gdb/aarch64-linux-nat.c

   1 /* Native-dependent code for GNU/Linux AArch64.
   2
   3    Copyright (C) 2011-2015 Free Software Foundation, Inc.
   4    Contributed by ARM Ltd.
   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
  23 #include "inferior.h"
  24 #include "gdbcore.h"
  25 #include "regcache.h"
  26 #include "linux-nat.h"
  27 #include "target-descriptions.h"
  28 #include "auxv.h"
  29 #include "gdbcmd.h"
  30 #include "aarch64-tdep.h"
  31 #include "aarch64-linux-tdep.h"
  32 #include "aarch32-linux-nat.h"
  33 #include "nat/aarch64-linux.h"
  34 #include "nat/aarch64-linux-hw-point.h"
  35
  36 #include "elf/external.h"
  37 #include "elf/common.h"
  38
  39 #include "nat/gdb_ptrace.h"
  40 #include <sys/utsname.h>
  41 #include <asm/ptrace.h>
  42
  43 #include "gregset.h"
  44
  45 /* Defines ps_err_e, struct ps_prochandle.  */
  46 #include "gdb_proc_service.h"
  47
  48 #ifndef TRAP_HWBKPT
  49 #define TRAP_HWBKPT 0x0004
  50 #endif
  51
  52 /* Per-process data.  We don't bind this to a per-inferior registry
  53    because of targets like x86 GNU/Linux that need to keep track of
  54    processes that aren't bound to any inferior (e.g., fork children,
  55    checkpoints).  */
  56
  57 struct aarch64_process_info
  58 {
  59   /* Linked list.  */
  60   struct aarch64_process_info *next;
  61
  62   /* The process identifier.  */
  63   pid_t pid;
  64
  65   /* Copy of aarch64 hardware debug registers.  */
  66   struct aarch64_debug_reg_state state;
  67 };
  68
  69 static struct aarch64_process_info *aarch64_process_list = NULL;
  70
  71 /* Find process data for process PID.  */
  72
  73 static struct aarch64_process_info *
  74 aarch64_find_process_pid (pid_t pid)
  75 {
  76   struct aarch64_process_info *proc;
  77
  78   for (proc = aarch64_process_list; proc; proc = proc->next)
  79     if (proc->pid == pid)
  80       return proc;
  81
  82   return NULL;
  83 }
  84
  85 /* Add process data for process PID.  Returns newly allocated info
  86    object.  */
  87
  88 static struct aarch64_process_info *
  89 aarch64_add_process (pid_t pid)
  90 {
  91   struct aarch64_process_info *proc;
  92
  93   proc = XCNEW (struct aarch64_process_info);
  94   proc->pid = pid;
  95
  96   proc->next = aarch64_process_list;
  97   aarch64_process_list = proc;
  98
  99   return proc;
 100 }
 101
 102 /* Get data specific info for process PID, creating it if necessary.
