gdb/gdbserver/linux-i386-low.c

   1 /* GNU/Linux/i386 specific low level interface, for the remote server for GDB.
   2    Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2004, 2005
   3    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 "server.h"
  23 #include "linux-low.h"
  24 #include "i387-fp.h"
  25
  26 /* Correct for all GNU/Linux targets (for quite some time).  */
  27 #define GDB_GREGSET_T elf_gregset_t
  28 #define GDB_FPREGSET_T elf_fpregset_t
  29
  30 #ifndef HAVE_ELF_FPREGSET_T
  31 /* Make sure we have said types.  Not all platforms bring in <linux/elf.h>
  32    via <sys/procfs.h>.  */
  33 #ifdef HAVE_LINUX_ELF_H
  34 #include <linux/elf.h>
  35 #endif
  36 #endif
  37
  38 #include "../gdb_proc_service.h"
  39
  40 #include <sys/ptrace.h>
  41
  42 #ifdef HAVE_SYS_REG_H
  43 #include <sys/reg.h>
  44 #endif
  45
  46 #ifndef PTRACE_GET_THREAD_AREA
  47 #define PTRACE_GET_THREAD_AREA 25
  48 #endif
  49
  50 /* This module only supports access to the general purpose registers.  */
  51
  52 #define i386_num_regs 16
  53
  54 /* This stuff comes from i386-linux-nat.c.  */
  55
  56 /* Mapping between the general-purpose registers in `struct user'
  57    format and GDB's register array layout.  */
  58 static int i386_regmap[] =
  59 {
  60   EAX * 4, ECX * 4, EDX * 4, EBX * 4,
  61   UESP * 4, EBP * 4, ESI * 4, EDI * 4,
  62   EIP * 4, EFL * 4, CS * 4, SS * 4,
  63   DS * 4, ES * 4, FS * 4, GS * 4
  64 };
  65
  66 /* Called by libthread_db.  */
  67
  68 ps_err_e
  69 ps_get_thread_area (const struct ps_prochandle *ph,
  70                     lwpid_t lwpid, int idx, void **base)
  71 {
  72   unsigned int desc[4];
  73
  74   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid,
  75               (void *) idx, (unsigned long) &desc) < 0)
  76     return PS_ERR;
  77
  78   *(int *)base = desc[1];
  79   return PS_OK;
  80 }
  81
  82 static int
  83 i386_cannot_store_register (int regno)
  84 {
  85   return (regno >= i386_num_regs);
  86 }
  87
  88 static int
  89 i386_cannot_fetch_register (int regno)
  90 {
  91   return (regno >= i386_num_regs);
  92 }
  93
  94
  95 #ifdef HAVE_LINUX_REGSETS
  96 #include <sys/procfs.h>
  97 #include <sys/ptrace.h>
  98
  99 static void
 100 i386_fill_gregset (void *buf)
 101 {
 102   int i;
 103
 104   for (i = 0; i < i386_num_regs; i++)
 105     collect_register (i, ((char *) buf) + i386_regmap[i]);
 106
 107   collect_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
 108 }
 109
 110 static void
 111 i386_store_gregset (const void *buf)
 112 {
 113   int i;
 114
 115   for (i = 0; i < i386_num_regs; i++)
 116     supply_register (i, ((char *) buf) + i386_regmap[i]);
 117
 118   supply_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
 119 }
 120
 121 static void
 122 i386_fill_fpregset (void *buf)
 123 {
 124   i387_cache_to_fsave (buf);
 125 }
 126
 127 static void
 128 i386_store_fpregset (const void *buf)
 129 {
 130   i387_fsave_to_cache (buf);
 131 }
 132
 133 static void
 134 i386_fill_fpxregset (void *buf)
 135 {
 136   i387_cache_to_fxsave (buf);
 137 }
 138
 139 static void
 140 i386_store_fpxregset (const void *buf)
 141 {
 142   i387_fxsave_to_cache (buf);
 143 }
 144
 145
 146 struct regset_info target_regsets[] = {
 147   { PTRACE_GETREGS, PTRACE_SETREGS, sizeof (elf_gregset_t),
 148     GENERAL_REGS,
 149     i386_fill_gregset, i386_store_gregset },
 150 #ifdef HAVE_PTRACE_GETFPXREGS
 151   { PTRACE_GETFPXREGS, PTRACE_SETFPXREGS, sizeof (elf_fpxregset_t),
 152     EXTENDED_REGS,
 153     i386_fill_fpxregset, i386_store_fpxregset },
 154 #endif
 155   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, sizeof (elf_fpregset_t),
 156     FP_REGS,
 157     i386_fill_fpregset, i386_store_fpregset },
 158   { 0, 0, -1, -1, NULL, NULL }
 159 };
 160
 161 #endif /* HAVE_LINUX_REGSETS */
 162
 163 static const unsigned char i386_breakpoint[] = { 0xCC };
 164 #define i386_breakpoint_len 1
 165
 166 extern int debug_threads;
 167
 168 static CORE_ADDR
 169 i386_get_pc ()
 170 {
 171   unsigned long pc;
 172
 173   collect_register_by_name ("eip", &pc);
 174
 175   if (debug_threads)
 176     fprintf (stderr, "stop pc (before any decrement) is %08lx\n", pc);
 177   return pc;
 178 }
 179
 180 static void
 181 i386_set_pc (CORE_ADDR newpc)
 182 {
 183   if (debug_threads)
 184     fprintf (stderr, "set pc to %08lx\n", (long) newpc);
 185   supply_register_by_name ("eip", &newpc);
 186 }
 187
 188 static int
 189 i386_breakpoint_at (CORE_ADDR pc)
 190 {
 191   unsigned char c;
 192
 193   read_inferior_memory (pc, &c, 1);
 194   if (c == 0xCC)
 195     return 1;
 196
 197   return 0;
 198 }
 199
 200 struct linux_target_ops the_low_target = {
 201   i386_num_regs,
 202   i386_regmap,
 203   i386_cannot_fetch_register,
 204   i386_cannot_store_register,
 205   i386_get_pc,
 206   i386_set_pc,
 207   i386_breakpoint,
 208   i386_breakpoint_len,
 209   NULL,
 210   1,
 211   i386_breakpoint_at,
 212 };