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
  31 #include "gdb_proc_service.h"
  32 #include "gregset.h"
  33
  34 #include <sys/ptrace.h>
  35
  36 #ifndef PTRACE_GET_THREAD_AREA
  37 #define PTRACE_GET_THREAD_AREA 25
  38 #endif
  39
  40 /* Assume that we have PTRACE_GETREGS et al. support.  If we do not,
  41    we'll clear this and use PTRACE_PEEKUSER instead.  */
  42 static int have_ptrace_regsets = 1;
  43
  44 /* Saved function pointers to fetch and store a single register using
  45    PTRACE_PEEKUSER and PTRACE_POKEUSER.  */
  46
  47 void (*super_fetch_registers) (struct regcache *, int);
  48 void (*super_store_registers) (struct regcache *, int);
  49
  50 /* Map gdb internal register number to ptrace ``address''.
  51    These ``addresses'' are normally defined in <asm/ptrace.h>.
  52
  53    ptrace does not provide a way to read (or set) MIPS_PS_REGNUM,
  54    and there's no point in reading or setting MIPS_ZERO_REGNUM.
  55    We also can not set BADVADDR, CAUSE, or FCRIR via ptrace().  */
  56
  57 static CORE_ADDR
  58 mips_linux_register_addr (struct gdbarch *gdbarch, int regno, int store)
  59 {
  60   CORE_ADDR regaddr;
  61
  62   if (regno < 0 || regno >= gdbarch_num_regs (current_gdbarch))
  63     error (_("Bogon register number %d."), regno);
  64
  65   if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32)
  66     regaddr = regno;
  67   else if ((regno >= mips_regnum (gdbarch)->fp0)
  68            && (regno < mips_regnum (gdbarch)->fp0 + 32))
  69     regaddr = FPR_BASE + (regno - mips_regnum (gdbarch)->fp0);
  70   else if (regno == mips_regnum (gdbarch)->pc)
  71     regaddr = PC;
  72   else if (regno == mips_regnum (gdbarch)->cause)
  73     regaddr = store? (CORE_ADDR) -1 : CAUSE;
  74   else if (regno == mips_regnum (gdbarch)->badvaddr)
  75     regaddr = store? (CORE_ADDR) -1 : BADVADDR;
  76   else if (regno == mips_regnum (gdbarch)->lo)
  77     regaddr = MMLO;
  78   else if (regno == mips_regnum (gdbarch)->hi)
  79     regaddr = MMHI;
  80   else if (regno == mips_regnum (gdbarch)->fp_control_status)
  81     regaddr = FPC_CSR;
  82   else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
  83     regaddr = store? (CORE_ADDR) -1 : FPC_EIR;
  84   else
  85     regaddr = (CORE_ADDR) -1;
  86
  87   return regaddr;
  88 }
  89
  90 static CORE_ADDR
  91 mips64_linux_register_addr (struct gdbarch *gdbarch, int regno, int store)
  92 {
  93   CORE_ADDR regaddr;
  94
  95   if (regno < 0 || regno >= gdbarch_num_regs (current_gdbarch))
  96     error (_("Bogon register number %d."), regno);
  97
  98   if (regno > MIPS_ZERO_REGNUM && regno < MIPS_ZERO_REGNUM + 32)
  99     regaddr = regno;
 100   else if ((regno >= mips_regnum (gdbarch)->fp0)
 101            && (regno < mips_regnum (gdbarch)->fp0 + 32))
 102     regaddr = MIPS64_FPR_BASE + (regno - FP0_REGNUM);
 103   else if (regno == mips_regnum (gdbarch)->pc)
 104     regaddr = MIPS64_PC;
 105   else if (regno == mips_regnum (gdbarch)->cause)
 106     regaddr = store? (CORE_ADDR) -1 : MIPS64_CAUSE;
 107   else if (regno == mips_regnum (gdbarch)->badvaddr)
 108     regaddr = store? (CORE_ADDR) -1 : MIPS64_BADVADDR;
 109   else if (regno == mips_regnum (gdbarch)->lo)
 110     regaddr = MIPS64_MMLO;
 111   else if (regno == mips_regnum (gdbarch)->hi)
 112     regaddr = MIPS64_MMHI;
 113   else if (regno == mips_regnum (gdbarch)->fp_control_status)
 114     regaddr = MIPS64_FPC_CSR;
 115   else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
 116     regaddr = store? (CORE_ADDR) -1 : MIPS64_FPC_EIR;
 117   else
 118     regaddr = (CORE_ADDR) -1;
 119
 120   return regaddr;
 121 }
 122
 123 /* Fetch the thread-local storage pointer for libthread_db.  */
 124
 125 ps_err_e
 126 ps_get_thread_area (const struct ps_prochandle *ph,
