summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c
blob: 598f56be9f1792590c04e880a8d5bd2f43e40f8f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
// SPDX-License-Identifier: GPL-2.0-only
/*
 * intel_pt_insn_decoder.c: Intel Processor Trace support
 * Copyright (c) 2013-2014, Intel Corporation.
 */

#include <stdio.h>
#include <string.h>
#include <endian.h>
#include <byteswap.h>

#include "event.h"

#include "insn.h"

#include "inat.c"
#include "insn.c"

#include "intel-pt-insn-decoder.h"
#include "dump-insn.h"

#if INTEL_PT_INSN_BUF_SZ < MAX_INSN_SIZE || INTEL_PT_INSN_BUF_SZ > MAX_INSN
#error Instruction buffer size too small
#endif

/* Based on branch_type() from arch/x86/events/intel/lbr.c */
static void intel_pt_insn_decoder(struct insn *insn,
				  struct intel_pt_insn *intel_pt_insn)
{
	enum intel_pt_insn_op op = INTEL_PT_OP_OTHER;
	enum intel_pt_insn_branch branch = INTEL_PT_BR_NO_BRANCH;
	int ext;

	intel_pt_insn->rel = 0;

	if (insn_is_avx(insn)) {
		intel_pt_insn->op = INTEL_PT_OP_OTHER;
		intel_pt_insn->branch = INTEL_PT_BR_NO_BRANCH;
		intel_pt_insn->length = insn->length;
		return;
	}

	switch (insn->opcode.bytes[0]) {
	case 0xf:
		switch (insn->opcode.bytes[1]) {
		case 0x05: /* syscall */
		case 0x34: /* sysenter */
			op = INTEL_PT_OP_SYSCALL;
			branch = INTEL_PT_BR_INDIRECT;
			break;
		case 0x07: /* sysret */
		case 0x35: /* sysexit */
			op = INTEL_PT_OP_SYSRET;
			branch = INTEL_PT_BR_INDIRECT;
			break;
		case 0x80 ... 0x8f: /* jcc */
			op = INTEL_PT_OP_JCC;
			branch = INTEL_PT_BR_CONDITIONAL;
			break;
		default:
			break;
		}
		break;
	case 0x70 ... 0x7f: /* jcc */
		op = INTEL_PT_OP_JCC;
		branch = INTEL_PT_BR_CONDITIONAL;
		break;
	case 0xc2: /* near ret */
	case 0xc3: /* near ret */
	case 0xca: /* far ret */
	case 0xcb: /* far ret */
		op = INTEL_PT_OP_RET;
		branch = INTEL_PT_BR_INDIRECT;
		break;
	case 0xcf: /* iret */
		op = INTEL_PT_OP_IRET;
		branch = INTEL_PT_BR_INDIRECT;
		break;
	case 0xcc ... 0xce: /* int */
		op = INTEL_PT_OP_INT;
		branch = INTEL_PT_BR_INDIRECT;
		break;
	case 0xe8: /* call near rel */
		op = INTEL_PT_OP_CALL;
		branch = INTEL_PT_BR_UNCONDITIONAL;
		break;
	case 0x9a: /* call far absolute */
		op = INTEL_PT_OP_CALL;
		branch = INTEL_PT_BR_INDIRECT;
		break;
	case 0xe0 ... 0xe2: /* loop */
		op = INTEL_PT_OP_LOOP;
		branch = INTEL_PT_BR_CONDITIONAL;
		break;
	case 0xe3: /* jcc */
		op = INTEL_PT_OP_JCC;
		branch = INTEL_PT_BR_CONDITIONAL;
		break;
	case 0xe9: /* jmp */
	case 0xeb: /* jmp */
		op = INTEL_PT_OP_JMP;
		branch = INTEL_PT_BR_UNCONDITIONAL;
		break;
	case 0xea: /* far jmp */
		op = INTEL_PT_OP_JMP;
		branch = INTEL_PT_BR_INDIRECT;
		break;
	case 0xff: /* call near absolute, call far absolute ind */
		ext = (insn->modrm.bytes[0] >> 3) & 0x7;
		switch (ext) {
		case 2: /* near ind call */
		case 3: /* far ind call */
			op = INTEL_PT_OP_CALL;
			branch = INTEL_PT_BR_INDIRECT;
			break;
		case 4:
		case 5:
			op = INTEL_PT_OP_JMP;
			branch = INTEL_PT_BR_INDIRECT;
			break;
		default:
			break;
		}
		break;
	default:
		break;
	}

	intel_pt_insn->op = op;
	intel_pt_insn->branch = branch;
	intel_pt_insn->length = insn->length;

