm = 1;
5277c478bd9Sstevel@tonic-gate 				}
5287c478bd9Sstevel@tonic-gate 
5297c478bd9Sstevel@tonic-gate 				tp->ftt_modrm = tp->ftt_instr[rmindex];
5307c478bd9Sstevel@tonic-gate 				tp->ftt_instr[rmindex] =
5317c478bd9Sstevel@tonic-gate 				    FASTTRAP_MODRM(2, reg, rm);
5327c478bd9Sstevel@tonic-gate 			}
5337c478bd9Sstevel@tonic-gate 		}
5347c478bd9Sstevel@tonic-gate 	}
5357c478bd9Sstevel@tonic-gate #endif
5367c478bd9Sstevel@tonic-gate 
5377c478bd9Sstevel@tonic-gate 	return (0);
5387c478bd9Sstevel@tonic-gate }
5397c478bd9Sstevel@tonic-gate 
5407c478bd9Sstevel@tonic-gate int
5417c478bd9Sstevel@tonic-gate fasttrap_tracepoint_install(proc_t *p, fasttrap_tracepoint_t *tp)
5427c478bd9Sstevel@tonic-gate {
5437c478bd9Sstevel@tonic-gate 	fasttrap_instr_t instr = FASTTRAP_INSTR;
5447c478bd9Sstevel@tonic-gate 
5457c478bd9Sstevel@tonic-gate 	if (uwrite(p, &instr, 1, tp->ftt_pc) != 0)
5467c478bd9Sstevel@tonic-gate 		return (-1);
5477c478bd9Sstevel@tonic-gate 
5487c478bd9Sstevel@tonic-gate 	return (0);
5497c478bd9Sstevel@tonic-gate }
5507c478bd9Sstevel@tonic-gate 
5517c478bd9Sstevel@tonic-gate int
5527c478bd9Sstevel@tonic-gate fasttrap_tracepoint_remove(proc_t *p, fasttrap_tracepoint_t *tp)
5537c478bd9Sstevel@tonic-gate {
5547c478bd9Sstevel@tonic-gate 	uint8_t instr;
5557c478bd9Sstevel@tonic-gate 
5567c478bd9Sstevel@tonic-gate 	/*
5577c478bd9Sstevel@tonic-gate 	 * Distinguish between read or write failures and a changed
5587c478bd9Sstevel@tonic-gate 	 * instruction.
5597c478bd9Sstevel@tonic-gate 	 */
5607c478bd9Sstevel@tonic-gate 	if (uread(p, &instr, 1, tp->ftt_pc) != 0)
5617c478bd9Sstevel@tonic-gate 		return (0);
5627c478bd9Sstevel@tonic-gate 	if (instr != FASTTRAP_INSTR)
5637c478bd9Sstevel@tonic-gate 		return (0);
5647c478bd9Sstevel@tonic-gate 	if (uwrite(p, &tp->ftt_instr[0], 1, tp->ftt_pc) != 0)
5657c478bd9Sstevel@tonic-gate 		return (-1);
5667c478bd9Sstevel@tonic-gate 
5677c478bd9Sstevel@tonic-gate 	return (0);
5687c478bd9Sstevel@tonic-gate }
5697c478bd9Sstevel@tonic-gate 
5707c478bd9Sstevel@tonic-gate static uintptr_t
5717c478bd9Sstevel@tonic-gate fasttrap_fulword_noerr(const void *uaddr)
5727c478bd9Sstevel@tonic-gate {
5737c478bd9Sstevel@tonic-gate 	uintptr_t ret;
5747c478bd9Sstevel@tonic-gate 
5757c478bd9Sstevel@tonic-gate 	if (fasttrap_fulword(uaddr, &ret) == 0)
5767c478bd9Sstevel@tonic-gate 		return (ret);
5777c478bd9Sstevel@tonic-gate 
5787c478bd9Sstevel@tonic-gate 	return (0);
5797c478bd9Sstevel@tonic-gate }
5807c478bd9Sstevel@tonic-gate 
5817c478bd9Sstevel@tonic-gate static uint32_t
5827c478bd9Sstevel@tonic-gate fasttrap_fuword32_noerr(const void *uaddr)
5837c478bd9Sstevel@tonic-gate {
5847c478bd9Sstevel@tonic-gate 	uint32_t ret;
5857c478bd9Sstevel@tonic-gate 
5867c478bd9Sstevel@tonic-gate 	if (fasttrap_fuword32(uaddr, &ret) == 0)
5877c478bd9Sstevel@tonic-gate 		return (ret);
5887c478bd9Sstevel@tonic-gate 
5897c478bd9Sstevel@tonic-gate 	return (0);
5907c478bd9Sstevel@tonic-gate }
5917c478bd9Sstevel@tonic-gate 
5927c478bd9Sstevel@tonic-gate /*ARGSUSED*/
5937c478bd9Sstevel@tonic-gate int
5947c478bd9Sstevel@tonic-gate fasttrap_probe(struct regs *rp)
5957c478bd9Sstevel@tonic-gate {
5967c478bd9Sstevel@tonic-gate #ifdef __amd64
5977c478bd9Sstevel@tonic-gate 	proc_t *p = curproc;
5987c478bd9Sstevel@tonic-gate #endif
5997c478bd9Sstevel@tonic-gate 
6007c478bd9Sstevel@tonic-gate #ifdef __amd64
6017c478bd9Sstevel@tonic-gate 	if (p->p_model == DATAMODEL_LP64) {
6027c478bd9Sstevel@tonic-gate 		dtrace_probe(fasttrap_probe_id, rp->r_rdi, rp->r_rsi,
6037c478bd9Sstevel@tonic-gate 		    rp->r_rdx, rp->r_rcx, rp->r_r8);
6047c478bd9Sstevel@tonic-gate 	} else {
6057c478bd9Sstevel@tonic-gate #endif
6067c478bd9Sstevel@tonic-gate 		uint32_t *stack = (uint32_t *)rp->r_sp;
6077c478bd9Sstevel@tonic-gate 		uintptr_t s0, s1, s2, s3, s4;
6087c478bd9Sstevel@tonic-gate 
6097c478bd9Sstevel@tonic-gate 		s0 = fasttrap_fuword32_noerr(&stack[1]);
6107c478bd9Sstevel@tonic-gate 		s1 = fasttrap_fuword32_noerr(&stack[2]);
6117c478bd9Sstevel@tonic-gate 		s2 = fasttrap_fuword32_noerr(&stack[3]);
6127c478bd9Sstevel@tonic-gate 		s3 = fasttrap_fuword32_noerr(&stack[4]);
6137c478bd9Sstevel@tonic-gate 		s4 = fasttrap_fuword32_noerr(&stack[5]);
6147c478bd9Sstevel@tonic-gate 
6157c478bd9Sstevel@tonic-gate 		dtrace_probe(fasttrap_probe_id, s0, s1, s2, s3, s4);
6167c478bd9Sstevel@tonic-gate #ifdef __amd64
6177c478bd9Sstevel@tonic-gate 	}
6187c478bd9Sstevel@tonic-gate #endif
6197c478bd9Sstevel@tonic-gate 
6207c478bd9Sstevel@tonic-gate 	return (0);
6217c478bd9Sstevel@tonic-gate }
6227c478bd9Sstevel@tonic-gate 
6237c478bd9Sstevel@tonic-gate static void
6247c478bd9Sstevel@tonic-gate fasttrap_return_common(struct regs *rp, uintptr_t pc, pid_t pid,
6257c478bd9Sstevel@tonic-gate     uintptr_t new_pc)
6267c478bd9Sstevel@tonic-gate {
6277c478bd9Sstevel@tonic-gate 	fasttrap_tracepoint_t *tp;
6287c478bd9Sstevel@tonic-gate 	fasttrap_bucket_t *bucket;
6297c478bd9Sstevel@tonic-gate 	fasttrap_id_t *id;
6307c478bd9Sstevel@tonic-gate 	kmutex_t *pid_mtx;
6317c478bd9Sstevel@tonic-gate 
6327c478bd9Sstevel@tonic-gate 	pid_mtx = &cpu_core[CPU->cpu_id].cpuc_pid_lock;
6337c478bd9Sstevel@tonic-gate 	mutex_enter(pid_mtx);
6347c478bd9Sstevel@tonic-gate 	bucket = &fasttrap_tpoints.fth_table[FASTTRAP_TPOINTS_INDEX(pid, pc)];
6357c478bd9Sstevel@tonic-gate 
6367c478bd9Sstevel@tonic-gate 	for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) {
6377c478bd9Sstevel@tonic-gate 		if (pid == tp->ftt_pid && pc == tp->ftt_pc &&
638b096140dSahl 		    !tp->ftt_proc->ftpc_defunct)
6397c478bd9Sstevel@tonic-gate 			break;
6407c478bd9Sstevel@tonic-gate 	}
6417c478bd9Sstevel@tonic-gate 
6427c478bd9Sstevel@tonic-gate 	/*
6437c478bd9Sstevel@tonic-gate 	 * Don't sweat it if we can't find the tracepoint again; unlike
6447c478bd9Sstevel@tonic-gate 	 * when we're in fasttrap_pid_probe(), finding the tracepoint here
6457c478bd9Sstevel@tonic-gate 	 * is not essential to the correct execution of the process.
6467c478bd9Sstevel@tonic-gate 	 */
6477c478bd9Sstevel@tonic-gate 	if (tp == NULL) {
6487c478bd9Sstevel@tonic-gate 		mutex_exit(pid_mtx);
6497c478bd9Sstevel@tonic-gate 		return;
6507c478bd9Sstevel@tonic-gate 	}
6517c478bd9Sstevel@tonic-gate 
6527c478bd9Sstevel@tonic-gate 	for (id = tp->ftt_retids; id != NULL; id = id->fti_next) {
6537c478bd9Sstevel@tonic-gate 		/*
6547c478bd9Sstevel@tonic-gate 		 * If there's a branch that could act as a return site, we
6557c478bd9Sstevel@tonic-gate 		 * need to trace it, and check here if the program counter is
6567c478bd9Sstevel@tonic-gate 		 * external to the function.
