gdb/ia64-linux-nat.c

   1 /* Functions specific to running gdb native on IA-64 running
   2    GNU/Linux.
   3
   4    Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
   5    2009, 2010, 2011 Free Software Foundation, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "gdb_string.h"
  24 #include "inferior.h"
  25 #include "target.h"
  26 #include "gdbcore.h"
  27 #include "regcache.h"
  28 #include "ia64-tdep.h"
  29 #include "linux-nat.h"
  30
  31 #include <signal.h>
  32 #include <sys/ptrace.h>
  33 #include "gdb_wait.h"
  34 #ifdef HAVE_SYS_REG_H
  35 #include <sys/reg.h>
  36 #endif
  37 #include <sys/syscall.h>
  38 #include <sys/user.h>
  39
  40 #include <asm/ptrace_offsets.h>
  41 #include <sys/procfs.h>
  42
  43 /* Prototypes for supply_gregset etc.  */
  44 #include "gregset.h"
  45
  46 /* These must match the order of the register names.
  47
  48    Some sort of lookup table is needed because the offsets associated
  49    with the registers are all over the board.  */
  50
  51 static int u_offsets[] =
  52   {
  53     /* general registers */
  54     -1,         /* gr0 not available; i.e, it's always zero.  */
  55     PT_R1,
  56     PT_R2,
  57     PT_R3,
  58     PT_R4,
  59     PT_R5,
  60     PT_R6,
  61     PT_R7,
  62     PT_R8,
  63     PT_R9,
  64     PT_R10,
  65     PT_R11,
  66     PT_R12,
  67     PT_R13,
  68     PT_R14,
  69     PT_R15,
  70     PT_R16,
  71     PT_R17,
  72     PT_R18,
  73     PT_R19,
  74     PT_R20,
  75     PT_R21,
  76     PT_R22,
  77     PT_R23,
  78     PT_R24,
  79     PT_R25,
  80     PT_R26,
  81     PT_R27,
  82     PT_R28,
  83     PT_R29,
  84     PT_R30,
  85     PT_R31,
  86     /* gr32 through gr127 not directly available via the ptrace interface.  */
  87     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  88     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  89     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  90     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  91     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  92     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  93     /* Floating point registers */
  94     -1, -1,     /* f0 and f1 not available (f0 is +0.0 and f1 is +1.0).  */
  95     PT_F2,
  96     PT_F3,
  97     PT_F4,
  98     PT_F5,
  99     PT_F6,
 100     PT_F7,
 101     PT_F8,
 102     PT_F9,
 103     PT_F10,
 104     PT_F11,
 105     PT_F12,
 106     PT_F13,
 107     PT_F14,
 108     PT_F15,
 109     PT_F16,
 110     PT_F17,
 111     PT_F18,
 112     PT_F19,
 113     PT_F20,
 114     PT_F21,
 115     PT_F22,
 116     PT_F23,
 117     PT_F24,
 118     PT_F25,
 119     PT_F26,
 120     PT_F27,
 121     PT_F28,
 122     PT_F29,
 123     PT_F30,
 124     PT_F31,
 125     PT_F32,
 126     PT_F33,
 127     PT_F34,
 128     PT_F35,
 129     PT_F36,
 130     PT_F37,
 131     PT_F38,
 132     PT_F39,
 133     PT_F40,
 134     PT_F41,
 135     PT_F42,
 136     PT_F43,
 137     PT_F44,
 138     PT_F45,
 139     PT_F46,
 140     PT_F47,
 141     PT_F48,
 142     PT_F49,