 103    Never returns NULL.  */
 104
 105 static struct aarch64_process_info *
 106 aarch64_process_info_get (pid_t pid)
 107 {
 108   struct aarch64_process_info *proc;
 109
 110   proc = aarch64_find_process_pid (pid);
 111   if (proc == NULL)
 112     proc = aarch64_add_process (pid);
 113
 114   return proc;
 115 }
 116
 117 /* Called whenever GDB is no longer debugging process PID.  It deletes
 118    data structures that keep track of debug register state.  */
 119
 120 static void
 121 aarch64_forget_process (pid_t pid)
 122 {
 123   struct aarch64_process_info *proc, **proc_link;
 124
 125   proc = aarch64_process_list;
 126   proc_link = &aarch64_process_list;
 127
 128   while (proc != NULL)
 129     {
 130       if (proc->pid == pid)
 131         {
 132           *proc_link = proc->next;
 133
 134           xfree (proc);
 135           return;
 136         }
 137
 138       proc_link = &proc->next;
 139       proc = *proc_link;
 140     }
 141 }
 142
 143 /* Get debug registers state for process PID.  */
 144
 145 struct aarch64_debug_reg_state *
 146 aarch64_get_debug_reg_state (pid_t pid)
 147 {
 148   return &aarch64_process_info_get (pid)->state;
 149 }
 150
 151 /* Fill GDB's register array with the general-purpose register values
 152    from the current thread.  */
 153
 154 static void
 155 fetch_gregs_from_thread (struct regcache *regcache)
 156 {
 157   int ret, tid;
 158   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 159   elf_gregset_t regs;
 160   struct iovec iovec;
 161
 162   /* Make sure REGS can hold all registers contents on both aarch64
 163      and arm.  */
 164   gdb_static_assert (sizeof (regs) >= 18 * 4);
 165
 166   tid = ptid_get_lwp (inferior_ptid);
 167
 168   iovec.iov_base = &regs;
 169   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
 170     iovec.iov_len = 18 * 4;
 171   else
 172     iovec.iov_len = sizeof (regs);
 173
 174   ret = ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, &iovec);
 175   if (ret < 0)
 176     perror_with_name (_("Unable to fetch general registers."));
 177
 178   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
 179     aarch32_gp_regcache_supply (regcache, (uint32_t *) regs, 1);
 180   else
 181     {
 182       int regno;
 183
 184       for (regno = AARCH64_X0_REGNUM; regno <= AARCH64_CPSR_REGNUM; regno++)
 185         regcache_raw_supply (regcache, regno, &regs[regno - AARCH64_X0_REGNUM]);
 186     }
 187 }
 188
 189 /* Store to the current thread the valid general-purpose register
 190    values in the GDB's register array.  */
 191
 192 static void
 193 store_gregs_to_thread (const struct regcache *regcache)
 194 {
 195   int ret, tid;
 196   elf_gregset_t regs;
 197   struct iovec iovec;
 198   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 199
 200   /* Make sure REGS can hold all registers contents on both aarch64
 201      and arm.  */
 202   gdb_static_assert (sizeof (regs) >= 18 * 4);
 203   tid = ptid_get_lwp (inferior_ptid);
 204
 205   iovec.iov_base = &regs;
 206   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
 207     iovec.iov_len = 18 * 4;
 208   else
 209     iovec.iov_len = sizeof (regs);
 210
 211   ret = ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, &iovec);
 212   if (ret < 0)
 213     perror_with_name (_("Unable to fetch general registers."));
 214
 215   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
 216     aarch32_gp_regcache_collect (regcache, (uint32_t *) regs, 1);
 217   else
 218     {
 219       int regno;
 220
 221       for (regno = AARCH64_X0_REGNUM; regno <= AARCH64_CPSR_REGNUM; regno++)
 222         if (REG_VALID == regcache_register_status (regcache, regno))
 223           regcache_raw_collect (regcache, regno,
 224                                 &regs[regno - AARCH64_X0_REGNUM]);
 225     }
 226
 227   ret = ptrace (PTRACE_SETREGSET, tid, NT_PRSTATUS, &iovec);
 228   if (ret < 0)
 229     perror_with_name (_("Unable to store general registers."));
 230 }
 231
 232 /* Fill GDB's register array with the fp/simd register values
