gdb/ia64-linux-nat.c

   1 /* Functions specific to running gdb native on IA-64 running
   2    GNU/Linux.
   3
   4    Copyright (C) 1999-2013 Free Software Foundation, Inc.
   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 "gdb_string.h"
  23 #include "inferior.h"
  24 #include "target.h"
  25 #include "gdbcore.h"
  26 #include "regcache.h"
  27 #include "ia64-tdep.h"
  28 #include "linux-nat.h"
  29
  30 #include <signal.h>
  31 #include <sys/ptrace.h>
  32 #include "gdb_wait.h"
  33 #ifdef HAVE_SYS_REG_H
  34 #include <sys/reg.h>
  35 #endif
  36 #include <sys/syscall.h>
  37 #include <sys/user.h>
  38
  39 #include <asm/ptrace_offsets.h>
  40 #include <sys/procfs.h>
  41
  42 /* Prototypes for supply_gregset etc.  */
  43 #include "gregset.h"
  44
  45 /* These must match the order of the register names.
  46
  47    Some sort of lookup table is needed because the offsets associated
  48    with the registers are all over the board.  */
  49
  50 static int u_offsets[] =
  51   {
  52     /* general registers */
  53     -1,         /* gr0 not available; i.e, it's always zero.  */
  54     PT_R1,
  55     PT_R2,
  56     PT_R3,
  57     PT_R4,
  58     PT_R5,
  59     PT_R6,
  60     PT_R7,
  61     PT_R8,
  62     PT_R9,
  63     PT_R10,
  64     PT_R11,
  65     PT_R12,
  66     PT_R13,
  67     PT_R14,
  68     PT_R15,
  69     PT_R16,
  70     PT_R17,
  71     PT_R18,
  72     PT_R19,
  73     PT_R20,
  74     PT_R21,
  75     PT_R22,
  76     PT_R23,
  77     PT_R24,
  78     PT_R25,
  79     PT_R26,
  80     PT_R27,
  81     PT_R28,
  82     PT_R29,
  83     PT_R30,
  84     PT_R31,
  85     /* gr32 through gr127 not directly available via the ptrace interface.  */
  86     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  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     /* Floating point registers */
  93     -1, -1,     /* f0 and f1 not available (f0 is +0.0 and f1 is +1.0).  */
  94     PT_F2,
  95     PT_F3,
  96     PT_F4,
  97     PT_F5,
  98     PT_F6,
  99     PT_F7,
 100     PT_F8,
 101     PT_F9,
 102     PT_F10,
 103     PT_F11,
 104     PT_F12,
 105     PT_F13,
 106     PT_F14,
 107     PT_F15,
 108     PT_F16,
 109     PT_F17,
 110     PT_F18,
 111     PT_F19,
 112     PT_F20,
 113     PT_F21,
 114     PT_F22,
 115     PT_F23,
 116     PT_F24,
 117     PT_F25,
 118     PT_F26,
 119     PT_F27,
 120     PT_F28,
 121     PT_F29,
 122     PT_F30,
 123     PT_F31,
 124     PT_F32,
 125     PT_F33,
 126     PT_F34,
 127     PT_F35,
 128     PT_F36,
 129     PT_F37,
 130     PT_F38,
 131     PT_F39,
 132     PT_F40,
 133     PT_F41,
 134     PT_F42,
 135     PT_F43,
 136     PT_F44,
 137     PT_F45,
 138     PT_F46,
 139     PT_F47,
 140     PT_F48,
 141     PT_F49,
 142     PT_F50,
 143     PT_F51,
 144     PT_F52,
 145     PT_F53,
 146     PT_F54,
 147     PT_F55,
 148     PT_F56,
 149     PT_F57,
 150     PT_F58,
 151     PT_F59,
 152     PT_F60,
 153     PT_F61,
 154     PT_F62,
 155     PT_F63,
 156     PT_F64,
 157     PT_F65,
 158     PT_F66,
 159     PT_F67,
 160     PT_F68,
 161     PT_F69,
 162     PT_F70,
 163     PT_F71,
 164     PT_F72,
 165     PT_F73,
 166     PT_F74,
 167     PT_F75,
 168     PT_F76,
 169     PT_F77,
 170     PT_F78,
 171     PT_F79,
 172     PT_F80,
 173     PT_F81,
 174     PT_F82,
 175     PT_F83,
 176     PT_F84,
 177     PT_F85,
 178     PT_F86,
 179     PT_F87,
 180     PT_F88,
