Files
86Box/src/gdbstub.c
2022-09-18 17:19:21 -04:00

1815 lines
64 KiB
C

/*
* 86Box A hypervisor and IBM PC system emulator that specializes in
* running old operating systems and software designed for IBM
* PC systems and compatibles from 1981 through fairly recent
* system designs based on the PCI bus.
*
* This file is part of the 86Box distribution.
*
* GDB stub server for remote debugging.
*
*
*
* Authors: RichardG, <richardg867@gmail.com>
*
* Copyright 2022 RichardG.
*/
#include <inttypes.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef _WIN32
# ifndef __clang__
# include <unistd.h>
# else
# include <io.h>
# define ssize_t long
# define strtok_r(a, b, c) strtok_s(a, b, c)
# endif
# include <winsock2.h>
# include <ws2tcpip.h>
#else
# include <unistd.h>
# include <arpa/inet.h>
# include <sys/socket.h>
# include <errno.h>
#endif
#define HAVE_STDARG_H
#include <86box/86box.h>
#include "cpu.h"
#include "x86seg.h"
#include "x87.h"
#include "x87_ops_conv.h"
#include <86box/io.h>
#include <86box/mem.h>
#include <86box/plat.h>
#include <86box/thread.h>
#include <86box/gdbstub.h>
#define FAST_RESPONSE(s) \
strcpy(client->response, s); \
client->response_pos = sizeof(s) - 1;
#define FAST_RESPONSE_HEX(s) gdbstub_client_respond_hex(client, (uint8_t *) s, sizeof(s));
enum {
GDB_SIGINT = 2,
GDB_SIGTRAP = 5
};
enum {
GDB_REG_EAX = 0,
GDB_REG_ECX,
GDB_REG_EDX,
GDB_REG_EBX,
GDB_REG_ESP,
GDB_REG_EBP,
GDB_REG_ESI,
GDB_REG_EDI,
GDB_REG_EIP,
GDB_REG_EFLAGS,
GDB_REG_CS,
GDB_REG_SS,
GDB_REG_DS,
GDB_REG_ES,
GDB_REG_FS,
GDB_REG_GS,
GDB_REG_FS_BASE,
GDB_REG_GS_BASE,
GDB_REG_CR0,
GDB_REG_CR2,
GDB_REG_CR3,
GDB_REG_CR4,
GDB_REG_EFER,
GDB_REG_ST0,
GDB_REG_ST1,
GDB_REG_ST2,
GDB_REG_ST3,
GDB_REG_ST4,
GDB_REG_ST5,
GDB_REG_ST6,
GDB_REG_ST7,
GDB_REG_FCTRL,
GDB_REG_FSTAT,
GDB_REG_FTAG,
GDB_REG_FISEG,
GDB_REG_FIOFF,
GDB_REG_FOSEG,
GDB_REG_FOOFF,
GDB_REG_FOP,
GDB_REG_MM0,
GDB_REG_MM1,
GDB_REG_MM2,
GDB_REG_MM3,
GDB_REG_MM4,
GDB_REG_MM5,
GDB_REG_MM6,
GDB_REG_MM7,
GDB_REG_MAX
};
enum {
GDB_MODE_BASE10 = 0,
GDB_MODE_HEX,
GDB_MODE_OCT,
GDB_MODE_BIN
};
typedef struct _gdbstub_client_ {
int socket;
struct sockaddr_in addr;
char packet[16384], response[16384];
int has_packet : 1, first_packet_received : 1, ida_mode : 1, waiting_stop : 1,
packet_pos, response_pos;
event_t *processed_event, *response_event;
uint16_t last_io_base, last_io_len, last_io_value;
struct _gdbstub_client_ *next;
} gdbstub_client_t;
typedef struct _gdbstub_breakpoint_ {
uint32_t addr;
union {
uint8_t orig_val;
uint32_t end;
};
struct _gdbstub_breakpoint_ *next;
} gdbstub_breakpoint_t;
#ifdef ENABLE_GDBSTUB_LOG
int gdbstub_do_log = ENABLE_GDBSTUB_LOG;
static void
gdbstub_log(const char *fmt, ...)
{
va_list ap;
if (gdbstub_do_log) {
va_start(ap, fmt);
pclog_ex(fmt, ap);
va_end(ap);
}
}
#else
# define gdbstub_log(fmt, ...)
#endif
static x86seg *segment_regs[] = { &cpu_state.seg_cs, &cpu_state.seg_ss, &cpu_state.seg_ds, &cpu_state.seg_es, &cpu_state.seg_fs, &cpu_state.seg_gs };
static uint32_t *cr_regs[] = { &cpu_state.CR0.l, &cr2, &cr3, &cr4 };
static void *fpu_regs[] = { &cpu_state.npxc, &cpu_state.npxs, NULL, &x87_pc_seg, &x87_pc_off, &x87_op_seg, &x87_op_off };
static char target_xml[] = /* QEMU gdb-xml/i386-32bit.xml with modifications (described in comments) */
// clang-format off
"<?xml version=\"1.0\"?>"
"<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
"<target>"
"<!-- architecture tag goes here -->" /* <architecture> patched in here (length must be kept) */
""
"<feature name=\"org.gnu.gdb.i386.core\">"
"<flags id=\"i386_eflags\" size=\"4\">"
"<field name=\"\" start=\"22\" end=\"31\"/>"
"<field name=\"ID\" start=\"21\" end=\"21\"/>"
"<field name=\"VIP\" start=\"20\" end=\"20\"/>"
"<field name=\"VIF\" start=\"19\" end=\"19\"/>"
"<field name=\"AC\" start=\"18\" end=\"18\"/>"
"<field name=\"VM\" start=\"17\" end=\"17\"/>"
"<field name=\"RF\" start=\"16\" end=\"16\"/>"
"<field name=\"\" start=\"15\" end=\"15\"/>"
"<field name=\"NT\" start=\"14\" end=\"14\"/>"
"<field name=\"IOPL\" start=\"12\" end=\"13\"/>"
"<field name=\"OF\" start=\"11\" end=\"11\"/>"
"<field name=\"DF\" start=\"10\" end=\"10\"/>"
"<field name=\"IF\" start=\"9\" end=\"9\"/>"
"<field name=\"TF\" start=\"8\" end=\"8\"/>"
"<field name=\"SF\" start=\"7\" end=\"7\"/>"
"<field name=\"ZF\" start=\"6\" end=\"6\"/>"
"<field name=\"\" start=\"5\" end=\"5\"/>"
"<field name=\"AF\" start=\"4\" end=\"4\"/>"
"<field name=\"PF\" start=\"2\" end=\"2\"/>"
"<field name=\"\" start=\"1\" end=\"1\"/>"
"<field name=\"CF\" start=\"0\" end=\"0\"/>"
"</flags>"
""
"<reg name=\"eax\" bitsize=\"32\" type=\"int32\" regnum=\"0\"/>"
"<reg name=\"ecx\" bitsize=\"32\" type=\"int32\"/>"
"<reg name=\"edx\" bitsize=\"32\" type=\"int32\"/>"
"<reg name=\"ebx\" bitsize=\"32\" type=\"int32\"/>"
"<reg name=\"esp\" bitsize=\"32\" type=\"data_ptr\"/>"
"<reg name=\"ebp\" bitsize=\"32\" type=\"data_ptr\"/>"
"<reg name=\"esi\" bitsize=\"32\" type=\"int32\"/>"
"<reg name=\"edi\" bitsize=\"32\" type=\"int32\"/>"
""
"<reg name=\"eip\" bitsize=\"32\" type=\"code_ptr\"/>"
"<reg name=\"eflags\" bitsize=\"32\" type=\"i386_eflags\"/>"
""
"<reg name=\"cs\" bitsize=\"16\" type=\"int32\"/>"
"<reg name=\"ss\" bitsize=\"16\" type=\"int32\"/>"
"<reg name=\"ds\" bitsize=\"16\" type=\"int32\"/>"
"<reg name=\"es\" bitsize=\"16\" type=\"int32\"/>"
"<reg name=\"fs\" bitsize=\"16\" type=\"int32\"/>"
"<reg name=\"gs\" bitsize=\"16\" type=\"int32\"/>"
""
"<flags id=\"i386_cr0\" size=\"4\">"
"<field name=\"PG\" start=\"31\" end=\"31\"/>"
"<field name=\"CD\" start=\"30\" end=\"30\"/>"
"<field name=\"NW\" start=\"29\" end=\"29\"/>"
"<field name=\"AM\" start=\"18\" end=\"18\"/>"
"<field name=\"WP\" start=\"16\" end=\"16\"/>"
"<field name=\"NE\" start=\"5\" end=\"5\"/>"
"<field name=\"ET\" start=\"4\" end=\"4\"/>"
"<field name=\"TS\" start=\"3\" end=\"3\"/>"
"<field name=\"EM\" start=\"2\" end=\"2\"/>"
"<field name=\"MP\" start=\"1\" end=\"1\"/>"
"<field name=\"PE\" start=\"0\" end=\"0\"/>"
