qemu/gdbstub.c

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/*
* gdb server stub
*
* Copyright (c) 2003-2005 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef CONFIG_USER_ONLY
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "qemu.h"
#else
#include "vl.h"
#endif
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <signal.h>
//#define DEBUG_GDB
enum RSState {
RS_IDLE,
RS_GETLINE,
RS_CHKSUM1,
RS_CHKSUM2,
};
/* XXX: This is not thread safe. Do we care? */
static int gdbserver_fd = -1;
typedef struct GDBState {
enum RSState state; /* parsing state */
int fd;
char line_buf[4096];
int line_buf_index;
int line_csum;
#ifdef CONFIG_USER_ONLY
int running_state;
#endif
} GDBState;
#ifdef CONFIG_USER_ONLY
/* XXX: remove this hack. */
static GDBState gdbserver_state;
#endif
static int get_char(GDBState *s)
{
uint8_t ch;
int ret;
for(;;) {
ret = read(s->fd, &ch, 1);
if (ret < 0) {
if (errno != EINTR && errno != EAGAIN)
return -1;
} else if (ret == 0) {
return -1;
} else {
break;
}
}
return ch;
}
static void put_buffer(GDBState *s, const uint8_t *buf, int len)
{
int ret;
while (len > 0) {
ret = write(s->fd, buf, len);
if (ret < 0) {
if (errno != EINTR && errno != EAGAIN)
return;
} else {
buf += ret;
len -= ret;
}
}
}
static inline int fromhex(int v)
{
if (v >= '0' && v <= '9')
return v - '0';
else if (v >= 'A' && v <= 'F')
return v - 'A' + 10;
else if (v >= 'a' && v <= 'f')
return v - 'a' + 10;
else
return 0;
}
static inline int tohex(int v)
{
if (v < 10)
return v + '0';
else
return v - 10 + 'a';
}
static void memtohex(char *buf, const uint8_t *mem, int len)
{
int i, c;
char *q;
q = buf;
for(i = 0; i < len; i++) {
c = mem[i];
*q++ = tohex(c >> 4);
*q++ = tohex(c & 0xf);
}
*q = '\0';
}
static void hextomem(uint8_t *mem, const char *buf, int len)
{
int i;
for(i = 0; i < len; i++) {
mem[i] = (fromhex(buf[0]) << 4) | fromhex(buf[1]);
buf += 2;
}
}
/* return -1 if error, 0 if OK */
static int put_packet(GDBState *s, char *buf)
{
char buf1[3];
int len, csum, ch, i;
#ifdef DEBUG_GDB
printf("reply='%s'\n", buf);
#endif
for(;;) {
buf1[0] = '$';
put_buffer(s, buf1, 1);
len = strlen(buf);
put_buffer(s, buf, len);
csum = 0;
for(i = 0; i < len; i++) {
csum += buf[i];
}
buf1[0] = '#';
buf1[1] = tohex((csum >> 4) & 0xf);
buf1[2] = tohex((csum) & 0xf);
put_buffer(s, buf1, 3);
ch = get_char(s);
if (ch < 0)
return -1;
if (ch == '+')
break;
}
return 0;
}
#if defined(TARGET_I386)
static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
{
uint32_t *registers = (uint32_t *)mem_buf;
int i, fpus;
for(i = 0; i < 8; i++) {
registers[i] = env->regs[i];
}
registers[8] = env->eip;
registers[9] = env->eflags;
registers[10] = env->segs[R_CS].selector;
registers[11] = env->segs[R_SS].selector;
registers[12] = env->segs[R_DS].selector;
registers[13] = env->segs[R_ES].selector;
registers[14] = env->segs[R_FS].selector;
registers[15] = env->segs[R_GS].selector;
/* XXX: convert floats */
for(i = 0; i < 8; i++) {
memcpy(mem_buf + 16 * 4 + i * 10, &env->fpregs[i], 10);
}
registers[36] = env->fpuc;
fpus = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11;
registers[37] = fpus;
registers[38] = 0; /* XXX: convert tags */