 233    from the current thread.  */
 234
 235 static void
 236 fetch_fpregs_from_thread (struct regcache *regcache)
 237 {
 238   int ret, tid;
 239   elf_fpregset_t regs;
 240   struct iovec iovec;
 241   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 242
 243   /* Make sure REGS can hold all VFP registers contents on both aarch64
 244      and arm.  */
 245   gdb_static_assert (sizeof regs >= VFP_REGS_SIZE);
 246
 247   tid = ptid_get_lwp (inferior_ptid);
 248
 249   iovec.iov_base = &regs;
 250
 251   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
 252     {
 253       iovec.iov_len = VFP_REGS_SIZE;
 254
 255       ret = ptrace (PTRACE_GETREGSET, tid, NT_ARM_VFP, &iovec);
 256       if (ret < 0)
 257         perror_with_name (_("Unable to fetch VFP registers."));
 258
 259       aarch32_vfp_regcache_supply (regcache, (gdb_byte *) &regs, 32);
 260     }
 261   else
 262     {
 263       int regno;
 264
 265       iovec.iov_len = sizeof (regs);
 266
 267       ret = ptrace (PTRACE_GETREGSET, tid, NT_FPREGSET, &iovec);
 268       if (ret < 0)
 269         perror_with_name (_("Unable to fetch vFP/SIMD registers."));
 270
 271       for (regno = AARCH64_V0_REGNUM; regno <= AARCH64_V31_REGNUM; regno++)
 272         regcache_raw_supply (regcache, regno,
 273                              &regs.vregs[regno - AARCH64_V0_REGNUM]);
 274
 275       regcache_raw_supply (regcache, AARCH64_FPSR_REGNUM, &regs.fpsr);
 276       regcache_raw_supply (regcache, AARCH64_FPCR_REGNUM, &regs.fpcr);
 277     }
 278 }
 279
 280 /* Store to the current thread the valid fp/simd register
 281    values in the GDB's register array.  */
 282
 283 static void
 284 store_fpregs_to_thread (const struct regcache *regcache)
 285 {
 286   int ret, tid;
 287   elf_fpregset_t regs;
 288   struct iovec iovec;
 289   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 290
 291   /* Make sure REGS can hold all VFP registers contents on both aarch64
 292      and arm.  */
 293   gdb_static_assert (sizeof regs >= VFP_REGS_SIZE);
 294   tid = ptid_get_lwp (inferior_ptid);
 295
 296   iovec.iov_base = &regs;
 297
 298   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
 299     {
 300       iovec.iov_len = VFP_REGS_SIZE;
 301
 302       ret = ptrace (PTRACE_GETREGSET, tid, NT_ARM_VFP, &iovec);
 303       if (ret < 0)
 304         perror_with_name (_("Unable to fetch VFP registers."));
 305
 306       aarch32_vfp_regcache_collect (regcache, (gdb_byte *) &regs, 32);
 307     }
 308   else
 309     {
 310       int regno;
 311
 312       iovec.iov_len = sizeof (regs);
 313
 314       ret = ptrace (PTRACE_GETREGSET, tid, NT_FPREGSET, &iovec);
 315       if (ret < 0)
 316         perror_with_name (_("Unable to fetch FP/SIMD registers."));
 317
 318       for (regno = AARCH64_V0_REGNUM; regno <= AARCH64_V31_REGNUM; regno++)
 319         if (REG_VALID == regcache_register_status (regcache, regno))
 320           regcache_raw_collect (regcache, regno,
 321                                 (char *) &regs.vregs[regno - AARCH64_V0_REGNUM]);
 322
 323       if (REG_VALID == regcache_register_status (regcache, AARCH64_FPSR_REGNUM))
 324         regcache_raw_collect (regcache, AARCH64_FPSR_REGNUM,
 325                               (char *) &regs.fpsr);
 326       if (REG_VALID == regcache_register_status (regcache, AARCH64_FPCR_REGNUM))
 327         regcache_raw_collect (regcache, AARCH64_FPCR_REGNUM,
 328                               (char *) &regs.fpcr);
 329     }
 330
 331   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
 332     {
 333       ret = ptrace (PTRACE_SETREGSET, tid, NT_ARM_VFP, &iovec);
 334       if (ret < 0)
 335         perror_with_name (_("Unable to store VFP registers."));
 336     }
 337   else
 338     {
 339       ret = ptrace (PTRACE_SETREGSET, tid, NT_FPREGSET, &iovec);
 340       if (ret < 0)
 341         perror_with_name (_("Unable to store FP/SIMD registers."));
 342     }
 343 }
 344
 345 /* Implement the "to_fetch_register" target_ops method.  */
 346
 347 static void
 348 aarch64_linux_fetch_inferior_registers (struct target_ops *ops,