"</flags>"
""
"<flags id=\"i386_cr3\" size=\"4\">"
"<field name=\"PDBR\" start=\"12\" end=\"31\"/>"
"<field name=\"PCID\" start=\"0\" end=\"11\"/>"
"</flags>"
""
"<flags id=\"i386_cr4\" size=\"4\">"
"<field name=\"VME\" start=\"0\" end=\"0\"/>"
"<field name=\"PVI\" start=\"1\" end=\"1\"/>"
"<field name=\"TSD\" start=\"2\" end=\"2\"/>"
"<field name=\"DE\" start=\"3\" end=\"3\"/>"
"<field name=\"PSE\" start=\"4\" end=\"4\"/>"
"<field name=\"PAE\" start=\"5\" end=\"5\"/>"
"<field name=\"MCE\" start=\"6\" end=\"6\"/>"
"<field name=\"PGE\" start=\"7\" end=\"7\"/>"
"<field name=\"PCE\" start=\"8\" end=\"8\"/>"
"<field name=\"OSFXSR\" start=\"9\" end=\"9\"/>"
"<field name=\"OSXMMEXCPT\" start=\"10\" end=\"10\"/>"
"<field name=\"UMIP\" start=\"11\" end=\"11\"/>"
"<field name=\"LA57\" start=\"12\" end=\"12\"/>"
"<field name=\"VMXE\" start=\"13\" end=\"13\"/>"
"<field name=\"SMXE\" start=\"14\" end=\"14\"/>"
"<field name=\"FSGSBASE\" start=\"16\" end=\"16\"/>"
"<field name=\"PCIDE\" start=\"17\" end=\"17\"/>"
"<field name=\"OSXSAVE\" start=\"18\" end=\"18\"/>"
"<field name=\"SMEP\" start=\"20\" end=\"20\"/>"
"<field name=\"SMAP\" start=\"21\" end=\"21\"/>"
"<field name=\"PKE\" start=\"22\" end=\"22\"/>"
"</flags>"
""
"<flags id=\"i386_efer\" size=\"4\">"
"<field name=\"TCE\" start=\"15\" end=\"15\"/>"
"<field name=\"FFXSR\" start=\"14\" end=\"14\"/>"
"<field name=\"LMSLE\" start=\"13\" end=\"13\"/>"
"<field name=\"SVME\" start=\"12\" end=\"12\"/>"
"<field name=\"NXE\" start=\"11\" end=\"11\"/>"
"<field name=\"LMA\" start=\"10\" end=\"10\"/>"
"<field name=\"LME\" start=\"8\" end=\"8\"/>"
"<field name=\"SCE\" start=\"0\" end=\"0\"/>"
"</flags>"
""
"<reg name=\"cr0\" bitsize=\"32\" type=\"i386_cr0\"/>"
"<reg name=\"cr2\" bitsize=\"32\" type=\"int32\"/>"
"<reg name=\"cr3\" bitsize=\"32\" type=\"i386_cr3\"/>"
"<reg name=\"cr4\" bitsize=\"32\" type=\"i386_cr4\"/>"
"<reg name=\"efer\" bitsize=\"64\" type=\"i386_efer\"/>"
""
"<reg name=\"st0\" bitsize=\"80\" type=\"i387_ext\"/>"
"<reg name=\"st1\" bitsize=\"80\" type=\"i387_ext\"/>"
"<reg name=\"st2\" bitsize=\"80\" type=\"i387_ext\"/>"
"<reg name=\"st3\" bitsize=\"80\" type=\"i387_ext\"/>"
"<reg name=\"st4\" bitsize=\"80\" type=\"i387_ext\"/>"
"<reg name=\"st5\" bitsize=\"80\" type=\"i387_ext\"/>"
"<reg name=\"st6\" bitsize=\"80\" type=\"i387_ext\"/>"
"<reg name=\"st7\" bitsize=\"80\" type=\"i387_ext\"/>"
""
"<reg name=\"fctrl\" bitsize=\"16\" type=\"int\" group=\"float\"/>"
"<reg name=\"fstat\" bitsize=\"16\" type=\"int\" group=\"float\"/>"
"<reg name=\"ftag\" bitsize=\"16\" type=\"int\" group=\"float\"/>"
"<reg name=\"fiseg\" bitsize=\"16\" type=\"int\" group=\"float\"/>"
"<reg name=\"fioff\" bitsize=\"32\" type=\"int\" group=\"float\"/>"
"<reg name=\"foseg\" bitsize=\"16\" type=\"int\" group=\"float\"/>"
"<reg name=\"fooff\" bitsize=\"32\" type=\"int\" group=\"float\"/>"
"<reg name=\"fop\" bitsize=\"16\" type=\"int\" group=\"float\"/>"
""
"<vector id=\"v8i8\" type=\"int8\" count=\"8\"/>"
"<vector id=\"v8u8\" type=\"uint8\" count=\"8\"/>"
"<vector id=\"v4i16\" type=\"int16\" count=\"4\"/>"
"<vector id=\"v4u16\" type=\"uint16\" count=\"4\"/>"
"<vector id=\"v2i32\" type=\"int32\" count=\"2\"/>"
"<vector id=\"v2u32\" type=\"uint32\" count=\"2\"/>"
"<union id=\"mmx\">"
"<field name=\"uint64\" type=\"uint64\"/>"
"<field name=\"v2_int32\" type=\"v2i32\"/>"
"<field name=\"v4_int16\" type=\"v4i16\"/>"
"<field name=\"v8_int8\" type=\"v8i8\"/>"
"</union>"
""
"<reg name=\"mm0\" bitsize=\"64\" type=\"mmx\" group=\"mmx\"/>"
"<reg name=\"mm1\" bitsize=\"64\" type=\"mmx\" group=\"mmx\"/>"
"<reg name=\"mm2\" bitsize=\"64\" type=\"mmx\" group=\"mmx\"/>"
"<reg name=\"mm3\" bitsize=\"64\" type=\"mmx\" group=\"mmx\"/>"
"<reg name=\"mm4\" bitsize=\"64\" type=\"mmx\" group=\"mmx\"/>"
"<reg name=\"mm5\" bitsize=\"64\" type=\"mmx\" group=\"mmx\"/>"
"<reg name=\"mm6\" bitsize=\"64\" type=\"mmx\" group=\"mmx\"/>"
"<reg name=\"mm7\" bitsize=\"64\" type=\"mmx\" group=\"mmx\"/>"
"</feature>"
"</target>";
// clang-format on
#ifdef _WIN32
static WSADATA wsa;
#endif
static int gdbstub_socket = -1, stop_reason_len = 0, in_gdbstub = 0;
static uint32_t watch_addr;
static char stop_reason[2048];
static gdbstub_client_t *first_client = NULL, *last_client = NULL;
static mutex_t *client_list_mutex;
static void (*cpu_exec_shadow)(int cycs);
static gdbstub_breakpoint_t *first_swbreak = NULL, *first_hwbreak = NULL,
*first_rwatch = NULL, *first_wwatch = NULL, *first_awatch = NULL;
int gdbstub_step = 0, gdbstub_next_asap = 0;
uint64_t gdbstub_watch_pages[(((uint32_t) -1) >> (MEM_GRANULARITY_BITS + 6)) + 1];
static void
gdbstub_break()
{
/* Pause CPU execution as soon as possible. */
if (gdbstub_step <= GDBSTUB_EXEC)
gdbstub_step = GDBSTUB_BREAK;
}
static void
gdbstub_jump(uint32_t new_pc)
{
/* Nasty hack; qemu always uses the full 32-bit EIP internally... */
if (cpu_state.op32 || ((new_pc >= cs) && (new_pc < (cs + 65536)))) {
cpu_state.pc = new_pc - cs;
} else {
loadseg((new_pc >> 4) & 0xf000, &cpu_state.seg_cs);
cpu_state.pc = new_pc & 0xffff;
}
flushmmucache();
}
static inline int
gdbstub_hex_decode(int c)
{
if ((c >= '0') && (c <= '9'))
return c - '0';
else if ((c >= 'A') && (c <= 'F'))
return c - 'A' + 10;
else if ((c >= 'a') && (c <= 'f'))
return c - 'a' + 10;
else
return 0;
}
static inline int
gdbstub_hex_encode(int c)
{
if (c < 10)
return c + '0';
else
return c - 10 + 'a';
}
static int
gdbstub_num_decode(char *p, int *dest, int mode)
{
/* Stop if the pointer is invalid. */
if (!p)
return 0;
/* Read sign. */
int sign = 1;
if ((p[0] == '+') || (p[0] == '-')) {
if (p[0] == '-')
sign = -1;
p++;
}
/* Read type identifer if present (0x/0o/0b/0n) */
if (p[0] == '0') {
switch (p[1]) {
case 'x':
mode = GDB_MODE_HEX;
break;
case '0' ... '7':
p -= 1;
/* fall-through */
case 'o':
mode = GDB_MODE_OCT;
break;
case 'b':
mode = GDB_MODE_BIN;
break;
case 'n':
mode = GDB_MODE_BASE10;
break;
default:
p -= 2;
break;
}
p += 2;
