gdb/amd64fbsd-nat.c

   1 /* Native-dependent code for FreeBSD/amd64.
   2
   3    Copyright 2003 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 "x86-64-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   -1,
  78   -1,
  79   -1,
  80   -1
  81 };
  82 \f
  83
  84 /* Mapping between the general-purpose registers in FreeBSD/amd64
  85    `struct reg' format and GDB's register cache layout for
  86    FreeBSD/i386.
  87
  88    Note that most FreeBSD/amd64 registers are 64-bit, while the
  89    FreeBSD/i386 registers are all 32-bit, but since we're
  90    little-endian we get away with that.  */
  91
  92 /* From <machine/reg.h>.  */
  93 static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
  94 {
  95   14 * 8, 13 * 8,               /* %eax, %ecx */
  96   12 * 8, 11 * 8,               /* %edx, %ebx */
  97   20 * 8, 10 * 8,               /* %esp, %ebp */
  98   9 * 8, 8 * 8,                 /* %esi, %edi */
  99   17 * 8, 19 * 8,               /* %eip, %eflags */
 100   18 * 8, 21 * 8,               /* %cs, %ss */
 101   -1, -1, -1, -1                /* %ds, %es, %fs, %gs */
 102 };
 103 \f
 104
 105 /* Transfering the registers between GDB, inferiors and core files.  */
 106
 107 /* Fill GDB's register array with the general-purpose register values
 108    in *GREGSETP.  */
 109
 110 void
 111 supply_gregset (gregset_t *gregsetp)
 112 {
 113   amd64_supply_native_gregset (current_regcache, gregsetp, -1);
 114 }
 115
 116 /* Fill register REGNUM (if it is a general-purpose register) in
 117    *GREGSETPS with the value in GDB's register array.  If REGNUM is -1,
 118    do this for all registers.  */
 119
 120 void
 121 fill_gregset (gregset_t *gregsetp, int regnum)
 122 {
 123   amd64_collect_native_gregset (current_regcache, gregsetp, regnum);
 124 }
 125
 126 /* Fill GDB's register array with the floating-point register values
 127    in *FPREGSETP.  */
 128
 129 void
 130 supply_fpregset (fpregset_t *fpregsetp)
 131 {
 132   x86_64_supply_fxsave (current_regcache, -1, fpregsetp);
 133 }
 134
 135 /* Fill register REGNUM (if it is a floating-point register) in
 136    *FPREGSETP with the value in GDB's register array.  If REGNUM is -1,
 137    do this for all registers.  */
 138
 139 void
 140 fill_fpregset (fpregset_t *fpregsetp, int regnum)
 141 {
 142   x86_64_fill_fxsave ((char *) fpregsetp, regnum);
 143 }
 144 \f
 145
 146 /* Provide a prototype to silence -Wmissing-prototypes.  */
 147 void _initialize_amd64fbsd_nat (void);
 148
 149 void
 150 _initialize_amd64fbsd_nat (void)
 151 {
 152   int offset;
 153
 154   amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
 155   amd64_native_gregset64_reg_offset = reg_offset;
 156
 157   /* To support the recognition of signal handlers, i386bsd-tdep.c
 158      hardcodes some constants.  Inclusion of this file means that we
 159      are compiling a native debugger, which means that we can use the
 160      system header files and sysctl(3) to get at the relevant
 161      information.  */
 162
 163 #define SC_REG_OFFSET amd64fbsd_sc_reg_offset
 164
 165   /* We only check the program counter, stack pointer and frame
 166      pointer since these members of `struct sigcontext' are essential
 167      for providing backtraces.  */
 168
 169 #define SC_RIP_OFFSET SC_REG_OFFSET[X86_64_RIP_REGNUM]
 170 #define SC_RSP_OFFSET SC_REG_OFFSET[X86_64_RSP_REGNUM]
 171 #define SC_RBP_OFFSET SC_REG_OFFSET[X86_64_RBP_REGNUM]
 172
 173   /* Override the default value for the offset of the program counter
 174      in the sigcontext structure.  */
 175   offset = offsetof (struct sigcontext, sc_rip);
 176
 177   if (SC_RIP_OFFSET != offset)
 178     {
 179       warning ("\
 180 offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
 181 Please report this to <bug-gdb@gnu.org>.",
 182                offset, SC_RIP_OFFSET);
 183     }
 184
 185   SC_RIP_OFFSET = offset;
 186
 187   /* Likewise for the stack pointer.  */
 188   offset = offsetof (struct sigcontext, sc_rsp);
 189
 190   if (SC_RSP_OFFSET != offset)
 191     {
 192       warning ("\
 193 offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
 194 Please report this to <bug-gdb@gnu.org>.",
 195                offset, SC_RSP_OFFSET);
 196     }
 197
 198   SC_RSP_OFFSET = offset;
 199
 200   /* And the frame pointer.  */
 201   offset = offsetof (struct sigcontext, sc_rbp);
 202
 203   if (SC_RBP_OFFSET != offset)
 204     {
 205       warning ("\
 206 offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
 207 Please report this to <bug-gdb@gnu.org>.",
 208                offset, SC_RBP_OFFSET);
 209     }
 210
 211   SC_RBP_OFFSET = offset;
 212
 213   /* FreeBSD provides a kern.ps_strings sysctl that we can use to
 214      locate the sigtramp.  That way we can still recognize a sigtramp
 215      if its location is changed in a new kernel.  Of course this is
 216      still based on the assumption that the sigtramp is placed
 217      directly under the location where the program arguments and
 218      environment can be found.  */
 219   {
 220     int mib[2];
 221     long ps_strings;
 222     size_t len;
 223
 224     mib[0] = CTL_KERN;
 225     mib[1] = KERN_PS_STRINGS;
 226     len = sizeof (ps_strings);
 227     if (sysctl (mib, 2, &ps_strings, &len, NULL, 0) == 0)
 228       {
 229         amd64fbsd_sigtramp_start = ps_strings - 32;
 230         amd64fbsd_sigtramp_end = ps_strings;
 231       }
 232   }
 233 }