 143     PT_F50,
 144     PT_F51,
 145     PT_F52,
 146     PT_F53,
 147     PT_F54,
 148     PT_F55,
 149     PT_F56,
 150     PT_F57,
 151     PT_F58,
 152     PT_F59,
 153     PT_F60,
 154     PT_F61,
 155     PT_F62,
 156     PT_F63,
 157     PT_F64,
 158     PT_F65,
 159     PT_F66,
 160     PT_F67,
 161     PT_F68,
 162     PT_F69,
 163     PT_F70,
 164     PT_F71,
 165     PT_F72,
 166     PT_F73,
 167     PT_F74,
 168     PT_F75,
 169     PT_F76,
 170     PT_F77,
 171     PT_F78,
 172     PT_F79,
 173     PT_F80,
 174     PT_F81,
 175     PT_F82,
 176     PT_F83,
 177     PT_F84,
 178     PT_F85,
 179     PT_F86,
 180     PT_F87,
 181     PT_F88,
 182     PT_F89,
 183     PT_F90,
 184     PT_F91,
 185     PT_F92,
 186     PT_F93,
 187     PT_F94,
 188     PT_F95,
 189     PT_F96,
 190     PT_F97,
 191     PT_F98,
 192     PT_F99,
 193     PT_F100,
 194     PT_F101,
 195     PT_F102,
 196     PT_F103,
 197     PT_F104,
 198     PT_F105,
 199     PT_F106,
 200     PT_F107,
 201     PT_F108,
 202     PT_F109,
 203     PT_F110,
 204     PT_F111,
 205     PT_F112,
 206     PT_F113,
 207     PT_F114,
 208     PT_F115,
 209     PT_F116,
 210     PT_F117,
 211     PT_F118,
 212     PT_F119,
 213     PT_F120,
 214     PT_F121,
 215     PT_F122,
 216     PT_F123,
 217     PT_F124,
 218     PT_F125,
 219     PT_F126,
 220     PT_F127,
 221     /* Predicate registers - we don't fetch these individually.  */
 222     -1, -1, -1, -1, -1, -1, -1, -1,
 223     -1, -1, -1, -1, -1, -1, -1, -1,
 224     -1, -1, -1, -1, -1, -1, -1, -1,
 225     -1, -1, -1, -1, -1, -1, -1, -1,
 226     -1, -1, -1, -1, -1, -1, -1, -1,
 227     -1, -1, -1, -1, -1, -1, -1, -1,
 228     -1, -1, -1, -1, -1, -1, -1, -1,
 229     -1, -1, -1, -1, -1, -1, -1, -1,
 230     /* branch registers */
 231     PT_B0,
 232     PT_B1,
 233     PT_B2,
 234     PT_B3,
 235     PT_B4,
 236     PT_B5,
 237     PT_B6,
 238     PT_B7,
 239     /* Virtual frame pointer and virtual return address pointer.  */
 240     -1, -1,
 241     /* other registers */
 242     PT_PR,
 243     PT_CR_IIP,  /* ip */
 244     PT_CR_IPSR, /* psr */
 245     PT_CFM,     /* cfm */
 246     /* kernel registers not visible via ptrace interface (?)  */
 247     -1, -1, -1, -1, -1, -1, -1, -1,
 248     /* hole */
 249     -1, -1, -1, -1, -1, -1, -1, -1,
 250     PT_AR_RSC,
 251     PT_AR_BSP,
 252     PT_AR_BSPSTORE,
 253     PT_AR_RNAT,
 254     -1,
 255     -1,         /* Not available: FCR, IA32 floating control register.  */
 256     -1, -1,
 257     -1,         /* Not available: EFLAG */
 258     -1,         /* Not available: CSD */
 259     -1,         /* Not available: SSD */
 260     -1,         /* Not available: CFLG */
 261     -1,         /* Not available: FSR */
 262     -1,         /* Not available: FIR */
 263     -1,         /* Not available: FDR */
 264     -1,
 265     PT_AR_CCV,
 266     -1, -1, -1,
 267     PT_AR_UNAT,
 268     -1, -1, -1,
 269     PT_AR_FPSR,
 270     -1, -1, -1,
 271     -1,         /* Not available: ITC */