}
/* Parse each character. */
*dest = 0;
while (*p) {
switch (mode) {
case GDB_MODE_BASE10:
if ((*p >= '0') && (*p <= '9'))
*dest = ((*dest) * 10) + ((*p) - '0');
else
return 0;
break;
case GDB_MODE_HEX:
if (((*p >= '0') && (*p <= '9')) || ((*p >= 'A') && (*p <= 'F')) || ((*p >= 'a') && (*p <= 'f')))
*dest = ((*dest) << 4) | gdbstub_hex_decode(*p);
else
return 0;
break;
case GDB_MODE_OCT:
if ((*p >= '0') && (*p <= '7'))
*dest = ((*dest) << 3) | ((*p) - '0');
else
return 0;
break;
case GDB_MODE_BIN:
if ((*p == '0') || (*p == '1'))
*dest = ((*dest) << 1) | ((*p) - '0');
else
return 0;
break;
}
p++;
}
/* Apply sign. */
if (sign < 0)
*dest = -(*dest);
/* Return success. */
return 1;
}
static int
gdbstub_client_read_word(gdbstub_client_t *client, int *dest)
{
char *p = &client->packet[client->packet_pos], *q = p;
while (((*p >= '0') && (*p <= '9')) || ((*p >= 'A') && (*p <= 'F')) || ((*p >= 'a') && (*p <= 'f')))
*dest = ((*dest) << 4) | gdbstub_hex_decode(*p++);
return p - q;
}
static int
gdbstub_client_read_hex(gdbstub_client_t *client, uint8_t *buf, int size)
{
int pp = client->packet_pos;
while (size-- && (pp < (sizeof(client->packet) - 2))) {
*buf = gdbstub_hex_decode(client->packet[pp++]) << 4;
*buf++ |= gdbstub_hex_decode(client->packet[pp++]);
}
return pp - client->packet_pos;
}
static int
gdbstub_client_read_string(gdbstub_client_t *client, char *buf, int size, char terminator)
{
int pp = client->packet_pos;
char c;
while (size-- && (pp < (sizeof(client->packet) - 1))) {
c = client->packet[pp];
if ((c == terminator) || (c == '\0')) {
*buf = '\0';
break;
}
pp++;
*buf++ = c;
}
return pp - client->packet_pos;
}
static int
gdbstub_client_write_reg(int index, uint8_t *buf)
{
int width = 4;
switch (index) {
case GDB_REG_EAX ... GDB_REG_EDI:
cpu_state.regs[index - GDB_REG_EAX].l = *((uint32_t *) buf);
break;
case GDB_REG_EIP:
gdbstub_jump(*((uint32_t *) buf));
break;
case GDB_REG_EFLAGS:
cpu_state.flags = *((uint16_t *) &buf[0]);
cpu_state.eflags = *((uint16_t *) &buf[2]);
break;
case GDB_REG_CS ... GDB_REG_GS:
width = 2;
loadseg(*((uint16_t *) buf), segment_regs[index - GDB_REG_CS]);
flushmmucache();
break;
case GDB_REG_FS_BASE ... GDB_REG_GS_BASE:
/* Do what qemu does and just load the base. */
segment_regs[(index - 16) + (GDB_REG_FS - GDB_REG_CS)]->base = *((uint32_t *) buf);
break;
case GDB_REG_CR0 ... GDB_REG_CR4:
*cr_regs[index - GDB_REG_CR0] = *((uint32_t *) buf);
flushmmucache();
break;
case GDB_REG_EFER:
msr.amd_efer = *((uint64_t *) buf);
break;
case GDB_REG_ST0 ... GDB_REG_ST7:
width = 10;
x87_conv_t conv = {
.eind = { .ll = *((uint64_t *) &buf[0]) },
.begin = *((uint16_t *) &buf[8])
};
cpu_state.ST[(cpu_state.TOP + (index - GDB_REG_ST0)) & 7] = x87_from80(&conv);
break;
case GDB_REG_FCTRL:
case GDB_REG_FISEG:
case GDB_REG_FOSEG:
width = 2;
*((uint16_t *) fpu_regs[index - GDB_REG_FCTRL]) = *((uint16_t *) buf);
if (index >= GDB_REG_FISEG)
flushmmucache();
break;
case GDB_REG_FSTAT:
case GDB_REG_FOP:
width = 2;
break;
case GDB_REG_FTAG:
width = 2;
x87_settag(*((uint16_t *) buf));
break;
case GDB_REG_FIOFF:
case GDB_REG_FOOFF:
*((uint32_t *) fpu_regs[index - GDB_REG_FCTRL]) = *((uint32_t *) buf);
break;
case GDB_REG_MM0 ... GDB_REG_MM7:
width = 8;
cpu_state.MM[index - GDB_REG_MM0].q = *((uint64_t *) buf);
break;
default:
width = 0;
}
#ifdef ENABLE_GDBSTUB_LOG
char logbuf[256], *p = logbuf + sprintf(logbuf, "GDB Stub: Setting register %d to ", index);
for (int i = width - 1; i >= 0; i--)
p += sprintf(p, "%02X", buf[i]);
sprintf(p, "\n");
gdbstub_log(logbuf);
#endif
return width;
}
static void
gdbstub_client_respond(gdbstub_client_t *client)
{
/* Calculate checksum. */
int checksum = 0, i;
for (i = 0; i < client->response_pos; i++)
checksum += client->response[i];
/* Send response packet. */
client->response[client->response_pos] = '\0';
#ifdef ENABLE_GDBSTUB_LOG
i = client->response[995]; /* pclog_ex buffer too small */
client->response[995] = '\0';
gdbstub_log("GDB Stub: Sending response: %s\n", client->response);
client->response[995] = i;
#endif
send(client->socket, "$", 1, 0);
send(client->socket, client->response, client->response_pos, 0);
char response_cksum[3] = { '#', gdbstub_hex_encode((checksum >> 4) & 0x0f), gdbstub_hex_encode(checksum & 0x0f) };
send(client->socket, response_cksum, sizeof(response_cksum), 0);
}
static void
gdbstub_client_respond_partial(gdbstub_client_t *client)
{
/* Send response. */
gdbstub_client_respond(client);
/* Wait for the response to be acknowledged. */
thread_wait_event(client->response_event, -1);
thread_reset_event(client->response_event);
}
static void
gdbstub_client_respond_hex(gdbstub_client_t *client, uint8_t *buf, int size)
{
while (size-- && (client->response_pos < (sizeof(client->response) - 2))) {
client->response[client->response_pos++] = gdbstub_hex_encode((*buf) >> 4);
client->response[client->response_pos++] = gdbstub_hex_encode((*buf++) & 0x0f);
}
}
static int
gdbstub_client_read_reg(int index, uint8_t *buf)
{
int width = 4;
switch (index) {
case GDB_REG_EAX ... GDB_REG_EDI:
*((uint32_t *) buf) = cpu_state.regs[index].l;
break;
case GDB_REG_EIP:
*((uint32_t *) buf) = cs + cpu_state.pc;
break;
case GDB_REG_EFLAGS:
*((uint16_t *) &buf[0]) = cpu_state.flags;
*((uint16_t *) &buf[2]) = cpu_state.eflags;
break;
case GDB_REG_CS ... GDB_REG_GS:
*((uint16_t *) buf) = segment_regs[index - GDB_REG_CS]->seg;
break;
case GDB_REG_FS_BASE ... GDB_REG_GS_BASE:
*((uint32_t *) buf) = segment_regs[(index - 16) + (GDB_REG_FS - GDB_REG_CS)]->base;
break;
case GDB_REG_CR0 ... GDB_REG_CR4:
*((uint32_t *) buf) = *cr_regs[index - GDB_REG_CR0];
break;
case GDB_REG_EFER:
*((uint64_t *) buf) = msr.amd_efer;
break;
case GDB_REG_ST0 ... GDB_REG_ST7:
width = 10;
x87_conv_t conv;
x87_to80(cpu_state.ST[(cpu_state.TOP + (index - GDB_REG_ST0)) & 7], &conv);
*((uint64_t *) &buf[0]) = conv.eind.ll;
*((uint16_t *) &buf[8]) = conv.begin;
break;
case GDB_REG_FCTRL ... GDB_REG_FSTAT:
case GDB_REG_FISEG:
