gdb/i386bsd-nat.c

   1 /* Native-dependent code for modern i386 BSD's.
   2    Copyright 2000, 2001 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22 #include "inferior.h"
  23 #include "regcache.h"
  24
  25 #include "gdb_assert.h"
  26 #include <sys/types.h>
  27 #include <sys/ptrace.h>
  28 #include <machine/reg.h>
  29 #include <machine/frame.h>
  30
  31 #ifdef HAVE_SYS_PROCFS_H
  32 #include <sys/procfs.h>
  33 #endif
  34
  35 #ifndef HAVE_GREGSET_T
  36 typedef struct reg gregset_t;
  37 #endif
  38
  39 #ifndef HAVE_FPREGSET_T
  40 typedef struct fpreg fpregset_t;
  41 #endif
  42
  43 #include "gregset.h"
  44 \f
  45
  46 /* In older BSD versions we cannot get at some of the segment
  47    registers.  FreeBSD for example didn't support the %fs and %gs
  48    registers until the 3.0 release.  We have autoconf checks for their
  49    presence, and deal gracefully with their absence.  */
  50
  51 /* Registers we shouldn't try to fetch.  */
  52 #if !defined (CANNOT_FETCH_REGISTER)
  53 #define CANNOT_FETCH_REGISTER(regno) cannot_fetch_register (regno)
  54 #endif
  55
  56 /* Registers we shouldn't try to store.  */
  57 #if !defined (CANNOT_STORE_REGISTER)
  58 #define CANNOT_STORE_REGISTER(regno) cannot_fetch_register (regno)
  59 #endif
  60
  61 /* Offset to the gregset_t location where REG is stored.  */
  62 #define REG_OFFSET(reg) offsetof (gregset_t, reg)
  63
  64 /* At reg_offset[REGNO] you'll find the offset to the gregset_t
  65    location where the GDB register REGNO is stored.  Unsupported
  66    registers are marked with `-1'.  */
  67 static int reg_offset[] =
  68 {
  69   REG_OFFSET (r_eax),
  70   REG_OFFSET (r_ecx),
  71   REG_OFFSET (r_edx),
  72   REG_OFFSET (r_edx),
  73   REG_OFFSET (r_esp),
  74   REG_OFFSET (r_ebp),
  75   REG_OFFSET (r_esi),
  76   REG_OFFSET (r_edi),
  77   REG_OFFSET (r_eip),
  78   REG_OFFSET (r_eflags),
  79   REG_OFFSET (r_cs),
  80   REG_OFFSET (r_ss),
  81   REG_OFFSET (r_ds),
  82   REG_OFFSET (r_es),
  83 #ifdef HAVE_STRUCT_REG_R_FS
  84   REG_OFFSET (r_fs),
  85 #else
  86   -1,
  87 #endif
  88 #ifdef HAVE_STRUCT_REG_R_GS
  89   REG_OFFSET (r_gs)
  90 #else
  91   -1
  92 #endif
  93 };
  94
  95 #define REG_ADDR(regset, regno) ((char *) (regset) + reg_offset[regno])
  96
  97 /* Return nonzero if we shouldn't try to fetch register REGNO.  */
  98
  99 static int
 100 cannot_fetch_register (int regno)
 101 {
 102   return (reg_offset[regno] == -1);
 103 }
 104 \f
 105
 106 /* Transfering the registers between GDB, inferiors and core files.  */
 107
 108 /* Fill GDB's register array with the general-purpose register values
 109    in *GREGSETP.  */
 110
 111 void
 112 supply_gregset (gregset_t *gregsetp)
 113 {
 114   int i;
 115
 116   for (i = 0; i < NUM_GREGS; i++)
 117     {
 118       if (CANNOT_FETCH_REGISTER (i))
 119         supply_register (i, NULL);
 120       else
 121         supply_register (i, REG_ADDR (gregsetp, i));
 122     }
 123 }
 124
 125 /* Fill register REGNO (if it is a general-purpose register) in
 126    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
 127    do this for all registers.  */
 128
 129 void
 130 fill_gregset (gregset_t *gregsetp, int regno)
 131 {
 132   int i;
 133
 134   for (i = 0; i < NUM_GREGS; i++)
 135     if ((regno == -1 || regno == i) && ! CANNOT_STORE_REGISTER (i))
 136       memcpy (REG_ADDR (gregsetp, i), &registers[REGISTER_BYTE (i)],
 137               REGISTER_RAW_SIZE (i));
 138 }
 139
 140 #include "i387-nat.h"
 141
 142 /* Fill GDB's register array with the floating-point register values
 143    in *FPREGSETP.  */
 144
 145 void
 146 supply_fpregset (fpregset_t *fpregsetp)
 147 {
 148   i387_supply_fsave ((char *) fpregsetp);
 149 }
 150
 151 /* Fill register REGNO (if it is a floating-point register) in
 152    *FPREGSETP with the value in GDB's register array.  If REGNO is -1,
 153    do this for all registers.  */
 154
 155 void
 156 fill_fpregset (fpregset_t *fpregsetp, int regno)
 157 {
 158   i387_fill_fsave ((char *) fpregsetp, regno);
 159 }
 160
 161 /* Fetch register REGNO from the inferior.  If REGNO is -1, do this
 162    for all registers (including the floating point registers).  */
 163
 164 void
 165 fetch_inferior_registers (int regno)
 166 {
 167   gregset_t gregs;
 168
