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 "linux-nat.h"
  28 #include "mips-linux-tdep.h"
  29
  30 #include "gdb_proc_service.h"
  31
  32 #include <sys/ptrace.h>
  33
  34 #ifndef PTRACE_GET_THREAD_AREA
  35 #define PTRACE_GET_THREAD_AREA 25
  36 #endif
  37
  38 /* Assume that we have PTRACE_GETREGS et al. support.  If we do not,
  39    we'll clear this and use PTRACE_PEEKUSER instead.  */
  40 static int have_ptrace_regsets = 1;
  41
  42 /* Saved function pointers to fetch and store a single register using
  43    PTRACE_PEEKUSER and PTRACE_POKEUSER.  */
  44
  45 void (*super_fetch_registers) (int);
  46 void (*super_store_registers) (int);
  47
  48 /* Pseudo registers can not be read.  ptrace does not provide a way to
  49    read (or set) MIPS_PS_REGNUM, and there's no point in reading or
  50    setting MIPS_ZERO_REGNUM.  We also can not set BADVADDR, CAUSE, or
  51    FCRIR via ptrace().  */
  52
  53 int
  54 mips_linux_cannot_fetch_register (int regno)
  55 {
  56   if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32)
  57     return 0;
  58   else if (regno >= mips_regnum (current_gdbarch)->fp0
  59            && regno <= mips_regnum (current_gdbarch)->fp0 + 32)
  60     return 0;
  61   else if (regno == mips_regnum (current_gdbarch)->lo
  62            || regno == mips_regnum (current_gdbarch)->hi
  63            || regno == mips_regnum (current_gdbarch)->badvaddr
  64            || regno == mips_regnum (current_gdbarch)->cause
  65            || regno == mips_regnum (current_gdbarch)->pc
  66            || regno == mips_regnum (current_gdbarch)->fp_control_status
  67            || regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
  68     return 0;
  69   else
  70     return 1;
  71 }
  72
  73 int
  74 mips_linux_cannot_store_register (int regno)
  75 {
  76   if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32)
  77     return 0;
  78   else if (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 32)
  79     return 0;
  80   else if (regno == mips_regnum (current_gdbarch)->lo
  81            || regno == mips_regnum (current_gdbarch)->hi
  82            || regno == mips_regnum (current_gdbarch)->pc
  83            || regno == mips_regnum (current_gdbarch)->fp_control_status)
  84     return 0;
  85   else
  86     return 1;
  87 }
  88
  89 /* Map gdb internal register number to ptrace ``address''.
  90    These ``addresses'' are normally defined in <asm/ptrace.h>.  */
  91
  92 static CORE_ADDR
  93 mips_linux_register_addr (int regno)
  94 {
  95   int regaddr;
  96
  97   if (regno < 0 || regno >= NUM_REGS)
  98     error (_("Bogon register number %d."), regno);
  99
 100   if (regno < 32)
 101     regaddr = regno;
 102   else if ((regno >= mips_regnum (current_gdbarch)->fp0)
 103            && (regno < mips_regnum (current_gdbarch)->fp0 + 32))
 104     regaddr = FPR_BASE + (regno - mips_regnum (current_gdbarch)->fp0);
 105   else if (regno == mips_regnum (current_gdbarch)->pc)
 106     regaddr = PC;
 107   else if (regno == mips_regnum (current_gdbarch)->cause)
 108     regaddr = CAUSE;
 109   else if (regno == mips_regnum (current_gdbarch)->badvaddr)
 110     regaddr = BADVADDR;
 111   else if (regno == mips_regnum (current_gdbarch)->lo)
 112     regaddr = MMLO;
 113   else if (regno == mips_regnum (current_gdbarch)->hi)
 114     regaddr = MMHI;
 115   else if (regno == mips_regnum (current_gdbarch)->fp_control_status)
 116     regaddr = FPC_CSR;
 117   else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
 118     regaddr = FPC_EIR;
 119   else