 181     PT_F89,
 182     PT_F90,
 183     PT_F91,
 184     PT_F92,
 185     PT_F93,
 186     PT_F94,
 187     PT_F95,
 188     PT_F96,
 189     PT_F97,
 190     PT_F98,
 191     PT_F99,
 192     PT_F100,
 193     PT_F101,
 194     PT_F102,
 195     PT_F103,
 196     PT_F104,
 197     PT_F105,
 198     PT_F106,
 199     PT_F107,
 200     PT_F108,
 201     PT_F109,
 202     PT_F110,
 203     PT_F111,
 204     PT_F112,
 205     PT_F113,
 206     PT_F114,
 207     PT_F115,
 208     PT_F116,
 209     PT_F117,
 210     PT_F118,
 211     PT_F119,
 212     PT_F120,
 213     PT_F121,
 214     PT_F122,
 215     PT_F123,
 216     PT_F124,
 217     PT_F125,
 218     PT_F126,
 219     PT_F127,
 220     /* Predicate registers - we don't fetch these individually.  */
 221     -1, -1, -1, -1, -1, -1, -1, -1,
 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     /* branch registers */
 230     PT_B0,
 231     PT_B1,
 232     PT_B2,
 233     PT_B3,
 234     PT_B4,
 235     PT_B5,
 236     PT_B6,
 237     PT_B7,
 238     /* Virtual frame pointer and virtual return address pointer.  */
 239     -1, -1,
 240     /* other registers */
 241     PT_PR,
 242     PT_CR_IIP,  /* ip */
 243     PT_CR_IPSR, /* psr */
 244     PT_CFM,     /* cfm */
 245     /* kernel registers not visible via ptrace interface (?)  */
 246     -1, -1, -1, -1, -1, -1, -1, -1,
 247     /* hole */
 248     -1, -1, -1, -1, -1, -1, -1, -1,
 249     PT_AR_RSC,
 250     PT_AR_BSP,
 251     PT_AR_BSPSTORE,
 252     PT_AR_RNAT,
 253     -1,
 254     -1,         /* Not available: FCR, IA32 floating control register.  */
 255     -1, -1,
 256     -1,         /* Not available: EFLAG */
 257     -1,         /* Not available: CSD */
 258     -1,         /* Not available: SSD */
 259     -1,         /* Not available: CFLG */
 260     -1,         /* Not available: FSR */
 261     -1,         /* Not available: FIR */
 262     -1,         /* Not available: FDR */
 263     -1,
 264     PT_AR_CCV,
 265     -1, -1, -1,
 266     PT_AR_UNAT,
 267     -1, -1, -1,
 268     PT_AR_FPSR,
 269     -1, -1, -1,
 270     -1,         /* Not available: ITC */
 271     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 272     -1, -1, -1, -1, -1, -1, -1, -1, -1,
 273     PT_AR_PFS,
 274     PT_AR_LC,
 275     PT_AR_EC,
 276     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 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,
 283     /* nat bits - not fetched directly; instead we obtain these bits from
 284        either rnat or unat or from memory.  */
 285     -1, -1, -1, -1, -1, -1, -1, -1,
 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   };
 302
 303 static CORE_ADDR
 304 ia64_register_addr (struct gdbarch *gdbarch, int regno)
 305 {
 306   CORE_ADDR addr;
 307
 308   if (regno < 0 || regno >= gdbarch_num_regs (gdbarch))
 309     error (_("Invalid register number %d."), regno);
 310
 311   if (u_offsets[regno] == -1)
 312     addr = 0;
 313   else
 314     addr = (CORE_ADDR) u_offsets[regno];
 315
 316   return addr;
 317 }
 318
 319 static int
 320 ia64_cannot_fetch_register (struct gdbarch *gdbarch, int regno)
 321 {
 322   return regno < 0
 323          || regno >= gdbarch_num_regs (gdbarch)
 324          || u_offsets[regno] == -1;
 325 }
 326
 327 static int
 328 ia64_cannot_store_register (struct gdbarch *gdbarch, int regno)
 329 {
 330   /* Rationale behind not permitting stores to bspstore...
