gdb/gdbserver/spu-low.c

   1 /* Low level interface to SPUs, for the remote server for GDB.
   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 "server.h"
  22
  23 #include <sys/wait.h>
  24 #include <stdio.h>
  25 #include <sys/ptrace.h>
  26 #include <fcntl.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <errno.h>
  31 #include <sys/syscall.h>
  32
  33 /* Some older glibc versions do not define this.  */
  34 #ifndef __WNOTHREAD
  35 #define __WNOTHREAD     0x20000000      /* Don't wait on children of other
  36                                            threads in this group */
  37 #endif
  38
  39 #define PTRACE_TYPE_RET long
  40 #define PTRACE_TYPE_ARG3 long
  41
  42 /* Number of registers.  */
  43 #define SPU_NUM_REGS         130
  44 #define SPU_NUM_CORE_REGS    128
  45
  46 /* Special registers.  */
  47 #define SPU_ID_REGNUM        128
  48 #define SPU_PC_REGNUM        129
  49
  50 /* PPU side system calls.  */
  51 #define INSTR_SC        0x44000002
  52 #define NR_spu_run      0x0116
  53
  54 /* Get current thread ID (Linux task ID).  */
  55 #define current_tid ((struct inferior_list_entry *)current_inferior)->id
  56
  57 /* These are used in remote-utils.c.  */
  58 int using_threads = 0;
  59
  60 /* Defined in auto-generated file reg-spu.c.  */
  61 void init_registers_spu (void);
  62
  63
  64 /* Fetch PPU register REGNO.  */
  65 static CORE_ADDR
  66 fetch_ppc_register (int regno)
  67 {
  68   PTRACE_TYPE_RET res;
  69
  70   int tid = current_tid;
  71
  72 #ifndef __powerpc64__
  73   /* If running as a 32-bit process on a 64-bit system, we attempt
  74      to get the full 64-bit register content of the target process.
  75      If the PPC special ptrace call fails, we're on a 32-bit system;
  76      just fall through to the regular ptrace call in that case.  */
  77   {
  78     char buf[8];
  79
  80     errno = 0;
  81     ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
  82             (PTRACE_TYPE_ARG3) (regno * 8), buf);
  83     if (errno == 0)
  84       ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
  85               (PTRACE_TYPE_ARG3) (regno * 8 + 4), buf + 4);
  86     if (errno == 0)
  87       return (CORE_ADDR) *(unsigned long long *)buf;
  88   }
  89 #endif
  90
  91   errno = 0;
  92   res = ptrace (PT_READ_U, tid,
  93                 (PTRACE_TYPE_ARG3) (regno * sizeof (PTRACE_TYPE_RET)), 0);
  94   if (errno != 0)
  95     {
  96       char mess[128];
  97       sprintf (mess, "reading PPC register #%d", regno);
  98       perror_with_name (mess);
  99     }
 100
 101   return (CORE_ADDR) (unsigned long) res;
 102 }
 103
 104 /* Fetch WORD from PPU memory at (aligned) MEMADDR in thread TID.  */
 105 static int
 106 fetch_ppc_memory_1 (int tid, CORE_ADDR memaddr, PTRACE_TYPE_RET *word)
 107 {
 108   errno = 0;
 109
 110 #ifndef __powerpc64__
 111   if (memaddr >> 32)
 112     {
 113       unsigned long long addr_8 = (unsigned long long) memaddr;
 114       ptrace (PPC_PTRACE_PEEKTEXT_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
 115     }
 116   else
 117 #endif
 118     *word = ptrace (PT_READ_I, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, 0);
 119
 120   return errno;
 121 }
 122
 123 /* Store WORD into PPU memory at (aligned) MEMADDR in thread TID.  */
 124 static int
 125 store_ppc_memory_1 (int tid, CORE_ADDR memaddr, PTRACE_TYPE_RET word)
 126 {
 127   errno = 0;
 128
 129 #ifndef __powerpc64__
 130   if (memaddr >> 32)
 131     {
 132       unsigned long long addr_8 = (unsigned long long) memaddr;
 133       ptrace (PPC_PTRACE_POKEDATA_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
 134     }
 135   else
 136 #endif
