gdb/arm-linux-nat.c

   1 /* GNU/Linux on ARM native support.
   2    Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007
   3    Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "inferior.h"
  24 #include "gdbcore.h"
  25 #include "gdb_string.h"
  26 #include "regcache.h"
  27 #include "target.h"
  28 #include "linux-nat.h"
  29 #include "target-descriptions.h"
  30 #include "xml-support.h"
  31
  32 #include "arm-tdep.h"
  33 #include "arm-linux-tdep.h"
  34
  35 #include <sys/user.h>
  36 #include <sys/ptrace.h>
  37 #include <sys/utsname.h>
  38 #include <sys/procfs.h>
  39
  40 /* Prototypes for supply_gregset etc. */
  41 #include "gregset.h"
  42
  43 /* Defines ps_err_e, struct ps_prochandle.  */
  44 #include "gdb_proc_service.h"
  45
  46 #ifndef PTRACE_GET_THREAD_AREA
  47 #define PTRACE_GET_THREAD_AREA 22
  48 #endif
  49
  50 #ifndef PTRACE_GETWMMXREGS
  51 #define PTRACE_GETWMMXREGS 18
  52 #define PTRACE_SETWMMXREGS 19
  53 #endif
  54
  55 /* A flag for whether the WMMX registers are available.  */
  56 static int arm_linux_has_wmmx_registers;
  57
  58 extern int arm_apcs_32;
  59
  60 /* The following variables are used to determine the version of the
  61    underlying GNU/Linux operating system.  Examples:
  62
  63    GNU/Linux 2.0.35             GNU/Linux 2.2.12
  64    os_version = 0x00020023      os_version = 0x0002020c
  65    os_major = 2                 os_major = 2
  66    os_minor = 0                 os_minor = 2
  67    os_release = 35              os_release = 12
  68
  69    Note: os_version = (os_major << 16) | (os_minor << 8) | os_release
  70
  71    These are initialized using get_linux_version() from
  72    _initialize_arm_linux_nat().  */
  73
  74 static unsigned int os_version, os_major, os_minor, os_release;
  75
  76 /* On GNU/Linux, threads are implemented as pseudo-processes, in which
  77    case we may be tracing more than one process at a time.  In that
  78    case, inferior_ptid will contain the main process ID and the
  79    individual thread (process) ID.  get_thread_id () is used to get
  80    the thread id if it's available, and the process id otherwise.  */
  81
  82 int
  83 get_thread_id (ptid_t ptid)
  84 {
  85   int tid = TIDGET (ptid);
  86   if (0 == tid)
  87     tid = PIDGET (ptid);
  88   return tid;
  89 }
  90 #define GET_THREAD_ID(PTID)     get_thread_id (PTID)
  91
  92 /* Get the value of a particular register from the floating point
  93    state of the process and store it into regcache.  */
  94
  95 static void
  96 fetch_fpregister (int regno)
  97 {
  98   int ret, tid;
  99   gdb_byte fp[ARM_LINUX_SIZEOF_NWFPE];
 100
 101   /* Get the thread id for the ptrace call.  */
 102   tid = GET_THREAD_ID (inferior_ptid);
 103
 104   /* Read the floating point state.  */
 105   ret = ptrace (PT_GETFPREGS, tid, 0, fp);
 106   if (ret < 0)
 107     {
 108       warning (_("Unable to fetch floating point register."));
 109       return;
 110     }
 111
 112   /* Fetch fpsr.  */
 113   if (ARM_FPS_REGNUM == regno)
 114     regcache_raw_supply (current_regcache, ARM_FPS_REGNUM,
 115                          fp + NWFPE_FPSR_OFFSET);
 116
 117   /* Fetch the floating point register.  */
 118   if (regno >= ARM_F0_REGNUM && regno <= ARM_F7_REGNUM)
 119     supply_nwfpe_register (current_regcache, regno, fp);
 120 }
 121
 122 /* Get the whole floating point state of the process and store it
 123    into regcache.  */
 124
 125 static void
 126 fetch_fpregs (void)
 127 {
 128   int ret, regno, tid;
 129   gdb_byte fp[ARM_LINUX_SIZEOF_NWFPE];
 130
 131   /* Get the thread id for the ptrace call.  */
 132   tid = GET_THREAD_ID (inferior_ptid);
 133
 134   /* Read the floating point state.  */
 135   ret = ptrace (PT_GETFPREGS, tid, 0, fp);
 136   if (ret < 0)
 137     {
 138       warning (_("Unable to fetch the floating point registers."));
 139       return;
 140     }
 141
 142   /* Fetch fpsr.  */
 143   regcache_raw_supply (current_regcache, ARM_FPS_REGNUM,