 349                                         struct regcache *regcache,
 350                                         int regno)
 351 {
 352   if (regno == -1)
 353     {
 354       fetch_gregs_from_thread (regcache);
 355       fetch_fpregs_from_thread (regcache);
 356     }
 357   else if (regno < AARCH64_V0_REGNUM)
 358     fetch_gregs_from_thread (regcache);
 359   else
 360     fetch_fpregs_from_thread (regcache);
 361 }
 362
 363 /* Implement the "to_store_register" target_ops method.  */
 364
 365 static void
 366 aarch64_linux_store_inferior_registers (struct target_ops *ops,
 367                                         struct regcache *regcache,
 368                                         int regno)
 369 {
 370   if (regno == -1)
 371     {
 372       store_gregs_to_thread (regcache);
 373       store_fpregs_to_thread (regcache);
 374     }
 375   else if (regno < AARCH64_V0_REGNUM)
 376     store_gregs_to_thread (regcache);
 377   else
 378     store_fpregs_to_thread (regcache);
 379 }
 380
 381 /* Fill register REGNO (if it is a general-purpose register) in
 382    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
 383    do this for all registers.  */
 384
 385 void
 386 fill_gregset (const struct regcache *regcache,
 387               gdb_gregset_t *gregsetp, int regno)
 388 {
 389   regcache_collect_regset (&aarch64_linux_gregset, regcache,
 390                            regno, (gdb_byte *) gregsetp,
 391                            AARCH64_LINUX_SIZEOF_GREGSET);
 392 }
 393
 394 /* Fill GDB's register array with the general-purpose register values
 395    in *GREGSETP.  */
 396
 397 void
 398 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
 399 {
 400   regcache_supply_regset (&aarch64_linux_gregset, regcache, -1,
 401                           (const gdb_byte *) gregsetp,
 402                           AARCH64_LINUX_SIZEOF_GREGSET);
 403 }
 404
 405 /* Fill register REGNO (if it is a floating-point register) in
 406    *FPREGSETP with the value in GDB's register array.  If REGNO is -1,
 407    do this for all registers.  */
 408
 409 void
 410 fill_fpregset (const struct regcache *regcache,
 411                gdb_fpregset_t *fpregsetp, int regno)
 412 {
 413   regcache_collect_regset (&aarch64_linux_fpregset, regcache,
 414                            regno, (gdb_byte *) fpregsetp,
 415                            AARCH64_LINUX_SIZEOF_FPREGSET);
 416 }
 417
 418 /* Fill GDB's register array with the floating-point register values
 419    in *FPREGSETP.  */
 420
 421 void
 422 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregsetp)
 423 {
 424   regcache_supply_regset (&aarch64_linux_fpregset, regcache, -1,
 425                           (const gdb_byte *) fpregsetp,
 426                           AARCH64_LINUX_SIZEOF_FPREGSET);
 427 }
 428
 429 /* linux_nat_new_fork hook.   */
 430
 431 static void
 432 aarch64_linux_new_fork (struct lwp_info *parent, pid_t child_pid)
 433 {
 434   pid_t parent_pid;
 435   struct aarch64_debug_reg_state *parent_state;
 436   struct aarch64_debug_reg_state *child_state;
 437
 438   /* NULL means no watchpoint has ever been set in the parent.  In
 439      that case, there's nothing to do.  */
 440   if (parent->arch_private == NULL)
 441     return;
 442
 443   /* GDB core assumes the child inherits the watchpoints/hw
 444      breakpoints of the parent, and will remove them all from the
 445      forked off process.  Copy the debug registers mirrors into the
 446      new process so that all breakpoints and watchpoints can be
 447      removed together.  */
 448
 449   parent_pid = ptid_get_pid (parent->ptid);
 450   parent_state = aarch64_get_debug_reg_state (parent_pid);
 451   child_state = aarch64_get_debug_reg_state (child_pid);
 452   *child_state = *parent_state;
 453 }
 454 \f
 455
 456 /* Called by libthread_db.  Returns a pointer to the thread local
 457    storage (or its descriptor).  */
 458
 459 ps_err_e
 460 ps_get_thread_area (const struct ps_prochandle *ph,
 461                     lwpid_t lwpid, int idx, void **base)