 137     ptrace (PT_WRITE_D, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, word);
 138
 139   return errno;
 140 }
 141
 142 /* Fetch LEN bytes of PPU memory at MEMADDR to MYADDR.  */
 143 static int
 144 fetch_ppc_memory (CORE_ADDR memaddr, char *myaddr, int len)
 145 {
 146   int i, ret;
 147
 148   CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_TYPE_RET);
 149   int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
 150                / sizeof (PTRACE_TYPE_RET));
 151   PTRACE_TYPE_RET *buffer;
 152
 153   int tid = current_tid;
 154
 155   buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
 156   for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
 157     if ((ret = fetch_ppc_memory_1 (tid, addr, &buffer[i])) != 0)
 158       return ret;
 159
 160   memcpy (myaddr,
 161           (char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
 162           len);
 163
 164   return 0;
 165 }
 166
 167 /* Store LEN bytes from MYADDR to PPU memory at MEMADDR.  */
 168 static int
 169 store_ppc_memory (CORE_ADDR memaddr, char *myaddr, int len)
 170 {
 171   int i, ret;
 172
 173   CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_TYPE_RET);
 174   int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
 175                / sizeof (PTRACE_TYPE_RET));
 176   PTRACE_TYPE_RET *buffer;
 177
 178   int tid = current_tid;
 179
 180   buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
 181
 182   if (addr != memaddr || len < (int) sizeof (PTRACE_TYPE_RET))
 183     if ((ret = fetch_ppc_memory_1 (tid, addr, &buffer[0])) != 0)
 184       return ret;
 185
 186   if (count > 1)
 187     if ((ret = fetch_ppc_memory_1 (tid, addr + (count - 1)
 188                                                * sizeof (PTRACE_TYPE_RET),
 189                                    &buffer[count - 1])) != 0)
 190       return ret;
 191
 192   memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
 193           myaddr, len);
 194
 195   for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
 196     if ((ret = store_ppc_memory_1 (tid, addr, buffer[i])) != 0)
 197       return ret;
 198
 199   return 0;
 200 }
 201
 202
 203 /* If the PPU thread is currently stopped on a spu_run system call,
 204    return to FD and ADDR the file handle and NPC parameter address
 205    used with the system call.  Return non-zero if successful.  */
 206 static int
 207 parse_spufs_run (int *fd, CORE_ADDR *addr)
 208 {
 209   char buf[4];
 210   CORE_ADDR pc = fetch_ppc_register (32);  /* nip */
 211
 212   /* Fetch instruction preceding current NIP.  */
 213   if (fetch_ppc_memory (pc-4, buf, 4) != 0)
 214     return 0;
 215   /* It should be a "sc" instruction.  */
 216   if (*(unsigned int *)buf != INSTR_SC)
 217     return 0;
 218   /* System call number should be NR_spu_run.  */
 219   if (fetch_ppc_register (0) != NR_spu_run)
 220     return 0;
 221
 222   /* Register 3 contains fd, register 4 the NPC param pointer.  */
 223   *fd = fetch_ppc_register (34);  /* orig_gpr3 */
 224   *addr = fetch_ppc_register (4);
 225   return 1;
 226 }
 227
 228
 229 /* Copy LEN bytes at OFFSET in spufs file ANNEX into/from READBUF or WRITEBUF,
 230    using the /proc file system.  */
 231 static int
 232 spu_proc_xfer_spu (const char *annex, unsigned char *readbuf,
 233                    const unsigned char *writebuf,
 234                    CORE_ADDR offset, int len)
 235 {
 236   char buf[128];
 237   int fd = 0;
 238   int ret = -1;
 239
 240   if (!annex)
 241     return 0;
 242
 243   sprintf (buf, "/proc/%ld/fd/%s", current_tid, 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 /* Start an inferior process and returns its pid.
