gdb/gdbserver/linux-i386-low.c

   1 /* GNU/Linux/i386 specific low level interface, for the remote server for GDB.
   2    Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2006,
   3    2007, 2008 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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "server.h"
  21 #include "linux-low.h"
  22 #include "i387-fp.h"
  23
  24 #include "gdb_proc_service.h"
  25
  26 #include <sys/ptrace.h>
  27
  28 #ifdef HAVE_SYS_REG_H
  29 #include <sys/reg.h>
  30 #endif
  31
  32 #ifndef PTRACE_GET_THREAD_AREA
  33 #define PTRACE_GET_THREAD_AREA 25
  34 #endif
  35
  36 /* This module only supports access to the general purpose registers.  */
  37
  38 #define i386_num_regs 16
  39
  40 /* This stuff comes from i386-linux-nat.c.  */
  41
  42 /* Mapping between the general-purpose registers in `struct user'
  43    format and GDB's register array layout.  */
  44 static int i386_regmap[] =
  45 {
  46   EAX * 4, ECX * 4, EDX * 4, EBX * 4,
  47   UESP * 4, EBP * 4, ESI * 4, EDI * 4,
  48   EIP * 4, EFL * 4, CS * 4, SS * 4,
  49   DS * 4, ES * 4, FS * 4, GS * 4
  50 };
  51
  52 /* Called by libthread_db.  */
  53
  54 ps_err_e
  55 ps_get_thread_area (const struct ps_prochandle *ph,
  56                     lwpid_t lwpid, int idx, void **base)
  57 {
  58   unsigned int desc[4];
  59
  60   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid,
  61               (void *) idx, (unsigned long) &desc) < 0)
  62     return PS_ERR;
  63
  64   *(int *)base = desc[1];
  65   return PS_OK;
  66 }
  67
  68 static int
  69 i386_cannot_store_register (int regno)
  70 {
  71   return (regno >= i386_num_regs);
  72 }
  73
  74 static int
  75 i386_cannot_fetch_register (int regno)
  76 {
  77   return (regno >= i386_num_regs);
  78 }
  79
  80
  81 #ifdef HAVE_PTRACE_GETREGS
  82 #include <sys/procfs.h>
  83 #include <sys/ptrace.h>
  84
  85 static void
  86 i386_fill_gregset (void *buf)
  87 {
  88   int i;
  89
  90   for (i = 0; i < i386_num_regs; i++)
  91     collect_register (i, ((char *) buf) + i386_regmap[i]);
  92
  93   collect_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
  94 }
  95
  96 static void
  97 i386_store_gregset (const void *buf)
  98 {
  99   int i;
 100
 101   for (i = 0; i < i386_num_regs; i++)
 102     supply_register (i, ((char *) buf) + i386_regmap[i]);
 103
 104   supply_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
 105 }
 106
 107 static void
 108 i386_fill_fpregset (void *buf)
 109 {
 110   i387_cache_to_fsave (buf);
 111 }
 112
 113 static void
 114 i386_store_fpregset (const void *buf)
 115 {
 116   i387_fsave_to_cache (buf);
 117 }
 118
 119 static void
 120 i386_fill_fpxregset (void *buf)
 121 {
 122   i387_cache_to_fxsave (buf);
 123 }
 124
 125 static void
 126 i386_store_fpxregset (const void *buf)
 127 {
 128   i387_fxsave_to_cache (buf);
 129 }
 130
 131 #endif /* HAVE_PTRACE_GETREGS */
 132
 133 struct regset_info target_regsets[] = {
 134 #ifdef HAVE_PTRACE_GETREGS
 135   { PTRACE_GETREGS, PTRACE_SETREGS, sizeof (elf_gregset_t),
 136     GENERAL_REGS,
 137     i386_fill_gregset, i386_store_gregset },
 138 # ifdef HAVE_PTRACE_GETFPXREGS
 139   { PTRACE_GETFPXREGS, PTRACE_SETFPXREGS, sizeof (elf_fpxregset_t),
 140     EXTENDED_REGS,
 141     i386_fill_fpxregset, i386_store_fpxregset },
 142 # endif
 143   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, sizeof (elf_fpregset_t),
 144     FP_REGS,
 145     i386_fill_fpregset, i386_store_fpregset },
 146 #endif /* HAVE_PTRACE_GETREGS */
 147   { 0, 0, -1, -1, NULL, NULL }
 148 };
 149
 150 static const unsigned char i386_breakpoint[] = { 0xCC };
 151 #define i386_breakpoint_len 1
 152
 153 extern int debug_threads;
 154
 155 static CORE_ADDR
 156 i386_get_pc ()
 157 {
 158   unsigned long pc;
 159
 160   collect_register_by_name ("eip", &pc);
 161
 162   if (debug_threads)
 163     fprintf (stderr, "stop pc (before any decrement) is %08lx\n", pc);
 164   return pc;
 165 }
 166
 167 static void
 168 i386_set_pc (CORE_ADDR newpc)
 169 {
 170   if (debug_threads)
 171     fprintf (stderr, "set pc to %08lx\n", (long) newpc);
 172   supply_register_by_name ("eip", &newpc);
 173 }
 174
 175 static int
 176 i386_breakpoint_at (CORE_ADDR pc)
 177 {
 178   unsigned char c;
 179
 180   read_inferior_memory (pc, &c, 1);
 181   if (c == 0xCC)
 182     return 1;
 183
 184   return 0;
 185 }
 186
 187 struct linux_target_ops the_low_target = {
 188   i386_num_regs,
 189   i386_regmap,
 190   i386_cannot_fetch_register,
 191   i386_cannot_store_register,
 192   i386_get_pc,
 193   i386_set_pc,
 194   i386_breakpoint,
 195   i386_breakpoint_len,
 196   NULL,
 197   1,
 198   i386_breakpoint_at,
 199   NULL,
 200   NULL,
 201   NULL,
 202   NULL,
 203   0,
 204   "i386"
 205 };