gdb/spu-linux-nat.c

   1 /* SPU native-dependent code for GDB, the GNU debugger.
   2    Copyright (C) 2006, 2007, 2008, 2009 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   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
 208   gdb_byte buf[4];
 209   ULONGEST pc = fetch_ppc_register (32);  /* nip */
 210
 211   /* Fetch instruction preceding current NIP.  */
 212   if (fetch_ppc_memory (pc-4, buf, 4) != 0)
 213     return 0;
 214   /* It should be a "sc" instruction.  */
 215   if (extract_unsigned_integer (buf, 4, byte_order) != INSTR_SC)
 216     return 0;
 217   /* System call number should be NR_spu_run.  */
 218   if (fetch_ppc_register (0) != NR_spu_run)
 219     return 0;
 220
 221   /* Register 3 contains fd, register 4 the NPC param pointer.  */
 222   *fd = fetch_ppc_register (34);  /* orig_gpr3 */
 223   *addr = fetch_ppc_register (4);
 224   return 1;
 225 }
 226
 227
 228 /* Copy LEN bytes at OFFSET in spufs file ANNEX into/from READBUF or WRITEBUF,
 229    using the /proc file system.  */
 230 static LONGEST
 231 spu_proc_xfer_spu (const char *annex, gdb_byte *readbuf,
 232                    const gdb_byte *writebuf,
 233                    ULONGEST offset, LONGEST len)
 234 {
 235   char buf[128];
 236   int fd = 0;
 237   int ret = -1;
 238   int pid = PIDGET (inferior_ptid);
 239
 240   if (!annex)
 241     return 0;
 242
 243   xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
 244   fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
 245   if (fd <= 0)
 246     return -1;
 247
 248   if (offset != 0
 249       && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
 250     {
 251       close (fd);
 252       return 0;
 253     }
 254
 255   if (writebuf)
 256     ret = write (fd, writebuf, (size_t) len);
 257   else if (readbuf)
 258     ret = read (fd, readbuf, (size_t) len);
 259
 260   close (fd);
 261   return ret;
 262 }
 263
 264
 265 /* Inferior memory should contain an SPE executable image at location ADDR.
 266    Allocate a BFD representing that executable.  Return NULL on error.  */
 267
 268 static void *
 269 spu_bfd_iovec_open (struct bfd *nbfd, void *open_closure)
 270 {
 271   return open_closure;
 272 }
 273
 274 static int
 275 spu_bfd_iovec_close (struct bfd *nbfd, void *stream)
 276 {
 277   xfree (stream);
 278   return 1;
 279 }
 280
 281 static file_ptr
 282 spu_bfd_iovec_pread (struct bfd *abfd, void *stream, void *buf,
 283                      file_ptr nbytes, file_ptr offset)
 284 {
 285   ULONGEST addr = *(ULONGEST *)stream;
 286
 287   if (fetch_ppc_memory (addr + offset, buf, nbytes) != 0)
 288     {
 289       bfd_set_error (bfd_error_invalid_operation);
 290       return -1;
 291     }
 292
 293   return nbytes;
 294 }
 295
 296 static int
 297 spu_bfd_iovec_stat (struct bfd *abfd, void *stream, struct stat *sb)
 298 {
 299   /* We don't have an easy way of finding the size of embedded spu
 300      images.  We could parse the in-memory ELF header and section
 301      table to find the extent of the last section but that seems
 302      pointless when the size is needed only for checks of other
 303      parsed values in dbxread.c.  */
 304   sb->st_size = INT_MAX;
 305   return 0;
 306 }
 307
 308 static bfd *
 309 spu_bfd_open (ULONGEST addr)
 310 {
 311   struct bfd *nbfd;
 312   asection *spu_name;
 313
 314   ULONGEST *open_closure = xmalloc (sizeof (ULONGEST));
 315   *open_closure = addr;
 316
 317   nbfd = bfd_openr_iovec (xstrdup ("<in-memory>"), "elf32-spu",
 318                           spu_bfd_iovec_open, open_closure,
 319                           spu_bfd_iovec_pread, spu_bfd_iovec_close,
 320                           spu_bfd_iovec_stat);
 321   if (!nbfd)
 322     return NULL;
 323
 324   if (!bfd_check_format (nbfd, bfd_object))
 325     {
 326       bfd_close (nbfd);
 327       return NULL;
 328     }
 329
 330   /* Retrieve SPU name note and update BFD name.  */
 331   spu_name = bfd_get_section_by_name (nbfd, ".note.spu_name");
 332   if (spu_name)
 333     {
 334       int sect_size = bfd_section_size (nbfd, spu_name);
 335       if (sect_size > 20)
 336         {
 337           char *buf = alloca (sect_size - 20 + 1);
 338           bfd_get_section_contents (nbfd, spu_name, buf, 20, sect_size - 20);
 339           buf[sect_size - 20] = '\0';
 340
 341           xfree ((char *)nbfd->filename);
