gem5/util/statetrace/arch/amd64/tracechild.cc
2011-04-15 10:44:06 -07:00

405 lines
14 KiB
C++

/*
* Copyright (c) 2007 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Gabe Black
*/
#include <sys/ptrace.h>
#include <stdint.h>
#include <cerrno>
#include <cstring>
#include <iomanip>
#include <iostream>
#include "arch/amd64/tracechild.hh"
using namespace std;
bool
AMD64TraceChild::sendState(int socket)
{
uint64_t regVal64 = 0;
uint32_t regVal32 = 0;
for (int x = 0; x <= R15; x++) {
regVal64 = getRegVal(x);
if (write(socket, &regVal64, sizeof(regVal64)) == -1) {
cerr << "Write failed! " << strerror(errno) << endl;
tracing = false;
return false;
}
}
regVal64 = getRegVal(RIP);
if (write(socket, &regVal64, sizeof(regVal64)) == -1) {
cerr << "Write failed! " << strerror(errno) << endl;
tracing = false;
return false;
}
for (int x = MMX0_0; x <= MMX7_1; x++) {
regVal32 = getRegVal(x);
if (write(socket, &regVal32, sizeof(regVal32)) == -1) {
cerr << "Write failed! " << strerror(errno) << endl;
tracing = false;
return false;
}
}
for (int x = XMM0_0; x <= XMM15_3; x++) {
regVal32 = getRegVal(x);
if (write(socket, &regVal32, sizeof(regVal32)) == -1) {
cerr << "Write failed! " << strerror(errno) << endl;
tracing = false;
return false;
}
}
return true;
}
int64_t
AMD64TraceChild::getRegs(user_regs_struct & myregs,
user_fpregs_struct & myfpregs, int num)
{
assert(num < numregs && num >= 0);
switch (num) {
//GPRs
case RAX: return myregs.rax;
case RBX: return myregs.rbx;
case RCX: return myregs.rcx;
case RDX: return myregs.rdx;
//Index registers
case RSI: return myregs.rsi;
case RDI: return myregs.rdi;
//Base pointer and stack pointer
case RBP: return myregs.rbp;
case RSP: return myregs.rsp;
//New 64 bit mode registers
case R8: return myregs.r8;
case R9: return myregs.r9;
case R10: return myregs.r10;
case R11: return myregs.r11;
case R12: return myregs.r12;
case R13: return myregs.r13;
case R14: return myregs.r14;
case R15: return myregs.r15;
//Segmentation registers
case CS: return myregs.cs;
case DS: return myregs.ds;
case ES: return myregs.es;
case FS: return myregs.fs;
case GS: return myregs.gs;
case SS: return myregs.ss;
case FS_BASE: return myregs.fs_base;
case GS_BASE: return myregs.gs_base;
//PC
case RIP: return myregs.rip;
//Flags
case EFLAGS: return myregs.eflags;
//MMX
case MMX0_0: return myfpregs.st_space[0];
case MMX0_1: return myfpregs.st_space[1];
case MMX1_0: return myfpregs.st_space[2];
case MMX1_1: return myfpregs.st_space[3];
case MMX2_0: return myfpregs.st_space[4];
case MMX2_1: return myfpregs.st_space[5];
case MMX3_0: return myfpregs.st_space[6];
case MMX3_1: return myfpregs.st_space[7];
case MMX4_0: return myfpregs.st_space[8];
case MMX4_1: return myfpregs.st_space[9];
case MMX5_0: return myfpregs.st_space[10];
case MMX5_1: return myfpregs.st_space[11];
case MMX6_0: return myfpregs.st_space[12];
case MMX6_1: return myfpregs.st_space[13];
case MMX7_0: return myfpregs.st_space[14];
case MMX7_1: return myfpregs.st_space[15];
//XMM
case XMM0_0: return myfpregs.xmm_space[0];
case XMM0_1: return myfpregs.xmm_space[1];
case XMM0_2: return myfpregs.xmm_space[2];
case XMM0_3: return myfpregs.xmm_space[3];
case XMM1_0: return myfpregs.xmm_space[4];
case XMM1_1: return myfpregs.xmm_space[5];
case XMM1_2: return myfpregs.xmm_space[6];
case XMM1_3: return myfpregs.xmm_space[7];
case XMM2_0: return myfpregs.xmm_space[8];
case XMM2_1: return myfpregs.xmm_space[9];
case XMM2_2: return myfpregs.xmm_space[10];
case XMM2_3: return myfpregs.xmm_space[11];
case XMM3_0: return myfpregs.xmm_space[12];
case XMM3_1: return myfpregs.xmm_space[13];
case XMM3_2: return myfpregs.xmm_space[14];
case XMM3_3: return myfpregs.xmm_space[15];
case XMM4_0: return myfpregs.xmm_space[16];
case XMM4_1: return myfpregs.xmm_space[17];
case XMM4_2: return myfpregs.xmm_space[18];
case XMM4_3: return myfpregs.xmm_space[19];
case XMM5_0: return myfpregs.xmm_space[20];
case XMM5_1: return myfpregs.xmm_space[21];