 331
 332      The IA-64 architecture provides bspstore and bsp which refer
 333      memory locations in the RSE's backing store.  bspstore is the
 334      next location which will be written when the RSE needs to write
 335      to memory.  bsp is the address at which r32 in the current frame
 336      would be found if it were written to the backing store.
 337
 338      The IA-64 architecture provides read-only access to bsp and
 339      read/write access to bspstore (but only when the RSE is in
 340      the enforced lazy mode).  It should be noted that stores
 341      to bspstore also affect the value of bsp.  Changing bspstore
 342      does not affect the number of dirty entries between bspstore
 343      and bsp, so changing bspstore by N words will also cause bsp
 344      to be changed by (roughly) N as well.  (It could be N-1 or N+1
 345      depending upon where the NaT collection bits fall.)
 346
 347      OTOH, the Linux kernel provides read/write access to bsp (and
 348      currently read/write access to bspstore as well).  But it
 349      is definitely the case that if you change one, the other
 350      will change at the same time.  It is more useful to gdb to
 351      be able to change bsp.  So in order to prevent strange and
 352      undesirable things from happening when a dummy stack frame
 353      is popped (after calling an inferior function), we allow
 354      bspstore to be read, but not written.  (Note that popping
 355      a (generic) dummy stack frame causes all registers that
 356      were previously read from the inferior process to be written
 357      back.)  */
 358
 359   return regno < 0
 360          || regno >= gdbarch_num_regs (gdbarch)
 361          || u_offsets[regno] == -1
 362          || regno == IA64_BSPSTORE_REGNUM;
 363 }
 364
 365 void
 366 supply_gregset (struct regcache *regcache, const gregset_t *gregsetp)
 367 {
 368   int regi;
 369   const greg_t *regp = (const greg_t *) gregsetp;
 370
 371   for (regi = IA64_GR0_REGNUM; regi <= IA64_GR31_REGNUM; regi++)
 372     {
 373       regcache_raw_supply (regcache, regi, regp + (regi - IA64_GR0_REGNUM));
 374     }
 375
 376   /* FIXME: NAT collection bits are at index 32; gotta deal with these
 377      somehow...  */
 378
 379   regcache_raw_supply (regcache, IA64_PR_REGNUM, regp + 33);
 380
 381   for (regi = IA64_BR0_REGNUM; regi <= IA64_BR7_REGNUM; regi++)
 382     {
 383       regcache_raw_supply (regcache, regi,
 384                            regp + 34 + (regi - IA64_BR0_REGNUM));
 385     }
 386
 387   regcache_raw_supply (regcache, IA64_IP_REGNUM, regp + 42);
 388   regcache_raw_supply (regcache, IA64_CFM_REGNUM, regp + 43);
 389   regcache_raw_supply (regcache, IA64_PSR_REGNUM, regp + 44);
 390   regcache_raw_supply (regcache, IA64_RSC_REGNUM, regp + 45);
 391   regcache_raw_supply (regcache, IA64_BSP_REGNUM, regp + 46);
 392   regcache_raw_supply (regcache, IA64_BSPSTORE_REGNUM, regp + 47);
 393   regcache_raw_supply (regcache, IA64_RNAT_REGNUM, regp + 48);
 394   regcache_raw_supply (regcache, IA64_CCV_REGNUM, regp + 49);
 395   regcache_raw_supply (regcache, IA64_UNAT_REGNUM, regp + 50);
 396   regcache_raw_supply (regcache, IA64_FPSR_REGNUM, regp + 51);
 397   regcache_raw_supply (regcache, IA64_PFS_REGNUM, regp + 52);
 398   regcache_raw_supply (regcache, IA64_LC_REGNUM, regp + 53);