 144                        fp + NWFPE_FPSR_OFFSET);
 145
 146   /* Fetch the floating point registers.  */
 147   for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
 148     supply_nwfpe_register (current_regcache, regno, fp);
 149 }
 150
 151 /* Save a particular register into the floating point state of the
 152    process using the contents from regcache.  */
 153
 154 static void
 155 store_fpregister (int regno)
 156 {
 157   int ret, tid;
 158   gdb_byte fp[ARM_LINUX_SIZEOF_NWFPE];
 159
 160   /* Get the thread id for the ptrace call.  */
 161   tid = GET_THREAD_ID (inferior_ptid);
 162
 163   /* Read the floating point state.  */
 164   ret = ptrace (PT_GETFPREGS, tid, 0, fp);
 165   if (ret < 0)
 166     {
 167       warning (_("Unable to fetch the floating point registers."));
 168       return;
 169     }
 170
 171   /* Store fpsr.  */
 172   if (ARM_FPS_REGNUM == regno && register_cached (ARM_FPS_REGNUM))
 173     regcache_raw_collect (current_regcache, ARM_FPS_REGNUM,
 174                           fp + NWFPE_FPSR_OFFSET);
 175
 176   /* Store the floating point register.  */
 177   if (regno >= ARM_F0_REGNUM && regno <= ARM_F7_REGNUM)
 178     collect_nwfpe_register (current_regcache, regno, fp);
 179
 180   ret = ptrace (PTRACE_SETFPREGS, tid, 0, fp);
 181   if (ret < 0)
 182     {
 183       warning (_("Unable to store floating point register."));
 184       return;
 185     }
 186 }
 187
 188 /* Save the whole floating point state of the process using
 189    the contents from regcache.  */
 190
 191 static void
 192 store_fpregs (void)
 193 {
 194   int ret, regno, tid;
 195   gdb_byte fp[ARM_LINUX_SIZEOF_NWFPE];
 196
 197   /* Get the thread id for the ptrace call.  */
 198   tid = GET_THREAD_ID (inferior_ptid);
 199
 200   /* Read the floating point state.  */
 201   ret = ptrace (PT_GETFPREGS, tid, 0, fp);
 202   if (ret < 0)
 203     {
 204       warning (_("Unable to fetch the floating point registers."));
 205       return;
 206     }
 207
 208   /* Store fpsr.  */
 209   if (register_cached (ARM_FPS_REGNUM))
 210     regcache_raw_collect (current_regcache, ARM_FPS_REGNUM,
 211                           fp + NWFPE_FPSR_OFFSET);
 212
 213   /* Store the floating point registers.  */
 214   for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
 215     if (register_cached (regno))
 216       collect_nwfpe_register (current_regcache, regno, fp);
 217
 218   ret = ptrace (PTRACE_SETFPREGS, tid, 0, fp);
 219   if (ret < 0)
 220     {
 221       warning (_("Unable to store floating point registers."));
 222       return;
 223     }
 224 }
 225
 226 /* Fetch a general register of the process and store into
 227    regcache.  */
 228
 229 static void
 230 fetch_register (int regno)
 231 {
 232   int ret, tid;
 233   elf_gregset_t regs;
 234
 235   /* Get the thread id for the ptrace call.  */
 236   tid = GET_THREAD_ID (inferior_ptid);
 237
 238   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 239   if (ret < 0)
 240     {
 241       warning (_("Unable to fetch general register."));
 242       return;
 243     }
 244
 245   if (regno >= ARM_A1_REGNUM && regno < ARM_PC_REGNUM)
 246     regcache_raw_supply (current_regcache, regno, (char *) &regs[regno]);
 247
 248   if (ARM_PS_REGNUM == regno)
 249     {
 250       if (arm_apcs_32)
 251         regcache_raw_supply (current_regcache, ARM_PS_REGNUM,
 252                              (char *) &regs[ARM_CPSR_REGNUM]);
 253       else
 254         regcache_raw_supply (current_regcache, ARM_PS_REGNUM,
 255                              (char *) &regs[ARM_PC_REGNUM]);
 256     }
 257
 258   if (ARM_PC_REGNUM == regno)
 259     {
 260       regs[ARM_PC_REGNUM] = ADDR_BITS_REMOVE (regs[ARM_PC_REGNUM]);
 261       regcache_raw_supply (current_regcache, ARM_PC_REGNUM,
 262                            (char *) &regs[ARM_PC_REGNUM]);
 263     }
 264 }
 265
 266 /* Fetch all general registers of the process and store into
 267    regcache.  */
 268
 269 static void
 270 fetch_regs (void)
 271 {