 342           nbfd->filename = xstrdup (buf);
 343         }
 344     }
 345
 346   return nbfd;
 347 }
 348
 349 /* INFERIOR_FD is a file handle passed by the inferior to the
 350    spu_run system call.  Assuming the SPE context was allocated
 351    by the libspe library, try to retrieve the main SPE executable
 352    file from its copy within the target process.  */
 353 static void
 354 spu_symbol_file_add_from_memory (int inferior_fd)
 355 {
 356   ULONGEST addr;
 357   struct bfd *nbfd;
 358
 359   char id[128];
 360   char annex[32];
 361   int len;
 362
 363   /* Read object ID.  */
 364   xsnprintf (annex, sizeof annex, "%d/object-id", inferior_fd);
 365   len = spu_proc_xfer_spu (annex, id, NULL, 0, sizeof id);
 366   if (len <= 0 || len >= sizeof id)
 367     return;
 368   id[len] = 0;
 369   addr = strtoulst (id, NULL, 16);
 370   if (!addr)
 371     return;
 372
 373   /* Open BFD representing SPE executable and read its symbols.  */
 374   nbfd = spu_bfd_open (addr);
 375   if (nbfd)
 376     symbol_file_add_from_bfd (nbfd, SYMFILE_VERBOSE | SYMFILE_MAINLINE,
 377                               NULL, 0);
 378 }
 379
 380
 381 /* Override the post_startup_inferior routine to continue running
 382    the inferior until the first spu_run system call.  */
 383 static void
 384 spu_child_post_startup_inferior (ptid_t ptid)
 385 {
 386   int fd;
 387   ULONGEST addr;
 388
 389   int tid = TIDGET (ptid);
 390   if (tid == 0)
 391     tid = PIDGET (ptid);
 392
 393   while (!parse_spufs_run (&fd, &addr))
 394     {
 395       ptrace (PT_SYSCALL, tid, (PTRACE_TYPE_ARG3) 0, 0);
 396       waitpid (tid, NULL, __WALL | __WNOTHREAD);
 397     }
 398 }
 399
 400 /* Override the post_attach routine to try load the SPE executable
 401    file image from its copy inside the target process.  */
 402 static void
 403 spu_child_post_attach (int pid)
 404 {
 405   int fd;
 406   ULONGEST addr;
 407
 408   /* Like child_post_startup_inferior, if we happened to attach to
 409      the inferior while it wasn't currently in spu_run, continue
 410      running it until we get back there.  */
 411   while (!parse_spufs_run (&fd, &addr))
 412     {
 413       ptrace (PT_SYSCALL, pid, (PTRACE_TYPE_ARG3) 0, 0);
 414       waitpid (pid, NULL, __WALL | __WNOTHREAD);
 415     }
 416
 417   /* If the user has not provided an executable file, try to extract
 418      the image from inside the target process.  */
 419   if (!get_exec_file (0))
 420     spu_symbol_file_add_from_memory (fd);
 421 }
 422
 423 /* Wait for child PTID to do something.  Return id of the child,
 424    minus_one_ptid in case of error; store status into *OURSTATUS.  */
 425 static ptid_t
 426 spu_child_wait (struct target_ops *ops,
 427                 ptid_t ptid, struct target_waitstatus *ourstatus, int options)
 428 {
 429   int save_errno;
 430   int status;
 431   pid_t pid;
 432
 433   do
 434     {
 435       set_sigint_trap ();       /* Causes SIGINT to be passed on to the
 436                                    attached process.  */
 437
 438       pid = waitpid (PIDGET (ptid), &status, 0);
 439       if (pid == -1 && errno == ECHILD)
 440         /* Try again with __WCLONE to check cloned processes.  */
 441         pid = waitpid (PIDGET (ptid), &status, __WCLONE);
 442
 443       save_errno = errno;
 444
 445       /* Make sure we don't report an event for the exit of the
 446          original program, if we've detached from it.  */
 447       if (pid != -1 && !WIFSTOPPED (status) && pid != PIDGET (inferior_ptid))
 448         {
 449           pid = -1;
 450           save_errno = EINTR;
 451         }
 452
 453       clear_sigint_trap ();
 454     }
 455   while (pid == -1 && save_errno == EINTR);
 456
 457   if (pid == -1)
 458     {
 459       warning (_("Child process unexpectedly missing: %s"),
 460                safe_strerror (save_errno));
 461
 462       /* Claim it exited with unknown signal.  */
 463       ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
 464       ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
 465       return inferior_ptid;
 466     }
 467
 468   store_waitstatus (ourstatus, status);
 469   return pid_to_ptid (pid);
 470 }
 471
 472 /* Override the fetch_inferior_register routine.  */
 473 static void
 474 spu_fetch_inferior_registers (struct target_ops *ops,
