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 /* Returns the number of hardware watchpoints of type TYPE that we can
 547    set.  Value is positive if we can set CNT watchpoints, zero if
 548    setting watchpoints of type TYPE is not supported, and negative if
 549    CNT is more than the maximum number of watchpoints of type TYPE
 550    that we can support.  TYPE is one of bp_hardware_watchpoint,
 551    bp_read_watchpoint, bp_write_watchpoint, or bp_hardware_breakpoint.
 552    CNT is the number of such watchpoints used so far (including this
 553    one).  OTHERTYPE is non-zero if other types of watchpoints are
 554    currently enabled.  */
 555
 556 static int
 557 aarch64_linux_can_use_hw_breakpoint (struct target_ops *self,
 558                                      enum bptype type,
 559                                      int cnt, int othertype)
 560 {
 561   if (type == bp_hardware_watchpoint || type == bp_read_watchpoint
 562       || type == bp_access_watchpoint || type == bp_watchpoint)
 563     {
 564       if (aarch64_num_wp_regs == 0)
 565         return 0;
 566     }
 567   else if (type == bp_hardware_breakpoint)
 568     {
 569       if (aarch64_num_bp_regs == 0)
 570         return 0;
 571     }
 572   else
 573     gdb_assert_not_reached ("unexpected breakpoint type");
 574
 575   /* We always return 1 here because we don't have enough information
 576      about possible overlap of addresses that they want to watch.  As an
 577      extreme example, consider the case where all the watchpoints watch
 578      the same address and the same region length: then we can handle a
 579      virtually unlimited number of watchpoints, due to debug register
 580      sharing implemented via reference counts.  */
 581   return 1;
 582 }
 583
 584 /* Insert a hardware-assisted breakpoint at BP_TGT->reqstd_address.
 585    Return 0 on success, -1 on failure.  */
 586
 587 static int
 588 aarch64_linux_insert_hw_breakpoint (struct target_ops *self,
 589                                     struct gdbarch *gdbarch,
 590                                     struct bp_target_info *bp_tgt)
 591 {
 592   int ret;
 593   CORE_ADDR addr = bp_tgt->placed_address = bp_tgt->reqstd_address;
 594   const int len = 4;
 595   const enum target_hw_bp_type type = hw_execute;
 596   struct aarch64_debug_reg_state *state
 597     = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 598
 599   if (show_debug_regs)
 600     fprintf_unfiltered
 601       (gdb_stdlog,
 602        "insert_hw_breakpoint on entry (addr=0x%08lx, len=%d))\n",
 603        (unsigned long) addr, len);
 604
 605   ret = aarch64_handle_breakpoint (type, addr, len, 1 /* is_insert */, state);
 606
 607   if (show_debug_regs)
 608     {
 609       aarch64_show_debug_reg_state (state,
 610                                     "insert_hw_breakpoint", addr, len, type);
 611     }
 612
 613   return ret;
 614 }
 615
 616 /* Remove a hardware-assisted breakpoint at BP_TGT->placed_address.
 617    Return 0 on success, -1 on failure.  */
 618
 619 static int
 620 aarch64_linux_remove_hw_breakpoint (struct target_ops *self,
 621                                     struct gdbarch *gdbarch,
 622                                     struct bp_target_info *bp_tgt)
 623 {
 624   int ret;
 625   CORE_ADDR addr = bp_tgt->placed_address;
 626   const int len = 4;
 627   const enum target_hw_bp_type type = hw_execute;
 628   struct aarch64_debug_reg_state *state
 629     = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 630
 631   if (show_debug_regs)
 632     fprintf_unfiltered
 633       (gdb_stdlog, "remove_hw_breakpoint on entry (addr=0x%08lx, len=%d))\n",
 634        (unsigned long) addr, len);
 635
 636   ret = aarch64_handle_breakpoint (type, addr, len, 0 /* is_insert */, state);
 637
 638   if (show_debug_regs)
 639     {
 640       aarch64_show_debug_reg_state (state,
 641                                     "remove_hw_watchpoint", addr, len, type);
 642     }
 643
 644   return ret;
 645 }
 646
 647 /* Implement the "to_insert_watchpoint" target_ops method.