case XMM5_2: return myfpregs.xmm_space[22];
case XMM5_3: return myfpregs.xmm_space[23];
case XMM6_0: return myfpregs.xmm_space[24];
case XMM6_1: return myfpregs.xmm_space[25];
case XMM6_2: return myfpregs.xmm_space[26];
case XMM6_3: return myfpregs.xmm_space[27];
case XMM7_0: return myfpregs.xmm_space[28];
case XMM7_1: return myfpregs.xmm_space[29];
case XMM7_2: return myfpregs.xmm_space[30];
case XMM7_3: return myfpregs.xmm_space[31];
case XMM8_0: return myfpregs.xmm_space[32];
case XMM8_1: return myfpregs.xmm_space[33];
case XMM8_2: return myfpregs.xmm_space[34];
case XMM8_3: return myfpregs.xmm_space[35];
case XMM9_0: return myfpregs.xmm_space[36];
case XMM9_1: return myfpregs.xmm_space[37];
case XMM9_2: return myfpregs.xmm_space[38];
case XMM9_3: return myfpregs.xmm_space[39];
case XMM10_0: return myfpregs.xmm_space[40];
case XMM10_1: return myfpregs.xmm_space[41];
case XMM10_2: return myfpregs.xmm_space[42];
case XMM10_3: return myfpregs.xmm_space[43];
case XMM11_0: return myfpregs.xmm_space[44];
case XMM11_1: return myfpregs.xmm_space[45];
case XMM11_2: return myfpregs.xmm_space[46];
case XMM11_3: return myfpregs.xmm_space[47];
case XMM12_0: return myfpregs.xmm_space[48];
case XMM12_1: return myfpregs.xmm_space[49];
case XMM12_2: return myfpregs.xmm_space[50];
case XMM12_3: return myfpregs.xmm_space[51];
case XMM13_0: return myfpregs.xmm_space[52];
case XMM13_1: return myfpregs.xmm_space[53];
case XMM13_2: return myfpregs.xmm_space[54];
case XMM13_3: return myfpregs.xmm_space[55];
case XMM14_0: return myfpregs.xmm_space[56];
case XMM14_1: return myfpregs.xmm_space[57];
case XMM14_2: return myfpregs.xmm_space[58];
case XMM14_3: return myfpregs.xmm_space[59];
case XMM15_0: return myfpregs.xmm_space[60];
case XMM15_1: return myfpregs.xmm_space[61];
case XMM15_2: return myfpregs.xmm_space[62];
case XMM15_3: return myfpregs.xmm_space[63];
default:
assert(0);
return 0;
}
}
bool
AMD64TraceChild::update(int pid)
{
oldregs = regs;
oldfpregs = fpregs;
if (ptrace(PTRACE_GETREGS, pid, 0, &regs) != 0) {
cerr << "update: " << strerror(errno) << endl;
return false;
}
if (ptrace(PTRACE_GETFPREGS, pid, 0, &fpregs) != 0) {
cerr << "update: " << strerror(errno) << endl;
return false;
}
for (unsigned int x = 0; x < numregs; x++)
regDiffSinceUpdate[x] = (getRegVal(x) != getOldRegVal(x));
return true;
}
AMD64TraceChild::AMD64TraceChild()
{
for (unsigned int x = 0; x < numregs; x++)
regDiffSinceUpdate[x] = false;
}
int64_t
AMD64TraceChild::getRegVal(int num)
{
return getRegs(regs, fpregs, num);
}
int64_t
AMD64TraceChild::getOldRegVal(int num)
{
return getRegs(oldregs, oldfpregs, num);
}
ostream &
AMD64TraceChild::outputStartState(ostream & os)
{
uint64_t sp = getSP();
uint64_t pc = getPC();
uint64_t highestInfo = 0;
char obuf[1024];
sprintf(obuf, "Initial stack pointer = 0x%016lx\n", sp);
os << obuf;
sprintf(obuf, "Initial program counter = 0x%016lx\n", pc);
os << obuf;
//Output the argument count
uint64_t cargc = ptrace(PTRACE_PEEKDATA, pid, sp, 0);
sprintf(obuf, "0x%016lx: Argc = 0x%016lx\n", sp, cargc);
os << obuf;
sp += 8;
//Output argv pointers
int argCount = 0;
uint64_t cargv;
do {
cargv = ptrace(PTRACE_PEEKDATA, pid, sp, 0);
sprintf(obuf, "0x%016lx: argv[%d] = 0x%016lx\n",
sp, argCount++, cargv);
if (cargv)
if (highestInfo < cargv)
highestInfo = cargv;
os << obuf;
sp += 8;
} while(cargv);
//Output the envp pointers
int envCount = 0;
uint64_t cenvp;
do {
cenvp = ptrace(PTRACE_PEEKDATA, pid, sp, 0);
sprintf(obuf, "0x%016lx: envp[%d] = 0x%016lx\n",
sp, envCount++, cenvp);
os << obuf;
sp += 8;
} while(cenvp);
uint64_t auxType, auxVal;
do {
auxType = ptrace(PTRACE_PEEKDATA, pid, sp, 0);
sp += 8;
auxVal = ptrace(PTRACE_PEEKDATA, pid, sp, 0);
sp += 8;
sprintf(obuf, "0x%016lx: Auxiliary vector = {0x%016lx, 0x%016lx}\n",
sp - 16, auxType, auxVal);
os << obuf;
} while(auxType != 0 || auxVal != 0);
//Print out the argument strings, environment strings, and file name.