case GDB_REG_FOSEG:
width = 2;
*((uint16_t *) buf) = *((uint16_t *) fpu_regs[index - GDB_REG_FCTRL]);
break;
case GDB_REG_FTAG:
width = 2;
*((uint16_t *) buf) = x87_gettag();
break;
case GDB_REG_FIOFF:
case GDB_REG_FOOFF:
*((uint32_t *) buf) = *((uint32_t *) fpu_regs[index - GDB_REG_FCTRL]);
break;
case GDB_REG_FOP:
width = 2;
*((uint16_t *) buf) = 0; /* we don't store the FPU opcode */
break;
case GDB_REG_MM0 ... GDB_REG_MM7:
width = 8;
*((uint64_t *) buf) = cpu_state.MM[index - GDB_REG_MM0].q;
break;
default:
width = 0;
}
return width;
}
static void
gdbstub_client_packet(gdbstub_client_t *client)
{
gdbstub_breakpoint_t *breakpoint, *prev_breakpoint = NULL, **first_breakpoint = NULL;
#ifdef GDBSTUB_CHECK_CHECKSUM /* msys2 gdb 11.1 transmits qSupported and H with invalid checksum... */
uint8_t rcv_checksum = 0, checksum = 0;
#endif
int i, j = 0, k = 0, l;
uint8_t buf[10] = { 0 };
char *p;
/* Validate checksum. */
client->packet_pos -= 2;
#ifdef GDBSTUB_CHECK_CHECKSUM
gdbstub_client_read_hex(client, &rcv_checksum, 1);
#endif
*((uint16_t *) &client->packet[--client->packet_pos]) = 0;
#ifdef GDBSTUB_CHECK_CHECKSUM
for (i = 0; i < client->packet_pos; i++)
checksum += client->packet[i];
if (checksum != rcv_checksum) {
/* Send negative acknowledgement. */
# ifdef ENABLE_GDBSTUB_LOG
i = client->packet[953]; /* pclog_ex buffer too small */
client->packet[953] = '\0';
gdbstub_log("GDB Stub: Received packet with invalid checksum (expected %02X got %02X): %s\n", checksum, rcv_checksum, client->packet);
client->packet[953] = i;
# endif
send(client->socket, "-", 1, 0);
return;
}
#endif
/* Send positive acknowledgement. */
#ifdef ENABLE_GDBSTUB_LOG
i = client->packet[996]; /* pclog_ex buffer too small */
client->packet[996] = '\0';
gdbstub_log("GDB Stub: Received packet: %s\n", client->packet);
client->packet[996] = i;
#endif
send(client->socket, "+", 1, 0);
/* Block other responses from being written while this one (if any is produced) isn't acknowledged. */
if ((client->packet[0] != 'c') && (client->packet[0] != 's') && (client->packet[0] != 'v')) {
thread_wait_event(client->response_event, -1);
thread_reset_event(client->response_event);
}
client->response_pos = 0;
client->packet_pos = 1;
/* Handle IDA-specific hacks. */
if (!client->first_packet_received) {
client->first_packet_received = 1;
if (!strcmp(client->packet, "qSupported:xmlRegisters=i386,arm,mips")) {
gdbstub_log("GDB Stub: Enabling IDA mode\n");
client->ida_mode = 1;
}
}
/* Parse command. */
switch (client->packet[0]) {
case '?': /* stop reason */
/* Respond with a stop reply packet if one is present. */
if (stop_reason_len) {
strcpy(client->response, stop_reason);
client->response_pos = strlen(client->response);
}
break;
case 'c': /* continue */
case 's': /* step */
/* Flag that the client is waiting for a stop reason. */
client->waiting_stop = 1;
/* Jump to address if specified. */
if (client->packet[1] && gdbstub_client_read_word(client, &j))
gdbstub_jump(j);
/* Resume CPU. */
gdbstub_step = gdbstub_next_asap = (client->packet[0] == 's') ? GDBSTUB_SSTEP : GDBSTUB_EXEC;
return;
case 'D': /* detach */
/* Resume emulation. */
gdbstub_step = GDBSTUB_EXEC;
/* Respond positively. */
ok:
FAST_RESPONSE("OK");
break;
case 'g': /* read all registers */
/* Output the values of all registers. */
for (i = 0; i < GDB_REG_MAX; i++)
gdbstub_client_respond_hex(client, buf, gdbstub_client_read_reg(i, buf));
break;
case 'G': /* write all registers */
/* Write the values of all registers. */
for (i = 0; i < GDB_REG_MAX; i++) {
if (i == GDB_REG_MAX)
goto e22;
if (!gdbstub_client_read_hex(client, buf, sizeof(buf)))
break;
client->packet_pos += gdbstub_client_write_reg(i, buf) << 1;
}
/* Respond positively. */
goto ok;
case 'H': /* set thread */
/* Read operation type and thread ID. */
if ((client->packet[1] == '\0') || (client->packet[2] == '\0')) {
e22:
FAST_RESPONSE("E22");
break;
}
/* Respond positively only on thread 1. */
if ((client->packet[2] == '1') && !client->packet[3])
goto ok;
else
goto e22;
case 'm': /* read memory */
/* Read address and length. */
if (!(i = gdbstub_client_read_word(client, &j)))
goto e22;
client->packet_pos += i + 1;
gdbstub_client_read_word(client, &k);
if (!k)
goto e22;
/* Clamp length. */
if (k >= (sizeof(client->response) >> 1))
k = (sizeof(client->response) >> 1) - 1;
/* Read by qwords, then by dwords, then by words, then by bytes. */
i = 0;
if (is386) {
for (; i < (k & ~7); i += 8) {
*((uint64_t *) buf) = readmemql(j);
j += 8;
gdbstub_client_respond_hex(client, buf, 8);
}
for (; i < (k & ~3); i += 4) {
*((uint32_t *) buf) = readmemll(j);
j += 4;
gdbstub_client_respond_hex(client, buf, 4);
}
}
for (; i < (k & ~1); i += 2) {
*((uint16_t *) buf) = readmemwl(j);
j += 2;
gdbstub_client_respond_hex(client, buf, 2);
}
for (; i < k; i++) {
buf[0] = readmembl(j++);
gdbstub_client_respond_hex(client, buf, 1);
}
break;
case 'M': /* write memory */
case 'X': /* write memory binary */
/* Read address and length. */
if (!(i = gdbstub_client_read_word(client, &j)))
goto e22;
client->packet_pos += i + 1;
client->packet_pos += gdbstub_client_read_word(client, &k) + 1;
if (!k)
goto e22;
/* Clamp length. */
if (k >= ((sizeof(client->response) >> 1) - client->packet_pos))
k = (sizeof(client->response) >> 1) - client->packet_pos - 1;
/* Decode the data. */
if (client->packet[0] == 'M') { /* hex encoded */
gdbstub_client_read_hex(client, (uint8_t *) client->packet, k);
} else { /* binary encoded */
i = 0;
while (i < k) {
if (client->packet[client->packet_pos] == '}') {
client->packet_pos++;
client->packet[i++] = client->packet[client->packet_pos++] ^ 0x20;
} else {
client->packet[i++] = client->packet[client->packet_pos++];
}
}
}
/* Write by qwords, then by dwords, then by words, then by bytes. */
p = client->packet;
i = 0;
if (is386) {
for (; i < (k & ~7); i += 8) {
writememql(j, *((uint64_t *) p));
j += 8;
p += 8;
}
for (; i < (k & ~3); i += 4) {
