disas.c

   1 /* General "disassemble this chunk" code.  Used for debugging. */
   2 #include "qemu/osdep.h"
   3 #include "qemu-common.h"
   4 #include "disas/bfd.h"
   5 #include "elf.h"
   6
   7 #include "cpu.h"
   8 #include "disas/disas.h"
   9
  10 typedef struct CPUDebug {
  11     struct disassemble_info info;
  12     CPUState *cpu;
  13 } CPUDebug;
  14
  15 /* Filled in by elfload.c.  Simplistic, but will do for now. */
  16 struct syminfo *syminfos = NULL;
  17
  18 /* Get LENGTH bytes from info's buffer, at target address memaddr.
  19    Transfer them to myaddr.  */
  20 int
  21 buffer_read_memory(bfd_vma memaddr, bfd_byte *myaddr, int length,
  22                    struct disassemble_info *info)
  23 {
  24     if (memaddr < info->buffer_vma
  25         || memaddr + length > info->buffer_vma + info->buffer_length)
  26         /* Out of bounds.  Use EIO because GDB uses it.  */
  27         return EIO;
  28     memcpy (myaddr, info->buffer + (memaddr - info->buffer_vma), length);
  29     return 0;
  30 }
  31
  32 /* Get LENGTH bytes from info's buffer, at target address memaddr.
  33    Transfer them to myaddr.  */
  34 static int
  35 target_read_memory (bfd_vma memaddr,
  36                     bfd_byte *myaddr,
  37                     int length,
  38                     struct disassemble_info *info)
  39 {
  40     CPUDebug *s = container_of(info, CPUDebug, info);
  41
  42     cpu_memory_rw_debug(s->cpu, memaddr, myaddr, length, 0);
  43     return 0;
  44 }
  45
  46 /* Print an error message.  We can assume that this is in response to
  47    an error return from buffer_read_memory.  */
  48 void
  49 perror_memory (int status, bfd_vma memaddr, struct disassemble_info *info)
  50 {
  51   if (status != EIO)
  52     /* Can't happen.  */
  53     (*info->fprintf_func) (info->stream, "Unknown error %d\n", status);
  54   else
  55     /* Actually, address between memaddr and memaddr + len was
  56        out of bounds.  */
  57     (*info->fprintf_func) (info->stream,
  58                            "Address 0x%" PRIx64 " is out of bounds.\n", memaddr);
  59 }
  60
  61 /* This could be in a separate file, to save minuscule amounts of space
  62    in statically linked executables.  */
  63
  64 /* Just print the address is hex.  This is included for completeness even
  65    though both GDB and objdump provide their own (to print symbolic
  66    addresses).  */
  67
  68 void
  69 generic_print_address (bfd_vma addr, struct disassemble_info *info)
  70 {
  71     (*info->fprintf_func) (info->stream, "0x%" PRIx64, addr);
  72 }
  73
  74 /* Print address in hex, truncated to the width of a host virtual address. */
  75 static void
  76 generic_print_host_address(bfd_vma addr, struct disassemble_info *info)
  77 {
  78     uint64_t mask = ~0ULL >> (64 - (sizeof(void *) * 8));
  79     generic_print_address(addr & mask, info);
  80 }
  81
  82 /* Just return the given address.  */
  83
  84 int
  85 generic_symbol_at_address (bfd_vma addr, struct disassemble_info *info)
  86 {
  87   return 1;
  88 }
  89
  90 bfd_vma bfd_getl64 (const bfd_byte *addr)
  91 {
  92   unsigned long long v;
  93
  94   v = (unsigned long long) addr[0];
  95   v |= (unsigned long long) addr[1] << 8;
  96   v |= (unsigned long long) addr[2] << 16;
  97   v |= (unsigned long long) addr[3] << 24;
  98   v |= (unsigned long long) addr[4] << 32;
  99   v |= (unsigned long long) addr[5] << 40;
