gdb/amd64fbsd-nat.c

   1 /* Native-dependent code for FreeBSD/amd64.
   2
   3    Copyright 2003, 2004 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include "defs.h"
  23 #include "inferior.h"
  24 #include "regcache.h"
  25
  26 #include "gdb_assert.h"
  27 #include <signal.h>
  28 #include <stddef.h>
  29 #include <sys/types.h>
  30 #include <sys/ptrace.h>
  31 #include <sys/sysctl.h>
  32 #include <machine/reg.h>
  33
  34 #ifdef HAVE_SYS_PROCFS_H
  35 #include <sys/procfs.h>
  36 #endif
  37
  38 #ifndef HAVE_GREGSET_T
  39 typedef struct reg gregset_t;
  40 #endif
  41
  42 #ifndef HAVE_FPREGSET_T
  43 typedef struct fpreg fpregset_t;
  44 #endif
  45
  46 #include "gregset.h"
  47 #include "amd64-tdep.h"
  48 #include "amd64-nat.h"
  49 \f
  50
  51 /* Offset to the gregset_t location where REG is stored.  */
  52 #define REG_OFFSET(reg) offsetof (gregset_t, reg)
  53
  54 /* At reg_offset[REGNUM] you'll find the offset to the gregset_t
  55    location where the GDB register REGNUM is stored.  Unsupported
  56    registers are marked with `-1'.  */
  57 static int reg_offset[] =
  58 {
  59   REG_OFFSET (r_rax),
  60   REG_OFFSET (r_rbx),
  61   REG_OFFSET (r_rcx),
  62   REG_OFFSET (r_rdx),
  63   REG_OFFSET (r_rsi),
  64   REG_OFFSET (r_rdi),
  65   REG_OFFSET (r_rbp),
  66   REG_OFFSET (r_rsp),
  67   REG_OFFSET (r_r8),
  68   REG_OFFSET (r_r9),
  69   REG_OFFSET (r_r10),
  70   REG_OFFSET (r_r11),
  71   REG_OFFSET (r_r12),
  72   REG_OFFSET (r_r13),
  73   REG_OFFSET (r_r14),
  74   REG_OFFSET (r_r15),
  75   REG_OFFSET (r_rip),
  76   REG_OFFSET (r_rflags),
  77   REG_OFFSET (r_cs),
  78   REG_OFFSET (r_ss),
  79   -1,
  80   -1,
  81   -1,
  82   -1
  83 };
  84 \f
  85
  86 /* Mapping between the general-purpose registers in FreeBSD/amd64
  87    `struct reg' format and GDB's register cache layout for
  88    FreeBSD/i386.
  89
  90    Note that most FreeBSD/amd64 registers are 64-bit, while the
  91    FreeBSD/i386 registers are all 32-bit, but since we're
  92    little-endian we get away with that.  */
  93
  94 /* From <machine/reg.h>.  */
  95 static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
  96 {
  97   14 * 8, 13 * 8,               /* %eax, %ecx */
  98   12 * 8, 11 * 8,               /* %edx, %ebx */
  99   20 * 8, 10 * 8,               /* %esp, %ebp */
 100   9 * 8, 8 * 8,                 /* %esi, %edi */
 101   17 * 8, 19 * 8,               /* %eip, %eflags */
 102   18 * 8, 21 * 8,               /* %cs, %ss */
 103   -1, -1, -1, -1                /* %ds, %es, %fs, %gs */
 104 };
 105 \f
 106
 107 /* Transfering the registers between GDB, inferiors and core files.  */
 108
 109 /* Fill GDB's register array with the general-purpose register values
 110    in *GREGSETP.  */
 111
 112 void
 113 supply_gregset (gregset_t *gregsetp)
 114 {
 115   amd64_supply_native_gregset (current_regcache, gregsetp, -1);
 116 }
 117
 118 /* Fill register REGNUM (if it is a general-purpose register) in
 119    *GREGSETPS with the value in GDB's register array.  If REGNUM is -1,
 120    do this for all registers.  */
 121
 122 void
 123 fill_gregset (gregset_t *gregsetp, int regnum)
 124 {
 125   amd64_collect_native_gregset (current_regcache, gregsetp, regnum);
 126 }
 127
 128 /* Fill GDB's register array with the floating-point register values
 129    in *FPREGSETP.  */
 130
 131 void
 132 supply_fpregset (fpregset_t *fpregsetp)
 133 {
 134   amd64_supply_fxsave (current_regcache, -1, fpregsetp);