 120     error (_("Unknowable register number %d."), regno);
 121
 122   return regaddr;
 123 }
 124
 125 static CORE_ADDR
 126 mips64_linux_register_addr (int regno)
 127 {
 128   int regaddr;
 129
 130   if (regno < 0 || regno >= NUM_REGS)
 131     error (_("Bogon register number %d."), regno);
 132
 133   if (regno < 32)
 134     regaddr = regno;
 135   else if ((regno >= mips_regnum (current_gdbarch)->fp0)
 136            && (regno < mips_regnum (current_gdbarch)->fp0 + 32))
 137     regaddr = MIPS64_FPR_BASE + (regno - FP0_REGNUM);
 138   else if (regno == mips_regnum (current_gdbarch)->pc)
 139     regaddr = MIPS64_PC;
 140   else if (regno == mips_regnum (current_gdbarch)->cause)
 141     regaddr = MIPS64_CAUSE;
 142   else if (regno == mips_regnum (current_gdbarch)->badvaddr)
 143     regaddr = MIPS64_BADVADDR;
 144   else if (regno == mips_regnum (current_gdbarch)->lo)
 145     regaddr = MIPS64_MMLO;
 146   else if (regno == mips_regnum (current_gdbarch)->hi)
 147     regaddr = MIPS64_MMHI;
 148   else if (regno == mips_regnum (current_gdbarch)->fp_control_status)
 149     regaddr = MIPS64_FPC_CSR;
 150   else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
 151     regaddr = MIPS64_FPC_EIR;
 152   else
 153     error (_("Unknowable register number %d."), regno);
 154
 155   return regaddr;
 156 }
 157
 158 /* Fetch the thread-local storage pointer for libthread_db.  */
 159
 160 ps_err_e
 161 ps_get_thread_area (const struct ps_prochandle *ph,
 162                     lwpid_t lwpid, int idx, void **base)
 163 {
 164   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 165     return PS_ERR;
 166
 167   /* IDX is the bias from the thread pointer to the beginning of the
 168      thread descriptor.  It has to be subtracted due to implementation
 169      quirks in libthread_db.  */
 170   *base = (void *) ((char *)*base - idx);
 171
 172   return PS_OK;
 173 }
 174
 175 /* Fetch REGNO (or all registers if REGNO == -1) from the target
 176    using PTRACE_GETREGS et al.  */
 177
 178 static void
 179 mips64_linux_regsets_fetch_registers (int regno)
 180 {
 181   int is_fp;
 182   int tid;
 183
 184   if (regno >= mips_regnum (current_gdbarch)->fp0
 185       && regno <= mips_regnum (current_gdbarch)->fp0 + 32)
 186     is_fp = 1;
 187   else if (regno == mips_regnum (current_gdbarch)->fp_control_status)
 188     is_fp = 1;
 189   else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
 190     is_fp = 1;
 191   else
 192     is_fp = 0;
 193
 194   tid = ptid_get_lwp (inferior_ptid);
 195   if (tid == 0)
 196     tid = ptid_get_pid (inferior_ptid);
 197
 198   if (regno == -1 || !is_fp)
 199     {
 200       mips64_elf_gregset_t regs;
 201
 202       if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 203         {
 204           if (errno == EIO)
 205             {
 206               have_ptrace_regsets = 0;
 207               return;
 208             }
 209           perror_with_name (_("Couldn't get registers"));
 210         }
 211
 212       mips64_supply_gregset (&regs);
 213     }
 214
 215   if (regno == -1 || is_fp)
 216     {
 217       mips64_elf_fpregset_t fp_regs;
 218
 219       if (ptrace (PTRACE_GETFPREGS, tid, 0L,
 220                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 221         {
 222           if (errno == EIO)
 223             {
 224               have_ptrace_regsets = 0;
 225               return;
 226             }
 227           perror_with_name (_("Couldn't get FP registers"));
 228         }
 229
 230       mips64_supply_fpregset (&fp_regs);
 231     }
 232 }
 233