6577c478bd9Sstevel@tonic-gate 		 */
6587c478bd9Sstevel@tonic-gate 		if (tp->ftt_type != FASTTRAP_T_RET &&
6597c478bd9Sstevel@tonic-gate 		    tp->ftt_type != FASTTRAP_T_RET16 &&
6607c478bd9Sstevel@tonic-gate 		    new_pc - id->fti_probe->ftp_faddr <
6617c478bd9Sstevel@tonic-gate 		    id->fti_probe->ftp_fsize)
6627c478bd9Sstevel@tonic-gate 			continue;
6637c478bd9Sstevel@tonic-gate 
6647c478bd9Sstevel@tonic-gate 		dtrace_probe(id->fti_probe->ftp_id,
6657c478bd9Sstevel@tonic-gate 		    pc - id->fti_probe->ftp_faddr,
6667c478bd9Sstevel@tonic-gate 		    rp->r_r0, rp->r_r1, 0, 0);
6677c478bd9Sstevel@tonic-gate 	}
6687c478bd9Sstevel@tonic-gate 
6697c478bd9Sstevel@tonic-gate 	mutex_exit(pid_mtx);
6707c478bd9Sstevel@tonic-gate }
6717c478bd9Sstevel@tonic-gate 
6727c478bd9Sstevel@tonic-gate static void
6737c478bd9Sstevel@tonic-gate fasttrap_sigsegv(proc_t *p, kthread_t *t, uintptr_t addr)
6747c478bd9Sstevel@tonic-gate {
6757c478bd9Sstevel@tonic-gate 	sigqueue_t *sqp = kmem_zalloc(sizeof (sigqueue_t), KM_SLEEP);
6767c478bd9Sstevel@tonic-gate 
6777c478bd9Sstevel@tonic-gate 	sqp->sq_info.si_signo = SIGSEGV;
6787c478bd9Sstevel@tonic-gate 	sqp->sq_info.si_code = SEGV_MAPERR;
6797c478bd9Sstevel@tonic-gate 	sqp->sq_info.si_addr = (caddr_t)addr;
6807c478bd9Sstevel@tonic-gate 
6817c478bd9Sstevel@tonic-gate 	mutex_enter(&p->p_lock);
6827c478bd9Sstevel@tonic-gate 	sigaddqa(p, t, sqp);
6837c478bd9Sstevel@tonic-gate 	mutex_exit(&p->p_lock);
6847c478bd9Sstevel@tonic-gate 
6857c478bd9Sstevel@tonic-gate 	if (t != NULL)
6867c478bd9Sstevel@tonic-gate 		aston(t);
6877c478bd9Sstevel@tonic-gate }
6887c478bd9Sstevel@tonic-gate 
6897c478bd9Sstevel@tonic-gate #ifdef __amd64
6907c478bd9Sstevel@tonic-gate static void
6917c478bd9Sstevel@tonic-gate fasttrap_usdt_args64(fasttrap_probe_t *probe, struct regs *rp, int argc,
6927c478bd9Sstevel@tonic-gate     uintptr_t *argv)
6937c478bd9Sstevel@tonic-gate {
6947c478bd9Sstevel@tonic-gate 	int i, x, cap = MIN(argc, probe->ftp_nargs);
6957c478bd9Sstevel@tonic-gate 	uintptr_t *stack = (uintptr_t *)rp->r_sp;
6967c478bd9Sstevel@tonic-gate 
6977c478bd9Sstevel@tonic-gate 	for (i = 0; i < cap; i++) {
6987c478bd9Sstevel@tonic-gate 		x = probe->ftp_argmap[i];
6997c478bd9Sstevel@tonic-gate 
7007c478bd9Sstevel@tonic-gate 		if (x < 6)
7017c478bd9Sstevel@tonic-gate 			argv[i] = (&rp->r_rdi)[x];
7027c478bd9Sstevel@tonic-gate 		else
7037c478bd9Sstevel@tonic-gate 			argv[i] = fasttrap_fulword_noerr(&stack[x]);
7047c478bd9Sstevel@tonic-gate 	}
7057c478bd9Sstevel@tonic-gate 
7067c478bd9Sstevel@tonic-gate 	for (; i < argc; i++) {
7077c478bd9Sstevel@tonic-gate 		argv[i] = 0;
7087c478bd9Sstevel@tonic-gate 	}
7097c478bd9Sstevel@tonic-gate }
7107c478bd9Sstevel@tonic-gate #endif
7117c478bd9Sstevel@tonic-gate 
7127c478bd9Sstevel@tonic-gate static void
7137c478bd9Sstevel@tonic-gate fasttrap_usdt_args32(fasttrap_probe_t *probe, struct regs *rp, int argc,
7147c478bd9Sstevel@tonic-gate     uint32_t *argv)
7157c478bd9Sstevel@tonic-gate {
7167c478bd9Sstevel@tonic-gate 	int i, x, cap = MIN(argc, probe->ftp_nargs);
7177c478bd9Sstevel@tonic-gate 	uint32_t *stack = (uint32_t *)rp->r_sp;
7187c478bd9Sstevel@tonic-gate 
7197c478bd9Sstevel@tonic-gate 	for (i = 0; i < cap; i++) {
7207c478bd9Sstevel@tonic-gate 		x = probe->ftp_argmap[i];
7217c478bd9Sstevel@tonic-gate 
7227c478bd9Sstevel@tonic-gate 		argv[i] = fasttrap_fuword32_noerr(&stack[x]);
7237c478bd9Sstevel@tonic-gate 	}
7247c478bd9Sstevel@tonic-gate 
7257c478bd9Sstevel@tonic-gate 	for (; i < argc; i++) {
7267c478bd9Sstevel@tonic-gate 		argv[i] = 0;
7277c478bd9Sstevel@tonic-gate 	}
7287c478bd9Sstevel@tonic-gate }
7297c478bd9Sstevel@tonic-gate 
7307c478bd9Sstevel@tonic-gate int
7317c478bd9Sstevel@tonic-gate fasttrap_pid_probe(struct regs *rp)
7327c478bd9Sstevel@tonic-gate {
7337c478bd9Sstevel@tonic-gate 	proc_t *p = curproc;
7347c478bd9Sstevel@tonic-gate 	uintptr_t pc = rp->r_pc - 1, new_pc = 0;
7357c478bd9Sstevel@tonic-gate 	fasttrap_bucket_t *bucket;
7367c478bd9Sstevel@tonic-gate 	kmutex_t *pid_mtx;
7377c478bd9Sstevel@tonic-gate 	fasttrap_tracepoint_t *tp, tp_local;
7387c478bd9Sstevel@tonic-gate 	pid_t pid;
7397c478bd9Sstevel@tonic-gate 	dtrace_icookie_t cookie;
740*ac448965Sahl 	uint_t is_enabled = 0;
7417c478bd9Sstevel@tonic-gate 
7427c478bd9Sstevel@tonic-gate 	/*
7437c478bd9Sstevel@tonic-gate 	 * It's possible that a user (in a veritable orgy of bad planning)
7447c478bd9Sstevel@tonic-gate 	 * could redirect this thread's flow of control before it reached the
7457c478bd9Sstevel@tonic-gate 	 * return probe fasttrap. In this case we need to kill the process
7467c478bd9Sstevel@tonic-gate 	 * since it's in a unrecoverable state.
7477c478bd9Sstevel@tonic-gate 	 */
7487c478bd9Sstevel@tonic-gate 	if (curthread->t_dtrace_step) {
7497c478bd9Sstevel@tonic-gate 		ASSERT(curthread->t_dtrace_on);
7507c478bd9Sstevel@tonic-gate 		fasttrap_sigtrap(p, curthread, pc);
7517c478bd9Sstevel@tonic-gate 		return (0);
7527c478bd9Sstevel@tonic-gate 	}
7537c478bd9Sstevel@tonic-gate 
7547c478bd9Sstevel@tonic-gate 	/*
7557c478bd9Sstevel@tonic-gate 	 * Clear all user tracing flags.
7567c478bd9Sstevel@tonic-gate 	 */
7577c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_ft = 0;
7587c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_pc = 0;
7597c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_npc = 0;
7607c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_scrpc = 0;
7617c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_astpc = 0;
7627c478bd9Sstevel@tonic-gate #ifdef __amd64
7637c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_regv = 0;
7647c478bd9Sstevel@tonic-gate #endif
7657c478bd9Sstevel@tonic-gate 
7667c478bd9Sstevel@tonic-gate 	/*
7677c478bd9Sstevel@tonic-gate 	 * Treat a child created by a call to vfork(2) as if it were its
7687c478bd9Sstevel@tonic-gate 	 * parent. We know that there's only one thread of control in such a
7697c478bd9Sstevel@tonic-gate 	 * process: this one.
7707c478bd9Sstevel@tonic-gate 	 */
7717c478bd9Sstevel@tonic-gate 	while (p->p_flag & SVFORK) {
7727c478bd9Sstevel@tonic-gate 		p = p->p_parent;
7737c478bd9Sstevel@tonic-gate 	}
7747c478bd9Sstevel@tonic-gate 
7757c478bd9Sstevel@tonic-gate 	pid = p->p_pid;
7767c478bd9Sstevel@tonic-gate 	pid_mtx = &cpu_core[CPU->cpu_id].cpuc_pid_lock;
7777c478bd9Sstevel@tonic-gate 	mutex_enter(pid_mtx);
7787c478bd9Sstevel@tonic-gate 	bucket = &fasttrap_tpoints.fth_table[FASTTRAP_TPOINTS_INDEX(pid, pc)];
7797c478bd9Sstevel@tonic-gate 
7807c478bd9Sstevel@tonic-gate 	/*
7817c478bd9Sstevel@tonic-gate 	 * Lookup the tracepoint that the process just hit.
7827c478bd9Sstevel@tonic-gate 	 */
7837c478bd9Sstevel@tonic-gate 	for (tp = bucket->ftb_data; tp != NULL; tp = tp->ftt_next) {
7847c478bd9Sstevel@tonic-gate 		if (pid == tp->ftt_pid && pc == tp->ftt_pc &&
785b096140dSahl 		    !tp->ftt_proc->ftpc_defunct)
7867c478bd9Sstevel@tonic-gate 			break;
7877c478bd9Sstevel@tonic-gate 	}
7887c478bd9Sstevel@tonic-gate 
7897c478bd9Sstevel@tonic-gate 	/*
7907c478bd9Sstevel@tonic-gate 	 * If we couldn't find a matching tracepoint, either a tracepoint has
7917c478bd9Sstevel@tonic-gate 	 * been inserted without using the pid<pid> ioctl interface (see
7927c478bd9Sstevel@tonic-gate 	 * fasttrap_ioctl), or somehow we have mislaid this tracepoint.