 475                               struct regcache *regcache, int regno)
 476 {
 477   int fd;
 478   ULONGEST addr;
 479
 480   /* We must be stopped on a spu_run system call.  */
 481   if (!parse_spufs_run (&fd, &addr))
 482     return;
 483
 484   /* The ID register holds the spufs file handle.  */
 485   if (regno == -1 || regno == SPU_ID_REGNUM)
 486     {
 487       struct gdbarch *gdbarch = get_regcache_arch (regcache);
 488       enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 489       char buf[4];
 490       store_unsigned_integer (buf, 4, byte_order, fd);
 491       regcache_raw_supply (regcache, SPU_ID_REGNUM, buf);
 492     }
 493
 494   /* The NPC register is found at ADDR.  */
 495   if (regno == -1 || regno == SPU_PC_REGNUM)
 496     {
 497       gdb_byte buf[4];
 498       if (fetch_ppc_memory (addr, buf, 4) == 0)
 499         regcache_raw_supply (regcache, SPU_PC_REGNUM, buf);
 500     }
 501
 502   /* The GPRs are found in the "regs" spufs file.  */
 503   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
 504     {
 505       gdb_byte buf[16 * SPU_NUM_GPRS];
 506       char annex[32];
 507       int i;
 508
 509       xsnprintf (annex, sizeof annex, "%d/regs", fd);
 510       if (spu_proc_xfer_spu (annex, buf, NULL, 0, sizeof buf) == sizeof buf)
 511         for (i = 0; i < SPU_NUM_GPRS; i++)
 512           regcache_raw_supply (regcache, i, buf + i*16);
 513     }
 514 }
 515
 516 /* Override the store_inferior_register routine.  */
 517 static void
 518 spu_store_inferior_registers (struct target_ops *ops,
 519                               struct regcache *regcache, int regno)
 520 {
 521   int fd;
 522   ULONGEST addr;
 523
 524   /* We must be stopped on a spu_run system call.  */
 525   if (!parse_spufs_run (&fd, &addr))
 526     return;
 527
 528   /* The NPC register is found at ADDR.  */
 529   if (regno == -1 || regno == SPU_PC_REGNUM)
 530     {
 531       gdb_byte buf[4];
 532       regcache_raw_collect (regcache, SPU_PC_REGNUM, buf);
 533       store_ppc_memory (addr, buf, 4);
 534     }
 535
 536   /* The GPRs are found in the "regs" spufs file.  */
 537   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
 538     {
 539       gdb_byte buf[16 * SPU_NUM_GPRS];
 540       char annex[32];
 541       int i;
 542
 543       for (i = 0; i < SPU_NUM_GPRS; i++)
 544         regcache_raw_collect (regcache, i, buf + i*16);
 545
 546       xsnprintf (annex, sizeof annex, "%d/regs", fd);
 547       spu_proc_xfer_spu (annex, NULL, buf, 0, sizeof buf);
 548     }
 549 }
 550
 551 /* Override the to_xfer_partial routine.  */
 552 static LONGEST
 553 spu_xfer_partial (struct target_ops *ops,
 554                   enum target_object object, const char *annex,
 555                   gdb_byte *readbuf, const gdb_byte *writebuf,
 556                   ULONGEST offset, LONGEST len)
 557 {
 558   if (object == TARGET_OBJECT_SPU)
 559     return spu_proc_xfer_spu (annex, readbuf, writebuf, offset, len);
 560
 561   if (object == TARGET_OBJECT_MEMORY)
 562     {
 563       int fd;
 564       ULONGEST addr;
 565       char mem_annex[32];
 566
 567       /* We must be stopped on a spu_run system call.  */
 568       if (!parse_spufs_run (&fd, &addr))
 569         return 0;
 570
 571       /* Use the "mem" spufs file to access SPU local store.  */
 572       xsnprintf (mem_annex, sizeof mem_annex, "%d/mem", fd);
 573       return spu_proc_xfer_spu (mem_annex, readbuf, writebuf, offset, len);
 574     }
 575
 576   return -1;
 577 }
 578
 579 /* Override the to_can_use_hw_breakpoint routine.  */
 580 static int
 581 spu_can_use_hw_breakpoint (int type, int cnt, int othertype)
 582 {
 583   return 0;
 584 }
 585
 586
 587 /* Initialize SPU native target.  */
 588 void
 589 _initialize_spu_nat (void)
 590 {
 591   /* Generic ptrace methods.  */
 592   struct target_ops *t;
 593   t = inf_ptrace_target ();
 594
 595   /* Add SPU methods.  */
 596   t->to_post_attach = spu_child_post_attach;
 597   t->to_post_startup_inferior = spu_child_post_startup_inferior;
 598   t->to_wait = spu_child_wait;
 599   t->to_fetch_registers = spu_fetch_inferior_registers;
 600   t->to_store_registers = spu_store_inferior_registers;
 601   t->to_xfer_partial = spu_xfer_partial;
 602   t->to_can_use_hw_breakpoint = spu_can_use_hw_breakpoint;
 603
 604   /* Register SPU target.  */
 605   add_target (t);
 606 }