string current;
uint64_t buf;
uint64_t currentStart = sp;
bool clearedInitialPadding = false;
do {
buf = ptrace(PTRACE_PEEKDATA, pid, sp, 0);
char * cbuf = (char *)&buf;
for (int x = 0; x < sizeof(uint64_t); x++) {
if (cbuf[x])
current += cbuf[x];
else {
sprintf(obuf, "0x%016lx: \"%s\"\n",
currentStart, current.c_str());
os << obuf;
current = "";
currentStart = sp + x + 1;
}
}
sp += 8;
clearedInitialPadding = clearedInitialPadding || buf != 0;
} while (!clearedInitialPadding || buf != 0 || sp <= highestInfo);
return os;
}
uint64_t
AMD64TraceChild::findSyscall()
{
uint64_t rip = getPC();
bool foundOpcode = false;
bool twoByteOpcode = false;
for (;;) {
uint64_t buf = ptrace(PTRACE_PEEKDATA, pid, rip, 0);
for (int i = 0; i < sizeof(uint64_t); i++) {
unsigned char byte = buf & 0xFF;
if (!foundOpcode) {
if(!(byte == 0x66 || //operand override
byte == 0x67 || //address override
byte == 0x2E || //cs
byte == 0x3E || //ds
byte == 0x26 || //es
byte == 0x64 || //fs
byte == 0x65 || //gs
byte == 0x36 || //ss
byte == 0xF0 || //lock
byte == 0xF2 || //repe
byte == 0xF3 || //repne
(byte >= 0x40 && byte <= 0x4F) // REX
)) {
foundOpcode = true;
}
}
if (foundOpcode) {
if (twoByteOpcode) {
//SYSCALL or SYSENTER
if (byte == 0x05 || byte == 0x34)
return rip + 1;
else
return 0;
}
if (!twoByteOpcode) {
if (byte == 0xCC) // INT3
return rip + 1;
else if (byte == 0xCD) // INT with byte immediate
return rip + 2;
else if (byte == 0x0F) // two byte opcode prefix
twoByteOpcode = true;
else
return 0;
}
}
buf >>= 8;
rip++;
}
}
}
bool
AMD64TraceChild::step()
{
uint64_t ripAfterSyscall = findSyscall();
if (ripAfterSyscall) {
//Get the original contents of memory
uint64_t buf = ptrace(PTRACE_PEEKDATA, pid, ripAfterSyscall, 0);
//Patch the first two bytes of the memory immediately after this with
//jmp -2. Either single stepping will take over before this
//instruction, leaving the rip where it should be, or it will take
//over after this instruction, -still- leaving the rip where it should
//be.
uint64_t newBuf = (buf & ~0xFFFF) | 0xFEEB;
//Write the patched memory to the processes address space
ptrace(PTRACE_POKEDATA, pid, ripAfterSyscall, newBuf);
//Step and hit it
ptraceSingleStep();
//Put things back to the way they started
ptrace(PTRACE_POKEDATA, pid, ripAfterSyscall, buf);
} else {
//Get all the way past repe and repne string instructions in one shot.
uint64_t newPC, origPC = getPC();
do {
ptraceSingleStep();
newPC = getPC();
} while(newPC == origPC);
}
}
TraceChild * genTraceChild()
{
return new AMD64TraceChild;
}