7937c478bd9Sstevel@tonic-gate 	 */
7947c478bd9Sstevel@tonic-gate 	if (tp == NULL) {
7957c478bd9Sstevel@tonic-gate 		mutex_exit(pid_mtx);
7967c478bd9Sstevel@tonic-gate 		return (-1);
7977c478bd9Sstevel@tonic-gate 	}
7987c478bd9Sstevel@tonic-gate 
7997c478bd9Sstevel@tonic-gate 	/*
8007c478bd9Sstevel@tonic-gate 	 * Set the program counter to the address of the traced instruction
8017c478bd9Sstevel@tonic-gate 	 * so that it looks right in ustack() output.
8027c478bd9Sstevel@tonic-gate 	 */
8037c478bd9Sstevel@tonic-gate 	rp->r_pc = pc;
8047c478bd9Sstevel@tonic-gate 
8057c478bd9Sstevel@tonic-gate 	if (tp->ftt_ids != NULL) {
8067c478bd9Sstevel@tonic-gate 		fasttrap_id_t *id;
8077c478bd9Sstevel@tonic-gate 
8087c478bd9Sstevel@tonic-gate #ifdef __amd64
8097c478bd9Sstevel@tonic-gate 		if (p->p_model == DATAMODEL_LP64) {
8107c478bd9Sstevel@tonic-gate 			for (id = tp->ftt_ids; id != NULL; id = id->fti_next) {
8117c478bd9Sstevel@tonic-gate 				fasttrap_probe_t *probe = id->fti_probe;
8127c478bd9Sstevel@tonic-gate 
813*ac448965Sahl 				if (id->fti_ptype == DTFTP_ENTRY) {
8147c478bd9Sstevel@tonic-gate 					/*
8157c478bd9Sstevel@tonic-gate 					 * We note that this was an entry
8167c478bd9Sstevel@tonic-gate 					 * probe to help ustack() find the
8177c478bd9Sstevel@tonic-gate 					 * first caller.
8187c478bd9Sstevel@tonic-gate 					 */
8197c478bd9Sstevel@tonic-gate 					cookie = dtrace_interrupt_disable();
8207c478bd9Sstevel@tonic-gate 					DTRACE_CPUFLAG_SET(CPU_DTRACE_ENTRY);
8217c478bd9Sstevel@tonic-gate 					dtrace_probe(probe->ftp_id, rp->r_rdi,
8227c478bd9Sstevel@tonic-gate 					    rp->r_rsi, rp->r_rdx, rp->r_rcx,
8237c478bd9Sstevel@tonic-gate 					    rp->r_r8);
8247c478bd9Sstevel@tonic-gate 					DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_ENTRY);
8257c478bd9Sstevel@tonic-gate 					dtrace_interrupt_enable(cookie);
826*ac448965Sahl 				} else if (id->fti_ptype == DTFTP_IS_ENABLED) {
827*ac448965Sahl 					/*
828*ac448965Sahl 					 * Note that in this case, we don't
829*ac448965Sahl 					 * call dtrace_probe() since it's only
830*ac448965Sahl 					 * an artificial probe meant to change
831*ac448965Sahl 					 * the flow of control so that it
832*ac448965Sahl 					 * encounters the true probe.
833*ac448965Sahl 					 */
834*ac448965Sahl 					is_enabled = 1;
8357c478bd9Sstevel@tonic-gate 				} else if (probe->ftp_argmap == NULL) {
8367c478bd9Sstevel@tonic-gate 					dtrace_probe(probe->ftp_id, rp->r_rdi,
8377c478bd9Sstevel@tonic-gate 					    rp->r_rsi, rp->r_rdx, rp->r_rcx,
8387c478bd9Sstevel@tonic-gate 					    rp->r_r8);
8397c478bd9Sstevel@tonic-gate 				} else {
8407c478bd9Sstevel@tonic-gate 					uintptr_t t[5];
8417c478bd9Sstevel@tonic-gate 
8427c478bd9Sstevel@tonic-gate 					fasttrap_usdt_args64(probe, rp,
8437c478bd9Sstevel@tonic-gate 					    sizeof (t) / sizeof (t[0]), t);
8447c478bd9Sstevel@tonic-gate 
8457c478bd9Sstevel@tonic-gate 					dtrace_probe(probe->ftp_id, t[0], t[1],
8467c478bd9Sstevel@tonic-gate 					    t[2], t[3], t[4]);
8477c478bd9Sstevel@tonic-gate 				}
8487c478bd9Sstevel@tonic-gate 			}
8497c478bd9Sstevel@tonic-gate 		} else {
8507c478bd9Sstevel@tonic-gate #endif
8517c478bd9Sstevel@tonic-gate 			uintptr_t s0, s1, s2, s3, s4, s5;
8527c478bd9Sstevel@tonic-gate 			uint32_t *stack = (uint32_t *)rp->r_sp;
8537c478bd9Sstevel@tonic-gate 
8547c478bd9Sstevel@tonic-gate 			/*
8557c478bd9Sstevel@tonic-gate 			 * In 32-bit mode, all arguments are passed on the
8567c478bd9Sstevel@tonic-gate 			 * stack. If this is a function entry probe, we need
8577c478bd9Sstevel@tonic-gate 			 * to skip the first entry on the stack as it
8587c478bd9Sstevel@tonic-gate 			 * represents the return address rather than a
8597c478bd9Sstevel@tonic-gate 			 * parameter to the function.
8607c478bd9Sstevel@tonic-gate 			 */
8617c478bd9Sstevel@tonic-gate 			s0 = fasttrap_fuword32_noerr(&stack[0]);
8627c478bd9Sstevel@tonic-gate 			s1 = fasttrap_fuword32_noerr(&stack[1]);
8637c478bd9Sstevel@tonic-gate 			s2 = fasttrap_fuword32_noerr(&stack[2]);
8647c478bd9Sstevel@tonic-gate 			s3 = fasttrap_fuword32_noerr(&stack[3]);
8657c478bd9Sstevel@tonic-gate 			s4 = fasttrap_fuword32_noerr(&stack[4]);
8667c478bd9Sstevel@tonic-gate 			s5 = fasttrap_fuword32_noerr(&stack[5]);
8677c478bd9Sstevel@tonic-gate 
8687c478bd9Sstevel@tonic-gate 			for (id = tp->ftt_ids; id != NULL; id = id->fti_next) {
8697c478bd9Sstevel@tonic-gate 				fasttrap_probe_t *probe = id->fti_probe;
8707c478bd9Sstevel@tonic-gate 
871*ac448965Sahl 				if (id->fti_ptype == DTFTP_ENTRY) {
8727c478bd9Sstevel@tonic-gate 					/*
8737c478bd9Sstevel@tonic-gate 					 * We note that this was an entry
8747c478bd9Sstevel@tonic-gate 					 * probe to help ustack() find the
8757c478bd9Sstevel@tonic-gate 					 * first caller.
8767c478bd9Sstevel@tonic-gate 					 */
8777c478bd9Sstevel@tonic-gate 					cookie = dtrace_interrupt_disable();
8787c478bd9Sstevel@tonic-gate 					DTRACE_CPUFLAG_SET(CPU_DTRACE_ENTRY);
8797c478bd9Sstevel@tonic-gate 					dtrace_probe(probe->ftp_id, s1, s2,
8807c478bd9Sstevel@tonic-gate 					    s3, s4, s5);
8817c478bd9Sstevel@tonic-gate 					DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_ENTRY);
8827c478bd9Sstevel@tonic-gate 					dtrace_interrupt_enable(cookie);
883*ac448965Sahl 				} else if (id->fti_ptype == DTFTP_IS_ENABLED) {
884*ac448965Sahl 					/*
885*ac448965Sahl 					 * Note that in this case, we don't
886*ac448965Sahl 					 * call dtrace_probe() since it's only
887*ac448965Sahl 					 * an artificial probe meant to change
888*ac448965Sahl 					 * the flow of control so that it
889*ac448965Sahl 					 * encounters the true probe.
890*ac448965Sahl 					 */
891*ac448965Sahl 					is_enabled = 1;
8927c478bd9Sstevel@tonic-gate 				} else if (probe->ftp_argmap == NULL) {
8937c478bd9Sstevel@tonic-gate 					dtrace_probe(probe->ftp_id, s0, s1,
8947c478bd9Sstevel@tonic-gate 					    s2, s3, s4);
8957c478bd9Sstevel@tonic-gate 				} else {
8967c478bd9Sstevel@tonic-gate 					uint32_t t[5];
8977c478bd9Sstevel@tonic-gate 
8987c478bd9Sstevel@tonic-gate 					fasttrap_usdt_args32(probe, rp,
8997c478bd9Sstevel@tonic-gate 					    sizeof (t) / sizeof (t[0]), t);
9007c478bd9Sstevel@tonic-gate 
9017c478bd9Sstevel@tonic-gate 					dtrace_probe(probe->ftp_id, t[0], t[1],
9027c478bd9Sstevel@tonic-gate 					    t[2], t[3], t[4]);
9037c478bd9Sstevel@tonic-gate 				}
9047c478bd9Sstevel@tonic-gate 			}
9057c478bd9Sstevel@tonic-gate #ifdef __amd64
9067c478bd9Sstevel@tonic-gate 		}
9077c478bd9Sstevel@tonic-gate #endif
9087c478bd9Sstevel@tonic-gate 	}
9097c478bd9Sstevel@tonic-gate 
9107c478bd9Sstevel@tonic-gate 	/*
9117c478bd9Sstevel@tonic-gate 	 * We're about to do a bunch of work so we cache a local copy of
9127c478bd9Sstevel@tonic-gate 	 * the tracepoint to emulate the instruction, and then find the
9137c478bd9Sstevel@tonic-gate 	 * tracepoint again later if we need to light up any return probes.
9147c478bd9Sstevel@tonic-gate 	 */
9157c478bd9Sstevel@tonic-gate 	tp_local = *tp;
9167c478bd9Sstevel@tonic-gate 	mutex_exit(pid_mtx);
9177c478bd9Sstevel@tonic-gate 	tp = &tp_local;
9187c478bd9Sstevel@tonic-gate 
9197c478bd9Sstevel@tonic-gate 	/*
9207c478bd9Sstevel@tonic-gate 	 * Set the program counter to appear as though the traced instruction
9217c478bd9Sstevel@tonic-gate 	 * had completely executed. This ensures that fasttrap_getreg() will
9227c478bd9Sstevel@tonic-gate 	 * report the expected value for REG_RIP.
