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 #include "util/sample.h"
22
23 #if INTEL_PT_INSN_BUF_SZ < MAX_INSN_SIZE || INTEL_PT_INSN_BUF_SZ > MAX_INSN
24 #error Instruction buffer size too small
25 #endif
26
27 /* Based on branch_type() from arch/x86/events/intel/lbr.c */
intel_pt_insn_decoder(struct insn * insn,struct intel_pt_insn * intel_pt_insn)28 static void intel_pt_insn_decoder(struct insn *insn,
29 struct intel_pt_insn *intel_pt_insn)
30 {
31 enum intel_pt_insn_op op = INTEL_PT_OP_OTHER;
32 enum intel_pt_insn_branch branch = INTEL_PT_BR_NO_BRANCH;
33 int ext;
34
35 intel_pt_insn->rel = 0;
36 intel_pt_insn->emulated_ptwrite = false;
37
38 if (insn_is_avx(insn)) {
39 intel_pt_insn->op = INTEL_PT_OP_OTHER;
40 intel_pt_insn->branch = INTEL_PT_BR_NO_BRANCH;
41 intel_pt_insn->length = insn->length;
42 return;
43 }
44
45 switch (insn->opcode.bytes[0]) {
46 case 0xf:
47 switch (insn->opcode.bytes[1]) {
48 case 0x01:
49 switch (insn->modrm.bytes[0]) {
50 case 0xc2: /* vmlaunch */
51 case 0xc3: /* vmresume */
52 op = INTEL_PT_OP_VMENTRY;
53 branch = INTEL_PT_BR_INDIRECT;
54 break;
55 case 0xca:
56 switch (insn->prefixes.bytes[3]) {
57 case 0xf2: /* erets */
58 op = INTEL_PT_OP_ERETS;
59 branch = INTEL_PT_BR_INDIRECT;
60 break;
61 case 0xf3: /* eretu */
62 op = INTEL_PT_OP_ERETU;
63 branch = INTEL_PT_BR_INDIRECT;
64 break;
65 default:
66 break;
67 }
68 break;
69 default:
70 break;
71 }
72 break;
73 case 0x05: /* syscall */
74 case 0x34: /* sysenter */
75 op = INTEL_PT_OP_SYSCALL;
76 branch = INTEL_PT_BR_INDIRECT;
77 break;
78 case 0x07: /* sysret */
79 case 0x35: /* sysexit */
80 op = INTEL_PT_OP_SYSRET;
81 branch = INTEL_PT_BR_INDIRECT;
82 break;
83 case 0x80 ... 0x8f: /* jcc */
84 op = INTEL_PT_OP_JCC;
85 branch = INTEL_PT_BR_CONDITIONAL;
86 break;
87 default:
88 break;
89 }
90 break;
91 case 0x70 ... 0x7f: /* jcc */
92 op = INTEL_PT_OP_JCC;
93 branch = INTEL_PT_BR_CONDITIONAL;
94 break;
95 case 0xc2: /* near ret */
96 case 0xc3: /* near ret */
97 case 0xca: /* far ret */
98 case 0xcb: /* far ret */
99 op = INTEL_PT_OP_RET;
100 branch = INTEL_PT_BR_INDIRECT;
101 break;
102 case 0xcf: /* iret */
103 op = INTEL_PT_OP_IRET;
104 branch = INTEL_PT_BR_INDIRECT;
105 break;
106 case 0xcc ... 0xce: /* int */
107 op = INTEL_PT_OP_INT;
108 branch = INTEL_PT_BR_INDIRECT;
109 break;
110 case 0xe8: /* call near rel */
111 op = INTEL_PT_OP_CALL;
112 branch = INTEL_PT_BR_UNCONDITIONAL;
113 break;
114 case 0x9a: /* call far absolute */
115 op = INTEL_PT_OP_CALL;
116 branch = INTEL_PT_BR_INDIRECT;
117 break;
118 case 0xe0 ... 0xe2: /* loop */
119 op = INTEL_PT_OP_LOOP;
120 branch = INTEL_PT_BR_CONDITIONAL;
121 break;
122 case 0xe3: /* jcc */
123 op = INTEL_PT_OP_JCC;
124 branch = INTEL_PT_BR_CONDITIONAL;
125 break;