writememll(j, *((uint32_t *) p));
j += 4;
p += 4;
}
}
for (; i < (k & ~1); i += 2) {
writememwl(j, *((uint16_t *) p));
j += 2;
p += 2;
}
for (; i < k; i++) {
writemembl(j++, p[0]);
p++;
}
/* Respond positively. */
goto ok;
case 'p': /* read register */
/* Read register index. */
if (!gdbstub_client_read_word(client, &j)) {
e14:
FAST_RESPONSE("E14");
break;
}
/* Read the register's value. */
if (!(i = gdbstub_client_read_reg(j, buf)))
goto e14;
/* Return value. */
gdbstub_client_respond_hex(client, buf, i);
break;
case 'P': /* write register */
/* Read register index and value. */
if (!(i = gdbstub_client_read_word(client, &j)))
goto e14;
client->packet_pos += i + 1;
if (!gdbstub_client_read_hex(client, buf, sizeof(buf)))
goto e14;
/* Write the value to the register. */
if (!gdbstub_client_write_reg(j, buf))
goto e14;
/* Respond positively. */
goto ok;
case 'q': /* query */
/* Erase response, as we'll use it as a scratch buffer. */
memset(client->response, 0, sizeof(client->response));
/* Read the query type. */
client->packet_pos += gdbstub_client_read_string(client, client->response, sizeof(client->response) - 1,
(client->packet[1] == 'R') ? ',' : ':')
+ 1;
/* Perform the query. */
if (!strcmp(client->response, "Supported")) {
/* Go through the feature list and negate ones we don't support. */
while ((client->response_pos < (sizeof(client->response) - 1)) && (i = gdbstub_client_read_string(client, &client->response[client->response_pos], sizeof(client->response) - client->response_pos - 1, ';'))) {
client->packet_pos += i + 1;
if (strncmp(&client->response[client->response_pos], "PacketSize", 10) && strcmp(&client->response[client->response_pos], "swbreak") && strcmp(&client->response[client->response_pos], "hwbreak") && strncmp(&client->response[client->response_pos], "xmlRegisters", 12) && strcmp(&client->response[client->response_pos], "qXfer:features:read")) {
gdbstub_log("GDB Stub: Feature \"%s\" is not supported\n", &client->response[client->response_pos]);
client->response_pos += i;
client->response[client->response_pos++] = '-';
client->response[client->response_pos++] = ';';
} else {
gdbstub_log("GDB Stub: Feature \"%s\" is supported\n", &client->response[client->response_pos]);
}
}
/* Add our supported features to the end. */
if (client->response_pos < (sizeof(client->response) - 1))
client->response_pos += snprintf(&client->response[client->response_pos], sizeof(client->response) - client->response_pos,
"PacketSize=%lX;swbreak+;hwbreak+;qXfer:features:read+", sizeof(client->packet) - 1);
break;
} else if (!strcmp(client->response, "Xfer")) {
/* Read the transfer object. */
client->packet_pos += gdbstub_client_read_string(client, client->response, sizeof(client->response) - 1, ':') + 1;
if (!strcmp(client->response, "features")) {
/* Read the transfer operation. */
client->packet_pos += gdbstub_client_read_string(client, client->response, sizeof(client->response) - 1, ':') + 1;
if (!strcmp(client->response, "read")) {
/* Read the transfer annex. */
client->packet_pos += gdbstub_client_read_string(client, client->response, sizeof(client->response) - 1, ':') + 1;
if (!strcmp(client->response, "target.xml")) {
/* Patch architecture for IDA. */
p = strstr(target_xml, "<!-- architecture tag goes here -->");
if (p) {
if (client->ida_mode)
memcpy(p, "<architecture>i386</architecture> ", 35); /* make IDA not complain about i8086 being unknown */
else
memcpy(p, "<architecture>i8086</architecture> ", 35); /* start in 16-bit mode to work around known GDB bug preventing 32->16 switching */
}
/* Send target XML. */
p = target_xml;
} else {
p = NULL;
}
/* Stop if the file wasn't found. */
if (!p) {
e00:
FAST_RESPONSE("E00");
break;
}
/* Read offset and length. */
if (!(i = gdbstub_client_read_word(client, &j)))
goto e22;
client->packet_pos += i + 1;
client->packet_pos += gdbstub_client_read_word(client, &k) + 1;
if (!k)
goto e22;
/* Check if the offset is valid. */
l = strlen(p);
if (j > l)
goto e00;
p += j;
/* Return the more/less flag while also clamping the length. */
if (k >= ((sizeof(client->response) >> 1) - 2))
k = (sizeof(client->response) >> 1) - 3;
if (k < (l - j)) {
client->response[client->response_pos++] = 'm';
} else {
client->response[client->response_pos++] = 'l';
k = l - j;
}
/* Encode the data. */
while (k--) {
i = *p++;
if ((i == '\0') || (i == '#') || (i == '$') || (i == '*') || (i == '}')) {
client->response[client->response_pos++] = '}';
client->response[client->response_pos++] = i ^ 0x20;
} else {
client->response[client->response_pos++] = i;
}
}
break;
}
}
} else if (!strncmp(client->response, "Attached", 8)) {
FAST_RESPONSE("1");
} else if (!strcmp(client->response, "C")) {
FAST_RESPONSE("QC1");
} else if (!strcmp(client->response, "fThreadInfo")) {
FAST_RESPONSE("m 1");
} else if (!strcmp(client->response, "sThreadInfo")) {
FAST_RESPONSE("l");
} else if (!strcmp(client->response, "Rcmd")) {
/* Read and decode command in-place. */
i = gdbstub_client_read_hex(client, (uint8_t *) client->packet, strlen(client->packet) - client->packet_pos);
client->packet[i] = 0;
gdbstub_log("GDB Stub: Monitor command: %s\n", client->packet);
/* Parse the command name. */
char *strtok_save;
p = strtok_r(client->packet, " ", &strtok_save);
if (!p)
goto ok;
i = strlen(p) - 1; /* get last character offset */
/* Interpret the command. */
if (p[0] == 'i') {
/* Read I/O operation width. */
l = (i < 1) ? '\0' : p[i];
/* Read optional I/O port. */
if (!(p = strtok_r(NULL, " ", &strtok_save)) || !gdbstub_num_decode(p, &j, GDB_MODE_HEX) || (j < 0) || (j >= 65536))
j = client->last_io_base;
else
client->last_io_base = j;
/* Read optional length. */
if (!(p = strtok_r(NULL, " ", &strtok_save)) || !gdbstub_num_decode(p, &k, GDB_MODE_BASE10))
k = client->last_io_len;
else
client->last_io_len = k;
/* Clamp length. */
if (k < 1)
k = 1;
if (k > (65536 - j))
k = 65536 - j;
/* Read ports. */
i = 0;
while (i < k) {
if ((i % 16) == 0) {
if (i) {