 272     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 273     -1, -1, -1, -1, -1, -1, -1, -1, -1,
 274     PT_AR_PFS,
 275     PT_AR_LC,
 276     -1,         /* Not available: EC, the Epilog Count register.  */
 277     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 278     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 279     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 280     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 281     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 282     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 283     -1,
 284     /* nat bits - not fetched directly; instead we obtain these bits from
 285        either rnat or unat or from memory.  */
 286     -1, -1, -1, -1, -1, -1, -1, -1,
 287     -1, -1, -1, -1, -1, -1, -1, -1,
 288     -1, -1, -1, -1, -1, -1, -1, -1,
 289     -1, -1, -1, -1, -1, -1, -1, -1,
 290     -1, -1, -1, -1, -1, -1, -1, -1,
 291     -1, -1, -1, -1, -1, -1, -1, -1,
 292     -1, -1, -1, -1, -1, -1, -1, -1,
 293     -1, -1, -1, -1, -1, -1, -1, -1,
 294     -1, -1, -1, -1, -1, -1, -1, -1,
 295     -1, -1, -1, -1, -1, -1, -1, -1,
 296     -1, -1, -1, -1, -1, -1, -1, -1,
 297     -1, -1, -1, -1, -1, -1, -1, -1,
 298     -1, -1, -1, -1, -1, -1, -1, -1,
 299     -1, -1, -1, -1, -1, -1, -1, -1,
 300     -1, -1, -1, -1, -1, -1, -1, -1,
 301     -1, -1, -1, -1, -1, -1, -1, -1,
 302   };
 303
 304 static CORE_ADDR
 305 ia64_register_addr (struct gdbarch *gdbarch, int regno)
 306 {
 307   CORE_ADDR addr;
 308
 309   if (regno < 0 || regno >= gdbarch_num_regs (gdbarch))
 310     error (_("Invalid register number %d."), regno);
 311
 312   if (u_offsets[regno] == -1)
 313     addr = 0;
 314   else
 315     addr = (CORE_ADDR) u_offsets[regno];
 316
 317   return addr;
 318 }
 319
 320 static int
 321 ia64_cannot_fetch_register (struct gdbarch *gdbarch, int regno)
 322 {
 323   return regno < 0
 324          || regno >= gdbarch_num_regs (gdbarch)
 325          || u_offsets[regno] == -1;
 326 }
 327
 328 static int
 329 ia64_cannot_store_register (struct gdbarch *gdbarch, int regno)
 330 {
 331   /* Rationale behind not permitting stores to bspstore...
 332
 333      The IA-64 architecture provides bspstore and bsp which refer
 334      memory locations in the RSE's backing store.  bspstore is the
 335      next location which will be written when the RSE needs to write
 336      to memory.  bsp is the address at which r32 in the current frame
 337      would be found if it were written to the backing store.
 338
 339      The IA-64 architecture provides read-only access to bsp and
 340      read/write access to bspstore (but only when the RSE is in
 341      the enforced lazy mode).  It should be noted that stores
 342      to bspstore also affect the value of bsp.  Changing bspstore
 343      does not affect the number of dirty entries between bspstore
 344      and bsp, so changing bspstore by N words will also cause bsp
 345      to be changed by (roughly) N as well.  (It could be N-1 or N+1
 346      depending upon where the NaT collection bits fall.)