 127                     lwpid_t lwpid, int idx, void **base)
 128 {
 129   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 130     return PS_ERR;
 131
 132   /* IDX is the bias from the thread pointer to the beginning of the
 133      thread descriptor.  It has to be subtracted due to implementation
 134      quirks in libthread_db.  */
 135   *base = (void *) ((char *)*base - idx);
 136
 137   return PS_OK;
 138 }
 139
 140 /* Wrapper functions.  These are only used by libthread_db.  */
 141
 142 void
 143 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
 144 {
 145   if (mips_isa_regsize (current_gdbarch) == 4)
 146     mips_supply_gregset (regcache, (const mips_elf_gregset_t *) gregsetp);
 147   else
 148     mips64_supply_gregset (regcache, (const mips64_elf_gregset_t *) gregsetp);
 149 }
 150
 151 void
 152 fill_gregset (const struct regcache *regcache,
 153               gdb_gregset_t *gregsetp, int regno)
 154 {
 155   if (mips_isa_regsize (current_gdbarch) == 4)
 156     mips_fill_gregset (regcache, (mips_elf_gregset_t *) gregsetp, regno);
 157   else
 158     mips64_fill_gregset (regcache, (mips64_elf_gregset_t *) gregsetp, regno);
 159 }
 160
 161 void
 162 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregsetp)
 163 {
 164   if (mips_isa_regsize (current_gdbarch) == 4)
 165     mips_supply_fpregset (regcache, (const mips_elf_fpregset_t *) fpregsetp);
 166   else
 167     mips64_supply_fpregset (regcache, (const mips64_elf_fpregset_t *) fpregsetp);
 168 }
 169
 170 void
 171 fill_fpregset (const struct regcache *regcache,
 172                gdb_fpregset_t *fpregsetp, int regno)
 173 {
 174   if (mips_isa_regsize (current_gdbarch) == 4)
 175     mips_fill_fpregset (regcache, (mips_elf_fpregset_t *) fpregsetp, regno);
 176   else
 177     mips64_fill_fpregset (regcache, (mips64_elf_fpregset_t *) fpregsetp, regno);
 178 }
 179
 180
 181 /* Fetch REGNO (or all registers if REGNO == -1) from the target
 182    using PTRACE_GETREGS et al.  */
 183
 184 static void
 185 mips64_linux_regsets_fetch_registers (struct regcache *regcache, int regno)
 186 {
 187   int is_fp;
 188   int tid;
 189
 190   if (regno >= mips_regnum (current_gdbarch)->fp0
 191       && regno <= mips_regnum (current_gdbarch)->fp0 + 32)
 192     is_fp = 1;
 193   else if (regno == mips_regnum (current_gdbarch)->fp_control_status)
 194     is_fp = 1;
 195   else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
 196     is_fp = 1;
 197   else
 198     is_fp = 0;
 199
 200   tid = ptid_get_lwp (inferior_ptid);
 201   if (tid == 0)
 202     tid = ptid_get_pid (inferior_ptid);
 203
 204   if (regno == -1 || !is_fp)
 205     {
 206       mips64_elf_gregset_t regs;
 207
 208       if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 209         {
 210           if (errno == EIO)
 211             {
 212               have_ptrace_regsets = 0;
 213               return;
 214             }
 215           perror_with_name (_("Couldn't get registers"));
 216         }
 217
 218       mips64_supply_gregset (regcache,
 219                              (const mips64_elf_gregset_t *) &regs);
 220     }
 221
 222   if (regno == -1 || is_fp)
 223     {
 224       mips64_elf_fpregset_t fp_regs;
 225
 226       if (ptrace (PTRACE_GETFPREGS, tid, 0L,
 227                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 228         {
 229           if (errno == EIO)
 230             {
 231               have_ptrace_regsets = 0;
 232               return;
 233             }
 234           perror_with_name (_("Couldn't get FP registers"));
 235         }
 236
 237       mips64_supply_fpregset (regcache,
 238                               (const mips64_elf_fpregset_t *) &fp_regs);
 239     }
 240 }
 241
 242 /* Store REGNO (or all registers if REGNO == -1) to the target
