Bochs/bochs/gdbstub.cc

905 lines
23 KiB
C++

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#ifdef __MINGW32__
#include <winsock2.h>
#define SIGTRAP 5
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <signal.h>
#include <netdb.h>
#endif
#define NEED_CPU_REG_SHORTCUTS 1
#include "bochs.h"
#include "iodev/iodev.h"
#define LOG_THIS genlog->
#define IFDBG(x) x
static int last_stop_reason = GDBSTUB_STOP_NO_REASON;
#define GDBSTUB_EXECUTION_BREAKPOINT (0xac1)
#define GDBSTUB_TRACE (0xac2)
#define GDBSTUB_USER_BREAK (0xac3)
static int listen_socket_fd;
static int socket_fd;
static int hex(char ch)
{
if ((ch >= 'a') && (ch <= 'f')) return(ch - 'a' + 10);
if ((ch >= '0') && (ch <= '9')) return(ch - '0');
if ((ch >= 'A') && (ch <= 'F')) return(ch - 'A' + 10);
return(-1);
}
static void put_debug_char(char ch)
{
send(socket_fd, &ch, 1, 0);
}
static char get_debug_char(void)
{
char ch;
recv(socket_fd, &ch, 1, 0);
return(ch);
}
static const char hexchars[]="0123456789abcdef";
static void put_reply(char* buffer)
{
unsigned char csum;
int i;
BX_DEBUG (("put_buffer %s", buffer));
do
{
put_debug_char('$');
csum = 0;
i = 0;
while (buffer[i] != 0)
{
put_debug_char(buffer[i]);
csum = csum + buffer[i];
i++;
}
put_debug_char('#');
put_debug_char(hexchars[csum >> 4]);
put_debug_char(hexchars[csum % 16]);
} while (get_debug_char() != '+');
}
static void get_command(char* buffer)
{
unsigned char checksum;
unsigned char xmitcsum;
char ch;
unsigned int count;
unsigned int i;
do
{
while ((ch = get_debug_char()) != '$');
checksum = 0;
xmitcsum = 0;
count = 0;
while (1)
{
ch = get_debug_char();
if (ch == '#') break;
checksum = checksum + ch;
buffer[count] = ch;
count++;
}
buffer[count] = 0;
if (ch == '#')
{
xmitcsum = hex(get_debug_char()) << 4;
xmitcsum += hex(get_debug_char());
if (checksum != xmitcsum)
{
BX_INFO (("Bad checksum"));
}
}
if (checksum != xmitcsum)
{
put_debug_char('-');
}
else
{
put_debug_char('+');
if (buffer[2] == ':')
{
put_debug_char(buffer[0]);
put_debug_char(buffer[1]);
count = strlen(buffer);
for (i = 3; i <= count; i++)
{
buffer[i - 3] = buffer[i];
}
}
}
} while (checksum != xmitcsum);
}
void hex2mem(char* buf, unsigned char* mem, int count)
{
int i;
unsigned char ch;
for (i = 0; i<count; i++)
{
ch = hex(*buf++) << 4;
ch = ch + hex(*buf++);
*mem = ch;
mem++;
}
}
char* mem2hex(char* mem, char* buf, int count)
{
int i;
unsigned char ch;
for (i = 0; i<count; i++)
{
ch = *mem;
mem++;
*buf = hexchars[ch >> 4];
buf++;
*buf = hexchars[ch % 16];
buf++;
}
*buf = 0;
return(buf);
}
int hexdigit(char c)
{
if (isdigit(c))
return c - '0';
else if (isupper(c))
return c - 'A' + 10;
else
return c - 'a' + 10;
}
Bit64u read_little_endian_hex(char *&buf)
{
int byte;
Bit64u ret = 0;
int n = 0;
while (isxdigit(*buf)) {
byte = hexdigit(*buf++);
if (isxdigit(*buf))
byte = (byte << 4) | hexdigit(*buf++);
ret |= (unsigned long long)byte << (n*8);
++n;
}
return ret;