registers[39] = 0; /* fiseg */
registers[40] = 0; /* fioff */
registers[41] = 0; /* foseg */
registers[42] = 0; /* fooff */
registers[43] = 0; /* fop */
for(i = 0; i < 16; i++)
tswapls(&registers[i]);
for(i = 36; i < 44; i++)
tswapls(&registers[i]);
return 44 * 4;
}
static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
{
uint32_t *registers = (uint32_t *)mem_buf;
int i;
for(i = 0; i < 8; i++) {
env->regs[i] = tswapl(registers[i]);
}
env->eip = tswapl(registers[8]);
env->eflags = tswapl(registers[9]);
#if defined(CONFIG_USER_ONLY)
#define LOAD_SEG(index, sreg)\
if (tswapl(registers[index]) != env->segs[sreg].selector)\
cpu_x86_load_seg(env, sreg, tswapl(registers[index]));
LOAD_SEG(10, R_CS);
LOAD_SEG(11, R_SS);
LOAD_SEG(12, R_DS);
LOAD_SEG(13, R_ES);
LOAD_SEG(14, R_FS);
LOAD_SEG(15, R_GS);
#endif
}
#elif defined (TARGET_PPC)
static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
{
uint32_t *registers = (uint32_t *)mem_buf, tmp;
int i;
/* fill in gprs */
for(i = 0; i < 32; i++) {
registers[i] = tswapl(env->gpr[i]);
}
/* fill in fprs */
for (i = 0; i < 32; i++) {
registers[(i * 2) + 32] = tswapl(*((uint32_t *)&env->fpr[i]));
registers[(i * 2) + 33] = tswapl(*((uint32_t *)&env->fpr[i] + 1));
}
/* nip, msr, ccr, lnk, ctr, xer, mq */
registers[96] = tswapl(env->nip);
registers[97] = tswapl(_load_msr(env));
tmp = 0;
for (i = 0; i < 8; i++)
tmp |= env->crf[i] << (32 - ((i + 1) * 4));
registers[98] = tswapl(tmp);
registers[99] = tswapl(env->lr);
registers[100] = tswapl(env->ctr);
registers[101] = tswapl(_load_xer(env));
registers[102] = 0;
return 103 * 4;
}
static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
{
uint32_t *registers = (uint32_t *)mem_buf;
int i;
/* fill in gprs */
for (i = 0; i < 32; i++) {
env->gpr[i] = tswapl(registers[i]);
}
/* fill in fprs */
for (i = 0; i < 32; i++) {
*((uint32_t *)&env->fpr[i]) = tswapl(registers[(i * 2) + 32]);
*((uint32_t *)&env->fpr[i] + 1) = tswapl(registers[(i * 2) + 33]);
}
/* nip, msr, ccr, lnk, ctr, xer, mq */
env->nip = tswapl(registers[96]);
_store_msr(env, tswapl(registers[97]));
registers[98] = tswapl(registers[98]);
for (i = 0; i < 8; i++)
env->crf[i] = (registers[98] >> (32 - ((i + 1) * 4))) & 0xF;
env->lr = tswapl(registers[99]);
env->ctr = tswapl(registers[100]);
_store_xer(env, tswapl(registers[101]));
}
#elif defined (TARGET_SPARC)
static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
{
target_ulong *registers = (target_ulong *)mem_buf;
int i;
/* fill in g0..g7 */
for(i = 0; i < 7; i++) {
registers[i] = tswapl(env->gregs[i]);
}
/* fill in register window */
for(i = 0; i < 24; i++) {
registers[i + 8] = tswapl(env->regwptr[i]);
}
/* fill in fprs */
for (i = 0; i < 32; i++) {
registers[i + 32] = tswapl(*((uint32_t *)&env->fpr[i]));
}
#ifndef TARGET_SPARC64
/* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
registers[64] = tswapl(env->y);
{
target_ulong tmp;
tmp = GET_PSR(env);
registers[65] = tswapl(tmp);
}
registers[66] = tswapl(env->wim);
registers[67] = tswapl(env->tbr);
registers[68] = tswapl(env->pc);
registers[69] = tswapl(env->npc);
registers[70] = tswapl(env->fsr);
registers[71] = 0; /* csr */
registers[72] = 0;
