b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * intel_pt_insn_decoder.c: Intel Processor Trace support |
| 4 | * Copyright (c) 2013-2014, Intel Corporation. |
| 5 | */ |
| 6 | |
| 7 | #include <linux/kernel.h> |
| 8 | #include <stdio.h> |
| 9 | #include <string.h> |
| 10 | #include <endian.h> |
| 11 | #include <byteswap.h> |
| 12 | #include "../../../arch/x86/include/asm/insn.h" |
| 13 | |
| 14 | #include "../../../arch/x86/lib/inat.c" |
| 15 | #include "../../../arch/x86/lib/insn.c" |
| 16 | |
| 17 | #include "event.h" |
| 18 | |
| 19 | #include "intel-pt-insn-decoder.h" |
| 20 | #include "dump-insn.h" |
| 21 | |
| 22 | #if INTEL_PT_INSN_BUF_SZ < MAX_INSN_SIZE || INTEL_PT_INSN_BUF_SZ > MAX_INSN |
| 23 | #error Instruction buffer size too small |
| 24 | #endif |
| 25 | |
| 26 | /* Based on branch_type() from arch/x86/events/intel/lbr.c */ |
| 27 | static void intel_pt_insn_decoder(struct insn *insn, |
| 28 | struct intel_pt_insn *intel_pt_insn) |
| 29 | { |
| 30 | enum intel_pt_insn_op op = INTEL_PT_OP_OTHER; |
| 31 | enum intel_pt_insn_branch branch = INTEL_PT_BR_NO_BRANCH; |
| 32 | int ext; |
| 33 | |
| 34 | intel_pt_insn->rel = 0; |
| 35 | |
| 36 | if (insn_is_avx(insn)) { |
| 37 | intel_pt_insn->op = INTEL_PT_OP_OTHER; |
| 38 | intel_pt_insn->branch = INTEL_PT_BR_NO_BRANCH; |
| 39 | intel_pt_insn->length = insn->length; |
| 40 | return; |
| 41 | } |
| 42 | |
| 43 | switch (insn->opcode.bytes[0]) { |
| 44 | case 0xf: |
| 45 | switch (insn->opcode.bytes[1]) { |
| 46 | case 0x05: /* syscall */ |
| 47 | case 0x34: /* sysenter */ |
| 48 | op = INTEL_PT_OP_SYSCALL; |
| 49 | branch = INTEL_PT_BR_INDIRECT; |
| 50 | break; |
| 51 | case 0x07: /* sysret */ |
| 52 | case 0x35: /* sysexit */ |
| 53 | op = INTEL_PT_OP_SYSRET; |
| 54 | branch = INTEL_PT_BR_INDIRECT; |
| 55 | break; |
| 56 | case 0x80 ... 0x8f: /* jcc */ |
| 57 | op = INTEL_PT_OP_JCC; |
| 58 | branch = INTEL_PT_BR_CONDITIONAL; |
| 59 | break; |
| 60 | default: |
| 61 | break; |
| 62 | } |
| 63 | break; |
| 64 | case 0x70 ... 0x7f: /* jcc */ |
| 65 | op = INTEL_PT_OP_JCC; |
| 66 | branch = INTEL_PT_BR_CONDITIONAL; |
| 67 | break; |
| 68 | case 0xc2: /* near ret */ |
| 69 | case 0xc3: /* near ret */ |
| 70 | case 0xca: /* far ret */ |
| 71 | case 0xcb: /* far ret */ |
| 72 | op = INTEL_PT_OP_RET; |
| 73 | branch = INTEL_PT_BR_INDIRECT; |
| 74 | break; |
| 75 | case 0xcf: /* iret */ |
| 76 | op = INTEL_PT_OP_IRET; |
| 77 | branch = INTEL_PT_BR_INDIRECT; |
| 78 | break; |
| 79 | case 0xcc ... 0xce: /* int */ |
| 80 | op = INTEL_PT_OP_INT; |
| 81 | branch = INTEL_PT_BR_INDIRECT; |
| 82 | break; |
| 83 | case 0xe8: /* call near rel */ |
| 84 | op = INTEL_PT_OP_CALL; |
| 85 | branch = INTEL_PT_BR_UNCONDITIONAL; |
| 86 | break; |
| 87 | case 0x9a: /* call far absolute */ |
| 88 | op = INTEL_PT_OP_CALL; |
| 89 | branch = INTEL_PT_BR_INDIRECT; |
| 90 | break; |
| 91 | case 0xe0 ... 0xe2: /* loop */ |
| 92 | op = INTEL_PT_OP_LOOP; |
| 93 | branch = INTEL_PT_BR_CONDITIONAL; |
| 94 | break; |