 399   regcache_raw_supply (regcache, IA64_EC_REGNUM, regp + 54);
 400 }
 401
 402 void
 403 fill_gregset (const struct regcache *regcache, gregset_t *gregsetp, int regno)
 404 {
 405   int regi;
 406   greg_t *regp = (greg_t *) gregsetp;
 407
 408 #define COPY_REG(_idx_,_regi_) \
 409   if ((regno == -1) || regno == _regi_) \
 410     regcache_raw_collect (regcache, _regi_, regp + _idx_)
 411
 412   for (regi = IA64_GR0_REGNUM; regi <= IA64_GR31_REGNUM; regi++)
 413     {
 414       COPY_REG (regi - IA64_GR0_REGNUM, regi);
 415     }
 416
 417   /* FIXME: NAT collection bits at index 32?  */
 418
 419   COPY_REG (33, IA64_PR_REGNUM);
 420
 421   for (regi = IA64_BR0_REGNUM; regi <= IA64_BR7_REGNUM; regi++)
 422     {
 423       COPY_REG (34 + (regi - IA64_BR0_REGNUM), regi);
 424     }
 425
 426   COPY_REG (42, IA64_IP_REGNUM);
 427   COPY_REG (43, IA64_CFM_REGNUM);
 428   COPY_REG (44, IA64_PSR_REGNUM);
 429   COPY_REG (45, IA64_RSC_REGNUM);
 430   COPY_REG (46, IA64_BSP_REGNUM);
 431   COPY_REG (47, IA64_BSPSTORE_REGNUM);
 432   COPY_REG (48, IA64_RNAT_REGNUM);
 433   COPY_REG (49, IA64_CCV_REGNUM);
 434   COPY_REG (50, IA64_UNAT_REGNUM);
 435   COPY_REG (51, IA64_FPSR_REGNUM);
 436   COPY_REG (52, IA64_PFS_REGNUM);
 437   COPY_REG (53, IA64_LC_REGNUM);
 438   COPY_REG (54, IA64_EC_REGNUM);
 439 }
 440
 441 /*  Given a pointer to a floating point register set in /proc format
 442    (fpregset_t *), unpack the register contents and supply them as gdb's
 443    idea of the current floating point register values.  */
 444
 445 void
 446 supply_fpregset (struct regcache *regcache, const fpregset_t *fpregsetp)
 447 {
 448   int regi;
 449   const char *from;
 450   const gdb_byte f_zero[16] = { 0 };
 451   const gdb_byte f_one[16] =
 452     { 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0xff, 0, 0, 0, 0, 0, 0 };
 453
 454   /* Kernel generated cores have fr1==0 instead of 1.0.  Older GDBs
 455      did the same.  So ignore whatever might be recorded in fpregset_t
 456      for fr0/fr1 and always supply their expected values.  */
 457
 458   /* fr0 is always read as zero.  */
 459   regcache_raw_supply (regcache, IA64_FR0_REGNUM, f_zero);
 460   /* fr1 is always read as one (1.0).  */
 461   regcache_raw_supply (regcache, IA64_FR1_REGNUM, f_one);
 462
 463   for (regi = IA64_FR2_REGNUM; regi <= IA64_FR127_REGNUM; regi++)
 464     {
 465       from = (const char *) &((*fpregsetp)[regi - IA64_FR0_REGNUM]);
 466       regcache_raw_supply (regcache, regi, from);
 467     }
 468 }
 469
 470 /*  Given a pointer to a floating point register set in /proc format
 471    (fpregset_t *), update the register specified by REGNO from gdb's idea
 472    of the current floating point register set.  If REGNO is -1, update
 473    them all.  */
 474
 475 void
 476 fill_fpregset (const struct regcache *regcache,
 477                fpregset_t *fpregsetp, int regno)
 478 {
 479   int regi;
 480
 481   for (regi = IA64_FR0_REGNUM; regi <= IA64_FR127_REGNUM; regi++)
 482     {
 483       if ((regno == -1) || (regno == regi))
 484         regcache_raw_collect (regcache, regi,
 485                               &((*fpregsetp)[regi - IA64_FR0_REGNUM]));
 486     }
 487 }
 488
 489 #define IA64_PSR_DB (1UL << 24)
 490 #define IA64_PSR_DD (1UL << 39)
 491
 492 static void
 493 enable_watchpoints_in_psr (ptid_t ptid)
 494 {
 495   struct regcache *regcache = get_thread_regcache (ptid);