}
static int continue_thread = -1;
static int other_thread = 0;
#if !BX_SUPPORT_X86_64
#define NUMREGS (16)
#define NUMREGSBYTES (NUMREGS * 4)
static int registers[NUMREGS];
#endif
#define MAX_BREAKPOINTS (255)
static unsigned int breakpoints[MAX_BREAKPOINTS] = {0,};
static unsigned int nr_breakpoints = 0;
static int stub_trace_flag = 0;
static int instr_count = 0;
static int saved_eip = 0;
int bx_gdbstub_check(unsigned int eip)
{
unsigned int i;
unsigned char ch;
long arg;
int r;
#if defined(__CYGWIN__) || defined(__MINGW32__)
fd_set fds;
struct timeval tv = {0, 0};
#endif
instr_count++;
if ((instr_count % 500) == 0)
{
#if !defined(__CYGWIN__) && !defined(__MINGW32__)
arg = fcntl(socket_fd, F_GETFL);
fcntl(socket_fd, F_SETFL, arg | O_NONBLOCK);
r = recv(socket_fd, &ch, 1, 0);
fcntl(socket_fd, F_SETFL, arg);
#else
FD_ZERO(&fds);
FD_SET(socket_fd, &fds);
r = select(socket_fd + 1, &fds, NULL, NULL, &tv);
if (r == 1)
{
r = recv(socket_fd, (char *)&ch, 1, 0);
}
#endif
if (r == 1)
{
BX_INFO (("Got byte %x", (unsigned int)ch));
last_stop_reason = GDBSTUB_USER_BREAK;
return(GDBSTUB_USER_BREAK);
}
}
// why is trace before breakpoints? does that mean it would never
// hit a breakpoint during tracing?
if (stub_trace_flag == 1)
{
last_stop_reason = GDBSTUB_TRACE;
return(GDBSTUB_TRACE);
}
for (i = 0; i < nr_breakpoints; i++)
{
if (eip == breakpoints[i])
{
BX_INFO (("found breakpoint at %x", eip));
last_stop_reason = GDBSTUB_EXECUTION_BREAKPOINT;
return(GDBSTUB_EXECUTION_BREAKPOINT);
}
}
last_stop_reason = GDBSTUB_STOP_NO_REASON;
return(GDBSTUB_STOP_NO_REASON);
}
static int remove_breakpoint(unsigned int addr, int len)
{
unsigned int i;
if (len != 1)
{
return(0);
}
for (i = 0; i < MAX_BREAKPOINTS; i++)
{
if (breakpoints[i] == addr)
{
BX_INFO (("Removing breakpoint at %x", addr));
breakpoints[i] = 0;
return(1);
}
}
return(0);
}
static void insert_breakpoint(unsigned int addr)
{
unsigned int i;
BX_INFO (("setting breakpoint at %x", addr));
for (i = 0; i < (unsigned)MAX_BREAKPOINTS; i++)
{
if (breakpoints[i] == 0)
{
breakpoints[i] = addr;
if (i >= nr_breakpoints)
{
nr_breakpoints = i + 1;
}
return;
}
}
BX_INFO (("No slot for breakpoint"));
}
static void do_pc_breakpoint(int insert, unsigned long long addr, int len)
{
for (int i = 0; i < len; ++i)
if (insert)
insert_breakpoint(addr+i);
else
remove_breakpoint(addr+i, 1);
}
static void do_breakpoint(int insert, char* buffer)
{
char* ebuf;
unsigned long type = strtoul(buffer, &ebuf, 16);
unsigned long long addr = strtoull(ebuf+1, &ebuf, 16);
unsigned long len = strtoul(ebuf+1, &ebuf, 16);
switch (type) {
case 0:
case 1:
do_pc_breakpoint(insert, addr, len);
put_reply("OK");
break;
default:
put_reply("");
break;
}
}
static void write_signal(char* buf, int signal)
{
buf[0] = hexchars[signal >> 4];
buf[1] = hexchars[signal % 16];
buf[2] = 0;
}
static int access_linear(Bit64u laddress,
unsigned len,
unsigned int rw,