 648
 649    Insert a watchpoint to watch a memory region which starts at
 650    address ADDR and whose length is LEN bytes.  Watch memory accesses
 651    of the type TYPE.  Return 0 on success, -1 on failure.  */
 652
 653 static int
 654 aarch64_linux_insert_watchpoint (struct target_ops *self,
 655                                  CORE_ADDR addr, int len,
 656                                  enum target_hw_bp_type type,
 657                                  struct expression *cond)
 658 {
 659   int ret;
 660   struct aarch64_debug_reg_state *state
 661     = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 662
 663   if (show_debug_regs)
 664     fprintf_unfiltered (gdb_stdlog,
 665                         "insert_watchpoint on entry (addr=0x%08lx, len=%d)\n",
 666                         (unsigned long) addr, len);
 667
 668   gdb_assert (type != hw_execute);
 669
 670   ret = aarch64_handle_watchpoint (type, addr, len, 1 /* is_insert */, state);
 671
 672   if (show_debug_regs)
 673     {
 674       aarch64_show_debug_reg_state (state,
 675                                     "insert_watchpoint", addr, len, type);
 676     }
 677
 678   return ret;
 679 }
 680
 681 /* Implement the "to_remove_watchpoint" target_ops method.
 682    Remove a watchpoint that watched the memory region which starts at
 683    address ADDR, whose length is LEN bytes, and for accesses of the
 684    type TYPE.  Return 0 on success, -1 on failure.  */
 685
 686 static int
 687 aarch64_linux_remove_watchpoint (struct target_ops *self,
 688                                  CORE_ADDR addr, int len,
 689                                  enum target_hw_bp_type type,
 690                                  struct expression *cond)
 691 {
 692   int ret;
 693   struct aarch64_debug_reg_state *state
 694     = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 695
 696   if (show_debug_regs)
 697     fprintf_unfiltered (gdb_stdlog,
 698                         "remove_watchpoint on entry (addr=0x%08lx, len=%d)\n",
 699                         (unsigned long) addr, len);
 700
 701   gdb_assert (type != hw_execute);
 702
 703   ret = aarch64_handle_watchpoint (type, addr, len, 0 /* is_insert */, state);
 704
 705   if (show_debug_regs)
 706     {
 707       aarch64_show_debug_reg_state (state,
 708                                     "remove_watchpoint", addr, len, type);
 709     }
 710
 711   return ret;
 712 }
 713
 714 /* Implement the "to_region_ok_for_hw_watchpoint" target_ops method.  */
 715
 716 static int
 717 aarch64_linux_region_ok_for_hw_watchpoint (struct target_ops *self,
 718                                            CORE_ADDR addr, int len)
 719 {
 720   CORE_ADDR aligned_addr;
 721
 722   /* Can not set watchpoints for zero or negative lengths.  */
 723   if (len <= 0)
 724     return 0;
 725
 726   /* Must have hardware watchpoint debug register(s).  */
 727   if (aarch64_num_wp_regs == 0)
 728     return 0;
 729
 730   /* We support unaligned watchpoint address and arbitrary length,
 731      as long as the size of the whole watched area after alignment
 732      doesn't exceed size of the total area that all watchpoint debug
 733      registers can watch cooperatively.
 734
 735      This is a very relaxed rule, but unfortunately there are
 736      limitations, e.g. false-positive hits, due to limited support of
 737      hardware debug registers in the kernel.  See comment above
 738      aarch64_align_watchpoint for more information.  */
 739
 740   aligned_addr = addr & ~(AARCH64_HWP_MAX_LEN_PER_REG - 1);
 741   if (aligned_addr + aarch64_num_wp_regs * AARCH64_HWP_MAX_LEN_PER_REG
 742       < addr + len)
 743     return 0;
 744
 745   /* All tests passed so we are likely to be able to set the watchpoint.
 746      The reason that it is 'likely' rather than 'must' is because
 747      we don't check the current usage of the watchpoint registers, and
 748      there may not be enough registers available for this watchpoint.
