gdb/spu-linux-nat.c

   1 /* SPU native-dependent code for GDB, the GNU debugger.
   2    Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc.
   3
   4    Contributed by Ulrich Weigand <uweigand@de.ibm.com>.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "gdbcore.h"
  23 #include "gdb_string.h"
  24 #include "target.h"
  25 #include "inferior.h"
  26 #include "inf-ptrace.h"
  27 #include "regcache.h"
  28 #include "symfile.h"
  29 #include "gdb_wait.h"
  30 #include "gdbthread.h"
  31
  32 #include <sys/ptrace.h>
  33 #include <asm/ptrace.h>
  34 #include <sys/types.h>
  35 #include <sys/param.h>
  36
  37 #include "spu-tdep.h"
  38
  39 /* PPU side system calls.  */
  40 #define INSTR_SC        0x44000002
  41 #define NR_spu_run      0x0116
  42
  43
  44 /* Fetch PPU register REGNO.  */
  45 static ULONGEST
  46 fetch_ppc_register (int regno)
  47 {
  48   PTRACE_TYPE_RET res;
  49
  50   int tid = TIDGET (inferior_ptid);
  51   if (tid == 0)
  52     tid = PIDGET (inferior_ptid);
  53
  54 #ifndef __powerpc64__
  55   /* If running as a 32-bit process on a 64-bit system, we attempt
  56      to get the full 64-bit register content of the target process.
  57      If the PPC special ptrace call fails, we're on a 32-bit system;
  58      just fall through to the regular ptrace call in that case.  */
  59   {
  60     gdb_byte buf[8];
  61
  62     errno = 0;
  63     ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
  64             (PTRACE_TYPE_ARG3) (regno * 8), buf);
  65     if (errno == 0)
  66       ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
  67               (PTRACE_TYPE_ARG3) (regno * 8 + 4), buf + 4);
  68     if (errno == 0)
  69       return (ULONGEST) *(uint64_t *)buf;
  70   }
  71 #endif
  72
  73   errno = 0;
  74   res = ptrace (PT_READ_U, tid,
  75                 (PTRACE_TYPE_ARG3) (regno * sizeof (PTRACE_TYPE_RET)), 0);
  76   if (errno != 0)
  77     {
  78       char mess[128];
  79       xsnprintf (mess, sizeof mess, "reading PPC register #%d", regno);
  80       perror_with_name (_(mess));
  81     }
  82
  83   return (ULONGEST) (unsigned long) res;
  84 }
  85
  86 /* Fetch WORD from PPU memory at (aligned) MEMADDR in thread TID.  */
  87 static int
  88 fetch_ppc_memory_1 (int tid, ULONGEST memaddr, PTRACE_TYPE_RET *word)
  89 {
  90   errno = 0;
  91
  92 #ifndef __powerpc64__
  93   if (memaddr >> 32)
  94     {
  95       uint64_t addr_8 = (uint64_t) memaddr;
  96       ptrace (PPC_PTRACE_PEEKTEXT_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
  97     }
  98   else
  99 #endif
 100     *word = ptrace (PT_READ_I, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, 0);
 101
 102   return errno;
 103 }
 104
 105 /* Store WORD into PPU memory at (aligned) MEMADDR in thread TID.  */
 106 static int
 107 store_ppc_memory_1 (int tid, ULONGEST memaddr, PTRACE_TYPE_RET word)
 108 {
 109   errno = 0;
 110
 111 #ifndef __powerpc64__
 112   if (memaddr >> 32)
 113     {
 114       uint64_t addr_8 = (uint64_t) memaddr;
 115       ptrace (PPC_PTRACE_POKEDATA_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
 116     }
 117   else
 118 #endif
 119     ptrace (PT_WRITE_D, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, word);
 120
 121   return errno;
 122 }
 123
 124 /* Fetch LEN bytes of PPU memory at MEMADDR to MYADDR.  */
 125 static int
 126 fetch_ppc_memory (ULONGEST memaddr, gdb_byte *myaddr, int len)
 127 {
 128   int i, ret;
 129
 130   ULONGEST addr = memaddr & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
 131   int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
 132                / sizeof (PTRACE_TYPE_RET));
 133   PTRACE_TYPE_RET *buffer;
 134
 135   int tid = TIDGET (inferior_ptid);
 136   if (tid == 0)
 137     tid = PIDGET (inferior_ptid);
 138
