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, 2008, 2009
   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 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 "inferior.h"
  23 #include "mips-tdep.h"
  24 #include "target.h"
  25 #include "regcache.h"
  26 #include "linux-nat.h"
  27 #include "mips-linux-tdep.h"
  28 #include "target-descriptions.h"
  29
  30 #include "gdb_proc_service.h"
  31 #include "gregset.h"
  32
  33 #include <sgidefs.h>
  34 #include <sys/ptrace.h>
  35
  36 #include "features/mips-linux.c"
  37 #include "features/mips64-linux.c"
  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 target_ops *, struct regcache *, int);
  51 void (*super_store_registers) (struct target_ops *, 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 (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 (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 (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 (get_regcache_arch (regcache)) == 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 (get_regcache_arch (regcache)) == 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 (get_regcache_arch (regcache)) == 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 (get_regcache_arch (regcache)) == 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   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 195   int is_fp;
 196   int tid;
 197
 198   if (regno >= mips_regnum (gdbarch)->fp0
 199       && regno <= mips_regnum (gdbarch)->fp0 + 32)
 200     is_fp = 1;
 201   else if (regno == mips_regnum (gdbarch)->fp_control_status)
 202     is_fp = 1;
 203   else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
 204     is_fp = 1;
 205   else
 206     is_fp = 0;
 207
 208   tid = ptid_get_lwp (inferior_ptid);
 209   if (tid == 0)
 210     tid = ptid_get_pid (inferior_ptid);
 211
 212   if (regno == -1 || !is_fp)
 213     {
 214       mips64_elf_gregset_t regs;
 215
 216       if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 217         {
 218           if (errno == EIO)
 219             {
 220               have_ptrace_regsets = 0;
 221               return;
 222             }
 223           perror_with_name (_("Couldn't get registers"));
 224         }
 225
 226       mips64_supply_gregset (regcache,
 227                              (const mips64_elf_gregset_t *) &regs);
 228     }
 229
 230   if (regno == -1 || is_fp)
 231     {
 232       mips64_elf_fpregset_t fp_regs;
 233
 234       if (ptrace (PTRACE_GETFPREGS, tid, 0L,
 235                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 236         {
 237           if (errno == EIO)
 238             {
 239               have_ptrace_regsets = 0;
 240               return;
 241             }
 242           perror_with_name (_("Couldn't get FP registers"));
 243         }
 244
 245       mips64_supply_fpregset (regcache,
 246                               (const mips64_elf_fpregset_t *) &fp_regs);
 247     }
 248 }
 249
 250 /* Store REGNO (or all registers if REGNO == -1) to the target
 251    using PTRACE_SETREGS et al.  */
 252
 253 static void
 254 mips64_linux_regsets_store_registers (const struct regcache *regcache, int regno)
 255 {
 256   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 257   int is_fp;
 258   int tid;
 259
 260   if (regno >= mips_regnum (gdbarch)->fp0
 261       && regno <= mips_regnum (gdbarch)->fp0 + 32)
 262     is_fp = 1;
 263   else if (regno == mips_regnum (gdbarch)->fp_control_status)
 264     is_fp = 1;
 265   else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
 266     is_fp = 1;
 267   else
 268     is_fp = 0;
 269
 270   tid = ptid_get_lwp (inferior_ptid);
 271   if (tid == 0)
 272     tid = ptid_get_pid (inferior_ptid);
 273
 274   if (regno == -1 || !is_fp)
 275     {
 276       mips64_elf_gregset_t regs;
 277
 278       if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 279         perror_with_name (_("Couldn't get registers"));
 280
 281       mips64_fill_gregset (regcache, &regs, regno);
 282
 283       if (ptrace (PTRACE_SETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 284         perror_with_name (_("Couldn't set registers"));
 285     }
 286
 287   if (regno == -1 || is_fp)
 288     {
 289       mips64_elf_fpregset_t fp_regs;
 290
 291       if (ptrace (PTRACE_GETFPREGS, tid, 0L,
 292                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 293         perror_with_name (_("Couldn't get FP registers"));
 294
 295       mips64_fill_fpregset (regcache, &fp_regs, regno);
 296
 297       if (ptrace (PTRACE_SETFPREGS, tid, 0L,
 298                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 299         perror_with_name (_("Couldn't set FP registers"));
 300     }
 301 }
 302
 303 /* Fetch REGNO (or all registers if REGNO == -1) from the target
 304    using any working method.  */
 305
 306 static void
 307 mips64_linux_fetch_registers (struct target_ops *ops,
 308                               struct regcache *regcache, int regnum)
 309 {
 310   /* Unless we already know that PTRACE_GETREGS does not work, try it.  */
 311   if (have_ptrace_regsets)
 312     mips64_linux_regsets_fetch_registers (regcache, regnum);
 313
 314   /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
 315      back to PTRACE_PEEKUSER.  */
 316   if (!have_ptrace_regsets)
 317     super_fetch_registers (ops, regcache, regnum);
 318 }
 319
 320 /* Store REGNO (or all registers if REGNO == -1) to the target
 321    using any working method.  */
 322
 323 static void
 324 mips64_linux_store_registers (struct target_ops *ops,
 325                               struct regcache *regcache, int regnum)
 326 {
 327   /* Unless we already know that PTRACE_GETREGS does not work, try it.  */
 328   if (have_ptrace_regsets)
 329     mips64_linux_regsets_store_registers (regcache, regnum);
 330
 331   /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
 332      back to PTRACE_PEEKUSER.  */
 333   if (!have_ptrace_regsets)
 334     super_store_registers (ops, regcache, regnum);
 335 }
 336
 337 /* Return the address in the core dump or inferior of register
 338    REGNO.  */
 339
 340 static CORE_ADDR
 341 mips_linux_register_u_offset (struct gdbarch *gdbarch, int regno, int store_p)
 342 {
 343   if (mips_abi_regsize (gdbarch) == 8)
 344     return mips64_linux_register_addr (gdbarch, regno, store_p);
 345   else
 346     return mips_linux_register_addr (gdbarch, regno, store_p);
 347 }
 348
 349 static const struct target_desc *
 350 mips_linux_read_description (struct target_ops *ops)
 351 {
 352   /* Report that target registers are a size we know for sure
 353      that we can get from ptrace.  */
 354   if (_MIPS_SIM == _ABIO32)
 355     return tdesc_mips_linux;
 356   else
 357     return tdesc_mips64_linux;
 358 }
 359
 360 void _initialize_mips_linux_nat (void);
 361
 362 void
 363 _initialize_mips_linux_nat (void)
 364 {
 365   struct target_ops *t = linux_trad_target (mips_linux_register_u_offset);
 366
 367   super_fetch_registers = t->to_fetch_registers;
 368   super_store_registers = t->to_store_registers;
 369
 370   t->to_fetch_registers = mips64_linux_fetch_registers;
 371   t->to_store_registers = mips64_linux_store_registers;
 372
 373   t->to_read_description = mips_linux_read_description;
 374
 375   linux_nat_add_target (t);
 376
 377   /* Initialize the standard target descriptions.  */
 378   initialize_tdesc_mips_linux ();
 379   initialize_tdesc_mips64_linux ();
 380 }