 749      Ideally we should check the cached debug register state, however
 750      the checking is costly.  */
 751   return 1;
 752 }
 753
 754 /* Implement the "to_stopped_data_address" target_ops method.  */
 755
 756 static int
 757 aarch64_linux_stopped_data_address (struct target_ops *target,
 758                                     CORE_ADDR *addr_p)
 759 {
 760   siginfo_t siginfo;
 761   int i, tid;
 762   struct aarch64_debug_reg_state *state;
 763
 764   if (!linux_nat_get_siginfo (inferior_ptid, &siginfo))
 765     return 0;
 766
 767   /* This must be a hardware breakpoint.  */
 768   if (siginfo.si_signo != SIGTRAP
 769       || (siginfo.si_code & 0xffff) != TRAP_HWBKPT)
 770     return 0;
 771
 772   /* Check if the address matches any watched address.  */
 773   state = aarch64_get_debug_reg_state (ptid_get_pid (inferior_ptid));
 774   for (i = aarch64_num_wp_regs - 1; i >= 0; --i)
 775     {
 776       const unsigned int len = aarch64_watchpoint_length (state->dr_ctrl_wp[i]);
 777       const CORE_ADDR addr_trap = (CORE_ADDR) siginfo.si_addr;
 778       const CORE_ADDR addr_watch = state->dr_addr_wp[i];
 779
 780       if (state->dr_ref_count_wp[i]
 781           && DR_CONTROL_ENABLED (state->dr_ctrl_wp[i])
 782           && addr_trap >= addr_watch
 783           && addr_trap < addr_watch + len)
 784         {
 785           *addr_p = addr_trap;
 786           return 1;
 787         }
 788     }
 789
 790   return 0;
 791 }
 792
 793 /* Implement the "to_stopped_by_watchpoint" target_ops method.  */
 794
 795 static int
 796 aarch64_linux_stopped_by_watchpoint (struct target_ops *ops)
 797 {
 798   CORE_ADDR addr;
 799
 800   return aarch64_linux_stopped_data_address (ops, &addr);
 801 }
 802
 803 /* Implement the "to_watchpoint_addr_within_range" target_ops method.  */
 804
 805 static int
 806 aarch64_linux_watchpoint_addr_within_range (struct target_ops *target,
 807                                             CORE_ADDR addr,
 808                                             CORE_ADDR start, int length)
 809 {
 810   return start <= addr && start + length - 1 >= addr;
 811 }
 812
 813 /* Define AArch64 maintenance commands.  */
 814
 815 static void
 816 add_show_debug_regs_command (void)
 817 {
 818   /* A maintenance command to enable printing the internal DRi mirror
 819      variables.  */
 820   add_setshow_boolean_cmd ("show-debug-regs", class_maintenance,
 821                            &show_debug_regs, _("\
 822 Set whether to show variables that mirror the AArch64 debug registers."), _("\
 823 Show whether to show variables that mirror the AArch64 debug registers."), _("\
 824 Use \"on\" to enable, \"off\" to disable.\n\
 825 If enabled, the debug registers values are shown when GDB inserts\n\
 826 or removes a hardware breakpoint or watchpoint, and when the inferior\n\
 827 triggers a breakpoint or watchpoint."),
 828                            NULL,
 829                            NULL,
 830                            &maintenance_set_cmdlist,
 831                            &maintenance_show_cmdlist);
 832 }
 833
 834 /* -Wmissing-prototypes.  */
 835 void _initialize_aarch64_linux_nat (void);
 836
 837 void
 838 _initialize_aarch64_linux_nat (void)
 839 {
 840   struct target_ops *t;
 841
 842   /* Fill in the generic GNU/Linux methods.  */
 843   t = linux_target ();
 844
 845   add_show_debug_regs_command ();
 846
 847   /* Add our register access methods.  */
 848   t->to_fetch_registers = aarch64_linux_fetch_inferior_registers;
 849   t->to_store_registers = aarch64_linux_store_inferior_registers;
 850
 851   t->to_read_description = aarch64_linux_read_description;
 852
 853   t->to_can_use_hw_breakpoint = aarch64_linux_can_use_hw_breakpoint;
 854   t->to_insert_hw_breakpoint = aarch64_linux_insert_hw_breakpoint;
 855   t->to_remove_hw_breakpoint = aarch64_linux_remove_hw_breakpoint;
 856   t->to_region_ok_for_hw_watchpoint =
 857     aarch64_linux_region_ok_for_hw_watchpoint;
 858   t->to_insert_watchpoint = aarch64_linux_insert_watchpoint;
 859   t->to_remove_watchpoint = aarch64_linux_remove_watchpoint;
 860   t->to_stopped_by_watchpoint = aarch64_linux_stopped_by_watchpoint;
 861   t->to_stopped_data_address = aarch64_linux_stopped_data_address;
 862   t->to_watchpoint_addr_within_range =
 863     aarch64_linux_watchpoint_addr_within_range;
 864
 865   /* Override the GNU/Linux inferior startup hook.  */
 866   super_post_startup_inferior = t->to_post_startup_inferior;
 867   t->to_post_startup_inferior = aarch64_linux_child_post_startup_inferior;
 868
 869   /* Register the target.  */
 870   linux_nat_add_target (t);
 871   linux_nat_set_new_thread (t, aarch64_linux_new_thread);
 872   linux_nat_set_new_fork (t, aarch64_linux_new_fork);
 873   linux_nat_set_forget_process (t, aarch64_forget_process);
 874   linux_nat_set_prepare_to_resume (t, aarch64_linux_prepare_to_resume);
 875 }