 462 {
 463   struct iovec iovec;
 464   uint64_t reg;
 465
 466   iovec.iov_base = &reg;
 467   iovec.iov_len = sizeof (reg);
 468
 469   if (ptrace (PTRACE_GETREGSET, lwpid, NT_ARM_TLS, &iovec) != 0)
 470     return PS_ERR;
 471
 472   /* IDX is the bias from the thread pointer to the beginning of the
 473      thread descriptor.  It has to be subtracted due to implementation
 474      quirks in libthread_db.  */
 475   *base = (void *) (reg - idx);
 476
 477   return PS_OK;
 478 }
 479 \f
 480
 481 static void (*super_post_startup_inferior) (struct target_ops *self,
 482                                             ptid_t ptid);
 483
 484 /* Implement the "to_post_startup_inferior" target_ops method.  */
 485
 486 static void
 487 aarch64_linux_child_post_startup_inferior (struct target_ops *self,
 488                                            ptid_t ptid)
 489 {
 490   aarch64_forget_process (ptid_get_pid (ptid));
 491   aarch64_linux_get_debug_reg_capacity (ptid_get_pid (ptid));
 492   super_post_startup_inferior (self, ptid);
 493 }
 494
 495 extern struct target_desc *tdesc_arm_with_vfpv3;
 496 extern struct target_desc *tdesc_arm_with_neon;
 497
 498 /* Implement the "to_read_description" target_ops method.  */
 499
 500 static const struct target_desc *
 501 aarch64_linux_read_description (struct target_ops *ops)
 502 {
 503   CORE_ADDR at_phent;
 504
 505   if (target_auxv_search (ops, AT_PHENT, &at_phent) == 1)
 506     {
 507       if (at_phent == sizeof (Elf64_External_Phdr))
 508         return tdesc_aarch64;
 509       else
 510         {
 511           CORE_ADDR arm_hwcap = 0;
 512
 513           if (target_auxv_search (ops, AT_HWCAP, &arm_hwcap) != 1)
 514             return ops->beneath->to_read_description (ops->beneath);
 515
 516 #ifndef COMPAT_HWCAP_VFP
 517 #define COMPAT_HWCAP_VFP        (1 << 6)
 518 #endif
 519 #ifndef COMPAT_HWCAP_NEON
 520 #define COMPAT_HWCAP_NEON       (1 << 12)
 521 #endif
 522 #ifndef COMPAT_HWCAP_VFPv3
 523 #define COMPAT_HWCAP_VFPv3      (1 << 13)
 524 #endif
 525
 526           if (arm_hwcap & COMPAT_HWCAP_VFP)
 527             {
 528               char *buf;
 529               const struct target_desc *result = NULL;
 530
 531               if (arm_hwcap & COMPAT_HWCAP_NEON)
 532                 result = tdesc_arm_with_neon;
 533               else if (arm_hwcap & COMPAT_HWCAP_VFPv3)
 534                 result = tdesc_arm_with_vfpv3;
 535
 536               return result;
 537             }
 538
 539           return NULL;
 540         }
 541     }
 542
 543   return tdesc_aarch64;
 544 }
 545
 546 /* Convert a native/host siginfo object, into/from the siginfo in the
 547    layout of the inferiors' architecture.  Returns true if any
 548    conversion was done; false otherwise.  If DIRECTION is 1, then copy
 549    from INF to NATIVE.  If DIRECTION is 0, copy from NATIVE to
 550    INF.  */
 551
 552 static int
 553 aarch64_linux_siginfo_fixup (siginfo_t *native, gdb_byte *inf, int direction)
 554 {
 555   struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
 556
 557   /* Is the inferior 32-bit?  If so, then do fixup the siginfo
 558      object.  */
 559   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
 560     {
 561       if (direction == 0)
 562         aarch64_compat_siginfo_from_siginfo ((struct compat_siginfo *) inf,
 563                                              native);
 564       else
 565         aarch64_siginfo_from_compat_siginfo (native,
 566                                              (struct compat_siginfo *) inf);
 567
 568       return 1;
 569     }
 570
 571   return 0;
 572 }
 573
 574 /* Returns the number of hardware watchpoints of type TYPE that we can
 575    set.  Value is positive if we can set CNT watchpoints, zero if
 576    setting watchpoints of type TYPE is not supported, and negative if
 577    CNT is more than the maximum number of watchpoints of type TYPE
 578    that we can support.  TYPE is one of bp_hardware_watchpoint,
 579    bp_read_watchpoint, bp_write_watchpoint, or bp_hardware_breakpoint.