 243    using PTRACE_SETREGS et al.  */
 244
 245 static void
 246 mips64_linux_regsets_store_registers (const struct regcache *regcache, int regno)
 247 {
 248   int is_fp;
 249   int tid;
 250
 251   if (regno >= mips_regnum (current_gdbarch)->fp0
 252       && regno <= mips_regnum (current_gdbarch)->fp0 + 32)
 253     is_fp = 1;
 254   else if (regno == mips_regnum (current_gdbarch)->fp_control_status)
 255     is_fp = 1;
 256   else if (regno == mips_regnum (current_gdbarch)->fp_implementation_revision)
 257     is_fp = 1;
 258   else
 259     is_fp = 0;
 260
 261   tid = ptid_get_lwp (inferior_ptid);
 262   if (tid == 0)
 263     tid = ptid_get_pid (inferior_ptid);
 264
 265   if (regno == -1 || !is_fp)
 266     {
 267       mips64_elf_gregset_t regs;
 268
 269       if (ptrace (PTRACE_GETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 270         perror_with_name (_("Couldn't get registers"));
 271
 272       mips64_fill_gregset (regcache, &regs, regno);
 273
 274       if (ptrace (PTRACE_SETREGS, tid, 0L, (PTRACE_TYPE_ARG3) &regs) == -1)
 275         perror_with_name (_("Couldn't set registers"));
 276     }
 277
 278   if (regno == -1 || is_fp)
 279     {
 280       mips64_elf_fpregset_t fp_regs;
 281
 282       if (ptrace (PTRACE_GETFPREGS, tid, 0L,
 283                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 284         perror_with_name (_("Couldn't get FP registers"));
 285
 286       mips64_fill_fpregset (regcache, &fp_regs, regno);
 287
 288       if (ptrace (PTRACE_SETFPREGS, tid, 0L,
 289                   (PTRACE_TYPE_ARG3) &fp_regs) == -1)
 290         perror_with_name (_("Couldn't set FP registers"));
 291     }
 292 }
 293
 294 /* Fetch REGNO (or all registers if REGNO == -1) from the target
 295    using any working method.  */
 296
 297 static void
 298 mips64_linux_fetch_registers (struct regcache *regcache, int regnum)
 299 {
 300   /* Unless we already know that PTRACE_GETREGS does not work, try it.  */
 301   if (have_ptrace_regsets)
 302     mips64_linux_regsets_fetch_registers (regcache, regnum);
 303
 304   /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
 305      back to PTRACE_PEEKUSER.  */
 306   if (!have_ptrace_regsets)
 307     super_fetch_registers (regcache, regnum);
 308 }
 309
 310 /* Store REGNO (or all registers if REGNO == -1) to the target
 311    using any working method.  */
 312
 313 static void
 314 mips64_linux_store_registers (struct regcache *regcache, int regnum)
 315 {
 316   /* Unless we already know that PTRACE_GETREGS does not work, try it.  */
 317   if (have_ptrace_regsets)
 318     mips64_linux_regsets_store_registers (regcache, regnum);
 319
 320   /* If we know, or just found out, that PTRACE_GETREGS does not work, fall
 321      back to PTRACE_PEEKUSER.  */
 322   if (!have_ptrace_regsets)
 323     super_store_registers (regcache, regnum);
 324 }
 325
 326 /* Return the address in the core dump or inferior of register
 327    REGNO.  */
 328
 329 static CORE_ADDR
 330 mips_linux_register_u_offset (struct gdbarch *gdbarch, int regno, int store_p)
 331 {
 332   if (mips_abi_regsize (gdbarch) == 8)
 333     return mips64_linux_register_addr (gdbarch, regno, store_p);
 334   else
 335     return mips_linux_register_addr (gdbarch, regno, store_p);
 336 }
 337
 338 void _initialize_mips_linux_nat (void);
 339
 340 void
 341 _initialize_mips_linux_nat (void)
 342 {
 343   struct target_ops *t = linux_trad_target (mips_linux_register_u_offset);
 344
 345   super_fetch_registers = t->to_fetch_registers;
 346   super_store_registers = t->to_store_registers;
 347
 348   t->to_fetch_registers = mips64_linux_fetch_registers;
 349   t->to_store_registers = mips64_linux_store_registers;
 350
 351   linux_nat_add_target (t);
 352 }