 496   ULONGEST psr;
 497
 498   regcache_cooked_read_unsigned (regcache, IA64_PSR_REGNUM, &psr);
 499   if (!(psr & IA64_PSR_DB))
 500     {
 501       psr |= IA64_PSR_DB;       /* Set the db bit - this enables hardware
 502                                    watchpoints and breakpoints.  */
 503       regcache_cooked_write_unsigned (regcache, IA64_PSR_REGNUM, psr);
 504     }
 505 }
 506
 507 static long debug_registers[8];
 508
 509 static void
 510 store_debug_register (ptid_t ptid, int idx, long val)
 511 {
 512   int tid;
 513
 514   tid = TIDGET (ptid);
 515   if (tid == 0)
 516     tid = PIDGET (ptid);
 517
 518   (void) ptrace (PT_WRITE_U, tid, (PTRACE_TYPE_ARG3) (PT_DBR + 8 * idx), val);
 519 }
 520
 521 static void
 522 store_debug_register_pair (ptid_t ptid, int idx, long *dbr_addr,
 523                            long *dbr_mask)
 524 {
 525   if (dbr_addr)
 526     store_debug_register (ptid, 2 * idx, *dbr_addr);
 527   if (dbr_mask)
 528     store_debug_register (ptid, 2 * idx + 1, *dbr_mask);
 529 }
 530
 531 static int
 532 is_power_of_2 (int val)
 533 {
 534   int i, onecount;
 535
 536   onecount = 0;
 537   for (i = 0; i < 8 * sizeof (val); i++)
 538     if (val & (1 << i))
 539       onecount++;
 540
 541   return onecount <= 1;
 542 }
 543
 544 static int
 545 ia64_linux_insert_watchpoint (CORE_ADDR addr, int len, int rw,
 546                               struct expression *cond)
 547 {
 548   struct lwp_info *lp;
 549   int idx;
 550   long dbr_addr, dbr_mask;
 551   int max_watchpoints = 4;
 552
 553   if (len <= 0 || !is_power_of_2 (len))
 554     return -1;
 555
 556   for (idx = 0; idx < max_watchpoints; idx++)
 557     {
 558       dbr_mask = debug_registers[idx * 2 + 1];
 559       if ((dbr_mask & (0x3UL << 62)) == 0)
 560         {
 561           /* Exit loop if both r and w bits clear.  */
 562           break;
 563         }
 564     }
 565
 566   if (idx == max_watchpoints)
 567     return -1;
 568
 569   dbr_addr = (long) addr;
 570   dbr_mask = (~(len - 1) & 0x00ffffffffffffffL);  /* construct mask to match */
 571   dbr_mask |= 0x0800000000000000L;           /* Only match privilege level 3 */
 572   switch (rw)
 573     {
 574     case hw_write:
 575       dbr_mask |= (1L << 62);                   /* Set w bit */
 576       break;
 577     case hw_read:
 578       dbr_mask |= (1L << 63);                   /* Set r bit */
 579       break;
 580     case hw_access:
 581       dbr_mask |= (3L << 62);                   /* Set both r and w bits */
 582       break;
 583     default:
 584       return -1;
 585     }
 586
 587   debug_registers[2 * idx] = dbr_addr;
 588   debug_registers[2 * idx + 1] = dbr_mask;
 589   ALL_LWPS (lp)
 590     {
 591       store_debug_register_pair (lp->ptid, idx, &dbr_addr, &dbr_mask);
 592       enable_watchpoints_in_psr (lp->ptid);
 593     }
 594
 595   return 0;
 596 }
 597
 598 static int
 599 ia64_linux_remove_watchpoint (CORE_ADDR addr, int len, int type,
 600                               struct expression *cond)
 601 {
 602   int idx;
 603   long dbr_addr, dbr_mask;
 604   int max_watchpoints = 4;
 605
 606   if (len <= 0 || !is_power_of_2 (len))
 607     return -1;
 608
 609   for (idx = 0; idx < max_watchpoints; idx++)
 610     {
 611       dbr_addr = debug_registers[2 * idx];
 612       dbr_mask = debug_registers[2 * idx + 1];