 135 }
 136
 137 /* Fill register REGNUM (if it is a floating-point register) in
 138    *FPREGSETP with the value in GDB's register array.  If REGNUM is -1,
 139    do this for all registers.  */
 140
 141 void
 142 fill_fpregset (fpregset_t *fpregsetp, int regnum)
 143 {
 144   amd64_collect_fxsave (current_regcache, regnum, fpregsetp);
 145 }
 146 \f
 147
 148 /* Provide a prototype to silence -Wmissing-prototypes.  */
 149 void _initialize_amd64fbsd_nat (void);
 150
 151 void
 152 _initialize_amd64fbsd_nat (void)
 153 {
 154   int offset;
 155
 156   amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
 157   amd64_native_gregset64_reg_offset = reg_offset;
 158
 159   /* To support the recognition of signal handlers, i386bsd-tdep.c
 160      hardcodes some constants.  Inclusion of this file means that we
 161      are compiling a native debugger, which means that we can use the
 162      system header files and sysctl(3) to get at the relevant
 163      information.  */
 164
 165 #define SC_REG_OFFSET amd64fbsd_sc_reg_offset
 166
 167   /* We only check the program counter, stack pointer and frame
 168      pointer since these members of `struct sigcontext' are essential
 169      for providing backtraces.  */
 170
 171 #define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
 172 #define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
 173 #define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
 174
 175   /* Override the default value for the offset of the program counter
 176      in the sigcontext structure.  */
 177   offset = offsetof (struct sigcontext, sc_rip);
 178
 179   if (SC_RIP_OFFSET != offset)
 180     {
 181       warning ("\
 182 offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
 183 Please report this to <bug-gdb@gnu.org>.",
 184                offset, SC_RIP_OFFSET);
 185     }
 186
 187   SC_RIP_OFFSET = offset;
 188
 189   /* Likewise for the stack pointer.  */
 190   offset = offsetof (struct sigcontext, sc_rsp);
 191
 192   if (SC_RSP_OFFSET != offset)
 193     {
 194       warning ("\
 195 offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
 196 Please report this to <bug-gdb@gnu.org>.",
 197                offset, SC_RSP_OFFSET);
 198     }
 199
 200   SC_RSP_OFFSET = offset;
 201
 202   /* And the frame pointer.  */
 203   offset = offsetof (struct sigcontext, sc_rbp);
 204
 205   if (SC_RBP_OFFSET != offset)
 206     {
 207       warning ("\
 208 offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
 209 Please report this to <bug-gdb@gnu.org>.",
 210                offset, SC_RBP_OFFSET);
 211     }
 212
 213   SC_RBP_OFFSET = offset;
 214
 215   /* FreeBSD provides a kern.ps_strings sysctl that we can use to
 216      locate the sigtramp.  That way we can still recognize a sigtramp
 217      if its location is changed in a new kernel.  Of course this is
 218      still based on the assumption that the sigtramp is placed
 219      directly under the location where the program arguments and
 220      environment can be found.  */
 221   {
 222     int mib[2];
 223     long ps_strings;
 224     size_t len;
 225
 226     mib[0] = CTL_KERN;
 227     mib[1] = KERN_PS_STRINGS;
 228     len = sizeof (ps_strings);
 229     if (sysctl (mib, 2, &ps_strings, &len, NULL, 0) == 0)
 230       {
 231         amd64fbsd_sigtramp_start_addr = ps_strings - 32;
 232         amd64fbsd_sigtramp_end_addr = ps_strings;
 233       }
 234   }
 235 }