 266    ALLARGS is a vector of program-name and args. */
 267 static int
 268 spu_create_inferior (char *program, char **allargs)
 269 {
 270   int pid;
 271   ptid_t ptid;
 272
 273   pid = fork ();
 274   if (pid < 0)
 275     perror_with_name ("fork");
 276
 277   if (pid == 0)
 278     {
 279       ptrace (PTRACE_TRACEME, 0, 0, 0);
 280
 281       setpgid (0, 0);
 282
 283       execv (program, allargs);
 284       if (errno == ENOENT)
 285         execvp (program, allargs);
 286
 287       fprintf (stderr, "Cannot exec %s: %s.\n", program,
 288                strerror (errno));
 289       fflush (stderr);
 290       _exit (0177);
 291     }
 292
 293   add_process (pid, 0);
 294
 295   ptid = ptid_build (pid, pid, 0);
 296   add_thread (ptid, NULL);
 297   return pid;
 298 }
 299
 300 /* Attach to an inferior process.  */
 301 int
 302 spu_attach (unsigned long  pid)
 303 {
 304   ptid_t ptid;
 305
 306   if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
 307     {
 308       fprintf (stderr, "Cannot attach to process %ld: %s (%d)\n", pid,
 309                strerror (errno), errno);
 310       fflush (stderr);
 311       _exit (0177);
 312     }
 313
 314   add_process (pid, 1);
 315   ptid = ptid_build (pid, pid, 0);
 316   add_thread (ptid, NULL);
 317   return 0;
 318 }
 319
 320 /* Kill the inferior process.  */
 321 static int
 322 spu_kill (int)
 323 {
 324   ptrace (PTRACE_KILL, current_tid, 0, 0);
 325   remove_process (pid);
 326   return 0;
 327 }
 328
 329 /* Detach from inferior process.  */
 330 static int
 331 spu_detach (int pid)
 332 {
 333   ptrace (PTRACE_DETACH, current_tid, 0, 0);
 334   remove_process (pid);
 335   return 0;
 336 }
 337
 338 static void
 339 spu_join (int pid)
 340 {
 341   int status, ret;
 342
 343   do {
 344     ret = waitpid (current_tid, &status, 0);
 345     if (WIFEXITED (status) || WIFSIGNALED (status))
 346       break;
 347   } while (ret != -1 || errno != ECHILD);
 348 }
 349
 350 /* Return nonzero if the given thread is still alive.  */
 351 static int
 352 spu_thread_alive (ptid_t ptid)
 353 {
 354   return ptid_get_lwp (ptid) == current_tid;
 355 }
 356
 357 /* Resume process.  */
 358 static void
 359 spu_resume (struct thread_resume *resume_info, size_t n)
 360 {
 361   size_t i;
 362
 363   for (i = 0; i < n; i++)
 364     if (ptid_equal (resume_info[i].thread, minus_one_ptid)
 365         || ptid_get_lwp (resume_info[i].thread) == current_tid)
 366       break;
 367
 368   if (i == n)
 369     return;
 370
 371   /* We don't support hardware single-stepping right now, assume
 372      GDB knows to use software single-stepping.  */
 373   if (resume_info[i].kind == resume_step)
 374     fprintf (stderr, "Hardware single-step not supported.\n");
 375
 376   regcache_invalidate ();
 377
 378   errno = 0;
 379   ptrace (PTRACE_CONT, current_tid, 0, resume_info[i].sig);
 380   if (errno)
 381     perror_with_name ("ptrace");
 382 }
 383
 384 /* Wait for process, returns status.  */
 385 static ptid_t
 386 spu_wait (ptid_t ptid, struct target_waitstatus *ourstatus, int options)
 387 {
 388   int tid = current_tid;
 389   int w;
 390   int ret;
 391
 392   while (1)
 393     {
 394       ret = waitpid (tid, &w, WNOHANG | __WALL | __WNOTHREAD);
 395
 396       if (ret == -1)
 397         {