 100   v |= (unsigned long long) addr[6] << 48;
 101   v |= (unsigned long long) addr[7] << 56;
 102   return (bfd_vma) v;
 103 }
 104
 105 bfd_vma bfd_getl32 (const bfd_byte *addr)
 106 {
 107   unsigned long v;
 108
 109   v = (unsigned long) addr[0];
 110   v |= (unsigned long) addr[1] << 8;
 111   v |= (unsigned long) addr[2] << 16;
 112   v |= (unsigned long) addr[3] << 24;
 113   return (bfd_vma) v;
 114 }
 115
 116 bfd_vma bfd_getb32 (const bfd_byte *addr)
 117 {
 118   unsigned long v;
 119
 120   v = (unsigned long) addr[0] << 24;
 121   v |= (unsigned long) addr[1] << 16;
 122   v |= (unsigned long) addr[2] << 8;
 123   v |= (unsigned long) addr[3];
 124   return (bfd_vma) v;
 125 }
 126
 127 bfd_vma bfd_getl16 (const bfd_byte *addr)
 128 {
 129   unsigned long v;
 130
 131   v = (unsigned long) addr[0];
 132   v |= (unsigned long) addr[1] << 8;
 133   return (bfd_vma) v;
 134 }
 135
 136 bfd_vma bfd_getb16 (const bfd_byte *addr)
 137 {
 138   unsigned long v;
 139
 140   v = (unsigned long) addr[0] << 24;
 141   v |= (unsigned long) addr[1] << 16;
 142   return (bfd_vma) v;
 143 }
 144
 145 static int print_insn_objdump(bfd_vma pc, disassemble_info *info,
 146                               const char *prefix)
 147 {
 148     int i, n = info->buffer_length;
 149     uint8_t *buf = g_malloc(n);
 150
 151     info->read_memory_func(pc, buf, n, info);
 152
 153     for (i = 0; i < n; ++i) {
 154         if (i % 32 == 0) {
 155             info->fprintf_func(info->stream, "\n%s: ", prefix);
 156         }
 157         info->fprintf_func(info->stream, "%02x", buf[i]);
 158     }
 159
 160     g_free(buf);
 161     return n;
 162 }
 163
 164 static int print_insn_od_host(bfd_vma pc, disassemble_info *info)
 165 {
 166     return print_insn_objdump(pc, info, "OBJD-H");
 167 }
 168
 169 static int print_insn_od_target(bfd_vma pc, disassemble_info *info)
 170 {
 171     return print_insn_objdump(pc, info, "OBJD-T");
 172 }
 173
 174 /* Disassemble this for me please... (debugging). 'flags' has the following
 175    values:
 176     i386 - 1 means 16 bit code, 2 means 64 bit code
 177     ppc  - bits 0:15 specify (optionally) the machine instruction set;
 178            bit 16 indicates little endian.
 179     other targets - unused
 180  */
 181 void target_disas(FILE *out, CPUState *cpu, target_ulong code,
 182                   target_ulong size, int flags)
 183 {
 184     CPUClass *cc = CPU_GET_CLASS(cpu);
 185     target_ulong pc;
 186     int count;
 187     CPUDebug s;
 188
 189     INIT_DISASSEMBLE_INFO(s.info, out, fprintf);
 190
 191     s.cpu = cpu;
 192     s.info.read_memory_func = target_read_memory;
 193     s.info.buffer_vma = code;
 194     s.info.buffer_length = size;
 195     s.info.print_address_func = generic_print_address;
 196
 197 #ifdef TARGET_WORDS_BIGENDIAN
 198     s.info.endian = BFD_ENDIAN_BIG;
 199 #else
 200     s.info.endian = BFD_ENDIAN_LITTLE;
 201 #endif
 202
 203     if (cc->disas_set_info) {
 204         cc->disas_set_info(cpu, &s.info);
 205     }
 206
 207 #if defined(TARGET_I386)
 208     if (flags == 2) {
 209         s.info.mach = bfd_mach_x86_64;
 210     } else if (flags == 1) {
 211         s.info.mach = bfd_mach_i386_i8086;
 212     } else {
 213         s.info.mach = bfd_mach_i386_i386;
 214     }
 215     s.info.print_insn = print_insn_i386;
 216 #elif defined(TARGET_PPC)
 217     if ((flags >> 16) & 1) {