| 95 | case 0xe3: /* jcc */ |
| 96 | op = INTEL_PT_OP_JCC; |
| 97 | branch = INTEL_PT_BR_CONDITIONAL; |
| 98 | break; |
| 99 | case 0xe9: /* jmp */ |
| 100 | case 0xeb: /* jmp */ |
| 101 | op = INTEL_PT_OP_JMP; |
| 102 | branch = INTEL_PT_BR_UNCONDITIONAL; |
| 103 | break; |
| 104 | case 0xea: /* far jmp */ |
| 105 | op = INTEL_PT_OP_JMP; |
| 106 | branch = INTEL_PT_BR_INDIRECT; |
| 107 | break; |
| 108 | case 0xff: /* call near absolute, call far absolute ind */ |
| 109 | ext = (insn->modrm.bytes[0] >> 3) & 0x7; |
| 110 | switch (ext) { |
| 111 | case 2: /* near ind call */ |
| 112 | case 3: /* far ind call */ |
| 113 | op = INTEL_PT_OP_CALL; |
| 114 | branch = INTEL_PT_BR_INDIRECT; |
| 115 | break; |
| 116 | case 4: |
| 117 | case 5: |
| 118 | op = INTEL_PT_OP_JMP; |
| 119 | branch = INTEL_PT_BR_INDIRECT; |
| 120 | break; |
| 121 | default: |
| 122 | break; |
| 123 | } |
| 124 | break; |
| 125 | default: |
| 126 | break; |
| 127 | } |
| 128 | |
| 129 | intel_pt_insn->op = op; |
| 130 | intel_pt_insn->branch = branch; |
| 131 | intel_pt_insn->length = insn->length; |
| 132 | |
| 133 | if (branch == INTEL_PT_BR_CONDITIONAL || |
| 134 | branch == INTEL_PT_BR_UNCONDITIONAL) { |
| 135 | #if __BYTE_ORDER == __BIG_ENDIAN |
| 136 | switch (insn->immediate.nbytes) { |
| 137 | case 1: |
| 138 | intel_pt_insn->rel = insn->immediate.value; |
| 139 | break; |
| 140 | case 2: |
| 141 | intel_pt_insn->rel = |
| 142 | bswap_16((short)insn->immediate.value); |
| 143 | break; |
| 144 | case 4: |
| 145 | intel_pt_insn->rel = bswap_32(insn->immediate.value); |
| 146 | break; |
| 147 | default: |
| 148 | intel_pt_insn->rel = 0; |
| 149 | break; |
| 150 | } |
| 151 | #else |
| 152 | intel_pt_insn->rel = insn->immediate.value; |
| 153 | #endif |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | int intel_pt_get_insn(const unsigned char *buf, size_t len, int x86_64, |
| 158 | struct intel_pt_insn *intel_pt_insn) |
| 159 | { |
| 160 | struct insn insn; |
| 161 | |
| 162 | insn_init(&insn, buf, len, x86_64); |
| 163 | insn_get_length(&insn); |
| 164 | if (!insn_complete(&insn) || insn.length > len) |
| 165 | return -1; |
| 166 | intel_pt_insn_decoder(&insn, intel_pt_insn); |
| 167 | if (insn.length < INTEL_PT_INSN_BUF_SZ) |
| 168 | memcpy(intel_pt_insn->buf, buf, insn.length); |
| 169 | else |
| 170 | memcpy(intel_pt_insn->buf, buf, INTEL_PT_INSN_BUF_SZ); |
| 171 | return 0; |
| 172 | } |
| 173 | |
| 174 | int arch_is_branch(const unsigned char *buf, size_t len, int x86_64) |
| 175 | { |
| 176 | struct intel_pt_insn in; |
| 177 | if (intel_pt_get_insn(buf, len, x86_64, &in) < 0) |
| 178 | return -1; |
| 179 | return in.branch != INTEL_PT_BR_NO_BRANCH; |
| 180 | } |
| 181 | |
| 182 | const char *dump_insn(struct perf_insn *x, uint64_t ip __maybe_unused, |
| 183 | u8 *inbuf, int inlen, int *lenp) |
| 184 | { |
| 185 | struct insn insn; |
| 186 | int n, i; |
| 187 | int left; |
| 188 | |
| 189 | insn_init(&insn, inbuf, inlen, x->is64bit); |
| 190 | insn_get_length(&insn); |
