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