 218         s.info.endian = BFD_ENDIAN_LITTLE;
 219     }
 220     if (flags & 0xFFFF) {
 221         /* If we have a precise definition of the instruction set, use it. */
 222         s.info.mach = flags & 0xFFFF;
 223     } else {
 224 #ifdef TARGET_PPC64
 225         s.info.mach = bfd_mach_ppc64;
 226 #else
 227         s.info.mach = bfd_mach_ppc;
 228 #endif
 229     }
 230     s.info.disassembler_options = (char *)"any";
 231     s.info.print_insn = print_insn_ppc;
 232 #endif
 233     if (s.info.print_insn == NULL) {
 234         s.info.print_insn = print_insn_od_target;
 235     }
 236
 237     for (pc = code; size > 0; pc += count, size -= count) {
 238         fprintf(out, "0x" TARGET_FMT_lx ":  ", pc);
 239         count = s.info.print_insn(pc, &s.info);
 240 #if 0
 241         {
 242             int i;
 243             uint8_t b;
 244             fprintf(out, " {");
 245             for(i = 0; i < count; i++) {
 246                 target_read_memory(pc + i, &b, 1, &s.info);
 247                 fprintf(out, " %02x", b);
 248             }
 249             fprintf(out, " }");
 250         }
 251 #endif
 252         fprintf(out, "\n");
 253         if (count < 0)
 254             break;
 255         if (size < count) {
 256             fprintf(out,
 257                     "Disassembler disagrees with translator over instruction "
 258                     "decoding\n"
 259                     "Please report this to qemu-devel@nongnu.org\n");
 260             break;
 261         }
 262     }
 263 }
 264
 265 /* Disassemble this for me please... (debugging). */
 266 void disas(FILE *out, void *code, unsigned long size)
 267 {
 268     uintptr_t pc;
 269     int count;
 270     CPUDebug s;
 271     int (*print_insn)(bfd_vma pc, disassemble_info *info) = NULL;
 272
 273     INIT_DISASSEMBLE_INFO(s.info, out, fprintf);
 274     s.info.print_address_func = generic_print_host_address;
 275
 276     s.info.buffer = code;
 277     s.info.buffer_vma = (uintptr_t)code;
 278     s.info.buffer_length = size;
 279
 280 #ifdef HOST_WORDS_BIGENDIAN
 281     s.info.endian = BFD_ENDIAN_BIG;
 282 #else
 283     s.info.endian = BFD_ENDIAN_LITTLE;
 284 #endif
 285 #if defined(CONFIG_TCG_INTERPRETER)
 286     print_insn = print_insn_tci;
 287 #elif defined(__i386__)
 288     s.info.mach = bfd_mach_i386_i386;
 289     print_insn = print_insn_i386;
 290 #elif defined(__x86_64__)
 291     s.info.mach = bfd_mach_x86_64;
 292     print_insn = print_insn_i386;
 293 #elif defined(_ARCH_PPC)
 294     s.info.disassembler_options = (char *)"any";
 295     print_insn = print_insn_ppc;
 296 #elif defined(__aarch64__) && defined(CONFIG_ARM_A64_DIS)
 297     print_insn = print_insn_arm_a64;
 298 #elif defined(__alpha__)
 299     print_insn = print_insn_alpha;
 300 #elif defined(__sparc__)
 301     print_insn = print_insn_sparc;
 302     s.info.mach = bfd_mach_sparc_v9b;
 303 #elif defined(__arm__)
 304     print_insn = print_insn_arm;
 305 #elif defined(__MIPSEB__)
 306     print_insn = print_insn_big_mips;
 307 #elif defined(__MIPSEL__)
 308     print_insn = print_insn_little_mips;
 309 #elif defined(__m68k__)
 310     print_insn = print_insn_m68k;
 311 #elif defined(__s390__)
 312     print_insn = print_insn_s390;
 313 #elif defined(__ia64__)
 314     print_insn = print_insn_ia64;
 315 #endif
 316     if (print_insn == NULL) {
 317         print_insn = print_insn_od_host;
 318     }
 319     for (pc = (uintptr_t)code; size > 0; pc += count, size -= count) {