 272   int ret, regno, tid;
 273   elf_gregset_t regs;
 274
 275   /* Get the thread id for the ptrace call.  */
 276   tid = GET_THREAD_ID (inferior_ptid);
 277
 278   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 279   if (ret < 0)
 280     {
 281       warning (_("Unable to fetch general registers."));
 282       return;
 283     }
 284
 285   for (regno = ARM_A1_REGNUM; regno < ARM_PC_REGNUM; regno++)
 286     regcache_raw_supply (current_regcache, regno, (char *) &regs[regno]);
 287
 288   if (arm_apcs_32)
 289     regcache_raw_supply (current_regcache, ARM_PS_REGNUM,
 290                          (char *) &regs[ARM_CPSR_REGNUM]);
 291   else
 292     regcache_raw_supply (current_regcache, ARM_PS_REGNUM,
 293                          (char *) &regs[ARM_PC_REGNUM]);
 294
 295   regs[ARM_PC_REGNUM] = ADDR_BITS_REMOVE (regs[ARM_PC_REGNUM]);
 296   regcache_raw_supply (current_regcache, ARM_PC_REGNUM,
 297                        (char *) &regs[ARM_PC_REGNUM]);
 298 }
 299
 300 /* Store all general registers of the process from the values in
 301    regcache.  */
 302
 303 static void
 304 store_register (int regno)
 305 {
 306   int ret, tid;
 307   elf_gregset_t regs;
 308
 309   if (!register_cached (regno))
 310     return;
 311
 312   /* Get the thread id for the ptrace call.  */
 313   tid = GET_THREAD_ID (inferior_ptid);
 314
 315   /* Get the general registers from the process.  */
 316   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 317   if (ret < 0)
 318     {
 319       warning (_("Unable to fetch general registers."));
 320       return;
 321     }
 322
 323   if (regno >= ARM_A1_REGNUM && regno <= ARM_PC_REGNUM)
 324     regcache_raw_collect (current_regcache, regno, (char *) &regs[regno]);
 325   else if (arm_apcs_32 && regno == ARM_PS_REGNUM)
 326     regcache_raw_collect (current_regcache, regno,
 327                          (char *) &regs[ARM_CPSR_REGNUM]);
 328   else if (!arm_apcs_32 && regno == ARM_PS_REGNUM)
 329     regcache_raw_collect (current_regcache, ARM_PC_REGNUM,
 330                          (char *) &regs[ARM_PC_REGNUM]);
 331
 332   ret = ptrace (PTRACE_SETREGS, tid, 0, &regs);
 333   if (ret < 0)
 334     {
 335       warning (_("Unable to store general register."));
 336       return;
 337     }
 338 }
 339
 340 static void
 341 store_regs (void)
 342 {
 343   int ret, regno, tid;
 344   elf_gregset_t regs;
 345
 346   /* Get the thread id for the ptrace call.  */
 347   tid = GET_THREAD_ID (inferior_ptid);
 348
 349   /* Fetch the general registers.  */
 350   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 351   if (ret < 0)
 352     {
 353       warning (_("Unable to fetch general registers."));
 354       return;
 355     }
 356
 357   for (regno = ARM_A1_REGNUM; regno <= ARM_PC_REGNUM; regno++)
 358     {
 359       if (register_cached (regno))
 360         regcache_raw_collect (current_regcache, regno, (char *) &regs[regno]);
 361     }
 362
 363   if (arm_apcs_32 && register_cached (ARM_PS_REGNUM))
 364     regcache_raw_collect (current_regcache, ARM_PS_REGNUM,
 365                          (char *) &regs[ARM_CPSR_REGNUM]);
 366
 367   ret = ptrace (PTRACE_SETREGS, tid, 0, &regs);
 368
 369   if (ret < 0)
 370     {
 371       warning (_("Unable to store general registers."));
 372       return;
 373     }
 374 }
 375
 376 /* Fetch all WMMX registers of the process and store into
 377    regcache.  */
 378
 379 #define IWMMXT_REGS_SIZE (16 * 8 + 6 * 4)
 380
 381 static void
 382 fetch_wmmx_regs (void)
 383 {
 384   char regbuf[IWMMXT_REGS_SIZE];
 385   int ret, regno, tid;
 386
 387   /* Get the thread id for the ptrace call.  */
 388   tid = GET_THREAD_ID (inferior_ptid);
 389
 390   ret = ptrace (PTRACE_GETWMMXREGS, tid, 0, regbuf);
 391   if (ret < 0)
 392     {
 393       warning (_("Unable to fetch WMMX registers."));
 394       return;
 395     }
 396
 397   for (regno = 0; regno < 16; regno++)
 398     regcache_raw_supply (current_regcache, regno + ARM_WR0_REGNUM,
