gdbstub.c

   1 /*
   2  * gdb server stub
   3  *
   4  * Copyright (c) 2003 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <sys/socket.h>
  26 #include <netinet/in.h>
  27 #include <netinet/tcp.h>
  28 #include <signal.h>
  29
  30 #include "config.h"
  31 #include "cpu.h"
  32 #include "thunk.h"
  33 #include "exec-all.h"
  34
  35 //#define DEBUG_GDB
  36
  37 int gdbstub_fd = -1;
  38
  39 /* return 0 if OK */
  40 static int gdbstub_open(int port)
  41 {
  42     struct sockaddr_in sockaddr;
  43     socklen_t len;
  44     int fd, val, ret;
  45
  46     fd = socket(PF_INET, SOCK_STREAM, 0);
  47     if (fd < 0) {
  48         perror("socket");
  49         return -1;
  50     }
  51
  52     /* allow fast reuse */
  53     val = 1;
  54     setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
  55
  56     sockaddr.sin_family = AF_INET;
  57     sockaddr.sin_port = htons(port);
  58     sockaddr.sin_addr.s_addr = 0;
  59     ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
  60     if (ret < 0) {
  61         perror("bind");
  62         return -1;
  63     }
  64     ret = listen(fd, 0);
  65     if (ret < 0) {
  66         perror("listen");
  67         return -1;
  68     }
  69
  70     /* now wait for one connection */
  71     for(;;) {
  72         len = sizeof(sockaddr);
  73         gdbstub_fd = accept(fd, (struct sockaddr *)&sockaddr, &len);
  74         if (gdbstub_fd < 0 && errno != EINTR) {
  75             perror("accept");
  76             return -1;
  77         } else if (gdbstub_fd >= 0) {
  78             break;
  79         }
  80     }
  81
  82     /* set short latency */
  83     val = 1;
  84     setsockopt(gdbstub_fd, SOL_TCP, TCP_NODELAY, &val, sizeof(val));
  85     return 0;
  86 }
  87
  88 static int get_char(void)
  89 {
  90     uint8_t ch;
  91     int ret;
  92
  93     for(;;) {
  94         ret = read(gdbstub_fd, &ch, 1);
  95         if (ret < 0) {
  96             if (errno != EINTR && errno != EAGAIN)
  97                 return -1;
  98         } else if (ret == 0) {
  99             return -1;
 100         } else {
 101             break;
 102         }
 103     }
 104     return ch;
 105 }
 106
 107 static void put_buffer(const uint8_t *buf, int len)
 108 {
 109     int ret;
 110
 111     while (len > 0) {
 112         ret = write(gdbstub_fd, buf, len);
 113         if (ret < 0) {
 114             if (errno != EINTR && errno != EAGAIN)
 115                 return;
 116         } else {
 117             buf += ret;
 118             len -= ret;
 119         }
 120     }
 121 }
 122
 123 static inline int fromhex(int v)
 124 {
 125     if (v >= '0' && v <= '9')
 126         return v - '0';
 127     else if (v >= 'A' && v <= 'F')
 128         return v - 'A' + 10;
 129     else if (v >= 'a' && v <= 'f')
 130         return v - 'a' + 10;
 131     else
 132         return 0;
 133 }
 134
 135 static inline int tohex(int v)
 136 {
 137     if (v < 10)
 138         return v + '0';
 139     else
 140         return v - 10 + 'a';
 141 }
 142
 143 static void memtohex(char *buf, const uint8_t *mem, int len)
 144 {
 145     int i, c;
 146     char *q;
 147     q = buf;
 148     for(i = 0; i < len; i++) {
 149         c = mem[i];
 150         *q++ = tohex(c >> 4);
 151         *q++ = tohex(c & 0xf);
 152     }
 153     *q = '\0';
 154 }
 155
 156 static void hextomem(uint8_t *mem, const char *buf, int len)
 157 {
 158     int i;
 159
 160     for(i = 0; i < len; i++) {
 161         mem[i] = (fromhex(buf[0]) << 4) | fromhex(buf[1]);
 162         buf += 2;
 163     }
 164 }
 165
 166 /* return -1 if error or EOF */
 167 static int get_packet(char *buf, int buf_size)
 168 {
 169     int ch, len, csum, csum1;
 170     char reply[1];
 171
 172     for(;;) {
 173         for(;;) {
 174             ch = get_char();
 175             if (ch < 0)
 176                 return -1;
 177             if (ch == '$')
 178                 break;
 179         }
 180         len = 0;
 181         csum = 0;
 182         for(;;) {
 183             ch = get_char();
 184             if (ch < 0)
 185                 return -1;