 347
 348      OTOH, the Linux kernel provides read/write access to bsp (and
 349      currently read/write access to bspstore as well).  But it
 350      is definitely the case that if you change one, the other
 351      will change at the same time.  It is more useful to gdb to
 352      be able to change bsp.  So in order to prevent strange and
 353      undesirable things from happening when a dummy stack frame
 354      is popped (after calling an inferior function), we allow
 355      bspstore to be read, but not written.  (Note that popping
 356      a (generic) dummy stack frame causes all registers that
 357      were previously read from the inferior process to be written
 358      back.)  */
 359
 360   return regno < 0
 361          || regno >= gdbarch_num_regs (gdbarch)
 362          || u_offsets[regno] == -1
 363          || regno == IA64_BSPSTORE_REGNUM;
 364 }
 365
 366 void
 367 supply_gregset (struct regcache *regcache, const gregset_t *gregsetp)
 368 {
 369   int regi;
 370   const greg_t *regp = (const greg_t *) gregsetp;
 371
 372   for (regi = IA64_GR0_REGNUM; regi <= IA64_GR31_REGNUM; regi++)
 373     {
 374       regcache_raw_supply (regcache, regi, regp + (regi - IA64_GR0_REGNUM));
 375     }
 376
 377   /* FIXME: NAT collection bits are at index 32; gotta deal with these
 378      somehow...  */
 379
 380   regcache_raw_supply (regcache, IA64_PR_REGNUM, regp + 33);
 381
 382   for (regi = IA64_BR0_REGNUM; regi <= IA64_BR7_REGNUM; regi++)
 383     {
 384       regcache_raw_supply (regcache, regi,
 385                            regp + 34 + (regi - IA64_BR0_REGNUM));
 386     }
 387
 388   regcache_raw_supply (regcache, IA64_IP_REGNUM, regp + 42);
 389   regcache_raw_supply (regcache, IA64_CFM_REGNUM, regp + 43);
 390   regcache_raw_supply (regcache, IA64_PSR_REGNUM, regp + 44);
 391   regcache_raw_supply (regcache, IA64_RSC_REGNUM, regp + 45);
 392   regcache_raw_supply (regcache, IA64_BSP_REGNUM, regp + 46);
 393   regcache_raw_supply (regcache, IA64_BSPSTORE_REGNUM, regp + 47);
 394   regcache_raw_supply (regcache, IA64_RNAT_REGNUM, regp + 48);
 395   regcache_raw_supply (regcache, IA64_CCV_REGNUM, regp + 49);
 396   regcache_raw_supply (regcache, IA64_UNAT_REGNUM, regp + 50);
 397   regcache_raw_supply (regcache, IA64_FPSR_REGNUM, regp + 51);
 398   regcache_raw_supply (regcache, IA64_PFS_REGNUM, regp + 52);
 399   regcache_raw_supply (regcache, IA64_LC_REGNUM, regp + 53);
 400   regcache_raw_supply (regcache, IA64_EC_REGNUM, regp + 54);
 401 }
 402
 403 void
 404 fill_gregset (const struct regcache *regcache, gregset_t *gregsetp, int regno)
 405 {
 406   int regi;
 407   greg_t *regp = (greg_t *) gregsetp;
 408
 409 #define COPY_REG(_idx_,_regi_) \
 410   if ((regno == -1) || regno == _regi_) \
 411     regcache_raw_collect (regcache, _regi_, regp + _idx_)
 412
 413   for (regi = IA64_GR0_REGNUM; regi <= IA64_GR31_REGNUM; regi++)
 414     {
 415       COPY_REG (regi - IA64_GR0_REGNUM, regi);
 416     }
 417
 418   /* FIXME: NAT collection bits at index 32?  */
 419
 420   COPY_REG (33, IA64_PR_REGNUM);
 421
 422   for (regi = IA64_BR0_REGNUM; regi <= IA64_BR7_REGNUM; regi++)
 423     {
 424       COPY_REG (34 + (regi - IA64_BR0_REGNUM), regi);
 425     }
 426
 427   COPY_REG (42, IA64_IP_REGNUM);
 428   COPY_REG (43, IA64_CFM_REGNUM);
 429   COPY_REG (44, IA64_PSR_REGNUM);
 430   COPY_REG (45, IA64_RSC_REGNUM);
 431   COPY_REG (46, IA64_BSP_REGNUM);
 432   COPY_REG (47, IA64_BSPSTORE_REGNUM);
 433   COPY_REG (48, IA64_RNAT_REGNUM);
 434   COPY_REG (49, IA64_CCV_REGNUM);