 580    CNT is the number of such watchpoints used so far (including this
 581    one).  OTHERTYPE is non-zero if other types of watchpoints are
 582    currently enabled.  */
 583
 584 static int
 585 aarch64_linux_can_use_hw_breakpoint (struct target_ops *self,
 586                                      enum bptype type,
 587                                      int cnt, int othertype)
 588 {
 589   if (type == bp_hardware_watchpoint || type == bp_read_watchpoint
 590       || type == bp_access_watchpoint || type == bp_watchpoint)
 591     {
 592       if (aarch64_num_wp_regs == 0)
 593         return 0;
 594     }
 595   else if (type == bp_hardware_breakpoint)
 596     {
 597       if (aarch64_num_bp_regs == 0)
 598         return 0;
 599     }
 600   else
 601     gdb_assert_not_reached ("unexpected breakpoint type");
 602
 603   /* We always return 1 here because we don't have enough information
 604      about possible overlap of addresses that they want to watch.  As an
 605      extreme example, consider the case where all the watchpoints watch
 606      the same address and the same region length: then we can handle a
 607      virtually unlimited number of watchpoints, due to debug register
 608      sharing implemented via reference counts.  */
 609   return 1;
 610 }
 611
 612 /* Insert a hardware-assisted breakpoint at BP_TGT->reqstd_address.
 613    Return 0 on success, -1 on failure.  */
 614
 615 static int
 616 aarch64_linux_insert_hw_breakpoint (struct target_ops *self,
 617                                     struct gdbarch *gdbarch,
 618                                     struct bp_target_info *bp_tgt)
 619 {
 620   int ret;
 621   CORE_ADDR addr = bp_tgt->placed_address = bp_tgt->reqstd_address;
 622   const int len = 4;
 623   const enum target_hw_bp_type type = hw_execute;
 624   struct aarch64_debug_reg_state *state
 625     = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 626
 627   if (show_debug_regs)
 628     fprintf_unfiltered
 629       (gdb_stdlog,
 630        "insert_hw_breakpoint on entry (addr=0x%08lx, len=%d))\n",
 631        (unsigned long) addr, len);
 632
 633   ret = aarch64_handle_breakpoint (type, addr, len, 1 /* is_insert */, state);
 634
 635   if (show_debug_regs)
 636     {
 637       aarch64_show_debug_reg_state (state,
 638                                     "insert_hw_breakpoint", addr, len, type);
 639     }
 640
 641   return ret;
 642 }
 643
 644 /* Remove a hardware-assisted breakpoint at BP_TGT->placed_address.
 645    Return 0 on success, -1 on failure.  */
 646
 647 static int
 648 aarch64_linux_remove_hw_breakpoint (struct target_ops *self,
 649                                     struct gdbarch *gdbarch,
 650                                     struct bp_target_info *bp_tgt)
 651 {
 652   int ret;
 653   CORE_ADDR addr = bp_tgt->placed_address;
 654   const int len = 4;
 655   const enum target_hw_bp_type type = hw_execute;
 656   struct aarch64_debug_reg_state *state
 657     = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 658
 659   if (show_debug_regs)
 660     fprintf_unfiltered
 661       (gdb_stdlog, "remove_hw_breakpoint on entry (addr=0x%08lx, len=%d))\n",
 662        (unsigned long) addr, len);
 663
 664   ret = aarch64_handle_breakpoint (type, addr, len, 0 /* is_insert */, state);
 665
 666   if (show_debug_regs)
 667     {
 668       aarch64_show_debug_reg_state (state,
 669                                     "remove_hw_watchpoint", addr, len, type);
 670     }
 671
 672   return ret;
 673 }
 674
 675 /* Implement the "to_insert_watchpoint" target_ops method.