 186             if (ch == '#')
 187                 break;
 188             if (len > buf_size - 1)
 189                 return -1;
 190             buf[len++] = ch;
 191             csum += ch;
 192         }
 193         buf[len] = '\0';
 194         ch = get_char();
 195         if (ch < 0)
 196             return -1;
 197         csum1 = fromhex(ch) << 4;
 198         ch = get_char();
 199         if (ch < 0)
 200             return -1;
 201         csum1 |= fromhex(ch);
 202         if ((csum & 0xff) != csum1) {
 203             reply[0] = '-';
 204             put_buffer(reply, 1);
 205         } else {
 206             reply[0] = '+';
 207             put_buffer(reply, 1);
 208             break;
 209         }
 210     }
 211 #ifdef DEBUG_GDB
 212     printf("command='%s'\n", buf);
 213 #endif
 214     return len;
 215 }
 216
 217 /* return -1 if error, 0 if OK */
 218 static int put_packet(char *buf)
 219 {
 220     char buf1[3];
 221     int len, csum, ch, i;
 222
 223 #ifdef DEBUG_GDB
 224     printf("reply='%s'\n", buf);
 225 #endif
 226
 227     for(;;) {
 228         buf1[0] = '$';
 229         put_buffer(buf1, 1);
 230         len = strlen(buf);
 231         put_buffer(buf, len);
 232         csum = 0;
 233         for(i = 0; i < len; i++) {
 234             csum += buf[i];
 235         }
 236         buf1[0] = '#';
 237         buf1[1] = tohex((csum >> 4) & 0xf);
 238         buf1[2] = tohex((csum) & 0xf);
 239
 240         put_buffer(buf1, 3);
 241
 242         ch = get_char();
 243         if (ch < 0)
 244             return -1;
 245         if (ch == '+')
 246             break;
 247     }
 248     return 0;
 249 }
 250
 251 #if defined(TARGET_I386)
 252
 253 static void to_le32(uint8_t *p, int v)
 254 {
 255     p[0] = v;
 256     p[1] = v >> 8;
 257     p[2] = v >> 16;
 258     p[3] = v >> 24;
 259 }
 260
 261 static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
 262 {
 263     int i, fpus;
 264
 265     for(i = 0; i < 8; i++) {
 266         to_le32(mem_buf + i * 4, env->regs[i]);
 267     }
 268     to_le32(mem_buf + 8 * 4, env->eip);
 269     to_le32(mem_buf + 9 * 4, env->eflags);
 270     to_le32(mem_buf + 10 * 4, env->segs[R_CS].selector);
 271     to_le32(mem_buf + 11 * 4, env->segs[R_SS].selector);
 272     to_le32(mem_buf + 12 * 4, env->segs[R_DS].selector);
 273     to_le32(mem_buf + 13 * 4, env->segs[R_ES].selector);
 274     to_le32(mem_buf + 14 * 4, env->segs[R_FS].selector);
 275     to_le32(mem_buf + 15 * 4, env->segs[R_GS].selector);
 276     /* XXX: convert floats */
 277     for(i = 0; i < 8; i++) {
 278         memcpy(mem_buf + 16 * 4 + i * 10, &env->fpregs[i], 10);
 279     }
 280     to_le32(mem_buf + 36 * 4, env->fpuc);
 281     fpus = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11;
 282     to_le32(mem_buf + 37 * 4, fpus);
 283     to_le32(mem_buf + 38 * 4, 0); /* XXX: convert tags */
 284     to_le32(mem_buf + 39 * 4, 0); /* fiseg */
 285     to_le32(mem_buf + 40 * 4, 0); /* fioff */
 286     to_le32(mem_buf + 41 * 4, 0); /* foseg */
 287     to_le32(mem_buf + 42 * 4, 0); /* fooff */
 288     to_le32(mem_buf + 43 * 4, 0); /* fop */
 289     return 44 * 4;
 290 }
 291
 292 static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
 293 {
 294     uint32_t *registers = (uint32_t *)mem_buf;
 295     int i;
 296
 297     for(i = 0; i < 8; i++) {
 298         env->regs[i] = tswapl(registers[i]);
 299     }
 300     env->eip = registers[8];
 301     env->eflags = registers[9];
 302 #if defined(CONFIG_USER_ONLY)
 303 #define LOAD_SEG(index, sreg)\
 304             if (tswapl(registers[index]) != env->segs[sreg].selector)\
 305                 cpu_x86_load_seg(env, sreg, tswapl(registers[index]));
 306             LOAD_SEG(10, R_CS);
 307             LOAD_SEG(11, R_SS);
 308             LOAD_SEG(12, R_DS);
 309             LOAD_SEG(13, R_ES);
 310             LOAD_SEG(14, R_FS);
 311             LOAD_SEG(15, R_GS);
 312 #endif
 313 }
 314
 315 #elif defined (TARGET_PPC)
 316 static void to_le32(uint8_t *p, int v)
 317 {
 318     p[3] = v;
 319     p[2] = v >> 8;