client->packet[client->packet_pos++] = '\n';
/* Provide partial response with the last line. */
client->response_pos = 0;
client->response[client->response_pos++] = 'O';
gdbstub_client_respond_hex(client, (uint8_t *) client->packet, client->packet_pos);
gdbstub_client_respond_partial(client);
}
client->packet_pos = sprintf(client->packet, "%04X:", j + i);
}
/* Act according to I/O operation width. */
switch (l) {
case 'd':
case 'l':
client->packet_pos += sprintf(&client->packet[client->packet_pos], " %08X", inl(j + i));
i += 4;
break;
case 'w':
client->packet_pos += sprintf(&client->packet[client->packet_pos], " %04X", inw(j + i));
i += 2;
break;
case 'b':
case '\0':
client->packet_pos += sprintf(&client->packet[client->packet_pos], " %02X", inb(j + i));
i++;
break;
default:
goto unknown;
}
}
client->packet[client->packet_pos++] = '\n';
/* Respond with the final line. */
client->response_pos = 0;
gdbstub_client_respond_hex(client, (uint8_t *) &client->packet, client->packet_pos);
break;
} else if (p[0] == 'o') {
/* Read I/O operation width. */
l = (i < 1) ? '\0' : p[i];
/* Read optional I/O port. */
if (!(p = strtok_r(NULL, " ", &strtok_save)) || !gdbstub_num_decode(p, &j, GDB_MODE_HEX) || (j < 0) || (j >= 65536))
j = -1;
/* Read optional value. */
if (!(p = strtok_r(NULL, " ", &strtok_save)) || !gdbstub_num_decode(p, &k, GDB_MODE_HEX)) {
if (j == -1)
k = client->last_io_value;
else
k = j; /* only one specified = treat as value on last port */
j = -1;
}
if (j == -1)
j = client->last_io_base;
else
client->last_io_base = j;
client->last_io_value = k;
/* Write port. */
switch (l) {
case 'd':
case 'l':
outl(j, k);
break;
case 'w':
outw(j, k);
break;
case 'b':
case 't':
case '\0':
outb(j, k);
break;
default:
goto unknown;
}
} else if (p[0] == 'r') {
pc_reset_hard();
} else if ((p[0] == '?') || !strcmp(p, "help")) {
FAST_RESPONSE_HEX(
"Commands:\n"
"- ib/iw/il [port [length]] - Read {length} (default 1) I/O ports starting from {port} (default last)\n"
"- ob/ow/ol [[port] value] - Write {value} to I/O {port} (both default last)\n"
"- r - Hard reset the emulated machine\n");
break;
} else {
unknown:
FAST_RESPONSE_HEX("Unknown command\n");
break;
}
goto ok;
}
break;
case 'z': /* remove break/watchpoint */
case 'Z': /* insert break/watchpoint */
/* Parse breakpoint type. */
switch (client->packet[1]) {
case '0': /* software breakpoint */
first_breakpoint = &first_swbreak;
break;
case '1': /* hardware breakpoint */
first_breakpoint = &first_hwbreak;
break;
case '2': /* write watchpoint */
first_breakpoint = &first_wwatch;
break;
case '3': /* read watchpoint */
first_breakpoint = &first_rwatch;
break;
case '4': /* access watchpoint */
first_breakpoint = &first_awatch;
break;
default: /* unknown type */
client->packet[2] = '\0'; /* force address check to fail */
break;
}
/* Read address. */
if (client->packet[2] != ',')
break;
client->packet_pos = 3;
if (!(i = gdbstub_client_read_word(client, &j)))
break;
client->packet_pos += i;
if (client->packet[client->packet_pos++] == ',')
gdbstub_client_read_word(client, &k);
else
k = 1;
/* Test writability of software breakpoint. */
if (client->packet[1] == '0') {
buf[0] = readmembl(j);
writemembl(j, 0xcc);
buf[1] = readmembl(j);
writemembl(j, buf[0]);
if (buf[1] != 0xcc)
goto end;
}
/* Find an existing breakpoint with this address. */
breakpoint = *first_breakpoint;
while (breakpoint) {
if (breakpoint->addr == j)
break;
prev_breakpoint = breakpoint;
breakpoint = breakpoint->next;
}
/* Check if the breakpoint is already present (when inserting) or not found (when removing). */
if ((!!breakpoint) ^ (client->packet[0] == 'z'))
goto e22;
/* Insert or remove the breakpoint. */
if (client->packet[0] != 'z') {
/* Allocate a new breakpoint. */
breakpoint = malloc(sizeof(gdbstub_breakpoint_t));
breakpoint->addr = j;
breakpoint->end = j + k;
breakpoint->next = NULL;
/* Add the new breakpoint to the list. */
if (!(*first_breakpoint))
*first_breakpoint = breakpoint;
else if (prev_breakpoint)
prev_breakpoint->next = breakpoint;
} else {
/* Remove breakpoint from the list. */
if (breakpoint == *first_breakpoint)
*first_breakpoint = breakpoint->next;
else if (prev_breakpoint)
prev_breakpoint->next = breakpoint->next;
/* De-allocate breakpoint. */
free(breakpoint);
}
/* Update the page watchpoint map if we're dealing with a watchpoint. */
if (client->packet[1] >= '2') {
/* Clear this watchpoint's corresponding page map groups,
as everything is going to be recomputed soon anyway. */
memset(&gdbstub_watch_pages[j >> (MEM_GRANULARITY_BITS + 6)], 0,
(((k - 1) >> (MEM_GRANULARITY_BITS + 6)) + 1) * sizeof(gdbstub_watch_pages[0]));
/* Go through all watchpoint lists. */
l = 0;
breakpoint = first_rwatch;
while (1) {
if (breakpoint) {
/* Flag this watchpoint's corresponding pages as having a watchpoint. */
k = (breakpoint->end - 1) >> MEM_GRANULARITY_BITS;
for (i = breakpoint->addr >> MEM_GRANULARITY_BITS; i <= k; i++)
gdbstub_watch_pages[i >> 6] |= (1 << (i & 63));
breakpoint = breakpoint->next;
} else {
/* Jump from list to list as a shortcut. */
if (l == 0)
breakpoint = first_wwatch;
else if (l == 1)
breakpoint = first_awatch;
else
break;
l++;
}
}
}
/* Respond positively. */
goto ok;
}
end:
/* Send response. */
gdbstub_client_respond(client);
}
static void
gdbstub_cpu_exec(int cycs)
{
/* Flag that we're now in the debugger context to avoid triggering watchpoints. */
in_gdbstub = 1;
/* Handle CPU execution if it isn't paused. */
if (gdbstub_step <= GDBSTUB_SSTEP) {
/* Swap in any software breakpoints. */
gdbstub_breakpoint_t *swbreak = first_swbreak;
while (swbreak) {
/* Swap the INT 3 opcode into the address. */
swbreak->orig_val = readmembl(swbreak->addr);
writemembl(swbreak->addr, 0xcc);
swbreak = swbreak->next;
}
/* Call the original cpu_exec function outside the debugger context. */
if ((gdbstub_step == GDBSTUB_SSTEP) && ((cycles + cycs) <= 0))
cycs += -(cycles + cycs) + 1;
in_gdbstub = 0;
cpu_exec_shadow(cycs);
