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 /* Defined in auto-generated file reg-i386-linux.c.  */
  37 void init_registers_i386_linux (void);
  38
  39
  40 /* This module only supports access to the general purpose registers.  */
  41
  42 #define i386_num_regs 16
  43
  44 /* This stuff comes from i386-linux-nat.c.  */
  45
  46 /* Mapping between the general-purpose registers in `struct user'
  47    format and GDB's register array layout.  */
  48 static int i386_regmap[] =
  49 {
  50   EAX * 4, ECX * 4, EDX * 4, EBX * 4,
  51   UESP * 4, EBP * 4, ESI * 4, EDI * 4,
  52   EIP * 4, EFL * 4, CS * 4, SS * 4,
  53   DS * 4, ES * 4, FS * 4, GS * 4
  54 };
  55
  56 /* Called by libthread_db.  */
  57
  58 ps_err_e
  59 ps_get_thread_area (const struct ps_prochandle *ph,
  60                     lwpid_t lwpid, int idx, void **base)
  61 {
  62   unsigned int desc[4];
  63
  64   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid,
  65               (void *) idx, (unsigned long) &desc) < 0)
  66     return PS_ERR;
  67
  68   *(int *)base = desc[1];
  69   return PS_OK;
  70 }
  71
  72 static int
  73 i386_cannot_store_register (int regno)
  74 {
  75   return (regno >= i386_num_regs);
  76 }
  77
  78 static int
  79 i386_cannot_fetch_register (int regno)
  80 {
  81   return (regno >= i386_num_regs);
  82 }
  83
  84
  85 #ifdef HAVE_PTRACE_GETREGS
  86 #include <sys/procfs.h>
  87 #include <sys/ptrace.h>
  88
  89 static void
  90 i386_fill_gregset (void *buf)
  91 {
  92   int i;
  93
  94   for (i = 0; i < i386_num_regs; i++)
  95     collect_register (i, ((char *) buf) + i386_regmap[i]);
  96
  97   collect_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
  98 }
  99
 100 static void
 101 i386_store_gregset (const void *buf)
 102 {
 103   int i;
 104
 105   for (i = 0; i < i386_num_regs; i++)
 106     supply_register (i, ((char *) buf) + i386_regmap[i]);
 107
 108   supply_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
 109 }
 110
 111 static void
 112 i386_fill_fpregset (void *buf)
 113 {
 114   i387_cache_to_fsave (buf);
 115 }
 116
 117 static void
 118 i386_store_fpregset (const void *buf)
 119 {
 120   i387_fsave_to_cache (buf);
 121 }
 122
 123 static void
 124 i386_fill_fpxregset (void *buf)
 125 {
 126   i387_cache_to_fxsave (buf);
 127 }
 128
 129 static void
 130 i386_store_fpxregset (const void *buf)
 131 {
 132   i387_fxsave_to_cache (buf);
 133 }
 134
 135 #endif /* HAVE_PTRACE_GETREGS */
 136
 137 struct regset_info target_regsets[] = {
 138 #ifdef HAVE_PTRACE_GETREGS
 139   { PTRACE_GETREGS, PTRACE_SETREGS, sizeof (elf_gregset_t),
 140     GENERAL_REGS,
 141     i386_fill_gregset, i386_store_gregset },
 142 # ifdef HAVE_PTRACE_GETFPXREGS
 143   { PTRACE_GETFPXREGS, PTRACE_SETFPXREGS, sizeof (elf_fpxregset_t),
 144     EXTENDED_REGS,
 145     i386_fill_fpxregset, i386_store_fpxregset },
 146 # endif
 147   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, sizeof (elf_fpregset_t),
 148     FP_REGS,
 149     i386_fill_fpregset, i386_store_fpregset },
 150 #endif /* HAVE_PTRACE_GETREGS */
 151   { 0, 0, -1, -1, NULL, NULL }
 152 };
 153
 154 static const unsigned char i386_breakpoint[] = { 0xCC };
 155 #define i386_breakpoint_len 1
 156
 157 extern int debug_threads;
 158
 159 static CORE_ADDR
 160 i386_get_pc ()
 161 {
 162   unsigned long pc;
 163
 164   collect_register_by_name ("eip", &pc);
 165
 166   if (debug_threads)
 167     fprintf (stderr, "stop pc (before any decrement) is %08lx\n", pc);
 168   return pc;
 169 }
 170
 171 static void
 172 i386_set_pc (CORE_ADDR newpc)
 173 {
 174   if (debug_threads)
 175     fprintf (stderr, "set pc to %08lx\n", (long) newpc);
 176   supply_register_by_name ("eip", &newpc);
 177 }
 178
 179 static int
 180 i386_breakpoint_at (CORE_ADDR pc)
 181 {
 182   unsigned char c;
 183
 184   read_inferior_memory (pc, &c, 1);
 185   if (c == 0xCC)
 186     return 1;
 187
 188   return 0;
 189 }
 190
 191 struct linux_target_ops the_low_target = {
 192   init_registers_i386_linux,
 193   i386_num_regs,
 194   i386_regmap,
 195   i386_cannot_fetch_register,
 196   i386_cannot_store_register,
 197   i386_get_pc,
 198   i386_set_pc,
 199   i386_breakpoint,
 200   i386_breakpoint_len,
 201   NULL,
 202   1,
 203   i386_breakpoint_at,
 204   NULL,
 205   NULL,
 206   NULL,
 207   NULL,
 208   0,
 209   "i386"
 210 };