9237c478bd9Sstevel@tonic-gate 	 */
9247c478bd9Sstevel@tonic-gate 	rp->r_pc = pc + tp->ftt_size;
9257c478bd9Sstevel@tonic-gate 
926*ac448965Sahl 	/*
927*ac448965Sahl 	 * If there's an is-enabled probe connected to this tracepoint it
928*ac448965Sahl 	 * means that there was a 'xorl %eax, %eax' or 'xorq %rax, %rax'
929*ac448965Sahl 	 * instruction that was placed there by DTrace when the binary was
930*ac448965Sahl 	 * linked. As this probe is, in fact, enabled, we need to stuff 1
931*ac448965Sahl 	 * into %eax or %rax. Accordingly, we can bypass all the instruction
932*ac448965Sahl 	 * emulation logic since we know the inevitable result. It's possible
933*ac448965Sahl 	 * that a user could construct a scenario where the 'is-enabled'
934*ac448965Sahl 	 * probe was on some other instruction, but that would be a rather
935*ac448965Sahl 	 * exotic way to shoot oneself in the foot.
936*ac448965Sahl 	 */
937*ac448965Sahl 	if (is_enabled) {
938*ac448965Sahl 		rp->r_r0 = 1;
939*ac448965Sahl 		new_pc = rp->r_pc;
940*ac448965Sahl 		goto done;
941*ac448965Sahl 	}
942*ac448965Sahl 
943*ac448965Sahl 	/*
944*ac448965Sahl 	 * We emulate certain types of instructions to ensure correctness
945*ac448965Sahl 	 * (in the case of position dependent instructions) or optimize
946*ac448965Sahl 	 * common cases. The rest we have the thread execute back in user-
947*ac448965Sahl 	 * land.
948*ac448965Sahl 	 */
9497c478bd9Sstevel@tonic-gate 	switch (tp->ftt_type) {
9507c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_RET:
9517c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_RET16:
9527c478bd9Sstevel@tonic-gate 	{
9537c478bd9Sstevel@tonic-gate 		uintptr_t dst;
9547c478bd9Sstevel@tonic-gate 		uintptr_t addr;
9557c478bd9Sstevel@tonic-gate 		int ret;
9567c478bd9Sstevel@tonic-gate 
9577c478bd9Sstevel@tonic-gate 		/*
9587c478bd9Sstevel@tonic-gate 		 * We have to emulate _every_ facet of the behavior of a ret
9597c478bd9Sstevel@tonic-gate 		 * instruction including what happens if the load from %esp
9607c478bd9Sstevel@tonic-gate 		 * fails; in that case, we send a SIGSEGV.
9617c478bd9Sstevel@tonic-gate 		 */
9627c478bd9Sstevel@tonic-gate #ifdef __amd64
9637c478bd9Sstevel@tonic-gate 		if (p->p_model == DATAMODEL_NATIVE) {
9647c478bd9Sstevel@tonic-gate #endif
9657c478bd9Sstevel@tonic-gate 			ret = fasttrap_fulword((void *)rp->r_sp, &dst);
9667c478bd9Sstevel@tonic-gate 			addr = rp->r_sp + sizeof (uintptr_t);
9677c478bd9Sstevel@tonic-gate #ifdef __amd64
9687c478bd9Sstevel@tonic-gate 		} else {
9697c478bd9Sstevel@tonic-gate 			uint32_t dst32;
9707c478bd9Sstevel@tonic-gate 			ret = fasttrap_fuword32((void *)rp->r_sp, &dst32);
9717c478bd9Sstevel@tonic-gate 			dst = dst32;
9727c478bd9Sstevel@tonic-gate 			addr = rp->r_sp + sizeof (uint32_t);
9737c478bd9Sstevel@tonic-gate 		}
9747c478bd9Sstevel@tonic-gate #endif
9757c478bd9Sstevel@tonic-gate 
9767c478bd9Sstevel@tonic-gate 		if (ret == -1) {
9777c478bd9Sstevel@tonic-gate 			fasttrap_sigsegv(p, curthread, rp->r_sp);
9787c478bd9Sstevel@tonic-gate 			new_pc = pc;
9797c478bd9Sstevel@tonic-gate 			break;
9807c478bd9Sstevel@tonic-gate 		}
9817c478bd9Sstevel@tonic-gate 
9827c478bd9Sstevel@tonic-gate 		if (tp->ftt_type == FASTTRAP_T_RET16)
9837c478bd9Sstevel@tonic-gate 			addr += tp->ftt_dest;
9847c478bd9Sstevel@tonic-gate 
9857c478bd9Sstevel@tonic-gate 		rp->r_sp = addr;
9867c478bd9Sstevel@tonic-gate 		new_pc = dst;
9877c478bd9Sstevel@tonic-gate 		break;
9887c478bd9Sstevel@tonic-gate 	}
9897c478bd9Sstevel@tonic-gate 
9907c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_JCC:
9917c478bd9Sstevel@tonic-gate 	{
9927c478bd9Sstevel@tonic-gate 		uint_t taken;
9937c478bd9Sstevel@tonic-gate 
9947c478bd9Sstevel@tonic-gate 		switch (tp->ftt_code) {
9957c478bd9Sstevel@tonic-gate 		case FASTTRAP_JO:
9967c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_OF) != 0;
9977c478bd9Sstevel@tonic-gate 			break;
9987c478bd9Sstevel@tonic-gate 		case FASTTRAP_JNO:
9997c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_OF) == 0;
10007c478bd9Sstevel@tonic-gate 			break;
10017c478bd9Sstevel@tonic-gate 		case FASTTRAP_JB:
10027c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_CF) != 0;
10037c478bd9Sstevel@tonic-gate 			break;
10047c478bd9Sstevel@tonic-gate 		case FASTTRAP_JAE:
10057c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_CF) == 0;
10067c478bd9Sstevel@tonic-gate 			break;
10077c478bd9Sstevel@tonic-gate 		case FASTTRAP_JE:
10087c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_ZF) != 0;
10097c478bd9Sstevel@tonic-gate 			break;
10107c478bd9Sstevel@tonic-gate 		case FASTTRAP_JNE:
10117c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_ZF) == 0;
10127c478bd9Sstevel@tonic-gate 			break;
10137c478bd9Sstevel@tonic-gate 		case FASTTRAP_JBE:
10147c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_CF) != 0 ||
10157c478bd9Sstevel@tonic-gate 			    (rp->r_ps & FASTTRAP_EFLAGS_ZF) != 0;
10167c478bd9Sstevel@tonic-gate 			break;
10177c478bd9Sstevel@tonic-gate 		case FASTTRAP_JA:
10187c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_CF) == 0 &&
10197c478bd9Sstevel@tonic-gate 			    (rp->r_ps & FASTTRAP_EFLAGS_ZF) == 0;
10207c478bd9Sstevel@tonic-gate 			break;
10217c478bd9Sstevel@tonic-gate 		case FASTTRAP_JS:
10227c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_SF) != 0;
10237c478bd9Sstevel@tonic-gate 			break;
10247c478bd9Sstevel@tonic-gate 		case FASTTRAP_JNS:
10257c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_SF) == 0;
10267c478bd9Sstevel@tonic-gate 			break;
10277c478bd9Sstevel@tonic-gate 		case FASTTRAP_JP:
10287c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_PF) != 0;
10297c478bd9Sstevel@tonic-gate 			break;
10307c478bd9Sstevel@tonic-gate 		case FASTTRAP_JNP:
10317c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_PF) == 0;
10327c478bd9Sstevel@tonic-gate 			break;
10337c478bd9Sstevel@tonic-gate 		case FASTTRAP_JL:
10347c478bd9Sstevel@tonic-gate 			taken = ((rp->r_ps & FASTTRAP_EFLAGS_SF) == 0) !=
10357c478bd9Sstevel@tonic-gate 			    ((rp->r_ps & FASTTRAP_EFLAGS_OF) == 0);
10367c478bd9Sstevel@tonic-gate 			break;
10377c478bd9Sstevel@tonic-gate 		case FASTTRAP_JGE:
10387c478bd9Sstevel@tonic-gate 			taken = ((rp->r_ps & FASTTRAP_EFLAGS_SF) == 0) ==
10397c478bd9Sstevel@tonic-gate 			    ((rp->r_ps & FASTTRAP_EFLAGS_OF) == 0);
10407c478bd9Sstevel@tonic-gate 			break;
10417c478bd9Sstevel@tonic-gate 		case FASTTRAP_JLE:
10427c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_ZF) != 0 ||
10437c478bd9Sstevel@tonic-gate 			    ((rp->r_ps & FASTTRAP_EFLAGS_SF) == 0) !=
10447c478bd9Sstevel@tonic-gate 			    ((rp->r_ps & FASTTRAP_EFLAGS_OF) == 0);
10457c478bd9Sstevel@tonic-gate 			break;
10467c478bd9Sstevel@tonic-gate 		case FASTTRAP_JG:
10477c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_ZF) == 0 &&