in_gdbstub = 1;
/* Swap out any software breakpoints. */
swbreak = first_swbreak;
while (swbreak) {
if (readmembl(swbreak->addr) == 0xcc)
writemembl(swbreak->addr, swbreak->orig_val);
swbreak = swbreak->next;
}
}
/* Populate stop reason if we have stopped. */
stop_reason_len = 0;
if (gdbstub_step > GDBSTUB_EXEC) {
/* Assemble stop reason manually, avoiding sprintf and friends for performance. */
stop_reason[stop_reason_len++] = 'T';
stop_reason[stop_reason_len++] = '0';
stop_reason[stop_reason_len++] = '0' + ((gdbstub_step == GDBSTUB_BREAK) ? GDB_SIGINT : GDB_SIGTRAP);
/* Add extended break reason. */
if (gdbstub_step >= GDBSTUB_BREAK_RWATCH) {
if (gdbstub_step != GDBSTUB_BREAK_WWATCH)
stop_reason[stop_reason_len++] = (gdbstub_step == GDBSTUB_BREAK_RWATCH) ? 'r' : 'a';
stop_reason[stop_reason_len++] = 'w';
stop_reason[stop_reason_len++] = 'a';
stop_reason[stop_reason_len++] = 't';
stop_reason[stop_reason_len++] = 'c';
stop_reason[stop_reason_len++] = 'h';
stop_reason[stop_reason_len++] = ':';
stop_reason_len += sprintf(&stop_reason[stop_reason_len], "%X;", watch_addr);
} else if (gdbstub_step >= GDBSTUB_BREAK_SW) {
stop_reason[stop_reason_len++] = (gdbstub_step == GDBSTUB_BREAK_SW) ? 's' : 'h';
stop_reason[stop_reason_len++] = 'w';
stop_reason[stop_reason_len++] = 'b';
stop_reason[stop_reason_len++] = 'r';
stop_reason[stop_reason_len++] = 'e';
stop_reason[stop_reason_len++] = 'a';
stop_reason[stop_reason_len++] = 'k';
stop_reason[stop_reason_len++] = ':';
stop_reason[stop_reason_len++] = ';';
}
/* Add register dump. */
uint8_t buf[10] = { 0 };
int i, j, k;
for (i = 0; i < GDB_REG_MAX; i++) {
if (i >= 0x10)
stop_reason[stop_reason_len++] = gdbstub_hex_encode(i >> 4);
stop_reason[stop_reason_len++] = gdbstub_hex_encode(i & 0x0f);
stop_reason[stop_reason_len++] = ':';
j = gdbstub_client_read_reg(i, buf);
for (k = 0; k < j; k++) {
stop_reason[stop_reason_len++] = gdbstub_hex_encode(buf[k] >> 4);
stop_reason[stop_reason_len++] = gdbstub_hex_encode(buf[k] & 0x0f);
}
stop_reason[stop_reason_len++] = ';';
}
/* Don't execute the CPU any further if single-stepping. */
gdbstub_step = GDBSTUB_BREAK;
}
/* Return the framerate to normal. */
gdbstub_next_asap = 0;
/* Process client packets. */
thread_wait_mutex(client_list_mutex);
gdbstub_client_t *client = first_client;
while (client) {
/* Report stop reason if the client is waiting for one. */
if (client->waiting_stop && stop_reason_len) {
client->waiting_stop = 0;
/* Wait for any pending responses to be acknowledged. */
if (!thread_wait_event(client->response_event, -1)) {
/* Block other responses from being written while this one isn't acknowledged. */
thread_reset_event(client->response_event);
/* Write stop reason response. */
strcpy(client->response, stop_reason);
client->response_pos = stop_reason_len;
gdbstub_client_respond(client);
} else {
gdbstub_log("GDB Stub: Timed out waiting for client %s:%d\n", inet_ntoa(client->addr.sin_addr), client->addr.sin_port);
}
}
if (client->has_packet) {
gdbstub_client_packet(client);
client->has_packet = client->packet_pos = 0;
thread_set_event(client->processed_event);
}
#ifdef GDBSTUB_ALLOW_MULTI_CLIENTS
client = client->next;
#else
break;
#endif
}
thread_release_mutex(client_list_mutex);
/* Flag that we're now out of the debugger context. */
in_gdbstub = 0;
}
static void
gdbstub_client_thread(void *priv)
{
gdbstub_client_t *client = (gdbstub_client_t *) priv;
uint8_t buf[256];
ssize_t bytes_read;
int i;
gdbstub_log("GDB Stub: New connection from %s:%d\n", inet_ntoa(client->addr.sin_addr), client->addr.sin_port);
/* Allow packets to be processed. */
thread_set_event(client->processed_event);
/* Read data from client. */
while ((bytes_read = recv(client->socket, (char *) buf, sizeof(buf), 0)) > 0) {
for (i = 0; i < bytes_read; i++) {
switch (buf[i]) {
case '$': /* packet start */
/* Wait for any existing packets to be processed. */
thread_wait_event(client->processed_event, -1);
client->packet_pos = 0;
break;
case '-': /* negative acknowledgement */
/* Retransmit the current response. */
gdbstub_client_respond(client);
break;
case '+': /* positive acknowledgement */
/* Allow another response to be written. */
thread_set_event(client->response_event);
break;
case 0x03: /* break */
/* Wait for any existing packets to be processed. */
thread_wait_event(client->processed_event, -1);
/* Break immediately. */
gdbstub_log("GDB Stub: Break requested\n");
gdbstub_break();
break;
default:
/* Wait for any existing packets to be processed, just in case. */
thread_wait_event(client->processed_event, -1);
if (client->packet_pos < (sizeof(client->packet) - 1)) {
/* Append byte to the packet. */
client->packet[client->packet_pos++] = buf[i];
/* Check if we're at the end of a packet. */
if ((client->packet_pos >= 3) && (client->packet[client->packet_pos - 3] == '#')) { /* packet checksum start */
/* Small hack to speed up IDA instruction trace mode. */
if (*((uint32_t *) client->packet) == ('H' | ('c' << 8) | ('1' << 16) | ('#' << 24))) {
/* Send pre-computed response. */
send(client->socket, "+$OK#9A", 7, 0);
/* Skip processing. */
continue;
}
/* Flag that a packet should be processed. */
client->packet[client->packet_pos] = '\0';
thread_reset_event(client->processed_event);
gdbstub_next_asap = client->has_packet = 1;
}
}
break;
}
}
}
gdbstub_log("GDB Stub: Connection with %s:%d broken\n", inet_ntoa(client->addr.sin_addr), client->addr.sin_port);
/* Close socket. */
if (client->socket != -1) {
close(client->socket);
client->socket = -1;
}
/* Unblock anyone waiting on the response event. */
thread_set_event(client->response_event);
/* Remove this client from the list. */
thread_wait_mutex(client_list_mutex);
#ifdef GDBSTUB_ALLOW_MULTI_CLIENTS
if (client == first_client) {
#endif
first_client = client->next;
if (first_client == NULL) {
last_client = NULL;
gdbstub_step = GDBSTUB_EXEC; /* unpause CPU when all clients are disconnected */
}
#ifdef GDBSTUB_ALLOW_MULTI_CLIENTS