Bit8u* data)
{
Bit32u phys;
bx_bool valid;
if (((laddress & 0xfff) + len) > 4096)
{
valid = access_linear(laddress,
4096 - (laddress & 0xfff),
rw,
data);
if (!valid)
{
return(valid);
}
valid = access_linear(laddress,
len + (laddress & 0xfff) - 4096,
rw,
(Bit8u *)((unsigned int)data +
4096 - (laddress & 0xfff)));
return(valid);
}
BX_CPU(0)->dbg_xlate_linear2phy(laddress,
(Bit32u*)&phys,
(bx_bool*)&valid);
if (!valid)
{
return(0);
}
if (rw == BX_READ)
{
valid = BX_MEM(0)->dbg_fetch_mem(phys, len, data);
}
else
{
valid = BX_MEM(0)->dbg_set_mem(phys, len, data);
}
return(valid);
}
static void debug_loop(void)
{
char buffer[255];
char obuf[255];
int ne;
unsigned char mem[255];
ne = 0;
while (ne == 0)
{
get_command(buffer);
BX_DEBUG (("get_buffer %s", buffer));
switch (buffer[0])
{
case 'c':
{
char buf[255];
int new_eip;
if (buffer[1] != 0)
{
new_eip = atoi(buffer + 1);
BX_INFO (("continuing at %x", new_eip));
for (int i=0; i<BX_SMP_PROCESSORS; i++) {
BX_CPU(i)->invalidate_prefetch_q();
}
saved_eip = EIP;
BX_CPU(0)->dword.eip = new_eip;
}
stub_trace_flag = 0;
bx_cpu.ispanic = 0;
bx_cpu.cpu_loop(-1);
if (bx_cpu.ispanic)
{
last_stop_reason = GDBSTUB_EXECUTION_BREAKPOINT;
}
DEV_vga_refresh();
if (buffer[1] != 0)
{
bx_cpu.invalidate_prefetch_q();
BX_CPU_THIS_PTR dword.eip = saved_eip;
}
BX_INFO (("stopped with %x", last_stop_reason));
buf[0] = 'S';
if (last_stop_reason == GDBSTUB_EXECUTION_BREAKPOINT ||
last_stop_reason == GDBSTUB_TRACE)
{
write_signal(&buf[1], SIGTRAP);
}
else
{
write_signal(&buf[1], 0);
}
put_reply(buf);
break;
}
case 's':
{
char buf[255];
BX_INFO (("stepping"));
stub_trace_flag = 1;
bx_cpu.cpu_loop(-1);
DEV_vga_refresh();
stub_trace_flag = 0;
BX_INFO (("stopped with %x", last_stop_reason));
buf[0] = 'S';
if (last_stop_reason == GDBSTUB_EXECUTION_BREAKPOINT ||
last_stop_reason == GDBSTUB_TRACE)
{
write_signal(&buf[1], SIGTRAP);
}
else
{
write_signal(&buf[1], SIGTRAP);
}
put_reply(buf);
break;
}
case 'M':
{
Bit64u addr;
int len;
unsigned char mem[255];
char* ebuf;
addr = strtoull(&buffer[1], &ebuf, 16);
len = strtoul(ebuf + 1, &ebuf, 16);
hex2mem(ebuf + 1, mem, len);
if (len == 1 && mem[0] == 0xcc)
{
insert_breakpoint(addr);
put_reply("OK");
}
else if (remove_breakpoint(addr, len))
{
put_reply("OK");
}
else
{
if (access_linear(addr,
len,
BX_WRITE,
mem))
{
put_reply("OK");
}
else
{
put_reply("ENN");
}
}
break;
}
case 'm':
{
Bit64u addr;
int len;
char* ebuf;
addr = strtoull(&buffer[1], &ebuf, 16);
len = strtoul(ebuf + 1, NULL, 16);
BX_INFO (("addr %x len %x", addr, len));
access_linear(addr,
len,
BX_READ,
mem);
mem2hex((char *)mem, obuf, len);
put_reply(obuf);
break;
}
case 'P':
{
int reg;
unsigned long long value;
char* ebuf;
reg = strtoul(&buffer[1], &ebuf, 16);
++ebuf;
value = read_little_endian_hex(ebuf);
BX_INFO (("reg %d set to %llx", reg, value));
#if !BX_SUPPORT_X86_64
switch (reg)
{
case 1:
EAX = value;
break;
case 2:
ECX = value;
break;
case 3:
EBX = value;
break;
case 4:
ESP = value;
break;
case 5:
EBP = value;
break;
case 6:
ESI = value;
break;
case 7:
EDI = value;
break;
case 8:
EIP = value;
BX_CPU_THIS_PTR invalidate_prefetch_q();
break;
default:
break;
}
#else
switch (reg)
{
case 0:
RAX = value;
break;
case 1:
RBX = value;
break;
case 2:
RCX = value;
break;
case 3:
RDX = value;
break;
case 4:
RSI = value;
break;
case 5:
RDI = value;
break;
case 6:
ESP = value;
break;
case 7:
RBP = value;
break;
case 8:
R8 = value;
break;
case 9:
R9 = value;
break;
case 10:
R10 = value;
break;
case 11:
R11 = value;
break;
case 12:
R12 = value;
break;
case 13:
R13 = value;
break;
case 14:
R15 = value;
break;
case 15:
R15 = value;
break;
case 16:
RIP = value;
BX_CPU_THIS_PTR invalidate_prefetch_q();
break;
default:
break;
}
#endif
put_reply("OK");
break;
}
case 'g':
#if !BX_SUPPORT_X86_64
registers[0] = EAX;
registers[1] = ECX;
registers[2] = EDX;
registers[3] = EBX;
registers[4] = ESP;
registers[5] = EBP;
registers[6] = ESI;
registers[7] = EDI;
if (last_stop_reason == GDBSTUB_EXECUTION_BREAKPOINT)
{
registers[8] = EIP + 1;
}
else
{
registers[8] = EIP;
}
registers[9] = BX_CPU_THIS_PTR read_eflags();
registers[10] =
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value;
registers[11] =
BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value;
registers[12] =
BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value;
registers[13] =
BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value;
registers[14] =
BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value;
registers[15] =
BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value;
mem2hex((char *)registers, obuf, NUMREGSBYTES);
#else
#define PUTREG(buf, val, len) do { \
Bit64u u = (val); \
(buf) = mem2hex((char*)&u, (buf), (len)); \
} while (0)
char* buf;
buf = obuf;
PUTREG(buf, RAX, 8);
PUTREG(buf, RBX, 8);
PUTREG(buf, RCX, 8);
PUTREG(buf, RDX, 8);
PUTREG(buf, RSI, 8);
PUTREG(buf, RDI, 8);
PUTREG(buf, RBP, 8);
PUTREG(buf, RSP, 8);
PUTREG(buf, R8, 8);
PUTREG(buf, R9, 8);
PUTREG(buf, R10, 8);
PUTREG(buf, R11, 8);
PUTREG(buf, R12, 8);
PUTREG(buf, R13, 8);
PUTREG(buf, R14, 8);
PUTREG(buf, R15, 8);
Bit64u rip;
rip = RIP;
if (last_stop_reason == GDBSTUB_EXECUTION_BREAKPOINT)
{
++rip;
}
PUTREG(buf, rip, 8);
PUTREG(buf, BX_CPU_THIS_PTR read_eflags(), 4);
PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, 4);
PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value, 4);
PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value, 4);
PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value, 4);
PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value, 4);
PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value, 4);
#endif
put_reply(obuf);
break;
case '?':
sprintf(obuf, "S%02x", SIGTRAP);
put_reply(obuf);
break;
case 'H':
if (buffer[1] == 'c')
{
continue_thread = strtol(&buffer[2], NULL, 16);