 676
 677    Insert a watchpoint to watch a memory region which starts at
 678    address ADDR and whose length is LEN bytes.  Watch memory accesses
 679    of the type TYPE.  Return 0 on success, -1 on failure.  */
 680
 681 static int
 682 aarch64_linux_insert_watchpoint (struct target_ops *self,
 683                                  CORE_ADDR addr, int len,
 684                                  enum target_hw_bp_type type,
 685                                  struct expression *cond)
 686 {
 687   int ret;
 688   struct aarch64_debug_reg_state *state
 689     = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 690
 691   if (show_debug_regs)
 692     fprintf_unfiltered (gdb_stdlog,
 693                         "insert_watchpoint on entry (addr=0x%08lx, len=%d)\n",
 694                         (unsigned long) addr, len);
 695
 696   gdb_assert (type != hw_execute);
 697
 698   ret = aarch64_handle_watchpoint (type, addr, len, 1 /* is_insert */, state);
 699
 700   if (show_debug_regs)
 701     {
 702       aarch64_show_debug_reg_state (state,
 703                                     "insert_watchpoint", addr, len, type);
 704     }
 705
 706   return ret;
 707 }
 708
 709 /* Implement the "to_remove_watchpoint" target_ops method.
 710    Remove a watchpoint that watched the memory region which starts at
 711    address ADDR, whose length is LEN bytes, and for accesses of the
 712    type TYPE.  Return 0 on success, -1 on failure.  */
 713
 714 static int
 715 aarch64_linux_remove_watchpoint (struct target_ops *self,
 716                                  CORE_ADDR addr, int len,
 717                                  enum target_hw_bp_type type,
 718                                  struct expression *cond)
 719 {
 720   int ret;
 721   struct aarch64_debug_reg_state *state
 722     = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 723
 724   if (show_debug_regs)
 725     fprintf_unfiltered (gdb_stdlog,
 726                         "remove_watchpoint on entry (addr=0x%08lx, len=%d)\n",
 727                         (unsigned long) addr, len);
 728
 729   gdb_assert (type != hw_execute);
 730
 731   ret = aarch64_handle_watchpoint (type, addr, len, 0 /* is_insert */, state);
 732
 733   if (show_debug_regs)
 734     {
 735       aarch64_show_debug_reg_state (state,
 736                                     "remove_watchpoint", addr, len, type);
 737     }
 738
 739   return ret;
 740 }
 741
 742 /* Implement the "to_region_ok_for_hw_watchpoint" target_ops method.  */
 743
 744 static int
 745 aarch64_linux_region_ok_for_hw_watchpoint (struct target_ops *self,
 746                                            CORE_ADDR addr, int len)
 747 {
 748   return aarch64_linux_region_ok_for_watchpoint (addr, len);
 749 }
 750
 751 /* Implement the "to_stopped_data_address" target_ops method.  */
 752
 753 static int
 754 aarch64_linux_stopped_data_address (struct target_ops *target,
 755                                     CORE_ADDR *addr_p)
 756 {
 757   siginfo_t siginfo;
 758   int i, tid;
 759   struct aarch64_debug_reg_state *state;
 760
 761   if (!linux_nat_get_siginfo (inferior_ptid, &siginfo))
 762     return 0;
 763
 764   /* This must be a hardware breakpoint.  */
 765   if (siginfo.si_signo != SIGTRAP
 766       || (siginfo.si_code & 0xffff) != TRAP_HWBKPT)
 767     return 0;
 768
 769   /* Check if the address matches any watched address.  */
 770   state = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 771   for (i = aarch64_num_wp_regs - 1; i >= 0; --i)
 772     {
 773       const unsigned int len = aarch64_watchpoint_length (state->dr_ctrl_wp[i]);
 774       const CORE_ADDR addr_trap = (CORE_ADDR) siginfo.si_addr;
 775       const CORE_ADDR addr_watch = state->dr_addr_wp[i];
 776
 777       if (state->dr_ref_count_wp[i]