10487c478bd9Sstevel@tonic-gate 			    ((rp->r_ps & FASTTRAP_EFLAGS_SF) == 0) ==
10497c478bd9Sstevel@tonic-gate 			    ((rp->r_ps & FASTTRAP_EFLAGS_OF) == 0);
10507c478bd9Sstevel@tonic-gate 			break;
10517c478bd9Sstevel@tonic-gate 
10527c478bd9Sstevel@tonic-gate 		}
10537c478bd9Sstevel@tonic-gate 
10547c478bd9Sstevel@tonic-gate 		if (taken)
10557c478bd9Sstevel@tonic-gate 			new_pc = tp->ftt_dest;
10567c478bd9Sstevel@tonic-gate 		else
10577c478bd9Sstevel@tonic-gate 			new_pc = pc + tp->ftt_size;
10587c478bd9Sstevel@tonic-gate 		break;
10597c478bd9Sstevel@tonic-gate 	}
10607c478bd9Sstevel@tonic-gate 
10617c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_LOOP:
10627c478bd9Sstevel@tonic-gate 	{
10637c478bd9Sstevel@tonic-gate 		uint_t taken;
10647c478bd9Sstevel@tonic-gate #ifdef __amd64
10657c478bd9Sstevel@tonic-gate 		greg_t cx = rp->r_rcx--;
10667c478bd9Sstevel@tonic-gate #else
10677c478bd9Sstevel@tonic-gate 		greg_t cx = rp->r_ecx--;
10687c478bd9Sstevel@tonic-gate #endif
10697c478bd9Sstevel@tonic-gate 
10707c478bd9Sstevel@tonic-gate 		switch (tp->ftt_code) {
10717c478bd9Sstevel@tonic-gate 		case FASTTRAP_LOOPNZ:
10727c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_ZF) == 0 &&
10737c478bd9Sstevel@tonic-gate 			    cx != 0;
10747c478bd9Sstevel@tonic-gate 			break;
10757c478bd9Sstevel@tonic-gate 		case FASTTRAP_LOOPZ:
10767c478bd9Sstevel@tonic-gate 			taken = (rp->r_ps & FASTTRAP_EFLAGS_ZF) != 0 &&
10777c478bd9Sstevel@tonic-gate 			    cx != 0;
10787c478bd9Sstevel@tonic-gate 			break;
10797c478bd9Sstevel@tonic-gate 		case FASTTRAP_LOOP:
10807c478bd9Sstevel@tonic-gate 			taken = (cx != 0);
10817c478bd9Sstevel@tonic-gate 			break;
10827c478bd9Sstevel@tonic-gate 		}
10837c478bd9Sstevel@tonic-gate 
10847c478bd9Sstevel@tonic-gate 		if (taken)
10857c478bd9Sstevel@tonic-gate 			new_pc = tp->ftt_dest;
10867c478bd9Sstevel@tonic-gate 		else
10877c478bd9Sstevel@tonic-gate 			new_pc = pc + tp->ftt_size;
10887c478bd9Sstevel@tonic-gate 		break;
10897c478bd9Sstevel@tonic-gate 	}
10907c478bd9Sstevel@tonic-gate 
10917c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_JCXZ:
10927c478bd9Sstevel@tonic-gate 	{
10937c478bd9Sstevel@tonic-gate #ifdef __amd64
10947c478bd9Sstevel@tonic-gate 		greg_t cx = rp->r_rcx;
10957c478bd9Sstevel@tonic-gate #else
10967c478bd9Sstevel@tonic-gate 		greg_t cx = rp->r_ecx;
10977c478bd9Sstevel@tonic-gate #endif
10987c478bd9Sstevel@tonic-gate 
10997c478bd9Sstevel@tonic-gate 		if (cx == 0)
11007c478bd9Sstevel@tonic-gate 			new_pc = tp->ftt_dest;
11017c478bd9Sstevel@tonic-gate 		else
11027c478bd9Sstevel@tonic-gate 			new_pc = pc + tp->ftt_size;
11037c478bd9Sstevel@tonic-gate 		break;
11047c478bd9Sstevel@tonic-gate 	}
11057c478bd9Sstevel@tonic-gate 
11067c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_PUSHL_EBP:
11077c478bd9Sstevel@tonic-gate 	{
11087c478bd9Sstevel@tonic-gate 		int ret;
11097c478bd9Sstevel@tonic-gate 		uintptr_t addr;
11107c478bd9Sstevel@tonic-gate #ifdef __amd64
11117c478bd9Sstevel@tonic-gate 		if (p->p_model == DATAMODEL_NATIVE) {
11127c478bd9Sstevel@tonic-gate #endif
11137c478bd9Sstevel@tonic-gate 			addr = rp->r_sp - sizeof (uintptr_t);
11147c478bd9Sstevel@tonic-gate 			ret = fasttrap_sulword((void *)addr, rp->r_fp);
11157c478bd9Sstevel@tonic-gate #ifdef __amd64
11167c478bd9Sstevel@tonic-gate 		} else {
11177c478bd9Sstevel@tonic-gate 			addr = rp->r_sp - sizeof (uint32_t);
11187c478bd9Sstevel@tonic-gate 			ret = fasttrap_suword32((void *)addr,
11197c478bd9Sstevel@tonic-gate 			    (uint32_t)rp->r_fp);
11207c478bd9Sstevel@tonic-gate 		}
11217c478bd9Sstevel@tonic-gate #endif
11227c478bd9Sstevel@tonic-gate 
11237c478bd9Sstevel@tonic-gate 		if (ret == -1) {
11247c478bd9Sstevel@tonic-gate 			fasttrap_sigsegv(p, curthread, addr);
11257c478bd9Sstevel@tonic-gate 			new_pc = pc;
11267c478bd9Sstevel@tonic-gate 			break;
11277c478bd9Sstevel@tonic-gate 		}
11287c478bd9Sstevel@tonic-gate 
11297c478bd9Sstevel@tonic-gate 		rp->r_sp = addr;
11307c478bd9Sstevel@tonic-gate 		new_pc = pc + tp->ftt_size;
11317c478bd9Sstevel@tonic-gate 		break;
11327c478bd9Sstevel@tonic-gate 	}
11337c478bd9Sstevel@tonic-gate 
11347c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_JMP:
11357c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_CALL:
11367c478bd9Sstevel@tonic-gate 		if (tp->ftt_code == 0) {
11377c478bd9Sstevel@tonic-gate 			new_pc = tp->ftt_dest;
11387c478bd9Sstevel@tonic-gate 		} else {
11397c478bd9Sstevel@tonic-gate 			uintptr_t addr = tp->ftt_dest;
11407c478bd9Sstevel@tonic-gate 
11417c478bd9Sstevel@tonic-gate 			if (tp->ftt_base != FASTTRAP_NOREG)
11427c478bd9Sstevel@tonic-gate 				addr += fasttrap_getreg(rp, tp->ftt_base);
11437c478bd9Sstevel@tonic-gate 			if (tp->ftt_index != FASTTRAP_NOREG)
11447c478bd9Sstevel@tonic-gate 				addr += fasttrap_getreg(rp, tp->ftt_index) <<
11457c478bd9Sstevel@tonic-gate 				    tp->ftt_scale;
11467c478bd9Sstevel@tonic-gate 
11477c478bd9Sstevel@tonic-gate 			if (tp->ftt_code == 1) {
11487c478bd9Sstevel@tonic-gate #ifdef __amd64
11497c478bd9Sstevel@tonic-gate 				if (p->p_model == DATAMODEL_NATIVE) {
11507c478bd9Sstevel@tonic-gate #endif
11517c478bd9Sstevel@tonic-gate 					uintptr_t value;
11527c478bd9Sstevel@tonic-gate 					if (fasttrap_fulword((void *)addr,
11537c478bd9Sstevel@tonic-gate 					    &value) == -1) {
11547c478bd9Sstevel@tonic-gate 						fasttrap_sigsegv(p, curthread,
11557c478bd9Sstevel@tonic-gate 						    addr);
11567c478bd9Sstevel@tonic-gate 						new_pc = pc;
11577c478bd9Sstevel@tonic-gate 						break;
11587c478bd9Sstevel@tonic-gate 					}
11597c478bd9Sstevel@tonic-gate 					new_pc = value;
11607c478bd9Sstevel@tonic-gate #ifdef __amd64
11617c478bd9Sstevel@tonic-gate 				} else {
11627c478bd9Sstevel@tonic-gate 					uint32_t value;
11637c478bd9Sstevel@tonic-gate 					if (fasttrap_fuword32((void *)addr,
11647c478bd9Sstevel@tonic-gate 					    &value) == -1) {
11657c478bd9Sstevel@tonic-gate 						fasttrap_sigsegv(p, curthread,
11667c478bd9Sstevel@tonic-gate 						    addr);
11677c478bd9Sstevel@tonic-gate 						new_pc = pc;
11687c478bd9Sstevel@tonic-gate 						break;
11697c478bd9Sstevel@tonic-gate 					}
11707c478bd9Sstevel@tonic-gate 					new_pc = value;
11717c478bd9Sstevel@tonic-gate 				}
11727c478bd9Sstevel@tonic-gate #endif
11737c478bd9Sstevel@tonic-gate 			} else {
11747c478bd9Sstevel@tonic-gate 				new_pc = addr;
11757c478bd9Sstevel@tonic-gate 			}
11767c478bd9Sstevel@tonic-gate 		}
11777c478bd9Sstevel@tonic-gate 
11787c478bd9Sstevel@tonic-gate 		/*
11797c478bd9Sstevel@tonic-gate 		 * If this is a call instruction, we need to push the return
11807c478bd9Sstevel@tonic-gate 		 * address onto the stack. If this fails, we send the process
11817c478bd9Sstevel@tonic-gate 		 * a SIGSEGV and reset the pc to emulate what would happen if
11827c478bd9Sstevel@tonic-gate 		 * this instruction weren't traced.