| 191 | if (!insn_complete(&insn) || insn.length > inlen) |
| 192 | return "<bad>"; |
| 193 | if (lenp) |
| 194 | *lenp = insn.length; |
| 195 | left = sizeof(x->out); |
| 196 | n = snprintf(x->out, left, "insn: "); |
| 197 | left -= n; |
| 198 | for (i = 0; i < insn.length; i++) { |
| 199 | n += snprintf(x->out + n, left, "%02x ", inbuf[i]); |
| 200 | left -= n; |
| 201 | } |
| 202 | return x->out; |
| 203 | } |
| 204 | |
| 205 | const char *branch_name[] = { |
| 206 | [INTEL_PT_OP_OTHER] = "Other", |
| 207 | [INTEL_PT_OP_CALL] = "Call", |
| 208 | [INTEL_PT_OP_RET] = "Ret", |
| 209 | [INTEL_PT_OP_JCC] = "Jcc", |
| 210 | [INTEL_PT_OP_JMP] = "Jmp", |
| 211 | [INTEL_PT_OP_LOOP] = "Loop", |
| 212 | [INTEL_PT_OP_IRET] = "IRet", |
| 213 | [INTEL_PT_OP_INT] = "Int", |
| 214 | [INTEL_PT_OP_SYSCALL] = "Syscall", |
| 215 | [INTEL_PT_OP_SYSRET] = "Sysret", |
| 216 | }; |
| 217 | |
| 218 | const char *intel_pt_insn_name(enum intel_pt_insn_op op) |
| 219 | { |
| 220 | return branch_name[op]; |
| 221 | } |
| 222 | |
| 223 | int intel_pt_insn_desc(const struct intel_pt_insn *intel_pt_insn, char *buf, |
| 224 | size_t buf_len) |
| 225 | { |
| 226 | switch (intel_pt_insn->branch) { |
| 227 | case INTEL_PT_BR_CONDITIONAL: |
| 228 | case INTEL_PT_BR_UNCONDITIONAL: |
| 229 | return snprintf(buf, buf_len, "%s %s%d", |
| 230 | intel_pt_insn_name(intel_pt_insn->op), |
| 231 | intel_pt_insn->rel > 0 ? "+" : "", |
| 232 | intel_pt_insn->rel); |
| 233 | case INTEL_PT_BR_NO_BRANCH: |
| 234 | case INTEL_PT_BR_INDIRECT: |
| 235 | return snprintf(buf, buf_len, "%s", |
| 236 | intel_pt_insn_name(intel_pt_insn->op)); |
| 237 | default: |
| 238 | break; |
| 239 | } |
| 240 | return 0; |
| 241 | } |
| 242 | |
| 243 | int intel_pt_insn_type(enum intel_pt_insn_op op) |
| 244 | { |
| 245 | switch (op) { |
| 246 | case INTEL_PT_OP_OTHER: |
| 247 | return 0; |
| 248 | case INTEL_PT_OP_CALL: |
| 249 | return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL; |
| 250 | case INTEL_PT_OP_RET: |
| 251 | return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN; |
| 252 | case INTEL_PT_OP_JCC: |
| 253 | return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CONDITIONAL; |
| 254 | case INTEL_PT_OP_JMP: |
| 255 | return PERF_IP_FLAG_BRANCH; |
| 256 | case INTEL_PT_OP_LOOP: |
| 257 | return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CONDITIONAL; |
| 258 | case INTEL_PT_OP_IRET: |
| 259 | return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN | |
| 260 | PERF_IP_FLAG_INTERRUPT; |
| 261 | case INTEL_PT_OP_INT: |
| 262 | return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL | |
| 263 | PERF_IP_FLAG_INTERRUPT; |
| 264 | case INTEL_PT_OP_SYSCALL: |
| 265 | return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL | |
| 266 | PERF_IP_FLAG_SYSCALLRET; |
| 267 | case INTEL_PT_OP_SYSRET: |
| 268 | return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN | |
| 269 | PERF_IP_FLAG_SYSCALLRET; |
| 270 | default: |
| 271 | return 0; |
| 272 | } |
| 273 | } |