	if (branch == INTEL_PT_BR_CONDITIONAL ||
	    branch == INTEL_PT_BR_UNCONDITIONAL) {
#if __BYTE_ORDER == __BIG_ENDIAN
		switch (insn->immediate.nbytes) {
		case 1:
			intel_pt_insn->rel = insn->immediate.value;
			break;
		case 2:
			intel_pt_insn->rel =
					bswap_16((short)insn->immediate.value);
			break;
		case 4:
			intel_pt_insn->rel = bswap_32(insn->immediate.value);
			break;
		default:
			intel_pt_insn->rel = 0;
			break;
		}
#else
		intel_pt_insn->rel = insn->immediate.value;
#endif
	}
}

int intel_pt_get_insn(const unsigned char *buf, size_t len, int x86_64,
		      struct intel_pt_insn *intel_pt_insn)
{
	struct insn insn;

	insn_init(&insn, buf, len, x86_64);
	insn_get_length(&insn);
	if (!insn_complete(&insn) || insn.length > len)
		return -1;
	intel_pt_insn_decoder(&insn, intel_pt_insn);
	if (insn.length < INTEL_PT_INSN_BUF_SZ)
		memcpy(intel_pt_insn->buf, buf, insn.length);
	else
		memcpy(intel_pt_insn->buf, buf, INTEL_PT_INSN_BUF_SZ);
	return 0;
}

int arch_is_branch(const unsigned char *buf, size_t len, int x86_64)
{
	struct intel_pt_insn in;
	if (intel_pt_get_insn(buf, len, x86_64, &in) < 0)
		return -1;
	return in.branch != INTEL_PT_BR_NO_BRANCH;
}

const char *dump_insn(struct perf_insn *x, uint64_t ip __maybe_unused,
		      u8 *inbuf, int inlen, int *lenp)
{
	struct insn insn;
	int n, i;
	int left;

	insn_init(&insn, inbuf, inlen, x->is64bit);
	insn_get_length(&insn);
	if (!insn_complete(&insn) || insn.length > inlen)
		return "<bad>";
	if (lenp)
		*lenp = insn.length;
	left = sizeof(x->out);
	n = snprintf(x->out, left, "insn: ");
	left -= n;
	for (i = 0; i < insn.length; i++) {
		n += snprintf(x->out + n, left, "%02x ", inbuf[i]);
		left -= n;
	}
	return x->out;
}

const char *branch_name[] = {
	[INTEL_PT_OP_OTHER]	= "Other",
	[INTEL_PT_OP_CALL]	= "Call",
	[INTEL_PT_OP_RET]	= "Ret",
	[INTEL_PT_OP_JCC]	= "Jcc",
	[INTEL_PT_OP_JMP]	= "Jmp",
	[INTEL_PT_OP_LOOP]	= "Loop",
	[INTEL_PT_OP_IRET]	= "IRet",
	[INTEL_PT_OP_INT]	= "Int",
	[INTEL_PT_OP_SYSCALL]	= "Syscall",
	[INTEL_PT_OP_SYSRET]	= "Sysret",
};

const char *intel_pt_insn_name(enum intel_pt_insn_op op)
{
	return branch_name[op];
}

int intel_pt_insn_desc(const struct intel_pt_insn *intel_pt_insn, char *buf,
		       size_t buf_len)
{
	switch (intel_pt_insn->branch) {
	case INTEL_PT_BR_CONDITIONAL:
	case INTEL_PT_BR_UNCONDITIONAL:
		return snprintf(buf, buf_len, "%s %s%d",
				intel_pt_insn_name(intel_pt_insn->op),
				intel_pt_insn->rel > 0 ? "+" : "",
				intel_pt_insn->rel);
	case INTEL_PT_BR_NO_BRANCH:
	case INTEL_PT_BR_INDIRECT:
		return snprintf(buf, buf_len, "%s",
				intel_pt_insn_name(intel_pt_insn->op));
	default:
		break;
	}
	return 0;
}

int intel_pt_insn_type(enum intel_pt_insn_op op)
{
	switch (op) {
	case INTEL_PT_OP_OTHER:
		return 0;
	case INTEL_PT_OP_CALL:
		return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL;
	case INTEL_PT_OP_RET:
		return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN;
	case INTEL_PT_OP_JCC:
		return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CONDITIONAL;
	case INTEL_PT_OP_JMP:
		return PERF_IP_FLAG_BRANCH;
	case INTEL_PT_OP_LOOP:
		return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CONDITIONAL;
	case INTEL_PT_OP_IRET:
		return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN |
		       PERF_IP_FLAG_INTERRUPT;
	case INTEL_PT_OP_INT:
		return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL |
		       PERF_IP_FLAG_INTERRUPT;
	case INTEL_PT_OP_SYSCALL:
		return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL |
		       PERF_IP_FLAG_SYSCALLRET;
	case INTEL_PT_OP_SYSRET:
		return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN |
		       PERF_IP_FLAG_SYSCALLRET;
	default:
		return 0;
	}
}