126 case 0xe9: /* jmp */
127 case 0xeb: /* jmp */
128 op = INTEL_PT_OP_JMP;
129 branch = INTEL_PT_BR_UNCONDITIONAL;
130 break;
131 case 0xea: /* far jmp */
132 op = INTEL_PT_OP_JMP;
133 branch = INTEL_PT_BR_INDIRECT;
134 break;
135 case 0xff: /* call near absolute, call far absolute ind */
136 ext = (insn->modrm.bytes[0] >> 3) & 0x7;
137 switch (ext) {
138 case 2: /* near ind call */
139 case 3: /* far ind call */
140 op = INTEL_PT_OP_CALL;
141 branch = INTEL_PT_BR_INDIRECT;
142 break;
143 case 4:
144 case 5:
145 op = INTEL_PT_OP_JMP;
146 branch = INTEL_PT_BR_INDIRECT;
147 break;
148 default:
149 break;
150 }
151 break;
152 default:
153 break;
154 }
155
156 intel_pt_insn->op = op;
157 intel_pt_insn->branch = branch;
158 intel_pt_insn->length = insn->length;
159
160 if (branch == INTEL_PT_BR_CONDITIONAL ||
161 branch == INTEL_PT_BR_UNCONDITIONAL) {
162 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
163 switch (insn->immediate.nbytes) {
164 case 1:
165 intel_pt_insn->rel = insn->immediate.value;
166 break;
167 case 2:
168 intel_pt_insn->rel =
169 bswap_16((short)insn->immediate.value);
170 break;
171 case 4:
172 intel_pt_insn->rel = bswap_32(insn->immediate.value);
173 break;
174 default:
175 intel_pt_insn->rel = 0;
176 break;
177 }
178 #else
179 intel_pt_insn->rel = insn->immediate.value;
180 #endif
181 }
182 }
183
intel_pt_get_insn(const unsigned char * buf,size_t len,int x86_64,struct intel_pt_insn * intel_pt_insn)184 int intel_pt_get_insn(const unsigned char *buf, size_t len, int x86_64,
185 struct intel_pt_insn *intel_pt_insn)
186 {
187 struct insn insn;
188 int ret;
189
190 ret = insn_decode(&insn, buf, len,
191 x86_64 ? INSN_MODE_64 : INSN_MODE_32);
192 if (ret < 0 || insn.length > len)
193 return -1;
194
195 intel_pt_insn_decoder(&insn, intel_pt_insn);
196 if (insn.length < INTEL_PT_INSN_BUF_SZ)
197 memcpy(intel_pt_insn->buf, buf, insn.length);
198 else
199 memcpy(intel_pt_insn->buf, buf, INTEL_PT_INSN_BUF_SZ);
200 return 0;
201 }
202
arch_is_branch(const unsigned char * buf,size_t len,int x86_64)203 int arch_is_branch(const unsigned char *buf, size_t len, int x86_64)
204 {
205 struct intel_pt_insn in;
206 if (intel_pt_get_insn(buf, len, x86_64, &in) < 0)
207 return -1;
208 return in.branch != INTEL_PT_BR_NO_BRANCH;
209 }
210
dump_insn(struct perf_insn * x,uint64_t ip __maybe_unused,u8 * inbuf,int inlen,int * lenp)211 const char *dump_insn(struct perf_insn *x, uint64_t ip __maybe_unused,
212 u8 *inbuf, int inlen, int *lenp)
213 {
214 struct insn insn;
215 int n, i, ret;
216 int left;
217
218 ret = insn_decode(&insn, inbuf, inlen,
219 x->is64bit ? INSN_MODE_64 : INSN_MODE_32);
220
221 if (ret < 0 || insn.length > inlen)
222 return "<bad>";
223 if (lenp)
224 *lenp = insn.length;
225 left = sizeof(x->out);