 398           if (errno != ECHILD)
 399             perror_with_name ("waitpid");
 400         }
 401       else if (ret > 0)
 402         break;
 403
 404       usleep (1000);
 405     }
 406
 407   /* On the first wait, continue running the inferior until we are
 408      blocked inside an spu_run system call.  */
 409   if (!server_waiting)
 410     {
 411       int fd;
 412       CORE_ADDR addr;
 413
 414       while (!parse_spufs_run (&fd, &addr))
 415         {
 416           ptrace (PT_SYSCALL, tid, (PTRACE_TYPE_ARG3) 0, 0);
 417           waitpid (tid, NULL, __WALL | __WNOTHREAD);
 418         }
 419     }
 420
 421   ret = current_tid;
 422
 423   if (WIFEXITED (w))
 424     {
 425       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
 426       ourstatus->kind =  TARGET_WAITKIND_EXITED;
 427       ourstatus->value.integer = WEXITSTATUS (w);
 428       clear_inferiors ();
 429       remove_process (ret);
 430       return pid_to_ptid (ret);
 431     }
 432   else if (!WIFSTOPPED (w))
 433     {
 434       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
 435       ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
 436       ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
 437       clear_inferiors ();
 438       remove_process (ret);
 439       return pid_to_ptid (ret);
 440     }
 441
 442   /* After attach, we may have received a SIGSTOP.  Do not return this
 443      as signal to GDB, or else it will try to continue with SIGSTOP ...  */
 444   if (!server_waiting)
 445     {
 446       ourstatus->kind = TARGET_WAITKIND_STOPPED;
 447       ourstatus->value.sig = TARGET_SIGNAL_0;
 448       return ptid_build (ret, ret, 0);
 449     }
 450
 451   ourstatus->kind = TARGET_WAITKIND_STOPPED;
 452   ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
 453   return ptid_build (ret, ret, 0);
 454 }
 455
 456 /* Fetch inferior registers.  */
 457 static void
 458 spu_fetch_registers (int regno)
 459 {
 460   int fd;
 461   CORE_ADDR addr;
 462
 463   /* ??? Some callers use 0 to mean all registers.  */
 464   if (regno == 0)
 465     regno = -1;
 466
 467   /* We must be stopped on a spu_run system call.  */
 468   if (!parse_spufs_run (&fd, &addr))
 469     return;
 470
 471   /* The ID register holds the spufs file handle.  */
 472   if (regno == -1 || regno == SPU_ID_REGNUM)
 473     supply_register (SPU_ID_REGNUM, (char *)&fd);
 474
 475   /* The NPC register is found at ADDR.  */
 476   if (regno == -1 || regno == SPU_PC_REGNUM)
 477     {
 478       char buf[4];
 479       if (fetch_ppc_memory (addr, buf, 4) == 0)
 480         supply_register (SPU_PC_REGNUM, buf);
 481     }
 482
 483   /* The GPRs are found in the "regs" spufs file.  */
 484   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_CORE_REGS))
 485     {
 486       unsigned char buf[16*SPU_NUM_CORE_REGS];
 487       char annex[32];
 488       int i;
 489
 490       sprintf (annex, "%d/regs", fd);
 491       if (spu_proc_xfer_spu (annex, buf, NULL, 0, sizeof buf) == sizeof buf)
 492         for (i = 0; i < SPU_NUM_CORE_REGS; i++)
 493           supply_register (i, buf + i*16);
 494     }
 495 }
 496
 497 /* Store inferior registers.  */
 498 static void
 499 spu_store_registers (int regno)
 500 {
 501   int fd;
 502   CORE_ADDR addr;
 503