 234 /* Store REGNO (or all registers if REGNO == -1) to the target
 235    using PTRACE_SETREGS et al.  */
 236
 237 static void
 238 mips64_linux_regsets_store_registers (int regno)
 239 {
 240   int is_fp;
 241   int tid;
 242
 243   if (regno >= mips_regnum (current_gdbarch)->fp0
 244       && regno <= mips_regnum (current_gdbarch)->fp0 + 32)
 245     is_fp = 1;
 246   else if (regno == mips_regnum (current_gdbarch)->fp_control_status)
 247     is_fp = 1;
 248   else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
 249     is_fp = 1;
 250   else
 251     is_fp = 0;
 252
 253   tid = ptid_get_lwp (inferior_ptid);
 254   if (tid == 0)
 255     tid = ptid_get_pid (inferior_ptid);
 256
 257   if (regno == -1 || !is_fp)
 258     {
 259       mips64_elf_gregset_t regs;
 260
 261       if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 262         perror_with_name (_("Couldn't get registers"));
 263
 264       mips64_fill_gregset (&regs, regno);
 265
 266       if (ptrace (PTRACE_SETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 267         perror_with_name (_("Couldn't set registers"));
 268     }
 269
 270   if (regno == -1 || is_fp)
 271     {
 272       mips64_elf_fpregset_t fp_regs;
 273
 274       if (ptrace (PTRACE_GETFPREGS, tid, 0L,
 275                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 276         perror_with_name (_("Couldn't get FP registers"));
 277
 278       mips64_fill_fpregset (&fp_regs, regno);
 279
 280       if (ptrace (PTRACE_SETFPREGS, tid, 0L,
 281                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 282         perror_with_name (_("Couldn't set FP registers"));
 283     }
 284 }
 285
 286 /* Fetch REGNO (or all registers if REGNO == -1) from the target
 287    using any working method.  */
 288
 289 static void
 290 mips64_linux_fetch_registers (int regnum)
 291 {
 292   /* Unless we already know that PTRACE_GETREGS does not work, try it.  */
 293   if (have_ptrace_regsets)
 294     mips64_linux_regsets_fetch_registers (regnum);
 295
 296   /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
 297      back to PTRACE_PEEKUSER.  */
 298   if (!have_ptrace_regsets)
 299     super_fetch_registers (regnum);
 300 }
 301
 302 /* Store REGNO (or all registers if REGNO == -1) to the target
 303    using any working method.  */
 304
 305 static void
 306 mips64_linux_store_registers (int regnum)
 307 {
 308   /* Unless we already know that PTRACE_GETREGS does not work, try it.  */
 309   if (have_ptrace_regsets)
 310     mips64_linux_regsets_store_registers (regnum);
 311
 312   /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
 313      back to PTRACE_PEEKUSER.  */
 314   if (!have_ptrace_regsets)
 315     super_store_registers (regnum);
 316 }
 317
 318 /* Return the address in the core dump or inferior of register
 319    REGNO.  */
 320
 321 static CORE_ADDR
 322 mips_linux_register_u_offset (int regno)
 323 {
 324   if (mips_abi_regsize (current_gdbarch) == 8)
 325     return mips64_linux_register_addr (regno);
 326   else
 327     return mips_linux_register_addr (regno);
 328 }
 329
 330 void _initialize_mips_linux_nat (void);
 331
 332 void
 333 _initialize_mips_linux_nat (void)
 334 {
 335   struct target_ops *t = linux_trad_target (mips_linux_register_u_offset);
 336
 337   super_fetch_registers = t->to_fetch_registers;
 338   super_store_registers = t->to_store_registers;
 339
 340   t->to_fetch_registers = mips64_linux_fetch_registers;
 341   t->to_store_registers = mips64_linux_store_registers;
 342
 343   linux_nat_add_target (t);
 344 }