 139   buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
 140   for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
 141     {
 142       ret = fetch_ppc_memory_1 (tid, addr, &buffer[i]);
 143       if (ret)
 144         return ret;
 145     }
 146
 147   memcpy (myaddr,
 148           (char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
 149           len);
 150
 151   return 0;
 152 }
 153
 154 /* Store LEN bytes from MYADDR to PPU memory at MEMADDR.  */
 155 static int
 156 store_ppc_memory (ULONGEST memaddr, const gdb_byte *myaddr, int len)
 157 {
 158   int i, ret;
 159
 160   ULONGEST addr = memaddr & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
 161   int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
 162                / sizeof (PTRACE_TYPE_RET));
 163   PTRACE_TYPE_RET *buffer;
 164
 165   int tid = TIDGET (inferior_ptid);
 166   if (tid == 0)
 167     tid = PIDGET (inferior_ptid);
 168
 169   buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
 170
 171   if (addr != memaddr || len < (int) sizeof (PTRACE_TYPE_RET))
 172     {
 173       ret = fetch_ppc_memory_1 (tid, addr, &buffer[0]);
 174       if (ret)
 175         return ret;
 176     }
 177
 178   if (count > 1)
 179     {
 180       ret = fetch_ppc_memory_1 (tid, addr + (count - 1)
 181                                                * sizeof (PTRACE_TYPE_RET),
 182                                 &buffer[count - 1]);
 183       if (ret)
 184         return ret;
 185     }
 186
 187   memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
 188           myaddr, len);
 189
 190   for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
 191     {
 192       ret = store_ppc_memory_1 (tid, addr, buffer[i]);
 193       if (ret)
 194         return ret;
 195     }
 196
 197   return 0;
 198 }
 199
 200
 201 /* If the PPU thread is currently stopped on a spu_run system call,
 202    return to FD and ADDR the file handle and NPC parameter address
 203    used with the system call.  Return non-zero if successful.  */
 204 static int
 205 parse_spufs_run (int *fd, ULONGEST *addr)
 206 {
 207   gdb_byte buf[4];
 208   ULONGEST pc = fetch_ppc_register (32);  /* nip */
 209
 210   /* Fetch instruction preceding current NIP.  */
 211   if (fetch_ppc_memory (pc-4, buf, 4) != 0)
 212     return 0;
 213   /* It should be a "sc" instruction.  */
 214   if (extract_unsigned_integer (buf, 4) != INSTR_SC)
 215     return 0;
 216   /* System call number should be NR_spu_run.  */
 217   if (fetch_ppc_register (0) != NR_spu_run)
 218     return 0;
 219
 220   /* Register 3 contains fd, register 4 the NPC param pointer.  */
 221   *fd = fetch_ppc_register (34);  /* orig_gpr3 */
 222   *addr = fetch_ppc_register (4);
 223   return 1;
 224 }
 225
 226
 227 /* Copy LEN bytes at OFFSET in spufs file ANNEX into/from READBUF or WRITEBUF,
 228    using the /proc file system.  */
 229 static LONGEST
 230 spu_proc_xfer_spu (const char *annex, gdb_byte *readbuf,
 231                    const gdb_byte *writebuf,
 232                    ULONGEST offset, LONGEST len)
 233 {
 234   char buf[128];
 235   int fd = 0;
 236   int ret = -1;
 237   int pid = PIDGET (inferior_ptid);
 238
 239   if (!annex)
 240     return 0;
 241
 242   xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
 243   fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
 244   if (fd <= 0)
 245     return -1;
 246
 247   if (offset != 0
 248       && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
 249     {
 250       close (fd);
 251       return 0;
 252     }
 253
 254   if (writebuf)
 255     ret = write (fd, writebuf, (size_t) len);
 256   else if (readbuf)
 257     ret = read (fd, readbuf, (size_t) len);
 258
 259   close (fd);
 260   return ret;
 261 }
 262
 263
 264 /* Inferior memory should contain an SPE executable image at location ADDR.