 613       if ((dbr_mask & (0x3UL << 62)) && addr == (CORE_ADDR) dbr_addr)
 614         {
 615           struct lwp_info *lp;
 616
 617           debug_registers[2 * idx] = 0;
 618           debug_registers[2 * idx + 1] = 0;
 619           dbr_addr = 0;
 620           dbr_mask = 0;
 621
 622           ALL_LWPS (lp)
 623             store_debug_register_pair (lp->ptid, idx, &dbr_addr, &dbr_mask);
 624
 625           return 0;
 626         }
 627     }
 628   return -1;
 629 }
 630
 631 static void
 632 ia64_linux_new_thread (struct lwp_info *lp)
 633 {
 634   int i, any;
 635
 636   any = 0;
 637   for (i = 0; i < 8; i++)
 638     {
 639       if (debug_registers[i] != 0)
 640         any = 1;
 641       store_debug_register (lp->ptid, i, debug_registers[i]);
 642     }
 643
 644   if (any)
 645     enable_watchpoints_in_psr (lp->ptid);
 646 }
 647
 648 static int
 649 ia64_linux_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
 650 {
 651   CORE_ADDR psr;
 652   siginfo_t siginfo;
 653   struct regcache *regcache = get_current_regcache ();
 654
 655   if (!linux_nat_get_siginfo (inferior_ptid, &siginfo))
 656     return 0;
 657
 658   if (siginfo.si_signo != SIGTRAP
 659       || (siginfo.si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */)
 660     return 0;
 661
 662   regcache_cooked_read_unsigned (regcache, IA64_PSR_REGNUM, &psr);
 663   psr |= IA64_PSR_DD;   /* Set the dd bit - this will disable the watchpoint
 664                            for the next instruction.  */
 665   regcache_cooked_write_unsigned (regcache, IA64_PSR_REGNUM, psr);
 666
 667   *addr_p = (CORE_ADDR) siginfo.si_addr;
 668   return 1;
 669 }
 670
 671 static int
 672 ia64_linux_stopped_by_watchpoint (void)
 673 {
 674   CORE_ADDR addr;
 675   return ia64_linux_stopped_data_address (&current_target, &addr);
 676 }
 677
 678 static int
 679 ia64_linux_can_use_hw_breakpoint (int type, int cnt, int othertype)
 680 {
 681   return 1;
 682 }
 683
 684
 685 /* Fetch register REGNUM from the inferior.  */
 686
 687 static void
 688 ia64_linux_fetch_register (struct regcache *regcache, int regnum)
 689 {
 690   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 691   CORE_ADDR addr;
 692   size_t size;
 693   PTRACE_TYPE_RET *buf;
 694   int pid, i;
 695
 696   /* r0 cannot be fetched but is always zero.  */
 697   if (regnum == IA64_GR0_REGNUM)
 698     {
 699       const gdb_byte zero[8] = { 0 };
 700
 701       gdb_assert (sizeof (zero) == register_size (gdbarch, regnum));
 702       regcache_raw_supply (regcache, regnum, zero);
 703       return;
 704     }
 705
 706   /* fr0 cannot be fetched but is always zero.  */
 707   if (regnum == IA64_FR0_REGNUM)
 708     {
 709       const gdb_byte f_zero[16] = { 0 };
 710
 711       gdb_assert (sizeof (f_zero) == register_size (gdbarch, regnum));
 712       regcache_raw_supply (regcache, regnum, f_zero);
 713       return;
 714     }
 715
 716   /* fr1 cannot be fetched but is always one (1.0).  */
 717   if (regnum == IA64_FR1_REGNUM)
 718     {
 719       const gdb_byte f_one[16] =
 720         { 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0xff, 0, 0, 0, 0, 0, 0 };
 721
 722       gdb_assert (sizeof (f_one) == register_size (gdbarch, regnum));
 723       regcache_raw_supply (regcache, regnum, f_one);
 724       return;
 725     }
 726
 727   if (ia64_cannot_fetch_register (gdbarch, regnum))