 435   COPY_REG (50, IA64_UNAT_REGNUM);
 436   COPY_REG (51, IA64_FPSR_REGNUM);
 437   COPY_REG (52, IA64_PFS_REGNUM);
 438   COPY_REG (53, IA64_LC_REGNUM);
 439   COPY_REG (54, IA64_EC_REGNUM);
 440 }
 441
 442 /*  Given a pointer to a floating point register set in /proc format
 443    (fpregset_t *), unpack the register contents and supply them as gdb's
 444    idea of the current floating point register values.  */
 445
 446 void
 447 supply_fpregset (struct regcache *regcache, const fpregset_t *fpregsetp)
 448 {
 449   int regi;
 450   const char *from;
 451
 452   for (regi = IA64_FR0_REGNUM; regi <= IA64_FR127_REGNUM; regi++)
 453     {
 454       from = (const char *) &((*fpregsetp)[regi - IA64_FR0_REGNUM]);
 455       regcache_raw_supply (regcache, regi, from);
 456     }
 457 }
 458
 459 /*  Given a pointer to a floating point register set in /proc format
 460    (fpregset_t *), update the register specified by REGNO from gdb's idea
 461    of the current floating point register set.  If REGNO is -1, update
 462    them all.  */
 463
 464 void
 465 fill_fpregset (const struct regcache *regcache,
 466                fpregset_t *fpregsetp, int regno)
 467 {
 468   int regi;
 469
 470   for (regi = IA64_FR0_REGNUM; regi <= IA64_FR127_REGNUM; regi++)
 471     {
 472       if ((regno == -1) || (regno == regi))
 473         regcache_raw_collect (regcache, regi,
 474                               &((*fpregsetp)[regi - IA64_FR0_REGNUM]));
 475     }
 476 }
 477
 478 #define IA64_PSR_DB (1UL << 24)
 479 #define IA64_PSR_DD (1UL << 39)
 480
 481 static void
 482 enable_watchpoints_in_psr (ptid_t ptid)
 483 {
 484   struct regcache *regcache = get_thread_regcache (ptid);
 485   ULONGEST psr;
 486
 487   regcache_cooked_read_unsigned (regcache, IA64_PSR_REGNUM, &psr);
 488   if (!(psr & IA64_PSR_DB))
 489     {
 490       psr |= IA64_PSR_DB;       /* Set the db bit - this enables hardware
 491                                    watchpoints and breakpoints.  */
 492       regcache_cooked_write_unsigned (regcache, IA64_PSR_REGNUM, psr);
 493     }
 494 }
 495
 496 static long debug_registers[8];
 497
 498 static void
 499 store_debug_register (ptid_t ptid, int idx, long val)
 500 {
 501   int tid;
 502
 503   tid = TIDGET (ptid);
 504   if (tid == 0)
 505     tid = PIDGET (ptid);
 506
 507   (void) ptrace (PT_WRITE_U, tid, (PTRACE_TYPE_ARG3) (PT_DBR + 8 * idx), val);
 508 }
 509
 510 static void
 511 store_debug_register_pair (ptid_t ptid, int idx, long *dbr_addr,
 512                            long *dbr_mask)
 513 {
 514   if (dbr_addr)
 515     store_debug_register (ptid, 2 * idx, *dbr_addr);
 516   if (dbr_mask)
 517     store_debug_register (ptid, 2 * idx + 1, *dbr_mask);
 518 }
 519
 520 static int
 521 is_power_of_2 (int val)
 522 {
 523   int i, onecount;
 524
 525   onecount = 0;
 526   for (i = 0; i < 8 * sizeof (val); i++)
 527     if (val & (1 << i))
 528       onecount++;
 529
 530   return onecount <= 1;
 531 }
 532
 533 static int
 534 ia64_linux_insert_watchpoint (CORE_ADDR addr, int len, int rw,
 535                               struct expression *cond)
 536 {
 537   struct lwp_info *lp;
 538   ptid_t ptid;
 539   int idx;
 540   long dbr_addr, dbr_mask;
 541   int max_watchpoints = 4;
 542
 543   if (len <= 0 || !is_power_of_2 (len))
 544     return -1;
 545
 546   for (idx = 0; idx < max_watchpoints; idx++)
 547     {
 548       dbr_mask = debug_registers[idx * 2 + 1];
 549       if ((dbr_mask & (0x3UL << 62)) == 0)
 550         {