 265    Allocate a BFD representing that executable.  Return NULL on error.  */
 266
 267 static void *
 268 spu_bfd_iovec_open (struct bfd *nbfd, void *open_closure)
 269 {
 270   return open_closure;
 271 }
 272
 273 static int
 274 spu_bfd_iovec_close (struct bfd *nbfd, void *stream)
 275 {
 276   xfree (stream);
 277   return 1;
 278 }
 279
 280 static file_ptr
 281 spu_bfd_iovec_pread (struct bfd *abfd, void *stream, void *buf,
 282                      file_ptr nbytes, file_ptr offset)
 283 {
 284   ULONGEST addr = *(ULONGEST *)stream;
 285
 286   if (fetch_ppc_memory (addr + offset, buf, nbytes) != 0)
 287     {
 288       bfd_set_error (bfd_error_invalid_operation);
 289       return -1;
 290     }
 291
 292   return nbytes;
 293 }
 294
 295 static int
 296 spu_bfd_iovec_stat (struct bfd *abfd, void *stream, struct stat *sb)
 297 {
 298   /* We don't have an easy way of finding the size of embedded spu
 299      images.  We could parse the in-memory ELF header and section
 300      table to find the extent of the last section but that seems
 301      pointless when the size is needed only for checks of other
 302      parsed values in dbxread.c.  */
 303   sb->st_size = INT_MAX;
 304   return 0;
 305 }
 306
 307 static bfd *
 308 spu_bfd_open (ULONGEST addr)
 309 {
 310   struct bfd *nbfd;
 311
 312   ULONGEST *open_closure = xmalloc (sizeof (ULONGEST));
 313   *open_closure = addr;
 314
 315   nbfd = bfd_openr_iovec (xstrdup ("<in-memory>"), "elf32-spu",
 316                           spu_bfd_iovec_open, open_closure,
 317                           spu_bfd_iovec_pread, spu_bfd_iovec_close,
 318                           spu_bfd_iovec_stat);
 319   if (!nbfd)
 320     return NULL;
 321
 322   if (!bfd_check_format (nbfd, bfd_object))
 323     {
 324       bfd_close (nbfd);
 325       return NULL;
 326     }
 327
 328   return nbfd;
 329 }
 330
 331 /* INFERIOR_FD is a file handle passed by the inferior to the
 332    spu_run system call.  Assuming the SPE context was allocated
 333    by the libspe library, try to retrieve the main SPE executable
 334    file from its copy within the target process.  */
 335 static void
 336 spu_symbol_file_add_from_memory (int inferior_fd)
 337 {
 338   ULONGEST addr;
 339   struct bfd *nbfd;
 340
 341   char id[128];
 342   char annex[32];
 343   int len;
 344
 345   /* Read object ID.  */
 346   xsnprintf (annex, sizeof annex, "%d/object-id", inferior_fd);
 347   len = spu_proc_xfer_spu (annex, id, NULL, 0, sizeof id);
 348   if (len <= 0 || len >= sizeof id)
 349     return;
 350   id[len] = 0;
 351   addr = strtoulst (id, NULL, 16);
 352   if (!addr)
 353     return;
 354
 355   /* Open BFD representing SPE executable and read its symbols.  */
 356   nbfd = spu_bfd_open (addr);
 357   if (nbfd)
 358     symbol_file_add_from_bfd (nbfd, 0, NULL, 1, 0);
 359 }
 360
 361
 362 /* Override the post_startup_inferior routine to continue running
 363    the inferior until the first spu_run system call.  */
 364 static void
 365 spu_child_post_startup_inferior (ptid_t ptid)
 366 {
 367   int fd;
 368   ULONGEST addr;
 369
 370   int tid = TIDGET (ptid);
 371   if (tid == 0)
 372     tid = PIDGET (ptid);
 373
 374   while (!parse_spufs_run (&fd, &addr))
 375     {
 376       ptrace (PT_SYSCALL, tid, (PTRACE_TYPE_ARG3) 0, 0);
 377       waitpid (tid, NULL, __WALL | __WNOTHREAD);
