gdb/mips-linux-nat.c

   1 /* Native-dependent code for GNU/Linux on MIPS processors.
   2
   3    Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4    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 2 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, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include "defs.h"
  24 #include "inferior.h"
  25 #include "mips-tdep.h"
  26 #include "target.h"
  27 #include "regcache.h"
  28 #include "linux-nat.h"
  29 #include "mips-linux-tdep.h"
  30 #include "target-descriptions.h"
  31 #include "xml-support.h"
  32
  33 #include "gdb_proc_service.h"
  34 #include "gregset.h"
  35
  36 #include <sgidefs.h>
  37 #include <sys/ptrace.h>
  38
  39 #ifndef PTRACE_GET_THREAD_AREA
  40 #define PTRACE_GET_THREAD_AREA 25
  41 #endif
  42
  43 /* Assume that we have PTRACE_GETREGS et al. support.  If we do not,
  44    we'll clear this and use PTRACE_PEEKUSER instead.  */
  45 static int have_ptrace_regsets = 1;
  46
  47 /* Saved function pointers to fetch and store a single register using
  48    PTRACE_PEEKUSER and PTRACE_POKEUSER.  */
  49
  50 void (*super_fetch_registers) (struct regcache *, int);
  51 void (*super_store_registers) (struct regcache *, int);
  52
  53 /* Map gdb internal register number to ptrace ``address''.
  54    These ``addresses'' are normally defined in <asm/ptrace.h>.
  55
  56    ptrace does not provide a way to read (or set) MIPS_PS_REGNUM,
  57    and there's no point in reading or setting MIPS_ZERO_REGNUM.
  58    We also can not set BADVADDR, CAUSE, or FCRIR via ptrace().  */
  59
  60 static CORE_ADDR
  61 mips_linux_register_addr (struct gdbarch *gdbarch, int regno, int store)
  62 {
  63   CORE_ADDR regaddr;
  64
  65   if (regno < 0 || regno >= gdbarch_num_regs (current_gdbarch))
  66     error (_("Bogon register number %d."), regno);
  67
  68   if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32)
  69     regaddr = regno;
  70   else if ((regno >= mips_regnum (gdbarch)->fp0)
  71            && (regno < mips_regnum (gdbarch)->fp0 + 32))
  72     regaddr = FPR_BASE + (regno - mips_regnum (gdbarch)->fp0);
  73   else if (regno == mips_regnum (gdbarch)->pc)
  74     regaddr = PC;
  75   else if (regno == mips_regnum (gdbarch)->cause)
  76     regaddr = store? (CORE_ADDR) -1 : CAUSE;
  77   else if (regno == mips_regnum (gdbarch)->badvaddr)
  78     regaddr = store? (CORE_ADDR) -1 : BADVADDR;
  79   else if (regno == mips_regnum (gdbarch)->lo)
  80     regaddr = MMLO;
  81   else if (regno == mips_regnum (gdbarch)->hi)
  82     regaddr = MMHI;
  83   else if (regno == mips_regnum (gdbarch)->fp_control_status)
  84     regaddr = FPC_CSR;
  85   else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
  86     regaddr = store? (CORE_ADDR) -1 : FPC_EIR;
  87   else if (mips_linux_restart_reg_p (gdbarch) && regno == MIPS_RESTART_REGNUM)
  88     regaddr = 0;
  89   else
  90     regaddr = (CORE_ADDR) -1;
  91
  92   return regaddr;
  93 }
  94
  95 static CORE_ADDR
  96 mips64_linux_register_addr (struct gdbarch *gdbarch, int regno, int store)
  97 {
  98   CORE_ADDR regaddr;
  99
 100   if (regno < 0 || regno >= gdbarch_num_regs (current_gdbarch))
 101     error (_("Bogon register number %d."), regno);
 102
 103   if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32)
 104     regaddr = regno;
 105   else if ((regno >= mips_regnum (gdbarch)->fp0)
 106            && (regno < mips_regnum (gdbarch)->fp0 + 32))
 107     regaddr = MIPS64_FPR_BASE + (regno - gdbarch_fp0_regnum (current_gdbarch));
 108   else if (regno == mips_regnum (gdbarch)->pc)
 109     regaddr = MIPS64_PC;
 110   else if (regno == mips_regnum (gdbarch)->cause)
 111     regaddr = store? (CORE_ADDR) -1 : MIPS64_CAUSE;
 112   else if (regno == mips_regnum (gdbarch)->badvaddr)
 113     regaddr = store? (CORE_ADDR) -1 : MIPS64_BADVADDR;
 114   else if (regno == mips_regnum (gdbarch)->lo)
 115     regaddr = MIPS64_MMLO;
 116   else if (regno == mips_regnum (gdbarch)->hi)
 117     regaddr = MIPS64_MMHI;
 118   else if (regno == mips_regnum (gdbarch)->fp_control_status)
 119     regaddr = MIPS64_FPC_CSR;
 120   else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
 121     regaddr = store? (CORE_ADDR) -1 : MIPS64_FPC_EIR;
 122   else if (mips_linux_restart_reg_p (gdbarch) && regno == MIPS_RESTART_REGNUM)
 123     regaddr = 0;
 124   else
 125     regaddr = (CORE_ADDR) -1;
 126
 127   return regaddr;
 128 }
 129
 130 /* Fetch the thread-local storage pointer for libthread_db.  */