 551           /* Exit loop if both r and w bits clear.  */
 552           break;
 553         }
 554     }
 555
 556   if (idx == max_watchpoints)
 557     return -1;
 558
 559   dbr_addr = (long) addr;
 560   dbr_mask = (~(len - 1) & 0x00ffffffffffffffL);  /* construct mask to match */
 561   dbr_mask |= 0x0800000000000000L;           /* Only match privilege level 3 */
 562   switch (rw)
 563     {
 564     case hw_write:
 565       dbr_mask |= (1L << 62);                   /* Set w bit */
 566       break;
 567     case hw_read:
 568       dbr_mask |= (1L << 63);                   /* Set r bit */
 569       break;
 570     case hw_access:
 571       dbr_mask |= (3L << 62);                   /* Set both r and w bits */
 572       break;
 573     default:
 574       return -1;
 575     }
 576
 577   debug_registers[2 * idx] = dbr_addr;
 578   debug_registers[2 * idx + 1] = dbr_mask;
 579   ALL_LWPS (lp, ptid)
 580     {
 581       store_debug_register_pair (ptid, idx, &dbr_addr, &dbr_mask);
 582       enable_watchpoints_in_psr (ptid);
 583     }
 584
 585   return 0;
 586 }
 587
 588 static int
 589 ia64_linux_remove_watchpoint (CORE_ADDR addr, int len, int type,
 590                               struct expression *cond)
 591 {
 592   int idx;
 593   long dbr_addr, dbr_mask;
 594   int max_watchpoints = 4;
 595
 596   if (len <= 0 || !is_power_of_2 (len))
 597     return -1;
 598
 599   for (idx = 0; idx < max_watchpoints; idx++)
 600     {
 601       dbr_addr = debug_registers[2 * idx];
 602       dbr_mask = debug_registers[2 * idx + 1];
 603       if ((dbr_mask & (0x3UL << 62)) && addr == (CORE_ADDR) dbr_addr)
 604         {
 605           struct lwp_info *lp;
 606           ptid_t ptid;
 607
 608           debug_registers[2 * idx] = 0;
 609           debug_registers[2 * idx + 1] = 0;
 610           dbr_addr = 0;
 611           dbr_mask = 0;
 612
 613           ALL_LWPS (lp, ptid)
 614             store_debug_register_pair (ptid, idx, &dbr_addr, &dbr_mask);
 615
 616           return 0;
 617         }
 618     }
 619   return -1;
 620 }
 621
 622 static void
 623 ia64_linux_new_thread (ptid_t ptid)
 624 {
 625   int i, any;
 626
 627   any = 0;
 628   for (i = 0; i < 8; i++)
 629     {
 630       if (debug_registers[i] != 0)
 631         any = 1;
 632       store_debug_register (ptid, i, debug_registers[i]);
 633     }
 634
 635   if (any)
 636     enable_watchpoints_in_psr (ptid);
 637 }
 638
 639 static int
 640 ia64_linux_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
 641 {
 642   CORE_ADDR psr;
 643   struct siginfo *siginfo_p;
 644   struct regcache *regcache = get_current_regcache ();
 645
 646   siginfo_p = linux_nat_get_siginfo (inferior_ptid);
 647
 648   if (siginfo_p->si_signo != SIGTRAP
 649       || (siginfo_p->si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */)
 650     return 0;
 651
 652   regcache_cooked_read_unsigned (regcache, IA64_PSR_REGNUM, &psr);
 653   psr |= IA64_PSR_DD;   /* Set the dd bit - this will disable the watchpoint
 654                            for the next instruction.  */
 655   regcache_cooked_write_unsigned (regcache, IA64_PSR_REGNUM, psr);
 656
 657   *addr_p = (CORE_ADDR)siginfo_p->si_addr;
 658   return 1;
 659 }
 660
 661 static int
 662 ia64_linux_stopped_by_watchpoint (void)
 663 {
 664   CORE_ADDR addr;
 665   return ia64_linux_stopped_data_address (&current_target, &addr);
 666 }
 667
 668 static int
 669 ia64_linux_can_use_hw_breakpoint (int type, int cnt, int othertype)
 670 {
 671   return 1;
 672 }
 673
 674