11837c478bd9Sstevel@tonic-gate 		 */
11847c478bd9Sstevel@tonic-gate 		if (tp->ftt_type == FASTTRAP_T_CALL) {
11857c478bd9Sstevel@tonic-gate 			int ret;
11867c478bd9Sstevel@tonic-gate 			uintptr_t addr;
11877c478bd9Sstevel@tonic-gate #ifdef __amd64
11887c478bd9Sstevel@tonic-gate 			if (p->p_model == DATAMODEL_NATIVE) {
11897c478bd9Sstevel@tonic-gate 				addr = rp->r_sp - sizeof (uintptr_t);
11907c478bd9Sstevel@tonic-gate 				ret = fasttrap_sulword((void *)addr,
11917c478bd9Sstevel@tonic-gate 				    pc + tp->ftt_size);
11927c478bd9Sstevel@tonic-gate 			} else {
11937c478bd9Sstevel@tonic-gate #endif
11947c478bd9Sstevel@tonic-gate 				addr = rp->r_sp - sizeof (uint32_t);
11957c478bd9Sstevel@tonic-gate 				ret = fasttrap_suword32((void *)addr,
11967c478bd9Sstevel@tonic-gate 				    (uint32_t)(pc + tp->ftt_size));
11977c478bd9Sstevel@tonic-gate #ifdef __amd64
11987c478bd9Sstevel@tonic-gate 			}
11997c478bd9Sstevel@tonic-gate #endif
12007c478bd9Sstevel@tonic-gate 
12017c478bd9Sstevel@tonic-gate 			if (ret == -1) {
12027c478bd9Sstevel@tonic-gate 				fasttrap_sigsegv(p, curthread, addr);
12037c478bd9Sstevel@tonic-gate 				new_pc = pc;
12047c478bd9Sstevel@tonic-gate 				break;
12057c478bd9Sstevel@tonic-gate 			}
12067c478bd9Sstevel@tonic-gate 
12077c478bd9Sstevel@tonic-gate 			rp->r_sp = addr;
12087c478bd9Sstevel@tonic-gate 		}
12097c478bd9Sstevel@tonic-gate 
12107c478bd9Sstevel@tonic-gate 		break;
12117c478bd9Sstevel@tonic-gate 
12127c478bd9Sstevel@tonic-gate 	case FASTTRAP_T_COMMON:
12137c478bd9Sstevel@tonic-gate 	{
12147c478bd9Sstevel@tonic-gate 		uintptr_t addr;
12157c478bd9Sstevel@tonic-gate 		uint8_t scratch[2 * FASTTRAP_MAX_INSTR_SIZE + 5 + 2];
12167c478bd9Sstevel@tonic-gate 		uint_t i = 0;
12177c478bd9Sstevel@tonic-gate 		klwp_t *lwp = ttolwp(curthread);
12187c478bd9Sstevel@tonic-gate 
12197c478bd9Sstevel@tonic-gate 		/*
12207c478bd9Sstevel@tonic-gate 		 * Compute the address of the ulwp_t and step over the
12217c478bd9Sstevel@tonic-gate 		 * ul_self pointer. The method used to store the user-land
12227c478bd9Sstevel@tonic-gate 		 * thread pointer is very different on 32- and 64-bit
12237c478bd9Sstevel@tonic-gate 		 * kernels.
12247c478bd9Sstevel@tonic-gate 		 */
12257c478bd9Sstevel@tonic-gate #if defined(__amd64)
12267c478bd9Sstevel@tonic-gate 		if (p->p_model == DATAMODEL_LP64) {
12277c478bd9Sstevel@tonic-gate 			addr = lwp->lwp_pcb.pcb_fsbase;
12287c478bd9Sstevel@tonic-gate 			addr += sizeof (void *);
12297c478bd9Sstevel@tonic-gate 		} else {
12307c478bd9Sstevel@tonic-gate 			addr = lwp->lwp_pcb.pcb_gsbase;
12317c478bd9Sstevel@tonic-gate 			addr += sizeof (caddr32_t);
12327c478bd9Sstevel@tonic-gate 		}
12337c478bd9Sstevel@tonic-gate #elif defined(__i386)
12347c478bd9Sstevel@tonic-gate 		addr = USEGD_GETBASE(&lwp->lwp_pcb.pcb_gsdesc);
12357c478bd9Sstevel@tonic-gate 		addr += sizeof (void *);
12367c478bd9Sstevel@tonic-gate #endif
12377c478bd9Sstevel@tonic-gate 
12387c478bd9Sstevel@tonic-gate 		/*
12397c478bd9Sstevel@tonic-gate 		 * Generic Instruction Tracing
12407c478bd9Sstevel@tonic-gate 		 * ---------------------------
12417c478bd9Sstevel@tonic-gate 		 *
12427c478bd9Sstevel@tonic-gate 		 * This is the layout of the scratch space in the user-land
12437c478bd9Sstevel@tonic-gate 		 * thread structure for our generated instructions.
12447c478bd9Sstevel@tonic-gate 		 *
12457c478bd9Sstevel@tonic-gate 		 *	32-bit mode			bytes
12467c478bd9Sstevel@tonic-gate 		 *	------------------------	-----
12477c478bd9Sstevel@tonic-gate 		 * a:	<original instruction>		<= 15
12487c478bd9Sstevel@tonic-gate 		 *	jmp	<pc + tp->ftt_size>	    5
12497c478bd9Sstevel@tonic-gate 		 * b:	<original instrction>		<= 15
12507c478bd9Sstevel@tonic-gate 		 *	int	T_DTRACE_RET		    2
12517c478bd9Sstevel@tonic-gate 		 *					-----
12527c478bd9Sstevel@tonic-gate 		 *					<= 37
12537c478bd9Sstevel@tonic-gate 		 *
12547c478bd9Sstevel@tonic-gate 		 *	64-bit mode			bytes
12557c478bd9Sstevel@tonic-gate 		 *	------------------------	-----
12567c478bd9Sstevel@tonic-gate 		 * a:	<original instruction>		<= 15
12577c478bd9Sstevel@tonic-gate 		 *	jmp	0(%rip)			    6
12587c478bd9Sstevel@tonic-gate 		 *	<pc + tp->ftt_size>		    8
12597c478bd9Sstevel@tonic-gate 		 * b:	<original instruction>		<= 15
12607c478bd9Sstevel@tonic-gate 		 * 	int	T_DTRACE_RET		    2
12617c478bd9Sstevel@tonic-gate 		 * 					-----
12627c478bd9Sstevel@tonic-gate 		 * 					<= 46
12637c478bd9Sstevel@tonic-gate 		 *
12647c478bd9Sstevel@tonic-gate 		 * The %pc is set to a, and curthread->t_dtrace_astpc is set
12657c478bd9Sstevel@tonic-gate 		 * to b. If we encounter a signal on the way out of the
12667c478bd9Sstevel@tonic-gate 		 * kernel, trap() will set %pc to curthread->t_dtrace_astpc
12677c478bd9Sstevel@tonic-gate 		 * so that we execute the original instruction and re-enter
12687c478bd9Sstevel@tonic-gate 		 * the kernel rather than redirecting to the next instruction.
12697c478bd9Sstevel@tonic-gate 		 *
12707c478bd9Sstevel@tonic-gate 		 * If there are return probes (so we know that we're going to
12717c478bd9Sstevel@tonic-gate 		 * need to reenter the kernel after executing the original
12727c478bd9Sstevel@tonic-gate 		 * instruction), the scratch space will just contain the
12737c478bd9Sstevel@tonic-gate 		 * original instruction followed by an interrupt -- the same
12747c478bd9Sstevel@tonic-gate 		 * data as at b.
12757c478bd9Sstevel@tonic-gate 		 *
12767c478bd9Sstevel@tonic-gate 		 * %rip-relative Addressing
12777c478bd9Sstevel@tonic-gate 		 * ------------------------
12787c478bd9Sstevel@tonic-gate 		 *
12797c478bd9Sstevel@tonic-gate 		 * There's a further complication in 64-bit mode due to %rip-
12807c478bd9Sstevel@tonic-gate 		 * relative addressing. While this is clearly a beneficial
12817c478bd9Sstevel@tonic-gate 		 * architectural decision for position independent code, it's
12827c478bd9Sstevel@tonic-gate 		 * hard not to see it as a personal attack against the pid
12837c478bd9Sstevel@tonic-gate 		 * provider since before there was a relatively small set of
12847c478bd9Sstevel@tonic-gate 		 * instructions to emulate; with %rip-relative addressing,
12857c478bd9Sstevel@tonic-gate 		 * almost every instruction can potentially depend on the
12867c478bd9Sstevel@tonic-gate 		 * address at which it's executed. Rather than emulating
12877c478bd9Sstevel@tonic-gate 		 * the broad spectrum of instructions that can now be
12887c478bd9Sstevel@tonic-gate 		 * position dependent, we emulate jumps and others as in
12897c478bd9Sstevel@tonic-gate 		 * 32-bit mode, and take a different tack for instructions
12907c478bd9Sstevel@tonic-gate 		 * using %rip-relative addressing.
12917c478bd9Sstevel@tonic-gate 		 *
12927c478bd9Sstevel@tonic-gate 		 * For every instruction that uses the ModRM byte, the
12937c478bd9Sstevel@tonic-gate 		 * in-kernel disassembler reports its location. We use the
12947c478bd9Sstevel@tonic-gate 		 * ModRM byte to identify that an instruction uses
12957c478bd9Sstevel@tonic-gate 		 * %rip-relative addressing and to see what other registers
12967c478bd9Sstevel@tonic-gate 		 * the instruction uses. To emulate those instructions,
12977c478bd9Sstevel@tonic-gate 		 * we modify the instruction to be %rax-relative rather than
12987c478bd9Sstevel@tonic-gate 		 * %rip-relative (or %rcx-relative if the instruction uses
12997c478bd9Sstevel@tonic-gate 		 * %rax; or %r8- or %r9-relative if the REX.B is present so
13007c478bd9Sstevel@tonic-gate 		 * we don't have to rewrite the REX prefix). We then load
13017c478bd9Sstevel@tonic-gate 		 * the value that %rip would have been into the scratch
13027c478bd9Sstevel@tonic-gate 		 * register and generate an instruction to reset the scratch
13037c478bd9Sstevel@tonic-gate 		 * register back to its original value. The instruction
13047c478bd9Sstevel@tonic-gate 		 * sequence looks like this:
13057c478bd9Sstevel@tonic-gate 		 *
13067c478bd9Sstevel@tonic-gate 		 *	64-mode %rip-relative		bytes
13077c478bd9Sstevel@tonic-gate 		 *	------------------------	-----
13087c478bd9Sstevel@tonic-gate 		 * a:	<modified instruction>		<= 15
13097c478bd9Sstevel@tonic-gate 		 *	movq	$<value>, %<scratch>	    6
13107c478bd9Sstevel@tonic-gate 		 *	jmp	0(%rip)			    6
13117c478bd9Sstevel@tonic-gate 		 *	<pc + tp->ftt_size>		    8
13127c478bd9Sstevel@tonic-gate 		 * b:	<modified instruction>  	<= 15
13137c478bd9Sstevel@tonic-gate 		 * 	int	T_DTRACE_RET		    2
13147c478bd9Sstevel@tonic-gate 		 * 					-----
13157c478bd9Sstevel@tonic-gate 		 *					   52
13167c478bd9Sstevel@tonic-gate 		 *
13177c478bd9Sstevel@tonic-gate 		 * We set curthread->t_dtrace_regv so that upon receiving
13187c478bd9Sstevel@tonic-gate 		 * a signal we can reset the value of the scratch register.