 378     }
 379 }
 380
 381 /* Override the post_attach routine to try load the SPE executable
 382    file image from its copy inside the target process.  */
 383 static void
 384 spu_child_post_attach (int pid)
 385 {
 386   int fd;
 387   ULONGEST addr;
 388
 389   /* Like child_post_startup_inferior, if we happened to attach to
 390      the inferior while it wasn't currently in spu_run, continue
 391      running it until we get back there.  */
 392   while (!parse_spufs_run (&fd, &addr))
 393     {
 394       ptrace (PT_SYSCALL, pid, (PTRACE_TYPE_ARG3) 0, 0);
 395       waitpid (pid, NULL, __WALL | __WNOTHREAD);
 396     }
 397
 398   /* If the user has not provided an executable file, try to extract
 399      the image from inside the target process.  */
 400   if (!get_exec_file (0))
 401     spu_symbol_file_add_from_memory (fd);
 402 }
 403
 404 /* Wait for child PTID to do something.  Return id of the child,
 405    minus_one_ptid in case of error; store status into *OURSTATUS.  */
 406 static ptid_t
 407 spu_child_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
 408 {
 409   int save_errno;
 410   int status;
 411   pid_t pid;
 412
 413   do
 414     {
 415       set_sigint_trap ();       /* Causes SIGINT to be passed on to the
 416                                    attached process.  */
 417
 418       pid = waitpid (PIDGET (ptid), &status, 0);
 419       if (pid == -1 && errno == ECHILD)
 420         /* Try again with __WCLONE to check cloned processes.  */
 421         pid = waitpid (PIDGET (ptid), &status, __WCLONE);
 422
 423       save_errno = errno;
 424
 425       /* Make sure we don't report an event for the exit of the
 426          original program, if we've detached from it.  */
 427       if (pid != -1 && !WIFSTOPPED (status) && pid != PIDGET (inferior_ptid))
 428         {
 429           pid = -1;
 430           save_errno = EINTR;
 431         }
 432
 433       clear_sigint_trap ();
 434     }
 435   while (pid == -1 && save_errno == EINTR);
 436
 437   if (pid == -1)
 438     {
 439       warning (_("Child process unexpectedly missing: %s"),
 440                safe_strerror (save_errno));
 441
 442       /* Claim it exited with unknown signal.  */
 443       ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
 444       ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
 445       return inferior_ptid;
 446     }
 447
 448   store_waitstatus (ourstatus, status);
 449   return pid_to_ptid (pid);
 450 }
 451
 452 /* Override the fetch_inferior_register routine.  */
 453 static void
 454 spu_fetch_inferior_registers (struct regcache *regcache, int regno)
 455 {
 456   int fd;
 457   ULONGEST addr;
 458
 459   /* We must be stopped on a spu_run system call.  */
 460   if (!parse_spufs_run (&fd, &addr))
 461     return;
 462
 463   /* The ID register holds the spufs file handle.  */
 464   if (regno == -1 || regno == SPU_ID_REGNUM)
 465     {
 466       char buf[4];
 467       store_unsigned_integer (buf, 4, fd);
 468       regcache_raw_supply (regcache, SPU_ID_REGNUM, buf);
 469     }
 470
 471   /* The NPC register is found at ADDR.  */
 472   if (regno == -1 || regno == SPU_PC_REGNUM)
 473     {
 474       gdb_byte buf[4];
 475       if (fetch_ppc_memory (addr, buf, 4) == 0)
 476         regcache_raw_supply (regcache, SPU_PC_REGNUM, buf);
 477     }
 478