 320         fprintf(out, "0x%08" PRIxPTR ":  ", pc);
 321         count = print_insn(pc, &s.info);
 322         fprintf(out, "\n");
 323         if (count < 0)
 324             break;
 325     }
 326 }
 327
 328 /* Look up symbol for debugging purpose.  Returns "" if unknown. */
 329 const char *lookup_symbol(target_ulong orig_addr)
 330 {
 331     const char *symbol = "";
 332     struct syminfo *s;
 333
 334     for (s = syminfos; s; s = s->next) {
 335         symbol = s->lookup_symbol(s, orig_addr);
 336         if (symbol[0] != '\0') {
 337             break;
 338         }
 339     }
 340
 341     return symbol;
 342 }
 343
 344 #if !defined(CONFIG_USER_ONLY)
 345
 346 #include "monitor/monitor.h"
 347
 348 static int monitor_disas_is_physical;
 349
 350 static int
 351 monitor_read_memory (bfd_vma memaddr, bfd_byte *myaddr, int length,
 352                      struct disassemble_info *info)
 353 {
 354     CPUDebug *s = container_of(info, CPUDebug, info);
 355
 356     if (monitor_disas_is_physical) {
 357         cpu_physical_memory_read(memaddr, myaddr, length);
 358     } else {
 359         cpu_memory_rw_debug(s->cpu, memaddr, myaddr, length, 0);
 360     }
 361     return 0;
 362 }
 363
 364 /* Disassembler for the monitor.
 365    See target_disas for a description of flags. */
 366 void monitor_disas(Monitor *mon, CPUState *cpu,
 367                    target_ulong pc, int nb_insn, int is_physical, int flags)
 368 {
 369     CPUClass *cc = CPU_GET_CLASS(cpu);
 370     int count, i;
 371     CPUDebug s;
 372
 373     INIT_DISASSEMBLE_INFO(s.info, (FILE *)mon, monitor_fprintf);
 374
 375     s.cpu = cpu;
 376     monitor_disas_is_physical = is_physical;
 377     s.info.read_memory_func = monitor_read_memory;
 378     s.info.print_address_func = generic_print_address;
 379
 380     s.info.buffer_vma = pc;
 381
 382 #ifdef TARGET_WORDS_BIGENDIAN
 383     s.info.endian = BFD_ENDIAN_BIG;
 384 #else
 385     s.info.endian = BFD_ENDIAN_LITTLE;
 386 #endif
 387
 388     if (cc->disas_set_info) {
 389         cc->disas_set_info(cpu, &s.info);
 390     }
 391
 392 #if defined(TARGET_I386)
 393     if (flags == 2) {
 394         s.info.mach = bfd_mach_x86_64;
 395     } else if (flags == 1) {
 396         s.info.mach = bfd_mach_i386_i8086;
 397     } else {
 398         s.info.mach = bfd_mach_i386_i386;
 399     }
 400     s.info.print_insn = print_insn_i386;
 401 #elif defined(TARGET_PPC)
 402     if (flags & 0xFFFF) {
 403         /* If we have a precise definition of the instruction set, use it. */
 404         s.info.mach = flags & 0xFFFF;
 405     } else {
 406 #ifdef TARGET_PPC64
 407         s.info.mach = bfd_mach_ppc64;
 408 #else
 409         s.info.mach = bfd_mach_ppc;
 410 #endif
 411     }
 412     if ((flags >> 16) & 1) {
 413         s.info.endian = BFD_ENDIAN_LITTLE;
 414     }
 415     s.info.print_insn = print_insn_ppc;
 416 #endif
 417     if (!s.info.print_insn) {
 418         monitor_printf(mon, "0x" TARGET_FMT_lx
 419                        ": Asm output not supported on this arch\n", pc);
 420         return;
 421     }
 422
 423     for(i = 0; i < nb_insn; i++) {
 424         monitor_printf(mon, "0x" TARGET_FMT_lx ":  ", pc);
 425         count = s.info.print_insn(pc, &s.info);
 426         monitor_printf(mon, "\n");
 427         if (count < 0)
 428             break;
 429         pc += count;
 430     }
 431 }
 432 #endif