} else {
other_client = first_client;
while (other_client) {
if (other_client->next == client) {
if (last_client == client)
last_client = other_client;
other_client->next = client->next;
break;
}
other_client = other_client->next;
}
}
#endif
free(client);
thread_release_mutex(client_list_mutex);
}
static void
gdbstub_server_thread(void *priv)
{
/* Listen on GDB socket. */
listen(gdbstub_socket, 1);
/* Accept connections. */
gdbstub_client_t *client;
socklen_t sl = sizeof(struct sockaddr_in);
while (1) {
/* Allocate client structure. */
client = malloc(sizeof(gdbstub_client_t));
memset(client, 0, sizeof(gdbstub_client_t));
client->processed_event = thread_create_event();
client->response_event = thread_create_event();
/* Accept connection. */
client->socket = accept(gdbstub_socket, (struct sockaddr *) &client->addr, &sl);
if (client->socket < 0)
break;
/* Add to client list. */
thread_wait_mutex(client_list_mutex);
if (first_client) {
#ifdef GDBSTUB_ALLOW_MULTI_CLIENTS
last_client->next = client;
last_client = client;
#else
first_client->next = last_client = client;
close(first_client->socket);
#endif
} else {
first_client = last_client = client;
}
thread_release_mutex(client_list_mutex);
/* Pause CPU execution. */
gdbstub_break();
/* Start client thread. */
thread_create(gdbstub_client_thread, client);
}
/* Deallocate the redundant client structure. */
thread_destroy_event(client->processed_event);
thread_destroy_event(client->response_event);
free(client);
}
void
gdbstub_cpu_init()
{
/* Replace cpu_exec with our own function if the GDB stub is active. */
if ((gdbstub_socket != -1) && (cpu_exec != gdbstub_cpu_exec)) {
cpu_exec_shadow = cpu_exec;
cpu_exec = gdbstub_cpu_exec;
}
}
int
gdbstub_instruction()
{
/* Check hardware breakpoints if any are present. */
gdbstub_breakpoint_t *breakpoint = first_hwbreak;
if (breakpoint) {
/* Calculate the current instruction's address. */
uint32_t wanted_addr = cs + cpu_state.pc;
/* Go through the list of software breakpoints. */
do {
/* Check if the breakpoint coincides with this address. */
if (breakpoint->addr == wanted_addr) {
gdbstub_log("GDB Stub: Hardware breakpoint at %08X\n", wanted_addr);
/* Flag that we're in a hardware breakpoint. */
gdbstub_step = GDBSTUB_BREAK_HW;
/* Pause execution. */
return 1;
}
breakpoint = breakpoint->next;
} while (breakpoint);
}
/* No breakpoint found, continue execution or stop if execution is paused. */
return gdbstub_step - GDBSTUB_EXEC;
}
int
gdbstub_int3()
{
/* Check software breakpoints if any are present. */
gdbstub_breakpoint_t *breakpoint = first_swbreak;
if (breakpoint) {
/* Calculate the breakpoint instruction's address. */
uint32_t new_pc = cpu_state.pc - 1;
if (cpu_state.op32)
new_pc &= 0xffff;
uint32_t wanted_addr = cs + new_pc;
/* Go through the list of software breakpoints. */
do {
/* Check if the breakpoint coincides with this address. */
if (breakpoint->addr == wanted_addr) {
gdbstub_log("GDB Stub: Software breakpoint at %08X\n", wanted_addr);
/* Move EIP back to where the break instruction was. */
cpu_state.pc = new_pc;
/* Flag that we're in a software breakpoint. */
gdbstub_step = GDBSTUB_BREAK_SW;
/* Abort INT 3 execution. */
return 1;
}
breakpoint = breakpoint->next;
} while (breakpoint);
}
/* No breakpoint found, continue INT 3 execution as normal. */
return 0;
}
void
gdbstub_mem_access(uint32_t *addrs, int access)
{
/* Stop if we're in the debugger context. */
if (in_gdbstub)
return;
int width = access & (GDBSTUB_MEM_WRITE - 1), i;
/* Go through the lists of watchpoints for this type of access. */
gdbstub_breakpoint_t *watchpoint = (access & GDBSTUB_MEM_WRITE) ? first_wwatch : first_rwatch;
while (1) {
if (watchpoint) {
/* Check if any component of this address is within the breakpoint's range. */
for (i = 0; i < width; i++) {
if ((addrs[i] >= watchpoint->addr) && (addrs[i] < watchpoint->end))
break;
}
if (i < width) {
gdbstub_log("GDB Stub: %s watchpoint at %08X\n", (access & GDBSTUB_MEM_AWATCH) ? "Access" : ((access & GDBSTUB_MEM_WRITE) ? "Write" : "Read"), watch_addr);
/* Flag that we're in a read/write watchpoint. */
gdbstub_step = (access & GDBSTUB_MEM_AWATCH) ? GDBSTUB_BREAK_AWATCH : ((access & GDBSTUB_MEM_WRITE) ? GDBSTUB_BREAK_WWATCH : GDBSTUB_BREAK_RWATCH);
/* Stop looking. */
return;
}
watchpoint = watchpoint->next;
} else {
/* Jump from list to list as a shortcut. */
if (access & GDBSTUB_MEM_AWATCH) {
break;
} else {
watchpoint = first_awatch;
access |= GDBSTUB_MEM_AWATCH;
}
}
}
}
void
gdbstub_init()
{
#ifdef _WIN32
WSAStartup(MAKEWORD(2, 2), &wsa);
#endif
/* Create GDB server socket. */
if ((gdbstub_socket = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
pclog("GDB Stub: Failed to create socket\n");
return;
}
/* Bind GDB server socket. */
int port = 12345;
struct sockaddr_in bind_addr = {
.sin_family = AF_INET,
.sin_addr = { .s_addr = INADDR_ANY },
.sin_port = htons(port)
};
if (bind(gdbstub_socket, (struct sockaddr *) &bind_addr, sizeof(bind_addr)) == -1) {
pclog("GDB Stub: Failed to bind on port %d (%d)\n", port,
#ifdef _WIN32
WSAGetLastError()
#else
errno
#endif
);
gdbstub_socket = -1;
return;
}
/* Create client list mutex. */
client_list_mutex = thread_create_mutex();
/* Clear watchpoint page map. */
memset(gdbstub_watch_pages, 0, sizeof(gdbstub_watch_pages));
/* Start server thread. */
pclog("GDB Stub: Listening on port %d\n", port);
thread_create(gdbstub_server_thread, NULL);
/* Start the CPU paused. */
gdbstub_step = GDBSTUB_BREAK;
}
void
gdbstub_close()
{
/* Stop if the GDB server hasn't initialized. */
if (gdbstub_socket < 0)
return;
/* Close GDB server socket. */
close(gdbstub_socket);
/* Clear client list. */
thread_wait_mutex(client_list_mutex);
gdbstub_client_t *client = first_client;
int socket;
while (client) {
socket = client->socket;
client->socket = -1;
close(socket);
client = client->next;
}
thread_release_mutex(client_list_mutex);
thread_close_mutex(client_list_mutex);
}