1 // SPDX-License-Identifier: GPL-2.0-only
3 * intel_pt_insn_decoder.c: Intel Processor Trace support
4 * Copyright (c) 2013-2014, Intel Corporation.
19 #include "intel-pt-insn-decoder.h"
20 #include "dump-insn.h"
22 #if INTEL_PT_INSN_BUF_SZ < MAX_INSN_SIZE || INTEL_PT_INSN_BUF_SZ > MAX_INSN
23 #error Instruction buffer size too small
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)
30 enum intel_pt_insn_op op = INTEL_PT_OP_OTHER;
31 enum intel_pt_insn_branch branch = INTEL_PT_BR_NO_BRANCH;
34 intel_pt_insn->rel = 0;
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;
43 switch (insn->opcode.bytes[0]) {
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;
51 case 0x07: /* sysret */
52 case 0x35: /* sysexit */
53 op = INTEL_PT_OP_SYSRET;
54 branch = INTEL_PT_BR_INDIRECT;
56 case 0x80 ... 0x8f: /* jcc */
58 branch = INTEL_PT_BR_CONDITIONAL;
64 case 0x70 ... 0x7f: /* jcc */
66 branch = INTEL_PT_BR_CONDITIONAL;
68 case 0xc2: /* near ret */
69 case 0xc3: /* near ret */
70 case 0xca: /* far ret */
71 case 0xcb: /* far ret */
73 branch = INTEL_PT_BR_INDIRECT;
76 op = INTEL_PT_OP_IRET;
77 branch = INTEL_PT_BR_INDIRECT;
79 case 0xcc ... 0xce: /* int */
81 branch = INTEL_PT_BR_INDIRECT;
83 case 0xe8: /* call near rel */
84 op = INTEL_PT_OP_CALL;
85 branch = INTEL_PT_BR_UNCONDITIONAL;
87 case 0x9a: /* call far absolute */
88 op = INTEL_PT_OP_CALL;
89 branch = INTEL_PT_BR_INDIRECT;
91 case 0xe0 ... 0xe2: /* loop */
92 op = INTEL_PT_OP_LOOP;
93 branch = INTEL_PT_BR_CONDITIONAL;
97 branch = INTEL_PT_BR_CONDITIONAL;
101 op = INTEL_PT_OP_JMP;
102 branch = INTEL_PT_BR_UNCONDITIONAL;
104 case 0xea: /* far jmp */
105 op = INTEL_PT_OP_JMP;
106 branch = INTEL_PT_BR_INDIRECT;
108 case 0xff: /* call near absolute, call far absolute ind */
109 ext = (insn->modrm.bytes[0] >> 3) & 0x7;
111 case 2: /* near ind call */
112 case 3: /* far ind call */
113 op = INTEL_PT_OP_CALL;
114 branch = INTEL_PT_BR_INDIRECT;
118 op = INTEL_PT_OP_JMP;
119 branch = INTEL_PT_BR_INDIRECT;
129 intel_pt_insn->op = op;
130 intel_pt_insn->branch = branch;
131 intel_pt_insn->length = insn->length;
133 if (branch == INTEL_PT_BR_CONDITIONAL ||
134 branch == INTEL_PT_BR_UNCONDITIONAL) {
135 #if __BYTE_ORDER == __BIG_ENDIAN
136 switch (insn->immediate.nbytes) {
138 intel_pt_insn->rel = insn->immediate.value;
142 bswap_16((short)insn->immediate.value);
145 intel_pt_insn->rel = bswap_32(insn->immediate.value);
148 intel_pt_insn->rel = 0;
152 intel_pt_insn->rel = insn->immediate.value;
157 int intel_pt_get_insn(const unsigned char *buf, size_t len, int x86_64,
158 struct intel_pt_insn *intel_pt_insn)
162 insn_init(&insn, buf, len, x86_64);
163 insn_get_length(&insn);
164 if (!insn_complete(&insn) || insn.length > len)
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);
170 memcpy(intel_pt_insn->buf, buf, INTEL_PT_INSN_BUF_SZ);
174 int arch_is_branch(const unsigned char *buf, size_t len, int x86_64)
176 struct intel_pt_insn in;
177 if (intel_pt_get_insn(buf, len, x86_64, &in) < 0)
179 return in.branch != INTEL_PT_BR_NO_BRANCH;
182 const char *dump_insn(struct perf_insn *x, uint64_t ip __maybe_unused,
183 u8 *inbuf, int inlen, int *lenp)
189 insn_init(&insn, inbuf, inlen, x->is64bit);
190 insn_get_length(&insn);
191 if (!insn_complete(&insn) || insn.length > inlen)
195 left = sizeof(x->out);
196 n = snprintf(x->out, left, "insn: ");
198 for (i = 0; i < insn.length; i++) {
199 n += snprintf(x->out + n, left, "%02x ", inbuf[i]);
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",
218 const char *intel_pt_insn_name(enum intel_pt_insn_op op)
220 return branch_name[op];
223 int intel_pt_insn_desc(const struct intel_pt_insn *intel_pt_insn, char *buf,
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 ? "+" : "",
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));
243 int intel_pt_insn_type(enum intel_pt_insn_op op)
246 case INTEL_PT_OP_OTHER:
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;