 131
 132 ps_err_e
 133 ps_get_thread_area (const struct ps_prochandle *ph,
 134                     lwpid_t lwpid, int idx, void **base)
 135 {
 136   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 137     return PS_ERR;
 138
 139   /* IDX is the bias from the thread pointer to the beginning of the
 140      thread descriptor.  It has to be subtracted due to implementation
 141      quirks in libthread_db.  */
 142   *base = (void *) ((char *)*base - idx);
 143
 144   return PS_OK;
 145 }
 146
 147 /* Wrapper functions.  These are only used by libthread_db.  */
 148
 149 void
 150 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
 151 {
 152   if (mips_isa_regsize (current_gdbarch) == 4)
 153     mips_supply_gregset (regcache, (const mips_elf_gregset_t *) gregsetp);
 154   else
 155     mips64_supply_gregset (regcache, (const mips64_elf_gregset_t *) gregsetp);
 156 }
 157
 158 void
 159 fill_gregset (const struct regcache *regcache,
 160               gdb_gregset_t *gregsetp, int regno)
 161 {
 162   if (mips_isa_regsize (current_gdbarch) == 4)
 163     mips_fill_gregset (regcache, (mips_elf_gregset_t *) gregsetp, regno);
 164   else
 165     mips64_fill_gregset (regcache, (mips64_elf_gregset_t *) gregsetp, regno);
 166 }
 167
 168 void
 169 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregsetp)
 170 {
 171   if (mips_isa_regsize (current_gdbarch) == 4)
 172     mips_supply_fpregset (regcache, (const mips_elf_fpregset_t *) fpregsetp);
 173   else
 174     mips64_supply_fpregset (regcache, (const mips64_elf_fpregset_t *) fpregsetp);
 175 }
 176
 177 void
 178 fill_fpregset (const struct regcache *regcache,
 179                gdb_fpregset_t *fpregsetp, int regno)
 180 {
 181   if (mips_isa_regsize (current_gdbarch) == 4)
 182     mips_fill_fpregset (regcache, (mips_elf_fpregset_t *) fpregsetp, regno);
 183   else
 184     mips64_fill_fpregset (regcache, (mips64_elf_fpregset_t *) fpregsetp, regno);
 185 }
 186
 187
 188 /* Fetch REGNO (or all registers if REGNO == -1) from the target
 189    using PTRACE_GETREGS et al.  */
 190
 191 static void
 192 mips64_linux_regsets_fetch_registers (struct regcache *regcache, int regno)
 193 {
 194   int is_fp;
 195   int tid;
 196
 197   if (regno >= mips_regnum (current_gdbarch)->fp0
 198       && regno <= mips_regnum (current_gdbarch)->fp0 + 32)
 199     is_fp = 1;
 200   else if (regno == mips_regnum (current_gdbarch)->fp_control_status)
 201     is_fp = 1;
 202   else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
 203     is_fp = 1;
 204   else
 205     is_fp = 0;
 206
 207   tid = ptid_get_lwp (inferior_ptid);
 208   if (tid == 0)
 209     tid = ptid_get_pid (inferior_ptid);
 210
 211   if (regno == -1 || !is_fp)
 212     {
 213       mips64_elf_gregset_t regs;
 214
 215       if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 216         {
 217           if (errno == EIO)
 218             {
 219               have_ptrace_regsets = 0;
 220               return;
 221             }
 222           perror_with_name (_("Couldn't get registers"));
 223         }
 224
 225       mips64_supply_gregset (regcache,
 226                              (const mips64_elf_gregset_t *) &regs);
 227     }
 228
 229   if (regno == -1 || is_fp)
 230     {
 231       mips64_elf_fpregset_t fp_regs;
 232
 233       if (ptrace (PTRACE_GETFPREGS, tid, 0L,
 234                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 235         {
 236           if (errno == EIO)
 237             {
 238               have_ptrace_regsets = 0;
 239               return;
 240             }
 241           perror_with_name (_("Couldn't get FP registers"));
 242         }
 243
 244       mips64_supply_fpregset (regcache,
 245                               (const mips64_elf_fpregset_t *) &fp_regs);
 246     }
 247 }
 248
 249 /* Store REGNO (or all registers if REGNO == -1) to the target
 250    using PTRACE_SETREGS et al.  */
 251
 252 static void
 253 mips64_linux_regsets_store_registers (const struct regcache *regcache, int regno)
 254 {
 255   int is_fp;
 256   int tid;
 257
 258   if (regno >= mips_regnum (current_gdbarch)->fp0
 259       && regno <= mips_regnum (current_gdbarch)->fp0 + 32)
 260     is_fp = 1;
 261   else if (regno == mips_regnum (current_gdbarch)->fp_control_status)
 262     is_fp = 1;
 263   else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
 264     is_fp = 1;
 265   else
 266     is_fp = 0;
 267
 268   tid = ptid_get_lwp (inferior_ptid);
 269   if (tid == 0)
