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, 2006
   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 #include "gdb_proc_service.h"
  28
  29 #include <sys/reg.h>
  30 #include <sys/procfs.h>
  31 #include <sys/ptrace.h>
  32
  33 /* This definition comes from prctl.h, but some kernels may not have it.  */
  34 #ifndef PTRACE_ARCH_PRCTL
  35 #define PTRACE_ARCH_PRCTL      30
  36 #endif
  37
  38 /* The following definitions come from prctl.h, but may be absent
  39    for certain configurations.  */
  40 #ifndef ARCH_GET_FS
  41 #define ARCH_SET_GS 0x1001
  42 #define ARCH_SET_FS 0x1002
  43 #define ARCH_GET_FS 0x1003
  44 #define ARCH_GET_GS 0x1004
  45 #endif
  46
  47 static int x86_64_regmap[] = {
  48   RAX * 8, RBX * 8, RCX * 8, RDX * 8,
  49   RSI * 8, RDI * 8, RBP * 8, RSP * 8,
  50   R8 * 8, R9 * 8, R10 * 8, R11 * 8,
  51   R12 * 8, R13 * 8, R14 * 8, R15 * 8,
  52   RIP * 8, EFLAGS * 8, CS * 8, SS * 8,
  53   DS * 8, ES * 8, FS * 8, GS * 8,
  54   -1, -1, -1, -1, -1, -1, -1, -1,
  55   -1, -1, -1, -1, -1, -1, -1, -1,
  56   -1, -1, -1, -1, -1, -1, -1, -1,
  57   -1, -1, -1, -1, -1, -1, -1, -1, -1,
  58   ORIG_RAX * 8
  59 };
  60
  61 #define X86_64_NUM_GREGS (sizeof(x86_64_regmap)/sizeof(int))
  62
  63 /* Called by libthread_db.  */
  64
  65 ps_err_e
  66 ps_get_thread_area (const struct ps_prochandle *ph,
  67                     lwpid_t lwpid, int idx, void **base)
  68 {
  69   switch (idx)
  70     {
  71     case FS:
  72       if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0)
  73         return PS_OK;
  74       break;
  75     case GS:
  76       if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_GS) == 0)
  77         return PS_OK;
  78       break;
  79     default:
  80       return PS_BADADDR;
  81     }
  82   return PS_ERR;
  83 }
  84
  85 static void
  86 x86_64_fill_gregset (void *buf)
  87 {
  88   int i;
  89
  90   for (i = 0; i < X86_64_NUM_GREGS; i++)
  91     if (x86_64_regmap[i] != -1)
  92       collect_register (i, ((char *) buf) + x86_64_regmap[i]);
  93 }
  94
  95 static void
  96 x86_64_store_gregset (const void *buf)
  97 {
  98   int i;
  99
 100   for (i = 0; i < X86_64_NUM_GREGS; i++)
 101     if (x86_64_regmap[i] != -1)
 102       supply_register (i, ((char *) buf) + x86_64_regmap[i]);
 103 }
 104
 105 static void
 106 x86_64_fill_fpregset (void *buf)
 107 {
 108   i387_cache_to_fxsave (buf);
 109 }
 110
 111 static void
 112 x86_64_store_fpregset (const void *buf)
 113 {
 114   i387_fxsave_to_cache (buf);
 115 }
 116
 117 struct regset_info target_regsets[] = {
 118   { PTRACE_GETREGS, PTRACE_SETREGS, sizeof (elf_gregset_t),
 119     GENERAL_REGS,
 120     x86_64_fill_gregset, x86_64_store_gregset },
 121   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, sizeof (elf_fpregset_t),
 122     FP_REGS,
 123     x86_64_fill_fpregset, x86_64_store_fpregset },
 124   { 0, 0, -1, -1, NULL, NULL }
 125 };
 126
 127 static const unsigned char x86_64_breakpoint[] = { 0xCC };
 128 #define x86_64_breakpoint_len 1
 129
 130 extern int debug_threads;
 131
 132 static CORE_ADDR
 133 x86_64_get_pc ()
 134 {
 135   unsigned long pc;
 136
 137   collect_register_by_name ("rip", &pc);
 138
 139   if (debug_threads)
 140     fprintf (stderr, "stop pc (before any decrement) is %08lx\n", pc);
 141   return pc;
 142 }
 143
 144 static void
 145 x86_64_set_pc (CORE_ADDR newpc)
 146 {
 147   if (debug_threads)
 148     fprintf (stderr, "set pc to %08lx\n", (long) newpc);
 149   supply_register_by_name ("rip", &newpc);
 150 }
 151
 152 static int
 153 x86_64_breakpoint_at (CORE_ADDR pc)
 154 {
 155   unsigned char c;
 156
 157   read_inferior_memory (pc, &c, 1);
 158   if (c == 0xCC)
 159     return 1;
 160
 161   return 0;
 162 }
 163
 164 struct linux_target_ops the_low_target = {
 165   -1,
 166   NULL,
 167   NULL,
 168   NULL,
 169   x86_64_get_pc,
 170   x86_64_set_pc,
 171   x86_64_breakpoint,
 172   x86_64_breakpoint_len,
 173   NULL,
 174   1,
 175   x86_64_breakpoint_at,
 176 };