gdb/gdbserver/linux-x86-64-low.c

   1 /* GNU/Linux/x86-64 specific low level interface, for the remote server
   2    for GDB.
   3    Copyright (C) 2002, 2004, 2005
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include "server.h"
  24 #include "linux-low.h"
  25 #include "i387-fp.h"
  26
  27 /* Correct for all GNU/Linux targets (for quite some time).  */
  28 #define GDB_GREGSET_T elf_gregset_t
  29 #define GDB_FPREGSET_T elf_fpregset_t
  30
  31 #ifndef HAVE_ELF_FPREGSET_T
  32 /* Make sure we have said types.  Not all platforms bring in <linux/elf.h>
  33    via <sys/procfs.h>.  */
  34 #ifdef HAVE_LINUX_ELF_H
  35 #include <linux/elf.h>
  36 #endif
  37 #endif
  38
  39 #include "../gdb_proc_service.h"
  40
  41 #include <sys/reg.h>
  42 #include <sys/procfs.h>
  43 #include <sys/ptrace.h>
  44
  45 /* This definition comes from prctl.h, but some kernels may not have it.  */
  46 #ifndef PTRACE_ARCH_PRCTL
  47 #define PTRACE_ARCH_PRCTL      30
  48 #endif
  49
  50 /* The following definitions come from prctl.h, but may be absent
  51    for certain configurations.  */
  52 #ifndef ARCH_GET_FS
  53 #define ARCH_SET_GS 0x1001
  54 #define ARCH_SET_FS 0x1002
  55 #define ARCH_GET_FS 0x1003
  56 #define ARCH_GET_GS 0x1004
  57 #endif
  58
  59 static int x86_64_regmap[] = {
  60   RAX * 8, RBX * 8, RCX * 8, RDX * 8,
  61   RSI * 8, RDI * 8, RBP * 8, RSP * 8,
  62   R8 * 8, R9 * 8, R10 * 8, R11 * 8,
  63   R12 * 8, R13 * 8, R14 * 8, R15 * 8,
  64   RIP * 8, EFLAGS * 8, CS * 8, SS * 8,
  65   DS * 8, ES * 8, FS * 8, GS * 8
  66 };
  67
  68 #define X86_64_NUM_GREGS (sizeof(x86_64_regmap)/sizeof(int))
  69
  70 /* Called by libthread_db.  */
  71
  72 ps_err_e
  73 ps_get_thread_area (const struct ps_prochandle *ph,
  74                     lwpid_t lwpid, int idx, void **base)
  75 {
  76   switch (idx)
  77     {
  78     case FS:
  79       if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0)
  80         return PS_OK;
  81       break;
  82     case GS:
  83       if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_GS) == 0)
  84         return PS_OK;
  85       break;
  86     default:
  87       return PS_BADADDR;
  88     }
  89   return PS_ERR;
  90 }
  91
  92 static void
  93 x86_64_fill_gregset (void *buf)
  94 {
  95   int i;
  96
  97   for (i = 0; i < X86_64_NUM_GREGS; i++)
  98     collect_register (i, ((char *) buf) + x86_64_regmap[i]);
  99 }
 100
 101 static void
 102 x86_64_store_gregset (const void *buf)
 103 {
 104   int i;
 105
 106   for (i = 0; i < X86_64_NUM_GREGS; i++)
 107     supply_register (i, ((char *) buf) + x86_64_regmap[i]);
 108 }
 109
 110 static void
 111 x86_64_fill_fpregset (void *buf)
 112 {
 113   i387_cache_to_fxsave (buf);
 114 }
 115
 116 static void
 117 x86_64_store_fpregset (const void *buf)
 118 {
 119   i387_fxsave_to_cache (buf);
 120 }
 121
 122 struct regset_info target_regsets[] = {
 123   { PTRACE_GETREGS, PTRACE_SETREGS, sizeof (elf_gregset_t),
 124     GENERAL_REGS,
 125     x86_64_fill_gregset, x86_64_store_gregset },
 126   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, sizeof (elf_fpregset_t),
 127     FP_REGS,
 128     x86_64_fill_fpregset, x86_64_store_fpregset },
 129   { 0, 0, -1, -1, NULL, NULL }
 130 };
 131
 132 static const unsigned char x86_64_breakpoint[] = { 0xCC };
 133 #define x86_64_breakpoint_len 1
 134
 135 extern int debug_threads;
 136
 137 static CORE_ADDR
 138 x86_64_get_pc ()
 139 {
 140   unsigned long pc;
 141
 142   collect_register_by_name ("rip", &pc);
 143
 144   if (debug_threads)
 145     fprintf (stderr, "stop pc (before any decrement) is %08lx\n", pc);
 146   return pc;
 147 }
 148
 149 static void
 150 x86_64_set_pc (CORE_ADDR newpc)
 151 {
 152   if (debug_threads)
 153     fprintf (stderr, "set pc to %08lx\n", (long) newpc);
 154   supply_register_by_name ("rip", &newpc);
 155 }
 156
 157 static int
 158 x86_64_breakpoint_at (CORE_ADDR pc)
 159 {
 160   unsigned char c;
 161
 162   read_inferior_memory (pc, &c, 1);
 163   if (c == 0xCC)
 164     return 1;
 165
 166   return 0;
 167 }
 168
 169 struct linux_target_ops the_low_target = {
 170   -1,
 171   NULL,
 172   NULL,
 173   NULL,
 174   x86_64_get_pc,
 175   x86_64_set_pc,
 176   x86_64_breakpoint,
 177   x86_64_breakpoint_len,
 178   NULL,
 179   1,
 180   x86_64_breakpoint_at,
 181 };