 728     {
 729       regcache_raw_supply (regcache, regnum, NULL);
 730       return;
 731     }
 732
 733   /* Cater for systems like GNU/Linux, that implement threads as
 734      separate processes.  */
 735   pid = ptid_get_lwp (inferior_ptid);
 736   if (pid == 0)
 737     pid = ptid_get_pid (inferior_ptid);
 738
 739   /* This isn't really an address, but ptrace thinks of it as one.  */
 740   addr = ia64_register_addr (gdbarch, regnum);
 741   size = register_size (gdbarch, regnum);
 742
 743   gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
 744   buf = alloca (size);
 745
 746   /* Read the register contents from the inferior a chunk at a time.  */
 747   for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
 748     {
 749       errno = 0;
 750       buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)addr, 0);
 751       if (errno != 0)
 752         error (_("Couldn't read register %s (#%d): %s."),
 753                gdbarch_register_name (gdbarch, regnum),
 754                regnum, safe_strerror (errno));
 755
 756       addr += sizeof (PTRACE_TYPE_RET);
 757     }
 758   regcache_raw_supply (regcache, regnum, buf);
 759 }
 760
 761 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
 762    for all registers.  */
 763
 764 static void
 765 ia64_linux_fetch_registers (struct target_ops *ops,
 766                             struct regcache *regcache, int regnum)
 767 {
 768   if (regnum == -1)
 769     for (regnum = 0;
 770          regnum < gdbarch_num_regs (get_regcache_arch (regcache));
 771          regnum++)
 772       ia64_linux_fetch_register (regcache, regnum);
 773   else
 774     ia64_linux_fetch_register (regcache, regnum);
 775 }
 776
 777 /* Store register REGNUM into the inferior.  */
 778
 779 static void
 780 ia64_linux_store_register (const struct regcache *regcache, int regnum)
 781 {
 782   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 783   CORE_ADDR addr;
 784   size_t size;
 785   PTRACE_TYPE_RET *buf;
 786   int pid, i;
 787
 788   if (ia64_cannot_store_register (gdbarch, regnum))
 789     return;
 790
 791   /* Cater for systems like GNU/Linux, that implement threads as
 792      separate processes.  */
 793   pid = ptid_get_lwp (inferior_ptid);
 794   if (pid == 0)
 795     pid = ptid_get_pid (inferior_ptid);
 796
 797   /* This isn't really an address, but ptrace thinks of it as one.  */
 798   addr = ia64_register_addr (gdbarch, regnum);
 799   size = register_size (gdbarch, regnum);
 800
 801   gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
 802   buf = alloca (size);
 803
 804   /* Write the register contents into the inferior a chunk at a time.  */
 805   regcache_raw_collect (regcache, regnum, buf);
 806   for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
 807     {
 808       errno = 0;
 809       ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)addr, buf[i]);
 810       if (errno != 0)
 811         error (_("Couldn't write register %s (#%d): %s."),
 812                gdbarch_register_name (gdbarch, regnum),
 813                regnum, safe_strerror (errno));
 814
 815       addr += sizeof (PTRACE_TYPE_RET);
 816     }
 817 }
 818
 819 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
 820    this for all registers.  */
 821
 822 static void
 823 ia64_linux_store_registers (struct target_ops *ops,