 675 /* Fetch register REGNUM from the inferior.  */
 676
 677 static void
 678 ia64_linux_fetch_register (struct regcache *regcache, int regnum)
 679 {
 680   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 681   CORE_ADDR addr;
 682   size_t size;
 683   PTRACE_TYPE_RET *buf;
 684   int pid, i;
 685
 686   if (ia64_cannot_fetch_register (gdbarch, regnum))
 687     {
 688       regcache_raw_supply (regcache, regnum, NULL);
 689       return;
 690     }
 691
 692   /* Cater for systems like GNU/Linux, that implement threads as
 693      separate processes.  */
 694   pid = ptid_get_lwp (inferior_ptid);
 695   if (pid == 0)
 696     pid = ptid_get_pid (inferior_ptid);
 697
 698   /* This isn't really an address, but ptrace thinks of it as one.  */
 699   addr = ia64_register_addr (gdbarch, regnum);
 700   size = register_size (gdbarch, regnum);
 701
 702   gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
 703   buf = alloca (size);
 704
 705   /* Read the register contents from the inferior a chunk at a time.  */
 706   for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
 707     {
 708       errno = 0;
 709       buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)addr, 0);
 710       if (errno != 0)
 711         error (_("Couldn't read register %s (#%d): %s."),
 712                gdbarch_register_name (gdbarch, regnum),
 713                regnum, safe_strerror (errno));
 714
 715       addr += sizeof (PTRACE_TYPE_RET);
 716     }
 717   regcache_raw_supply (regcache, regnum, buf);
 718 }
 719
 720 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
 721    for all registers.  */
 722
 723 static void
 724 ia64_linux_fetch_registers (struct target_ops *ops,
 725                             struct regcache *regcache, int regnum)
 726 {
 727   if (regnum == -1)
 728     for (regnum = 0;
 729          regnum < gdbarch_num_regs (get_regcache_arch (regcache));
 730          regnum++)
 731       ia64_linux_fetch_register (regcache, regnum);
 732   else
 733     ia64_linux_fetch_register (regcache, regnum);
 734 }
 735
 736 /* Store register REGNUM into the inferior.  */
 737
 738 static void
 739 ia64_linux_store_register (const struct regcache *regcache, int regnum)
 740 {
 741   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 742   CORE_ADDR addr;
 743   size_t size;
 744   PTRACE_TYPE_RET *buf;
 745   int pid, i;
 746
 747   if (ia64_cannot_store_register (gdbarch, regnum))
 748     return;
 749
 750   /* Cater for systems like GNU/Linux, that implement threads as
 751      separate processes.  */
 752   pid = ptid_get_lwp (inferior_ptid);
 753   if (pid == 0)
 754     pid = ptid_get_pid (inferior_ptid);
 755
 756   /* This isn't really an address, but ptrace thinks of it as one.  */
 757   addr = ia64_register_addr (gdbarch, regnum);
 758   size = register_size (gdbarch, regnum);
 759
 760   gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
 761   buf = alloca (size);
 762
 763   /* Write the register contents into the inferior a chunk at a time.  */
 764   regcache_raw_collect (regcache, regnum, buf);
 765   for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
 766     {
 767       errno = 0;
 768       ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)addr, buf[i]);
 769       if (errno != 0)
 770         error (_("Couldn't write register %s (#%d): %s."),
 771                gdbarch_register_name (gdbarch, regnum),
 772                regnum, safe_strerror (errno));
 773
 774       addr += sizeof (PTRACE_TYPE_RET);
 775     }
 776 }
 777