 270     tid = ptid_get_pid (inferior_ptid);
 271
 272   if (regno == -1 || !is_fp)
 273     {
 274       mips64_elf_gregset_t regs;
 275
 276       if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 277         perror_with_name (_("Couldn't get registers"));
 278
 279       mips64_fill_gregset (regcache, &regs, regno);
 280
 281       if (ptrace (PTRACE_SETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 282         perror_with_name (_("Couldn't set registers"));
 283     }
 284
 285   if (regno == -1 || is_fp)
 286     {
 287       mips64_elf_fpregset_t fp_regs;
 288
 289       if (ptrace (PTRACE_GETFPREGS, tid, 0L,
 290                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 291         perror_with_name (_("Couldn't get FP registers"));
 292
 293       mips64_fill_fpregset (regcache, &fp_regs, regno);
 294
 295       if (ptrace (PTRACE_SETFPREGS, tid, 0L,
 296                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 297         perror_with_name (_("Couldn't set FP registers"));
 298     }
 299 }
 300
 301 /* Fetch REGNO (or all registers if REGNO == -1) from the target
 302    using any working method.  */
 303
 304 static void
 305 mips64_linux_fetch_registers (struct regcache *regcache, int regnum)
 306 {
 307   /* Unless we already know that PTRACE_GETREGS does not work, try it.  */
 308   if (have_ptrace_regsets)
 309     mips64_linux_regsets_fetch_registers (regcache, regnum);
 310
 311   /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
 312      back to PTRACE_PEEKUSER.  */
 313   if (!have_ptrace_regsets)
 314     super_fetch_registers (regcache, regnum);
 315 }
 316
 317 /* Store REGNO (or all registers if REGNO == -1) to the target
 318    using any working method.  */
 319
 320 static void
 321 mips64_linux_store_registers (struct regcache *regcache, int regnum)
 322 {
 323   /* Unless we already know that PTRACE_GETREGS does not work, try it.  */
 324   if (have_ptrace_regsets)
 325     mips64_linux_regsets_store_registers (regcache, regnum);
 326
 327   /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
 328      back to PTRACE_PEEKUSER.  */
 329   if (!have_ptrace_regsets)
 330     super_store_registers (regcache, regnum);
 331 }
 332
 333 /* Return the address in the core dump or inferior of register
 334    REGNO.  */
 335
 336 static CORE_ADDR
 337 mips_linux_register_u_offset (struct gdbarch *gdbarch, int regno, int store_p)
 338 {
 339   if (mips_abi_regsize (gdbarch) == 8)
 340     return mips64_linux_register_addr (gdbarch, regno, store_p);
 341   else
 342     return mips_linux_register_addr (gdbarch, regno, store_p);
 343 }
 344
 345 static LONGEST (*super_xfer_partial) (struct target_ops *, enum target_object,
 346                                       const char *, gdb_byte *, const gdb_byte *,
 347                                       ULONGEST, LONGEST);
 348
 349 static LONGEST
 350 mips_linux_xfer_partial (struct target_ops *ops,
 351                          enum target_object object,
 352                          const char *annex,
 353                          gdb_byte *readbuf, const gdb_byte *writebuf,
 354                          ULONGEST offset, LONGEST len)
 355 {
 356   if (object == TARGET_OBJECT_AVAILABLE_FEATURES)
 357     {
 358       if (annex != NULL && strcmp (annex, "target.xml") == 0)
 359         {
 360           /* Report that target registers are a size we know for sure
 361              that we can get from ptrace.  */
 362           if (_MIPS_SIM == _ABIO32)
 363             annex = "mips-linux.xml";
 364           else
 365             annex = "mips64-linux.xml";
 366         }
 367
 368       return xml_builtin_xfer_partial (annex, readbuf, writebuf, offset, len);
 369     }
 370
 371   return super_xfer_partial (ops, object, annex, readbuf, writebuf,
 372                              offset, len);
 373 }
 374
 375 void _initialize_mips_linux_nat (void);
 376
 377 void
 378 _initialize_mips_linux_nat (void)
 379 {
 380   struct target_ops *t = linux_trad_target (mips_linux_register_u_offset);
 381
 382   super_fetch_registers = t->to_fetch_registers;
 383   super_store_registers = t->to_store_registers;
 384
 385   t->to_fetch_registers = mips64_linux_fetch_registers;
 386   t->to_store_registers = mips64_linux_store_registers;
 387
 388   /* Override the default to_xfer_partial.  */
 389   super_xfer_partial = t->to_xfer_partial;
 390   t->to_xfer_partial = mips_linux_xfer_partial;
 391
 392   linux_nat_add_target (t);
 393 }