 778           && DR_CONTROL_ENABLED (state->dr_ctrl_wp[i])
 779           && addr_trap >= addr_watch
 780           && addr_trap < addr_watch + len)
 781         {
 782           *addr_p = addr_trap;
 783           return 1;
 784         }
 785     }
 786
 787   return 0;
 788 }
 789
 790 /* Implement the "to_stopped_by_watchpoint" target_ops method.  */
 791
 792 static int
 793 aarch64_linux_stopped_by_watchpoint (struct target_ops *ops)
 794 {
 795   CORE_ADDR addr;
 796
 797   return aarch64_linux_stopped_data_address (ops, &addr);
 798 }
 799
 800 /* Implement the "to_watchpoint_addr_within_range" target_ops method.  */
 801
 802 static int
 803 aarch64_linux_watchpoint_addr_within_range (struct target_ops *target,
 804                                             CORE_ADDR addr,
 805                                             CORE_ADDR start, int length)
 806 {
 807   return start <= addr && start + length - 1 >= addr;
 808 }
 809
 810 /* Define AArch64 maintenance commands.  */
 811
 812 static void
 813 add_show_debug_regs_command (void)
 814 {
 815   /* A maintenance command to enable printing the internal DRi mirror
 816      variables.  */
 817   add_setshow_boolean_cmd ("show-debug-regs", class_maintenance,
 818                            &show_debug_regs, _("\
 819 Set whether to show variables that mirror the AArch64 debug registers."), _("\
 820 Show whether to show variables that mirror the AArch64 debug registers."), _("\
 821 Use \"on\" to enable, \"off\" to disable.\n\
 822 If enabled, the debug registers values are shown when GDB inserts\n\
 823 or removes a hardware breakpoint or watchpoint, and when the inferior\n\
 824 triggers a breakpoint or watchpoint."),
 825                            NULL,
 826                            NULL,
 827                            &maintenance_set_cmdlist,
 828                            &maintenance_show_cmdlist);
 829 }
 830
 831 /* -Wmissing-prototypes.  */
 832 void _initialize_aarch64_linux_nat (void);
 833
 834 void
 835 _initialize_aarch64_linux_nat (void)
 836 {
 837   struct target_ops *t;
 838
 839   /* Fill in the generic GNU/Linux methods.  */
 840   t = linux_target ();
 841
 842   add_show_debug_regs_command ();
 843
 844   /* Add our register access methods.  */
 845   t->to_fetch_registers = aarch64_linux_fetch_inferior_registers;
 846   t->to_store_registers = aarch64_linux_store_inferior_registers;
 847
 848   t->to_read_description = aarch64_linux_read_description;
 849
 850   t->to_can_use_hw_breakpoint = aarch64_linux_can_use_hw_breakpoint;
 851   t->to_insert_hw_breakpoint = aarch64_linux_insert_hw_breakpoint;
 852   t->to_remove_hw_breakpoint = aarch64_linux_remove_hw_breakpoint;
 853   t->to_region_ok_for_hw_watchpoint =
 854     aarch64_linux_region_ok_for_hw_watchpoint;
 855   t->to_insert_watchpoint = aarch64_linux_insert_watchpoint;
 856   t->to_remove_watchpoint = aarch64_linux_remove_watchpoint;
 857   t->to_stopped_by_watchpoint = aarch64_linux_stopped_by_watchpoint;
 858   t->to_stopped_data_address = aarch64_linux_stopped_data_address;
 859   t->to_watchpoint_addr_within_range =
 860     aarch64_linux_watchpoint_addr_within_range;
 861
 862   /* Override the GNU/Linux inferior startup hook.  */
 863   super_post_startup_inferior = t->to_post_startup_inferior;
 864   t->to_post_startup_inferior = aarch64_linux_child_post_startup_inferior;
 865
 866   /* Register the target.  */
 867   linux_nat_add_target (t);
 868   linux_nat_set_new_thread (t, aarch64_linux_new_thread);
 869   linux_nat_set_new_fork (t, aarch64_linux_new_fork);
 870   linux_nat_set_forget_process (t, aarch64_forget_process);
 871   linux_nat_set_prepare_to_resume (t, aarch64_linux_prepare_to_resume);
 872
 873   /* Add our siginfo layout converter.  */
 874   linux_nat_set_siginfo_fixup (t, aarch64_linux_siginfo_fixup);
 875 }