 479   /* The GPRs are found in the "regs" spufs file.  */
 480   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
 481     {
 482       gdb_byte buf[16 * SPU_NUM_GPRS];
 483       char annex[32];
 484       int i;
 485
 486       xsnprintf (annex, sizeof annex, "%d/regs", fd);
 487       if (spu_proc_xfer_spu (annex, buf, NULL, 0, sizeof buf) == sizeof buf)
 488         for (i = 0; i < SPU_NUM_GPRS; i++)
 489           regcache_raw_supply (regcache, i, buf + i*16);
 490     }
 491 }
 492
 493 /* Override the store_inferior_register routine.  */
 494 static void
 495 spu_store_inferior_registers (struct regcache *regcache, int regno)
 496 {
 497   int fd;
 498   ULONGEST addr;
 499
 500   /* We must be stopped on a spu_run system call.  */
 501   if (!parse_spufs_run (&fd, &addr))
 502     return;
 503
 504   /* The NPC register is found at ADDR.  */
 505   if (regno == -1 || regno == SPU_PC_REGNUM)
 506     {
 507       gdb_byte buf[4];
 508       regcache_raw_collect (regcache, SPU_PC_REGNUM, buf);
 509       store_ppc_memory (addr, buf, 4);
 510     }
 511
 512   /* The GPRs are found in the "regs" spufs file.  */
 513   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
 514     {
 515       gdb_byte buf[16 * SPU_NUM_GPRS];
 516       char annex[32];
 517       int i;
 518
 519       for (i = 0; i < SPU_NUM_GPRS; i++)
 520         regcache_raw_collect (regcache, i, buf + i*16);
 521
 522       xsnprintf (annex, sizeof annex, "%d/regs", fd);
 523       spu_proc_xfer_spu (annex, NULL, buf, 0, sizeof buf);
 524     }
 525 }
 526
 527 /* Override the to_xfer_partial routine.  */
 528 static LONGEST
 529 spu_xfer_partial (struct target_ops *ops,
 530                   enum target_object object, const char *annex,
 531                   gdb_byte *readbuf, const gdb_byte *writebuf,
 532                   ULONGEST offset, LONGEST len)
 533 {
 534   if (object == TARGET_OBJECT_SPU)
 535     return spu_proc_xfer_spu (annex, readbuf, writebuf, offset, len);
 536
 537   if (object == TARGET_OBJECT_MEMORY)
 538     {
 539       int fd;
 540       ULONGEST addr;
 541       char mem_annex[32];
 542
 543       /* We must be stopped on a spu_run system call.  */
 544       if (!parse_spufs_run (&fd, &addr))
 545         return 0;
 546
 547       /* Use the "mem" spufs file to access SPU local store.  */
 548       xsnprintf (mem_annex, sizeof mem_annex, "%d/mem", fd);
 549       return spu_proc_xfer_spu (mem_annex, readbuf, writebuf, offset, len);
 550     }
 551
 552   return -1;
 553 }
 554
 555 /* Override the to_can_use_hw_breakpoint routine.  */
 556 static int
 557 spu_can_use_hw_breakpoint (int type, int cnt, int othertype)
 558 {
 559   return 0;
 560 }
 561
 562
 563 /* Initialize SPU native target.  */
 564 void
 565 _initialize_spu_nat (void)
 566 {
 567   /* Generic ptrace methods.  */
 568   struct target_ops *t;
 569   t = inf_ptrace_target ();
 570
 571   /* Add SPU methods.  */
 572   t->to_post_attach = spu_child_post_attach;
 573   t->to_post_startup_inferior = spu_child_post_startup_inferior;
 574   t->to_wait = spu_child_wait;
 575   t->to_fetch_registers = spu_fetch_inferior_registers;
 576   t->to_store_registers = spu_store_inferior_registers;
 577   t->to_xfer_partial = spu_xfer_partial;
 578   t->to_can_use_hw_breakpoint = spu_can_use_hw_breakpoint;
 579
 580   /* Register SPU target.  */
 581   add_target (t);
 582 }
 583