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