 778 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
 779    this for all registers.  */
 780
 781 static void
 782 ia64_linux_store_registers (struct target_ops *ops,
 783                             struct regcache *regcache, int regnum)
 784 {
 785   if (regnum == -1)
 786     for (regnum = 0;
 787          regnum < gdbarch_num_regs (get_regcache_arch (regcache));
 788          regnum++)
 789       ia64_linux_store_register (regcache, regnum);
 790   else
 791     ia64_linux_store_register (regcache, regnum);
 792 }
 793
 794
 795 static LONGEST (*super_xfer_partial) (struct target_ops *, enum target_object,
 796                                       const char *, gdb_byte *,
 797                                       const gdb_byte *, ULONGEST, LONGEST);
 798
 799 static LONGEST
 800 ia64_linux_xfer_partial (struct target_ops *ops,
 801                          enum target_object object,
 802                          const char *annex,
 803                          gdb_byte *readbuf, const gdb_byte *writebuf,
 804                          ULONGEST offset, LONGEST len)
 805 {
 806   if (object == TARGET_OBJECT_UNWIND_TABLE && writebuf == NULL && offset == 0)
 807     return syscall (__NR_getunwind, readbuf, len);
 808
 809   return super_xfer_partial (ops, object, annex, readbuf, writebuf,
 810                              offset, len);
 811 }
 812
 813 /* For break.b instruction ia64 CPU forgets the immediate value and generates
 814    SIGILL with ILL_ILLOPC instead of more common SIGTRAP with TRAP_BRKPT.
 815    ia64 does not use gdbarch_decr_pc_after_break so we do not have to make any
 816    difference for the signals here.  */
 817
 818 static int
 819 ia64_linux_status_is_event (int status)
 820 {
 821   return WIFSTOPPED (status) && (WSTOPSIG (status) == SIGTRAP
 822                                  || WSTOPSIG (status) == SIGILL);
 823 }
 824
 825 void _initialize_ia64_linux_nat (void);
 826
 827 void
 828 _initialize_ia64_linux_nat (void)
 829 {
 830   struct target_ops *t;
 831
 832   /* Fill in the generic GNU/Linux methods.  */
 833   t = linux_target ();
 834
 835   /* Override the default fetch/store register routines.  */
 836   t->to_fetch_registers = ia64_linux_fetch_registers;
 837   t->to_store_registers = ia64_linux_store_registers;
 838
 839   /* Override the default to_xfer_partial.  */
 840   super_xfer_partial = t->to_xfer_partial;
 841   t->to_xfer_partial = ia64_linux_xfer_partial;
 842
 843   /* Override watchpoint routines.  */
 844
 845   /* The IA-64 architecture can step over a watch point (without triggering
 846      it again) if the "dd" (data debug fault disable) bit in the processor
 847      status word is set.
 848
 849      This PSR bit is set in ia64_linux_stopped_by_watchpoint when the
 850      code there has determined that a hardware watchpoint has indeed
 851      been hit.  The CPU will then be able to execute one instruction
 852      without triggering a watchpoint.  */
 853
 854   t->to_have_steppable_watchpoint = 1;
 855   t->to_can_use_hw_breakpoint = ia64_linux_can_use_hw_breakpoint;
 856   t->to_stopped_by_watchpoint = ia64_linux_stopped_by_watchpoint;
 857   t->to_stopped_data_address = ia64_linux_stopped_data_address;
 858   t->to_insert_watchpoint = ia64_linux_insert_watchpoint;
 859   t->to_remove_watchpoint = ia64_linux_remove_watchpoint;
 860
 861   /* Register the target.  */
 862   linux_nat_add_target (t);
 863   linux_nat_set_new_thread (t, ia64_linux_new_thread);
 864   linux_nat_set_status_is_event (t, ia64_linux_status_is_event);
 865 }