 320     p[1] = v >> 16;
 321     p[0] = v >> 24;
 322 }
 323
 324 static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
 325 {
 326     uint32_t tmp;
 327     int i;
 328
 329     /* fill in gprs */
 330     for(i = 0; i < 8; i++) {
 331         to_le32(mem_buf + i * 4, env->gpr[i]);
 332     }
 333     /* fill in fprs */
 334     for (i = 0; i < 32; i++) {
 335         to_le32(mem_buf + (i * 2) + 32, *((uint32_t *)&env->fpr[i]));
 336         to_le32(mem_buf + (i * 2) + 33, *((uint32_t *)&env->fpr[i] + 1));
 337     }
 338     /* nip, msr, ccr, lnk, ctr, xer, mq */
 339     to_le32(mem_buf + 96, tswapl(env->nip));
 340     to_le32(mem_buf + 97, tswapl(_load_msr()));
 341     to_le32(mem_buf + 98, 0);
 342     tmp = 0;
 343     for (i = 0; i < 8; i++)
 344         tmp |= env->crf[i] << (32 - (i * 4));
 345     to_le32(mem_buf + 98, tmp);
 346     to_le32(mem_buf + 99, tswapl(env->lr));
 347     to_le32(mem_buf + 100, tswapl(env->ctr));
 348     to_le32(mem_buf + 101, tswapl(_load_xer()));
 349     to_le32(mem_buf + 102, 0);
 350
 351     return 102;
 352 }
 353
 354 static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
 355 {
 356     uint32_t *registers = (uint32_t *)mem_buf;
 357     int i;
 358
 359     /* fill in gprs */
 360     for (i = 0; i < 32; i++) {
 361         env->gpr[i] = tswapl(registers[i]);
 362     }
 363     /* fill in fprs */
 364     for (i = 0; i < 32; i++) {
 365         *((uint32_t *)&env->fpr[i]) = tswapl(registers[(i * 2) + 32]);
 366         *((uint32_t *)&env->fpr[i] + 1) = tswapl(registers[(i * 2) + 33]);
 367     }
 368     /* nip, msr, ccr, lnk, ctr, xer, mq */
 369     env->nip = tswapl(registers[96]);
 370     _store_msr(tswapl(registers[97]));
 371     registers[98] = tswapl(registers[98]);
 372     for (i = 0; i < 8; i++)
 373         env->crf[i] = (registers[98] >> (32 - (i * 4))) & 0xF;
 374     env->lr = tswapl(registers[99]);
 375     env->ctr = tswapl(registers[100]);
 376     _store_xer(tswapl(registers[101]));
 377 }
 378 #else
 379
 380 static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
 381 {
 382     return 0;
 383 }
 384
 385 static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
 386 {
 387 }
 388
 389 #endif
 390
 391 /* port = 0 means default port */
 392 int cpu_gdbstub(void *opaque, int (*main_loop)(void *opaque), int port)
 393 {
 394     CPUState *env;
 395     const char *p;
 396     int ret, ch, reg_size, type;
 397     char buf[4096];
 398     uint8_t mem_buf[2000];
 399     uint32_t *registers;
 400     uint32_t addr, len;
 401
 402     printf("Waiting gdb connection on port %d\n", port);
 403     if (gdbstub_open(port) < 0)
 404         return -1;
 405     printf("Connected\n");
 406     for(;;) {
 407         ret = get_packet(buf, sizeof(buf));
 408         if (ret < 0)
 409             break;
 410         p = buf;
 411         ch = *p++;
 412         switch(ch) {
 413         case '?':
 414             snprintf(buf, sizeof(buf), "S%02x", SIGTRAP);
 415             put_packet(buf);
 416             break;
 417         case 'c':
 418             if (*p != '\0') {
 419                 addr = strtoul(p, (char **)&p, 16);
 420                 env = cpu_gdbstub_get_env(opaque);
 421 #if defined(TARGET_I386)
 422                 env->eip = addr;
 423 #elif defined (TARGET_PPC)
 424                 env->nip = addr;
 425 #endif
 426             }
 427             ret = main_loop(opaque);
 428             if (ret == EXCP_DEBUG)
 429                 ret = SIGTRAP;
 430             else
 431                 ret = 0;
 432             snprintf(buf, sizeof(buf), "S%02x", ret);
 433             put_packet(buf);
 434             break;
 435         case 's':
 436             env = cpu_gdbstub_get_env(opaque);
 437             if (*p != '\0') {
 438                 addr = strtoul(p, (char **)&p, 16);
 439 #if defined(TARGET_I386)
 440                 env->eip = addr;
 441 #elif defined (TARGET_PPC)
 442                 env->nip = addr;
 443 #endif
 444             }
 445             cpu_single_step(env, 1);
 446             ret = main_loop(opaque);
 447             cpu_single_step(env, 0);