 399                          &regbuf[regno * 8]);
 400
 401   for (regno = 0; regno < 2; regno++)
 402     regcache_raw_supply (current_regcache, regno + ARM_WCSSF_REGNUM,
 403                          &regbuf[16 * 8 + regno * 4]);
 404
 405   for (regno = 0; regno < 4; regno++)
 406     regcache_raw_supply (current_regcache, regno + ARM_WCGR0_REGNUM,
 407                          &regbuf[16 * 8 + 2 * 4 + regno * 4]);
 408 }
 409
 410 static void
 411 store_wmmx_regs (void)
 412 {
 413   char regbuf[IWMMXT_REGS_SIZE];
 414   int ret, regno, tid;
 415
 416   /* Get the thread id for the ptrace call.  */
 417   tid = GET_THREAD_ID (inferior_ptid);
 418
 419   ret = ptrace (PTRACE_GETWMMXREGS, tid, 0, regbuf);
 420   if (ret < 0)
 421     {
 422       warning (_("Unable to fetch WMMX registers."));
 423       return;
 424     }
 425
 426   for (regno = 0; regno < 16; regno++)
 427     if (register_cached (regno + ARM_WR0_REGNUM))
 428       regcache_raw_collect (current_regcache, regno + ARM_WR0_REGNUM,
 429                             &regbuf[regno * 8]);
 430
 431   for (regno = 0; regno < 2; regno++)
 432     if (register_cached (regno + ARM_WCSSF_REGNUM))
 433       regcache_raw_collect (current_regcache, regno + ARM_WCSSF_REGNUM,
 434                             &regbuf[16 * 8 + regno * 4]);
 435
 436   for (regno = 0; regno < 4; regno++)
 437     if (register_cached (regno + ARM_WCGR0_REGNUM))
 438       regcache_raw_collect (current_regcache, regno + ARM_WCGR0_REGNUM,
 439                             &regbuf[16 * 8 + 2 * 4 + regno * 4]);
 440
 441   ret = ptrace (PTRACE_SETWMMXREGS, tid, 0, regbuf);
 442
 443   if (ret < 0)
 444     {
 445       warning (_("Unable to store WMMX registers."));
 446       return;
 447     }
 448 }
 449
 450 /* Fetch registers from the child process.  Fetch all registers if
 451    regno == -1, otherwise fetch all general registers or all floating
 452    point registers depending upon the value of regno.  */
 453
 454 static void
 455 arm_linux_fetch_inferior_registers (int regno)
 456 {
 457   if (-1 == regno)
 458     {
 459       fetch_regs ();
 460       fetch_fpregs ();
 461       if (arm_linux_has_wmmx_registers)
 462         fetch_wmmx_regs ();
 463     }
 464   else
 465     {
 466       if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
 467         fetch_register (regno);
 468       else if (regno >= ARM_F0_REGNUM && regno <= ARM_FPS_REGNUM)
 469         fetch_fpregister (regno);
 470       else if (arm_linux_has_wmmx_registers
 471                && regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
 472         fetch_wmmx_regs ();
 473     }
 474 }
 475
 476 /* Store registers back into the inferior.  Store all registers if
 477    regno == -1, otherwise store all general registers or all floating
 478    point registers depending upon the value of regno.  */
 479
 480 static void
 481 arm_linux_store_inferior_registers (int regno)
 482 {
 483   if (-1 == regno)
 484     {
 485       store_regs ();
 486       store_fpregs ();
 487       if (arm_linux_has_wmmx_registers)
 488         store_wmmx_regs ();
 489     }
 490   else
 491     {
 492       if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
 493         store_register (regno);
 494       else if ((regno >= ARM_F0_REGNUM) && (regno <= ARM_FPS_REGNUM))
 495         store_fpregister (regno);
 496       else if (arm_linux_has_wmmx_registers
 497                && regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
 498         store_wmmx_regs ();
 499     }
 500 }
 501
 502 /* Wrapper functions for the standard regset handling, used by
 503    thread debugging.  */
 504
 505 void
 506 fill_gregset (gdb_gregset_t *gregsetp, int regno)
 507 {
 508   arm_linux_collect_gregset (NULL, current_regcache, regno, gregsetp, 0);
 509 }
 510
 511 void
 512 supply_gregset (gdb_gregset_t *gregsetp)
 513 {
 514   arm_linux_supply_gregset (NULL, current_regcache, -1, gregsetp, 0);
 515 }
 516
 517 void
 518 fill_fpregset (gdb_fpregset_t *fpregsetp, int regno)