return 73 * sizeof(target_ulong);
#else
for (i = 0; i < 32; i += 2) {
registers[i/2 + 64] = tswapl(*((uint64_t *)&env->fpr[i]));
}
registers[81] = tswapl(env->pc);
registers[82] = tswapl(env->npc);
registers[83] = tswapl(env->tstate[env->tl]);
registers[84] = tswapl(env->fsr);
registers[85] = tswapl(env->fprs);
registers[86] = tswapl(env->y);
return 87 * sizeof(target_ulong);
#endif
}
static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
{
target_ulong *registers = (target_ulong *)mem_buf;
int i;
/* fill in g0..g7 */
for(i = 0; i < 7; i++) {
env->gregs[i] = tswapl(registers[i]);
}
/* fill in register window */
for(i = 0; i < 24; i++) {
env->regwptr[i] = tswapl(registers[i + 8]);
}
/* fill in fprs */
for (i = 0; i < 32; i++) {
*((uint32_t *)&env->fpr[i]) = tswapl(registers[i + 32]);
}
#ifndef TARGET_SPARC64
/* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
env->y = tswapl(registers[64]);
PUT_PSR(env, tswapl(registers[65]));
env->wim = tswapl(registers[66]);
env->tbr = tswapl(registers[67]);
env->pc = tswapl(registers[68]);
env->npc = tswapl(registers[69]);
env->fsr = tswapl(registers[70]);
#else
for (i = 0; i < 32; i += 2) {
uint64_t tmp;
tmp = tswapl(registers[i/2 + 64]) << 32;
tmp |= tswapl(registers[i/2 + 64 + 1]);
*((uint64_t *)&env->fpr[i]) = tmp;
}
env->pc = tswapl(registers[81]);
env->npc = tswapl(registers[82]);
env->tstate[env->tl] = tswapl(registers[83]);
env->fsr = tswapl(registers[84]);
env->fprs = tswapl(registers[85]);
env->y = tswapl(registers[86]);
#endif
}
#elif defined (TARGET_ARM)
static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
{
int i;
uint8_t *ptr;
ptr = mem_buf;
/* 16 core integer registers (4 bytes each). */
for (i = 0; i < 16; i++)
{
*(uint32_t *)ptr = tswapl(env->regs[i]);
ptr += 4;
}
/* 8 FPA registers (12 bytes each), FPS (4 bytes).
Not yet implemented. */
memset (ptr, 0, 8 * 12 + 4);
ptr += 8 * 12 + 4;
/* CPSR (4 bytes). */
*(uint32_t *)ptr = tswapl (env->cpsr);
ptr += 4;
return ptr - mem_buf;
}
static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
{
int i;
uint8_t *ptr;
ptr = mem_buf;
/* Core integer registers. */
for (i = 0; i < 16; i++)
{
env->regs[i] = tswapl(*(uint32_t *)ptr);
ptr += 4;
}
/* Ignore FPA regs and scr. */
ptr += 8 * 12 + 4;
env->cpsr = tswapl(*(uint32_t *)ptr);
}
#else
static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
{
return 0;
}
static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
{
}
#endif
static int gdb_handle_packet(GDBState *s, CPUState *env, const char *line_buf)
{
const char *p;
int ch, reg_size, type;
char buf[4096];
uint8_t mem_buf[2000];
uint32_t *registers;
uint32_t addr, len;
#ifdef DEBUG_GDB
printf("command='%s'\n", line_buf);
#endif
p = line_buf;
ch = *p++;
switch(ch) {
case '?':
/* TODO: Make this return the correct value for user-mode. */
snprintf(buf, sizeof(buf), "S%02x", SIGTRAP);
put_packet(s, buf);
break;
case 'c':
if (*p != '\0') {
addr = strtoul(p, (char **)&p, 16);
#if defined(TARGET_I386)
env->eip = addr;
#elif defined (TARGET_PPC)
env->nip = addr;
#elif defined (TARGET_SPARC)
env->pc = addr;
env->npc = addr + 4;
#endif
}
#ifdef CONFIG_USER_ONLY
s->running_state = 1;
#else
vm_start();
#endif