 448             if (ret == EXCP_DEBUG)
 449                 ret = SIGTRAP;
 450             else
 451                 ret = 0;
 452             snprintf(buf, sizeof(buf), "S%02x", ret);
 453             put_packet(buf);
 454             break;
 455         case 'g':
 456             env = cpu_gdbstub_get_env(opaque);
 457             reg_size = cpu_gdb_read_registers(env, mem_buf);
 458             memtohex(buf, mem_buf, reg_size);
 459             put_packet(buf);
 460             break;
 461         case 'G':
 462             env = cpu_gdbstub_get_env(opaque);
 463             registers = (void *)mem_buf;
 464             len = strlen(p) / 2;
 465             hextomem((uint8_t *)registers, p, len);
 466             cpu_gdb_write_registers(env, mem_buf, len);
 467             put_packet("OK");
 468             break;
 469         case 'm':
 470             env = cpu_gdbstub_get_env(opaque);
 471             addr = strtoul(p, (char **)&p, 16);
 472             if (*p == ',')
 473                 p++;
 474             len = strtoul(p, NULL, 16);
 475             if (cpu_memory_rw_debug(env, mem_buf, addr, len, 0) != 0)
 476                 memset(mem_buf, 0, len);
 477             memtohex(buf, mem_buf, len);
 478             put_packet(buf);
 479             break;
 480         case 'M':
 481             env = cpu_gdbstub_get_env(opaque);
 482             addr = strtoul(p, (char **)&p, 16);
 483             if (*p == ',')
 484                 p++;
 485             len = strtoul(p, (char **)&p, 16);
 486             if (*p == ',')
 487                 p++;
 488             hextomem(mem_buf, p, len);
 489             if (cpu_memory_rw_debug(env, mem_buf, addr, len, 1) != 0)
 490                 put_packet("ENN");
 491             else
 492                 put_packet("OK");
 493             break;
 494         case 'Z':
 495             type = strtoul(p, (char **)&p, 16);
 496             if (*p == ',')
 497                 p++;
 498             addr = strtoul(p, (char **)&p, 16);
 499             if (*p == ',')
 500                 p++;
 501             len = strtoul(p, (char **)&p, 16);
 502             if (type == 0 || type == 1) {
 503                 env = cpu_gdbstub_get_env(opaque);
 504                 if (cpu_breakpoint_insert(env, addr) < 0)
 505                     goto breakpoint_error;
 506                 put_packet("OK");
 507             } else {
 508             breakpoint_error:
 509                 put_packet("ENN");
 510             }
 511             break;
 512         case 'z':
 513             type = strtoul(p, (char **)&p, 16);
 514             if (*p == ',')
 515                 p++;
 516             addr = strtoul(p, (char **)&p, 16);
 517             if (*p == ',')
 518                 p++;
 519             len = strtoul(p, (char **)&p, 16);
 520             if (type == 0 || type == 1) {
 521                 env = cpu_gdbstub_get_env(opaque);
 522                 cpu_breakpoint_remove(env, addr);
 523                 put_packet("OK");
 524             } else {
 525                 goto breakpoint_error;
 526             }
 527             break;
 528         case 'Q':
 529             if (!strncmp(p, "Tinit", 5)) {
 530                 /* init traces */
 531                 put_packet("OK");
 532             } else if (!strncmp(p, "TStart", 6)) {
 533                 /* start log (gdb 'tstart' command) */
 534                 env = cpu_gdbstub_get_env(opaque);
 535                 tb_flush(env);
 536                 cpu_set_log(CPU_LOG_ALL);
 537                 put_packet("OK");
 538             } else if (!strncmp(p, "TStop", 5)) {
 539                 /* stop log (gdb 'tstop' command) */
 540                 cpu_set_log(0);
 541                 put_packet("OK");
 542             } else {
 543                 goto unknown_command;
 544             }
 545             break;
 546         default:
 547         unknown_command:
 548             /* put empty packet */
 549             buf[0] = '\0';
 550             put_packet(buf);
 551             break;
 552         }
 553     }
 554     return 0;
 555 }