 504   /* ??? Some callers use 0 to mean all registers.  */
 505   if (regno == 0)
 506     regno = -1;
 507
 508   /* We must be stopped on a spu_run system call.  */
 509   if (!parse_spufs_run (&fd, &addr))
 510     return;
 511
 512   /* The NPC register is found at ADDR.  */
 513   if (regno == -1 || regno == SPU_PC_REGNUM)
 514     {
 515       char buf[4];
 516       collect_register (SPU_PC_REGNUM, buf);
 517       store_ppc_memory (addr, buf, 4);
 518     }
 519
 520   /* The GPRs are found in the "regs" spufs file.  */
 521   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_CORE_REGS))
 522     {
 523       unsigned char buf[16*SPU_NUM_CORE_REGS];
 524       char annex[32];
 525       int i;
 526
 527       for (i = 0; i < SPU_NUM_CORE_REGS; i++)
 528         collect_register (i, buf + i*16);
 529
 530       sprintf (annex, "%d/regs", fd);
 531       spu_proc_xfer_spu (annex, NULL, buf, 0, sizeof buf);
 532     }
 533 }
 534
 535 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 536    to debugger memory starting at MYADDR.  */
 537 static int
 538 spu_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
 539 {
 540   int fd, ret;
 541   CORE_ADDR addr;
 542   char annex[32];
 543
 544   /* We must be stopped on a spu_run system call.  */
 545   if (!parse_spufs_run (&fd, &addr))
 546     return 0;
 547
 548   /* Use the "mem" spufs file to access SPU local store.  */
 549   sprintf (annex, "%d/mem", fd);
 550   ret = spu_proc_xfer_spu (annex, myaddr, NULL, memaddr, len);
 551   return ret == len ? 0 : EIO;
 552 }
 553
 554 /* Copy LEN bytes of data from debugger memory at MYADDR
 555    to inferior's memory at MEMADDR.
 556    On failure (cannot write the inferior)
 557    returns the value of errno.  */
 558 static int
 559 spu_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
 560 {
 561   int fd, ret;
 562   CORE_ADDR addr;
 563   char annex[32];
 564
 565   /* We must be stopped on a spu_run system call.  */
 566   if (!parse_spufs_run (&fd, &addr))
 567     return 0;
 568
 569   /* Use the "mem" spufs file to access SPU local store.  */
 570   sprintf (annex, "%d/mem", fd);
 571   ret = spu_proc_xfer_spu (annex, NULL, myaddr, memaddr, len);
 572   return ret == len ? 0 : EIO;
 573 }
 574
 575 /* Look up special symbols -- unneded here.  */
 576 static void
 577 spu_look_up_symbols (void)
 578 {
 579 }
 580
 581 /* Send signal to inferior.  */
 582 static void
 583 spu_request_interrupt (void)
 584 {
 585   syscall (SYS_tkill, current_tid, SIGINT);
 586 }
 587
 588 static struct target_ops spu_target_ops = {
 589   spu_create_inferior,
 590   spu_attach,
 591   spu_kill,
 592   spu_detach,
 593   spu_join,
 594   spu_thread_alive,
 595   spu_resume,
 596   spu_wait,
 597   spu_fetch_registers,
 598   spu_store_registers,
 599   spu_read_memory,
 600   spu_write_memory,
 601   spu_look_up_symbols,
 602   spu_request_interrupt,
 603   NULL,
 604   NULL,
 605   NULL,
 606   NULL,
 607   NULL,
 608   NULL,
 609   NULL,
 610   spu_proc_xfer_spu,
 611   hostio_last_error_from_errno,
 612 };
 613
 614 void
 615 initialize_low (void)
 616 {
 617   static const unsigned char breakpoint[] = { 0x00, 0x00, 0x3f, 0xff };
 618
 619   set_target_ops (&spu_target_ops);
 620   set_breakpoint_data (breakpoint, sizeof breakpoint);
 621   init_registers_spu ();
 622 }