 519 {
 520   arm_linux_collect_nwfpe (NULL, current_regcache, regno, fpregsetp, 0);
 521 }
 522
 523 /* Fill GDB's register array with the floating-point register values
 524    in *fpregsetp.  */
 525
 526 void
 527 supply_fpregset (gdb_fpregset_t *fpregsetp)
 528 {
 529   arm_linux_supply_nwfpe (NULL, current_regcache, -1, fpregsetp, 0);
 530 }
 531
 532 int
 533 arm_linux_kernel_u_size (void)
 534 {
 535   return (sizeof (struct user));
 536 }
 537
 538 /* Fetch the thread-local storage pointer for libthread_db.  */
 539
 540 ps_err_e
 541 ps_get_thread_area (const struct ps_prochandle *ph,
 542                     lwpid_t lwpid, int idx, void **base)
 543 {
 544   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 545     return PS_ERR;
 546
 547   /* IDX is the bias from the thread pointer to the beginning of the
 548      thread descriptor.  It has to be subtracted due to implementation
 549      quirks in libthread_db.  */
 550   *base = (void *) ((char *)*base - idx);
 551
 552   return PS_OK;
 553 }
 554
 555 static unsigned int
 556 get_linux_version (unsigned int *vmajor,
 557                    unsigned int *vminor,
 558                    unsigned int *vrelease)
 559 {
 560   struct utsname info;
 561   char *pmajor, *pminor, *prelease, *tail;
 562
 563   if (-1 == uname (&info))
 564     {
 565       warning (_("Unable to determine GNU/Linux version."));
 566       return -1;
 567     }
 568
 569   pmajor = strtok (info.release, ".");
 570   pminor = strtok (NULL, ".");
 571   prelease = strtok (NULL, ".");
 572
 573   *vmajor = (unsigned int) strtoul (pmajor, &tail, 0);
 574   *vminor = (unsigned int) strtoul (pminor, &tail, 0);
 575   *vrelease = (unsigned int) strtoul (prelease, &tail, 0);
 576
 577   return ((*vmajor << 16) | (*vminor << 8) | *vrelease);
 578 }
 579
 580 static LONGEST (*super_xfer_partial) (struct target_ops *, enum target_object,
 581                                       const char *, gdb_byte *, const gdb_byte *,
 582                                       ULONGEST, LONGEST);
 583
 584 static LONGEST
 585 arm_linux_xfer_partial (struct target_ops *ops,
 586                          enum target_object object,
 587                          const char *annex,
 588                          gdb_byte *readbuf, const gdb_byte *writebuf,
 589                          ULONGEST offset, LONGEST len)
 590 {
 591   if (object == TARGET_OBJECT_AVAILABLE_FEATURES)
 592     {
 593       if (annex != NULL && strcmp (annex, "target.xml") == 0)
 594         {
 595           int ret;
 596           char regbuf[IWMMXT_REGS_SIZE];
 597
 598           ret = ptrace (PTRACE_GETWMMXREGS, GET_THREAD_ID (inferior_ptid),
 599                         0, regbuf);
 600           if (ret < 0)
 601             arm_linux_has_wmmx_registers = 0;
 602           else
 603             arm_linux_has_wmmx_registers = 1;
 604
 605           if (arm_linux_has_wmmx_registers)
 606             annex = "arm-with-iwmmxt.xml";
 607           else
 608             return -1;
 609         }
 610
 611       return xml_builtin_xfer_partial (annex, readbuf, writebuf, offset, len);
 612     }
 613
 614   return super_xfer_partial (ops, object, annex, readbuf, writebuf,
 615                              offset, len);
 616 }
 617
 618 void _initialize_arm_linux_nat (void);
 619
 620 void
 621 _initialize_arm_linux_nat (void)
 622 {
 623   struct target_ops *t;
 624
 625   os_version = get_linux_version (&os_major, &os_minor, &os_release);
 626
 627   /* Fill in the generic GNU/Linux methods.  */
 628   t = linux_target ();
 629
 630   /* Add our register access methods.  */
 631   t->to_fetch_registers = arm_linux_fetch_inferior_registers;
 632   t->to_store_registers = arm_linux_store_inferior_registers;
 633
 634   /* Override the default to_xfer_partial.  */
 635   super_xfer_partial = t->to_xfer_partial;
 636   t->to_xfer_partial = arm_linux_xfer_partial;
 637
 638   /* Register the target.  */
 639   linux_nat_add_target (t);
 640 }