// SPDX-License-Identifier: GPL-2.0-only
/*
* intel_pt_insn_decoder.c: Intel Processor Trace support
* Copyright (c) 2013-2014, Intel Corporation.
*/
#include <linux/kernel.h>
#include <stdio.h>
#include <string.h>
#include <endian.h>
#include <byteswap.h>
#include "../../../arch/x86/include/asm/insn.h"
#include "../../../arch/x86/lib/inat.c"
#include "../../../arch/x86/lib/insn.c"
#include "event.h"
#include "intel-pt-insn-decoder.h"
#include "dump-insn.h"
#include "util/sample.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;
intel_pt_insn->emulated_ptwrite = false;
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 0x01:
switch (insn->modrm.bytes[0]) {
case 0xc2: /* vmlaunch */
case 0xc3: /* vmresume */
op = INTEL_PT_OP_VMENTRY;
branch = INTEL_PT_BR_INDIRECT;
break;
case 0xca:
switch (insn->prefixes.bytes[3]) {
case 0xf2: /* erets */
op = INTEL_PT_OP_ERETS;
branch = INTEL_PT_BR_INDIRECT;
break;
case 0xf3: /* eretu */
op = INTEL_PT_OP_ERETU;
branch = INTEL_PT_BR_INDIRECT;
break;
default:
break;
}
break;
default:
break;
}
break;
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 0xa1:
if (insn_is_rex2(insn)) { /* jmpabs */
intel_pt_insn->op = INTEL_PT_OP_JMP;
/* jmpabs causes a TIP packet like an indirect branch */
intel_pt_insn->branch = INTEL_PT_BR_INDIRECT;
intel_pt_insn->length = insn->length;
return;
}
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__ == __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;
int ret;
ret = insn_decode(&insn, buf, len,
x86_64 ? INSN_MODE_64 : INSN_MODE_32);
if (ret < 0 || 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_uncond_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_UNCONDITIONAL ||
in.branch == INTEL_PT_BR_INDIRECT;
}
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, ret;
int left;
ret = insn_decode(&insn, inbuf, inlen,
x->is64bit ? INSN_MODE_64 : INSN_MODE_32);
if (ret < 0 || 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",
[INTEL_PT_OP_VMENTRY] = "VMentry",
[INTEL_PT_OP_ERETS] = "Erets",
[INTEL_PT_OP_ERETU] = "Eretu",
};
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:
case INTEL_PT_OP_ERETS:
case INTEL_PT_OP_ERETU:
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;
case INTEL_PT_OP_VMENTRY:
return PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL |
PERF_IP_FLAG_VMENTRY;
default:
return 0;
}
}
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