return RS_IDLE;
case 's':
if (*p != '\0') {
addr = strtoul(p, (char **)&p, 16);
#if defined(TARGET_I386)
env->eip = addr;
#elif defined (TARGET_PPC)
env->nip = addr;
#elif defined (TARGET_SPARC)
env->pc = addr;
env->npc = addr + 4;
#endif
}
cpu_single_step(env, 1);
#ifdef CONFIG_USER_ONLY
s->running_state = 1;
#else
vm_start();
#endif
return RS_IDLE;
case 'g':
reg_size = cpu_gdb_read_registers(env, mem_buf);
memtohex(buf, mem_buf, reg_size);
put_packet(s, buf);
break;
case 'G':
registers = (void *)mem_buf;
len = strlen(p) / 2;
hextomem((uint8_t *)registers, p, len);
cpu_gdb_write_registers(env, mem_buf, len);
put_packet(s, "OK");
break;
case 'm':
addr = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
len = strtoul(p, NULL, 16);
if (cpu_memory_rw_debug(env, addr, mem_buf, len, 0) != 0)
memset(mem_buf, 0, len);
memtohex(buf, mem_buf, len);
put_packet(s, buf);
break;
case 'M':
addr = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
len = strtoul(p, (char **)&p, 16);
if (*p == ':')
p++;
hextomem(mem_buf, p, len);
if (cpu_memory_rw_debug(env, addr, mem_buf, len, 1) != 0)
put_packet(s, "E14");
else
put_packet(s, "OK");
break;
case 'Z':
type = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
addr = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
len = strtoul(p, (char **)&p, 16);
if (type == 0 || type == 1) {
if (cpu_breakpoint_insert(env, addr) < 0)
goto breakpoint_error;
put_packet(s, "OK");
} else {
breakpoint_error:
put_packet(s, "E22");
}
break;
case 'z':
type = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
addr = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
len = strtoul(p, (char **)&p, 16);
if (type == 0 || type == 1) {
cpu_breakpoint_remove(env, addr);
put_packet(s, "OK");
} else {
goto breakpoint_error;
}
break;
default:
// unknown_command:
/* put empty packet */
buf[0] = '\0';
put_packet(s, buf);
break;
}
return RS_IDLE;
}
extern void tb_flush(CPUState *env);
#ifndef CONFIG_USER_ONLY
static void gdb_vm_stopped(void *opaque, int reason)
{
GDBState *s = opaque;
char buf[256];
int ret;
/* disable single step if it was enable */
cpu_single_step(cpu_single_env, 0);
if (reason == EXCP_DEBUG) {
tb_flush(cpu_single_env);
ret = SIGTRAP;
}
else
ret = 0;
snprintf(buf, sizeof(buf), "S%02x", ret);
put_packet(s, buf);
}
#endif
static void gdb_read_byte(GDBState *s, CPUState *env, int ch)
{
int i, csum;
char reply[1];
#ifndef CONFIG_USER_ONLY
if (vm_running) {
/* when the CPU is running, we cannot do anything except stop
it when receiving a char */
vm_stop(EXCP_INTERRUPT);
} else
#endif
{
switch(s->state) {
case RS_IDLE:
if (ch == '$') {
s->line_buf_index = 0;
s->state = RS_GETLINE;
}
break;
case RS_GETLINE:
if (ch == '#') {
s->state = RS_CHKSUM1;
} else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {
s->state = RS_IDLE;
} else {
s->line_buf[s->line_buf_index++] = ch;
}
break;
case RS_CHKSUM1:
s->line_buf[s->line_buf_index] = '\0';
s->line_csum = fromhex(ch) << 4;
s->state = RS_CHKSUM2;
break;
case RS_CHKSUM2:
s->line_csum |= fromhex(ch);
csum = 0;
for(i = 0; i < s->line_buf_index; i++) {
csum += s->line_buf[i];
}
if (s->line_csum != (csum & 0xff)) {
reply[0] = '-';