 824                             struct regcache *regcache, int regnum)
 825 {
 826   if (regnum == -1)
 827     for (regnum = 0;
 828          regnum < gdbarch_num_regs (get_regcache_arch (regcache));
 829          regnum++)
 830       ia64_linux_store_register (regcache, regnum);
 831   else
 832     ia64_linux_store_register (regcache, regnum);
 833 }
 834
 835
 836 static LONGEST (*super_xfer_partial) (struct target_ops *, enum target_object,
 837                                       const char *, gdb_byte *,
 838                                       const gdb_byte *, ULONGEST, LONGEST);
 839
 840 static LONGEST
 841 ia64_linux_xfer_partial (struct target_ops *ops,
 842                          enum target_object object,
 843                          const char *annex,
 844                          gdb_byte *readbuf, const gdb_byte *writebuf,
 845                          ULONGEST offset, LONGEST len)
 846 {
 847   if (object == TARGET_OBJECT_UNWIND_TABLE && writebuf == NULL && offset == 0)
 848     return syscall (__NR_getunwind, readbuf, len);
 849
 850   return super_xfer_partial (ops, object, annex, readbuf, writebuf,
 851                              offset, len);
 852 }
 853
 854 /* For break.b instruction ia64 CPU forgets the immediate value and generates
 855    SIGILL with ILL_ILLOPC instead of more common SIGTRAP with TRAP_BRKPT.
 856    ia64 does not use gdbarch_decr_pc_after_break so we do not have to make any
 857    difference for the signals here.  */
 858
 859 static int
 860 ia64_linux_status_is_event (int status)
 861 {
 862   return WIFSTOPPED (status) && (WSTOPSIG (status) == SIGTRAP
 863                                  || WSTOPSIG (status) == SIGILL);
 864 }
 865
 866 void _initialize_ia64_linux_nat (void);
 867
 868 void
 869 _initialize_ia64_linux_nat (void)
 870 {
 871   struct target_ops *t;
 872
 873   /* Fill in the generic GNU/Linux methods.  */
 874   t = linux_target ();
 875
 876   /* Override the default fetch/store register routines.  */
 877   t->to_fetch_registers = ia64_linux_fetch_registers;
 878   t->to_store_registers = ia64_linux_store_registers;
 879
 880   /* Override the default to_xfer_partial.  */
 881   super_xfer_partial = t->to_xfer_partial;
 882   t->to_xfer_partial = ia64_linux_xfer_partial;
 883
 884   /* Override watchpoint routines.  */
 885
 886   /* The IA-64 architecture can step over a watch point (without triggering
 887      it again) if the "dd" (data debug fault disable) bit in the processor
 888      status word is set.
 889
 890      This PSR bit is set in ia64_linux_stopped_by_watchpoint when the
 891      code there has determined that a hardware watchpoint has indeed
 892      been hit.  The CPU will then be able to execute one instruction
 893      without triggering a watchpoint.  */
 894
 895   t->to_have_steppable_watchpoint = 1;
 896   t->to_can_use_hw_breakpoint = ia64_linux_can_use_hw_breakpoint;
 897   t->to_stopped_by_watchpoint = ia64_linux_stopped_by_watchpoint;
 898   t->to_stopped_data_address = ia64_linux_stopped_data_address;
 899   t->to_insert_watchpoint = ia64_linux_insert_watchpoint;
 900   t->to_remove_watchpoint = ia64_linux_remove_watchpoint;
 901
 902   /* Register the target.  */
 903   linux_nat_add_target (t);
 904   linux_nat_set_new_thread (t, ia64_linux_new_thread);
 905   linux_nat_set_status_is_event (t, ia64_linux_status_is_event);
 906 }