 169   if (ptrace (PT_GETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
 170     perror_with_name ("Couldn't get registers");
 171
 172   supply_gregset (&gregs);
 173
 174   if (regno == -1 || regno >= FP0_REGNUM)
 175     {
 176       fpregset_t fpregs;
 177
 178       if (ptrace (PT_GETFPREGS, inferior_pid,
 179                   (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
 180         perror_with_name ("Couldn't get floating point status");
 181
 182       supply_fpregset (&fpregs);
 183     }
 184 }
 185
 186 /* Store register REGNO back into the inferior.  If REGNO is -1, do
 187    this for all registers (including the floating point registers).  */
 188
 189 void
 190 store_inferior_registers (int regno)
 191 {
 192   gregset_t gregs;
 193
 194   if (ptrace (PT_GETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
 195     perror_with_name ("Couldn't get registers");
 196
 197   fill_gregset (&gregs, regno);
 198
 199   if (ptrace (PT_SETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
 200     perror_with_name ("Couldn't write registers");
 201
 202   if (regno == -1 || regno >= FP0_REGNUM)
 203     {
 204       fpregset_t fpregs;
 205
 206       if (ptrace (PT_GETFPREGS, inferior_pid,
 207                   (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
 208         perror_with_name ("Couldn't get floating point status");
 209
 210       fill_fpregset (&fpregs, regno);
 211
 212       if (ptrace (PT_SETFPREGS, inferior_pid,
 213                   (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
 214         perror_with_name ("Couldn't write floating point status");
 215     }
 216 }
 217 \f
 218
 219 /* Support for debug registers.  */
 220
 221 #ifdef HAVE_PT_GETDBREGS
 222
 223 /* Not all versions of FreeBSD/i386 that support the debug registers
 224    have this macro.  */
 225 #ifndef DBREG_DRX
 226 #define DBREG_DRX(d, x) ((&d->dr0)[x])
 227 #endif
 228
 229 static void
 230 i386bsd_dr_set (int regnum, unsigned int value)
 231 {
 232   struct dbreg dbregs;
 233
 234   if (ptrace (PT_GETDBREGS, inferior_pid, (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
 235     perror_with_name ("Couldn't get debug registers");
 236
 237   /* For some mysterious reason, some of the reserved bits in the
 238      debug control register get set.  Mask these off, otherwise the
 239      ptrace call below will fail.  */
 240   dbregs.dr7 &= ~(0x0000fc00);
 241
 242   DBREG_DRX ((&dbregs), regnum) = value;
 243
 244   if (ptrace (PT_SETDBREGS, inferior_pid, (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
 245     perror_with_name ("Couldn't write debug registers");
 246 }
 247
 248 void
 249 i386bsd_dr_set_control (unsigned long control)
 250 {
 251   i386bsd_dr_set (7, control);
 252 }
 253
 254 void
 255 i386bsd_dr_set_addr (int regnum, CORE_ADDR addr)
 256 {
 257   gdb_assert (regnum >= 0 && regnum <= 4);
 258
 259   i386bsd_dr_set (regnum, addr);
 260 }
 261
 262 void
 263 i386bsd_dr_reset_addr (int regnum)
 264 {
 265   gdb_assert (regnum >= 0 && regnum <= 4);
 266
 267   i386bsd_dr_set (regnum, 0);
 268 }
 269
 270 unsigned long
 271 i386bsd_dr_get_status (void)
 272 {
 273   struct dbreg dbregs;
 274
 275   /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the
 276      ptrace call fails breaks debugging remote targets.  The correct
 277      way to fix this is to add the hardware breakpoint and watchpoint
 278      stuff to the target vectore.  For now, just return zero if the
 279      ptrace call fails.  */
 280   if (ptrace (PT_GETDBREGS, inferior_pid, (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
 281 #if 0
 282     perror_with_name ("Couldn't read debug registers");
 283 #else
 284     return 0;
 285 #endif
 286
 287   return dbregs.dr6;
 288 }
 289
 290 #endif /* PT_GETDBREGS */
 291 \f
 292
 293 /* Support for the user struct.  */
 294
 295 /* Return the address register REGNO.  BLOCKEND is the value of
 296    u.u_ar0, which should point to the registers.  */
 297
 298 CORE_ADDR
 299 register_u_addr (CORE_ADDR blockend, int regno)
 300 {
 301   return (CORE_ADDR) REG_ADDR (blockend, regno);
 302 }
 303
 304 #include <sys/param.h>
 305 #include <sys/user.h>
 306
 307 /* Return the size of the user struct.  */
 308
 309 int
 310 kernel_u_size (void)
 311 {
 312   return (sizeof (struct user));
 313 }