put_buffer(s, reply, 1);
s->state = RS_IDLE;
} else {
reply[0] = '+';
put_buffer(s, reply, 1);
s->state = gdb_handle_packet(s, env, s->line_buf);
}
break;
}
}
}
#ifdef CONFIG_USER_ONLY
int
gdb_handlesig (CPUState *env, int sig)
{
GDBState *s;
char buf[256];
int n;
if (gdbserver_fd < 0)
return sig;
s = &gdbserver_state;
/* disable single step if it was enabled */
cpu_single_step(env, 0);
tb_flush(env);
if (sig != 0)
{
snprintf(buf, sizeof(buf), "S%02x", sig);
put_packet(s, buf);
}
sig = 0;
s->state = RS_IDLE;
s->running_state = 0;
while (s->running_state == 0) {
n = read (s->fd, buf, 256);
if (n > 0)
{
int i;
for (i = 0; i < n; i++)
gdb_read_byte (s, env, buf[i]);
}
else if (n == 0 || errno != EAGAIN)
{
/* XXX: Connection closed. Should probably wait for annother
connection before continuing. */
return sig;
}
}
return sig;
}
/* Tell the remote gdb that the process has exited. */
void gdb_exit(CPUState *env, int code)
{
GDBState *s;
char buf[4];
if (gdbserver_fd < 0)
return;
s = &gdbserver_state;
snprintf(buf, sizeof(buf), "W%02x", code);
put_packet(s, buf);
}
#else
static int gdb_can_read(void *opaque)
{
return 256;
}
static void gdb_read(void *opaque, const uint8_t *buf, int size)
{
GDBState *s = opaque;
int i;
if (size == 0) {
/* end of connection */
qemu_del_vm_stop_handler(gdb_vm_stopped, s);
qemu_del_fd_read_handler(s->fd);
qemu_free(s);
vm_start();
} else {
for(i = 0; i < size; i++)
gdb_read_byte(s, cpu_single_env, buf[i]);
}
}
#endif
static void gdb_accept(void *opaque, const uint8_t *buf, int size)
{
GDBState *s;
struct sockaddr_in sockaddr;
socklen_t len;
int val, fd;
for(;;) {
len = sizeof(sockaddr);
fd = accept(gdbserver_fd, (struct sockaddr *)&sockaddr, &len);
if (fd < 0 && errno != EINTR) {
perror("accept");
return;
} else if (fd >= 0) {
break;
}
}
/* set short latency */
val = 1;
setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val));
#ifdef CONFIG_USER_ONLY
s = &gdbserver_state;
memset (s, 0, sizeof (GDBState));
#else
s = qemu_mallocz(sizeof(GDBState));
if (!s) {
close(fd);
return;
}
#endif
s->fd = fd;
fcntl(fd, F_SETFL, O_NONBLOCK);
#ifndef CONFIG_USER_ONLY
/* stop the VM */
vm_stop(EXCP_INTERRUPT);
/* start handling I/O */
qemu_add_fd_read_handler(s->fd, gdb_can_read, gdb_read, s);
/* when the VM is stopped, the following callback is called */
qemu_add_vm_stop_handler(gdb_vm_stopped, s);
#endif
}
static int gdbserver_open(int port)
{
struct sockaddr_in sockaddr;
int fd, val, ret;
fd = socket(PF_INET, SOCK_STREAM, 0);
if (fd < 0) {
perror("socket");
return -1;
}
/* allow fast reuse */
val = 1;
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons(port);
sockaddr.sin_addr.s_addr = 0;
ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
if (ret < 0) {
perror("bind");
return -1;
}
ret = listen(fd, 0);
if (ret < 0) {
perror("listen");
return -1;
}
#ifndef CONFIG_USER_ONLY
fcntl(fd, F_SETFL, O_NONBLOCK);
#endif
return fd;
}
int gdbserver_start(int port)
{
gdbserver_fd = gdbserver_open(port);
if (gdbserver_fd < 0)
return -1;
/* accept connections */
#ifdef CONFIG_USER_ONLY
gdb_accept (NULL, NULL, 0);
#else
qemu_add_fd_read_handler(gdbserver_fd, NULL, gdb_accept, NULL);
#endif
return 0;
}