226 n = snprintf(x->out, left, "insn: ");
227 left -= n;
228 for (i = 0; i < insn.length; i++) {
229 n += snprintf(x->out + n, left, "%02x ", inbuf[i]);
230 left -= n;
231 }
232 return x->out;
233 }
234
235 const char *branch_name[] = {
236 [INTEL_PT_OP_OTHER] = "Other",
237 [INTEL_PT_OP_CALL] = "Call",
238 [INTEL_PT_OP_RET] = "Ret",
239 [INTEL_PT_OP_JCC] = "Jcc",
240 [INTEL_PT_OP_JMP] = "Jmp",
241 [INTEL_PT_OP_LOOP] = "Loop",
242 [INTEL_PT_OP_IRET] = "IRet",
243 [INTEL_PT_OP_INT] = "Int",
244 [INTEL_PT_OP_SYSCALL] = "Syscall",
245 [INTEL_PT_OP_SYSRET] = "Sysret",
246 [INTEL_PT_OP_VMENTRY] = "VMentry",
247 [INTEL_PT_OP_ERETS] = "Erets",
248 [INTEL_PT_OP_ERETU] = "Eretu",
249 };
250
intel_pt_insn_name(enum intel_pt_insn_op op)251 const char *intel_pt_insn_name(enum intel_pt_insn_op op)
252 {
253 return branch_name[op];
254 }
255
intel_pt_insn_desc(const struct intel_pt_insn * intel_pt_insn,char * buf,size_t buf_len)256 int intel_pt_insn_desc(const struct intel_pt_insn *intel_pt_insn, char *buf,
257 size_t buf_len)
258 {
259 switch (intel_pt_insn->branch) {
260 case INTEL_PT_BR_CONDITIONAL:
261 case INTEL_PT_BR_UNCONDITIONAL:
262 return snprintf(buf, buf_len, "%s %s%d",
263 intel_pt_insn_name(intel_pt_insn->op),
264 intel_pt_insn->rel > 0 ? "+" : "",
265 intel_pt_insn->rel);
266 case INTEL_PT_BR_NO_BRANCH:
267 case INTEL_PT_BR_INDIRECT:
268 return snprintf(buf, buf_len, "%s",
269 intel_pt_insn_name(intel_pt_insn->op));
270 default:
271 break;
272 }
273 return 0;
274 }
275
intel_pt_insn_type(enum intel_pt_insn_op op)276 int intel_pt_insn_type(enum intel_pt_insn_op op)
277 {
278 switch (op) {
279 case INTEL_PT_OP_OTHER:
280 return 0;
281 case INTEL_PT_OP_CALL:
282 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL;
283 case INTEL_PT_OP_RET:
284 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN;
285 case INTEL_PT_OP_JCC:
286 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CONDITIONAL;
287 case INTEL_PT_OP_JMP:
288 return PERF_IP_FLAG_BRANCH;
289 case INTEL_PT_OP_LOOP:
290 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CONDITIONAL;
291 case INTEL_PT_OP_IRET:
292 case INTEL_PT_OP_ERETS:
293 case INTEL_PT_OP_ERETU:
294 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN |
295 PERF_IP_FLAG_INTERRUPT;
296 case INTEL_PT_OP_INT:
297 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL |
298 PERF_IP_FLAG_INTERRUPT;
299 case INTEL_PT_OP_SYSCALL:
300 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL |
301 PERF_IP_FLAG_SYSCALLRET;
302 case INTEL_PT_OP_SYSRET:
303 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN |
304 PERF_IP_FLAG_SYSCALLRET;
305 case INTEL_PT_OP_VMENTRY:
306 return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL |
307 PERF_IP_FLAG_VMENTRY;
308 default:
309 return 0;
310 }
311 }
312