13197c478bd9Sstevel@tonic-gate 		 */
13207c478bd9Sstevel@tonic-gate 
13217c478bd9Sstevel@tonic-gate 		ASSERT(tp->ftt_size < FASTTRAP_MAX_INSTR_SIZE);
13227c478bd9Sstevel@tonic-gate 
13237c478bd9Sstevel@tonic-gate 		curthread->t_dtrace_scrpc = addr;
13247c478bd9Sstevel@tonic-gate 		bcopy(tp->ftt_instr, &scratch[i], tp->ftt_size);
13257c478bd9Sstevel@tonic-gate 		i += tp->ftt_size;
13267c478bd9Sstevel@tonic-gate 
13277c478bd9Sstevel@tonic-gate #ifdef __amd64
13287c478bd9Sstevel@tonic-gate 		if (tp->ftt_ripmode != 0) {
13297c478bd9Sstevel@tonic-gate 			greg_t *reg;
13307c478bd9Sstevel@tonic-gate 
13317c478bd9Sstevel@tonic-gate 			ASSERT(p->p_model == DATAMODEL_LP64);
13327c478bd9Sstevel@tonic-gate 			ASSERT(tp->ftt_ripmode &
13337c478bd9Sstevel@tonic-gate 			    (FASTTRAP_RIP_1 | FASTTRAP_RIP_2));
13347c478bd9Sstevel@tonic-gate 
13357c478bd9Sstevel@tonic-gate 			/*
13367c478bd9Sstevel@tonic-gate 			 * If this was a %rip-relative instruction, we change
13377c478bd9Sstevel@tonic-gate 			 * it to be either a %rax- or %rcx-relative
13387c478bd9Sstevel@tonic-gate 			 * instruction (depending on whether those registers
13397c478bd9Sstevel@tonic-gate 			 * are used as another operand; or %r8- or %r9-
13407c478bd9Sstevel@tonic-gate 			 * relative depending on the value of REX.B). We then
13417c478bd9Sstevel@tonic-gate 			 * set that register and generate a movq instruction
13427c478bd9Sstevel@tonic-gate 			 * to reset the value.
13437c478bd9Sstevel@tonic-gate 			 */
13447c478bd9Sstevel@tonic-gate 			if (tp->ftt_ripmode & FASTTRAP_RIP_X)
13457c478bd9Sstevel@tonic-gate 				scratch[i++] = FASTTRAP_REX(1, 0, 0, 1);
13467c478bd9Sstevel@tonic-gate 			else
13477c478bd9Sstevel@tonic-gate 				scratch[i++] = FASTTRAP_REX(1, 0, 0, 0);
13487c478bd9Sstevel@tonic-gate 
13497c478bd9Sstevel@tonic-gate 			if (tp->ftt_ripmode & FASTTRAP_RIP_1)
13507c478bd9Sstevel@tonic-gate 				scratch[i++] = FASTTRAP_MOV_EAX;
13517c478bd9Sstevel@tonic-gate 			else
13527c478bd9Sstevel@tonic-gate 				scratch[i++] = FASTTRAP_MOV_ECX;
13537c478bd9Sstevel@tonic-gate 
13547c478bd9Sstevel@tonic-gate 			switch (tp->ftt_ripmode) {
13557c478bd9Sstevel@tonic-gate 			case FASTTRAP_RIP_1:
13567c478bd9Sstevel@tonic-gate 				reg = &rp->r_rax;
13577c478bd9Sstevel@tonic-gate 				curthread->t_dtrace_reg = REG_RAX;
13587c478bd9Sstevel@tonic-gate 				break;
13597c478bd9Sstevel@tonic-gate 			case FASTTRAP_RIP_2:
13607c478bd9Sstevel@tonic-gate 				reg = &rp->r_rcx;
13617c478bd9Sstevel@tonic-gate 				curthread->t_dtrace_reg = REG_RCX;
13627c478bd9Sstevel@tonic-gate 				break;
13637c478bd9Sstevel@tonic-gate 			case FASTTRAP_RIP_1 | FASTTRAP_RIP_X:
13647c478bd9Sstevel@tonic-gate 				reg = &rp->r_r8;
13657c478bd9Sstevel@tonic-gate 				curthread->t_dtrace_reg = REG_R8;
13667c478bd9Sstevel@tonic-gate 				break;
13677c478bd9Sstevel@tonic-gate 			case FASTTRAP_RIP_2 | FASTTRAP_RIP_X:
13687c478bd9Sstevel@tonic-gate 				reg = &rp->r_r9;
13697c478bd9Sstevel@tonic-gate 				curthread->t_dtrace_reg = REG_R9;
13707c478bd9Sstevel@tonic-gate 				break;
13717c478bd9Sstevel@tonic-gate 			}
13727c478bd9Sstevel@tonic-gate 
13737c478bd9Sstevel@tonic-gate 			*(uint64_t *)&scratch[i] = *reg;
13747c478bd9Sstevel@tonic-gate 			curthread->t_dtrace_regv = *reg;
13757c478bd9Sstevel@tonic-gate 			*reg = pc + tp->ftt_size;
13767c478bd9Sstevel@tonic-gate 			i += sizeof (uint64_t);
13777c478bd9Sstevel@tonic-gate 		}
13787c478bd9Sstevel@tonic-gate #endif
13797c478bd9Sstevel@tonic-gate 
13807c478bd9Sstevel@tonic-gate 		/*
13817c478bd9Sstevel@tonic-gate 		 * Generate the branch instruction to what would have
13827c478bd9Sstevel@tonic-gate 		 * normally been the subsequent instruction. In 32-bit mode,
13837c478bd9Sstevel@tonic-gate 		 * this is just a relative branch; in 64-bit mode this is a
13847c478bd9Sstevel@tonic-gate 		 * %rip-relative branch that loads the 64-bit pc value
13857c478bd9Sstevel@tonic-gate 		 * immediately after the jmp instruction.
13867c478bd9Sstevel@tonic-gate 		 */
13877c478bd9Sstevel@tonic-gate #ifdef __amd64
13887c478bd9Sstevel@tonic-gate 		if (p->p_model == DATAMODEL_LP64) {
13897c478bd9Sstevel@tonic-gate 			scratch[i++] = FASTTRAP_GROUP5_OP;
13907c478bd9Sstevel@tonic-gate 			scratch[i++] = FASTTRAP_MODRM(0, 4, 5);
13917c478bd9Sstevel@tonic-gate 			*(uint32_t *)&scratch[i] = 0;
13927c478bd9Sstevel@tonic-gate 			i += sizeof (uint32_t);
13937c478bd9Sstevel@tonic-gate 			*(uint64_t *)&scratch[i] = pc + tp->ftt_size;
13947c478bd9Sstevel@tonic-gate 			i += sizeof (uint64_t);
13957c478bd9Sstevel@tonic-gate 		} else {
13967c478bd9Sstevel@tonic-gate #endif
13977c478bd9Sstevel@tonic-gate 			/*
13987c478bd9Sstevel@tonic-gate 			 * Set up the jmp to the next instruction; note that
13997c478bd9Sstevel@tonic-gate 			 * the size of the traced instruction cancels out.
14007c478bd9Sstevel@tonic-gate 			 */
14017c478bd9Sstevel@tonic-gate 			scratch[i++] = FASTTRAP_JMP32;
14027c478bd9Sstevel@tonic-gate 			*(uint32_t *)&scratch[i] = pc - addr - 5;
14037c478bd9Sstevel@tonic-gate 			i += sizeof (uint32_t);
14047c478bd9Sstevel@tonic-gate #ifdef __amd64
14057c478bd9Sstevel@tonic-gate 		}
14067c478bd9Sstevel@tonic-gate #endif
14077c478bd9Sstevel@tonic-gate 
14087c478bd9Sstevel@tonic-gate 		curthread->t_dtrace_astpc = addr + i;
14097c478bd9Sstevel@tonic-gate 		bcopy(tp->ftt_instr, &scratch[i], tp->ftt_size);
14107c478bd9Sstevel@tonic-gate 		i += tp->ftt_size;
14117c478bd9Sstevel@tonic-gate 		scratch[i++] = FASTTRAP_INT;
14127c478bd9Sstevel@tonic-gate 		scratch[i++] = T_DTRACE_RET;
14137c478bd9Sstevel@tonic-gate 
14147c478bd9Sstevel@tonic-gate 		if (fasttrap_copyout(scratch, (char *)addr, i)) {
14157c478bd9Sstevel@tonic-gate 			fasttrap_sigtrap(p, curthread, pc);
14167c478bd9Sstevel@tonic-gate 			new_pc = pc;
14177c478bd9Sstevel@tonic-gate 			break;
14187c478bd9Sstevel@tonic-gate 		}
14197c478bd9Sstevel@tonic-gate 
14207c478bd9Sstevel@tonic-gate 		if (tp->ftt_retids != NULL) {
14217c478bd9Sstevel@tonic-gate 			curthread->t_dtrace_step = 1;
14227c478bd9Sstevel@tonic-gate 			curthread->t_dtrace_ret = 1;
14237c478bd9Sstevel@tonic-gate 			new_pc = curthread->t_dtrace_astpc;
14247c478bd9Sstevel@tonic-gate 		} else {
14257c478bd9Sstevel@tonic-gate 			new_pc = curthread->t_dtrace_scrpc;
14267c478bd9Sstevel@tonic-gate 		}
14277c478bd9Sstevel@tonic-gate 
14287c478bd9Sstevel@tonic-gate 		curthread->t_dtrace_pc = pc;
14297c478bd9Sstevel@tonic-gate 		curthread->t_dtrace_npc = pc + tp->ftt_size;
14307c478bd9Sstevel@tonic-gate 		curthread->t_dtrace_on = 1;
14317c478bd9Sstevel@tonic-gate 		break;
14327c478bd9Sstevel@tonic-gate 	}
14337c478bd9Sstevel@tonic-gate 
14347c478bd9Sstevel@tonic-gate 	default:
14357c478bd9Sstevel@tonic-gate 		panic("fasttrap: mishandled an instruction");
14367c478bd9Sstevel@tonic-gate 	}
14377c478bd9Sstevel@tonic-gate 
1438*ac448965Sahl done:
14397c478bd9Sstevel@tonic-gate 	/*
14407c478bd9Sstevel@tonic-gate 	 * If there were no return probes when we first found the tracepoint,
14417c478bd9Sstevel@tonic-gate 	 * we should feel no obligation to honor any return probes that were
14427c478bd9Sstevel@tonic-gate 	 * subsequently enabled -- they'll just have to wait until the next
14437c478bd9Sstevel@tonic-gate 	 * time around.