put_reply("OK");
}
else if (buffer[1] == 'g')
{
other_thread = strtol(&buffer[2], NULL, 16);
put_reply("OK");
}
else
{
put_reply("ENN");
}
break;
case 'q':
if (buffer[1] == 'C')
{
sprintf(obuf,"%Lx", 1);
put_reply(obuf);
}
else if (strncmp(&buffer[1], "Offsets", strlen("Offsets")) == 0)
{
sprintf(obuf,
"Text=%x;Data=%x;Bss=%x",
bx_options.gdbstub.text_base,
bx_options.gdbstub.data_base,
bx_options.gdbstub.bss_base);
put_reply(obuf);
}
else
{
put_reply("ENN");
}
break;
case 'Z':
do_breakpoint(1, buffer+1);
break;
case 'z':
do_breakpoint(0, buffer+1);
break;
case 'k':
BX_PANIC (("Debugger asked us to quit\n"));
break;
default:
put_reply("");
break;
}
}
}
static void wait_for_connect(int portn)
{
struct sockaddr_in sockaddr;
socklen_t sockaddr_len;
struct protoent *protoent;
int r;
int opt;
listen_socket_fd = socket(PF_INET, SOCK_STREAM, 0);
if (listen_socket_fd == -1)
{
BX_PANIC (("Failed to create socket\n"));
exit(1);
}
/* Allow rapid reuse of this port */
opt = 1;
#if __MINGW32__
r = setsockopt(listen_socket_fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&opt, sizeof(opt));
#else
r = setsockopt(listen_socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
#endif
if (r == -1)
{
BX_INFO (("setsockopt(SO_REUSEADDR) failed\n"));
}
memset (&sockaddr, '\000', sizeof sockaddr);
#if BX_HAVE_SOCKADDR_IN_SIN_LEN
// if you don't have sin_len change that to #if 0. This is the subject of
// bug [ 626840 ] no 'sin_len' in 'struct sockaddr_in'.
sockaddr.sin_len = sizeof sockaddr;
#endif
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons(portn);
sockaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
r = bind(listen_socket_fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
if (r == -1)
{
BX_PANIC (("Failed to bind socket\n"));
}
r = listen(listen_socket_fd, 0);
if (r == -1)
{
BX_PANIC (("Failed to listen on socket\n"));
}
sockaddr_len = sizeof sockaddr;
socket_fd = accept(listen_socket_fd, (struct sockaddr *)&sockaddr, &sockaddr_len);
if (socket_fd == -1)
{
BX_PANIC (("Failed to accept on socket\n"));
}
close(listen_socket_fd);
protoent = getprotobyname ("tcp");
if (!protoent)
{
BX_INFO (("getprotobyname (\"tcp\") failed\n"));
return;
}
/* Disable Nagle - allow small packets to be sent without delay. */
opt = 1;
#ifdef __MINGW32__
r = setsockopt (socket_fd, protoent->p_proto, TCP_NODELAY, (const char *)&opt, sizeof(opt));
#else
r = setsockopt (socket_fd, protoent->p_proto, TCP_NODELAY, &opt, sizeof(opt));
#endif
if (r == -1)
{
BX_INFO (("setsockopt(TCP_NODELAY) failed\n"));
}
}
void bx_gdbstub_init(int argc, char* argv[])
{
int portn = bx_options.gdbstub.port;
#ifdef __MINGW32__
WSADATA wsaData;
WSAStartup(2, &wsaData);
#endif
bx_init_hardware();
/* Wait for connect */
printf("Waiting for gdb connection on localhost:%d\n", portn);
wait_for_connect(portn);
/* Do debugger command loop */
debug_loop();
/* CPU loop */
bx_cpu.cpu_loop(-1);
}