14447c478bd9Sstevel@tonic-gate 	 */
14457c478bd9Sstevel@tonic-gate 	if (tp->ftt_retids != NULL) {
14467c478bd9Sstevel@tonic-gate 		/*
14477c478bd9Sstevel@tonic-gate 		 * We need to wait until the results of the instruction are
14487c478bd9Sstevel@tonic-gate 		 * apparent before invoking any return probes. If this
14497c478bd9Sstevel@tonic-gate 		 * instruction was emulated we can just call
14507c478bd9Sstevel@tonic-gate 		 * fasttrap_return_common(); if it needs to be executed, we
14517c478bd9Sstevel@tonic-gate 		 * need to wait until the user thread returns to the kernel.
14527c478bd9Sstevel@tonic-gate 		 */
14537c478bd9Sstevel@tonic-gate 		if (tp->ftt_type != FASTTRAP_T_COMMON) {
14547c478bd9Sstevel@tonic-gate 			/*
14557c478bd9Sstevel@tonic-gate 			 * Set the program counter to the address of the traced
14567c478bd9Sstevel@tonic-gate 			 * instruction so that it looks right in ustack()
14577c478bd9Sstevel@tonic-gate 			 * output. We had previously set it to the end of the
14587c478bd9Sstevel@tonic-gate 			 * instruction to simplify %rip-relative addressing.
14597c478bd9Sstevel@tonic-gate 			 */
14607c478bd9Sstevel@tonic-gate 			rp->r_pc = pc;
14617c478bd9Sstevel@tonic-gate 
14627c478bd9Sstevel@tonic-gate 			fasttrap_return_common(rp, pc, pid, new_pc);
14637c478bd9Sstevel@tonic-gate 		} else {
14647c478bd9Sstevel@tonic-gate 			ASSERT(curthread->t_dtrace_ret != 0);
14657c478bd9Sstevel@tonic-gate 			ASSERT(curthread->t_dtrace_pc == pc);
14667c478bd9Sstevel@tonic-gate 			ASSERT(curthread->t_dtrace_scrpc != 0);
14677c478bd9Sstevel@tonic-gate 			ASSERT(new_pc == curthread->t_dtrace_astpc);
14687c478bd9Sstevel@tonic-gate 		}
14697c478bd9Sstevel@tonic-gate 	}
14707c478bd9Sstevel@tonic-gate 
14717c478bd9Sstevel@tonic-gate 	ASSERT(new_pc != 0);
14727c478bd9Sstevel@tonic-gate 	rp->r_pc = new_pc;
14737c478bd9Sstevel@tonic-gate 
14747c478bd9Sstevel@tonic-gate 	return (0);
14757c478bd9Sstevel@tonic-gate }
14767c478bd9Sstevel@tonic-gate 
14777c478bd9Sstevel@tonic-gate int
14787c478bd9Sstevel@tonic-gate fasttrap_return_probe(struct regs *rp)
14797c478bd9Sstevel@tonic-gate {
14807c478bd9Sstevel@tonic-gate 	proc_t *p = curproc;
14817c478bd9Sstevel@tonic-gate 	uintptr_t pc = curthread->t_dtrace_pc;
14827c478bd9Sstevel@tonic-gate 	uintptr_t npc = curthread->t_dtrace_npc;
14837c478bd9Sstevel@tonic-gate 
14847c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_pc = 0;
14857c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_npc = 0;
14867c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_scrpc = 0;
14877c478bd9Sstevel@tonic-gate 	curthread->t_dtrace_astpc = 0;
14887c478bd9Sstevel@tonic-gate 
14897c478bd9Sstevel@tonic-gate 	/*
14907c478bd9Sstevel@tonic-gate 	 * Treat a child created by a call to vfork(2) as if it were its
14917c478bd9Sstevel@tonic-gate 	 * parent. We know that there's only one thread of control in such a
14927c478bd9Sstevel@tonic-gate 	 * process: this one.
14937c478bd9Sstevel@tonic-gate 	 */
14947c478bd9Sstevel@tonic-gate 	while (p->p_flag & SVFORK) {
14957c478bd9Sstevel@tonic-gate 		p = p->p_parent;
14967c478bd9Sstevel@tonic-gate 	}
14977c478bd9Sstevel@tonic-gate 
14987c478bd9Sstevel@tonic-gate 	/*
14997c478bd9Sstevel@tonic-gate 	 * We set rp->r_pc to the address of the traced instruction so
15007c478bd9Sstevel@tonic-gate 	 * that it appears to dtrace_probe() that we're on the original
15017c478bd9Sstevel@tonic-gate 	 * instruction, and so that the user can't easily detect our
15027c478bd9Sstevel@tonic-gate 	 * complex web of lies. dtrace_return_probe() (our caller)
15037c478bd9Sstevel@tonic-gate 	 * will correctly set %pc after we return.
15047c478bd9Sstevel@tonic-gate 	 */
15057c478bd9Sstevel@tonic-gate 	rp->r_pc = pc;
15067c478bd9Sstevel@tonic-gate 
15077c478bd9Sstevel@tonic-gate 	fasttrap_return_common(rp, pc, p->p_pid, npc);
15087c478bd9Sstevel@tonic-gate 
15097c478bd9Sstevel@tonic-gate 	return (0);
15107c478bd9Sstevel@tonic-gate }
15117c478bd9Sstevel@tonic-gate 
15127c478bd9Sstevel@tonic-gate /*ARGSUSED*/
15137c478bd9Sstevel@tonic-gate uint64_t
15147c478bd9Sstevel@tonic-gate fasttrap_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
15157c478bd9Sstevel@tonic-gate {
15167c478bd9Sstevel@tonic-gate 	return (fasttrap_anarg(ttolwp(curthread)->lwp_regs, 1, argno));
15177c478bd9Sstevel@tonic-gate }
15187c478bd9Sstevel@tonic-gate 
15197c478bd9Sstevel@tonic-gate /*ARGSUSED*/
15207c478bd9Sstevel@tonic-gate uint64_t
15217c478bd9Sstevel@tonic-gate fasttrap_usdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno,
15227c478bd9Sstevel@tonic-gate     int aframes)
15237c478bd9Sstevel@tonic-gate {
15247c478bd9Sstevel@tonic-gate 	return (fasttrap_anarg(ttolwp(curthread)->lwp_regs, 0, argno));
15257c478bd9Sstevel@tonic-gate }
15267c478bd9Sstevel@tonic-gate 
15277c478bd9Sstevel@tonic-gate static ulong_t
15287c478bd9Sstevel@tonic-gate fasttrap_getreg(struct regs *rp, uint_t reg)
15297c478bd9Sstevel@tonic-gate {
15307c478bd9Sstevel@tonic-gate #ifdef __amd64
15317c478bd9Sstevel@tonic-gate 	switch (reg) {
15327c478bd9Sstevel@tonic-gate 	case REG_R15:		return (rp->r_r15);
15337c478bd9Sstevel@tonic-gate 	case REG_R14:		return (rp->r_r14);
15347c478bd9Sstevel@tonic-gate 	case REG_R13:		return (rp->r_r13);
15357c478bd9Sstevel@tonic-gate 	case REG_R12:		return (rp->r_r12);
15367c478bd9Sstevel@tonic-gate 	case REG_R11:		return (rp->r_r11);
15377c478bd9Sstevel@tonic-gate 	case REG_R10:		return (rp->r_r10);
15387c478bd9Sstevel@tonic-gate 	case REG_R9:		return (rp->r_r9);
15397c478bd9Sstevel@tonic-gate 	case REG_R8:		return (rp->r_r8);
15407c478bd9Sstevel@tonic-gate 	case REG_RDI:		return (rp->r_rdi);
15417c478bd9Sstevel@tonic-gate 	case REG_RSI:		return (rp->r_rsi);
15427c478bd9Sstevel@tonic-gate 	case REG_RBP:		return (rp->r_rbp);
15437c478bd9Sstevel@tonic-gate 	case REG_RBX:		return (rp->r_rbx);
15447c478bd9Sstevel@tonic-gate 	case REG_RDX:		return (rp->r_rdx);
15457c478bd9Sstevel@tonic-gate 	case REG_RCX:		return (rp->r_rcx);
15467c478bd9Sstevel@tonic-gate 	case REG_RAX:		return (rp->r_rax);
15477c478bd9Sstevel@tonic-gate 	case REG_TRAPNO:	return (rp->r_trapno);
15487c478bd9Sstevel@tonic-gate 	case REG_ERR:		return (rp->r_err);
15497c478bd9Sstevel@tonic-gate 	case REG_RIP:		return (rp->r_rip);
15507c478bd9Sstevel@tonic-gate 	case REG_CS:		return (rp->r_cs);
15517c478bd9Sstevel@tonic-gate 	case REG_RFL:		return (rp->r_rfl);
15527c478bd9Sstevel@tonic-gate 	case REG_RSP:		return (rp->r_rsp);
15537c478bd9Sstevel@tonic-gate 	case REG_SS:		return (rp->r_ss);
15547c478bd9Sstevel@tonic-gate 	case REG_FS:		return (rp->r_fs);
15557c478bd9Sstevel@tonic-gate 	case REG_GS:		return (rp->r_gs);
15567c478bd9Sstevel@tonic-gate 	case REG_DS:		return (rp->r_ds);
15577c478bd9Sstevel@tonic-gate 	case REG_ES:		return (rp->r_es);
15587c478bd9Sstevel@tonic-gate 	case REG_FSBASE:	return (rp->r_fsbase);
15597c478bd9Sstevel@tonic-gate 	case REG_GSBASE:	return (rp->r_gsbase);
15607c478bd9Sstevel@tonic-gate 	}
15617c478bd9Sstevel@tonic-gate 
15627c478bd9Sstevel@tonic-gate 	panic("dtrace: illegal register constant");
15637c478bd9Sstevel@tonic-gate 	/*NOTREACHED*/
15647c478bd9Sstevel@tonic-gate #else
15657c478bd9Sstevel@tonic-gate 	if (reg >= _NGREG)
15667c478bd9Sstevel@tonic-gate 		panic("dtrace: illegal register constant");
15677c478bd9Sstevel@tonic-gate 
15687c478bd9Sstevel@tonic-gate 	return (((greg_t *)&rp->r_gs)[reg]);
15697c478bd9Sstevel@tonic-gate #endif
15707c478bd9Sstevel@tonic-gate }
1571