gdb/x86-bsd-nat.c

   1 /* Native-dependent code for X86 BSD's.
   2
   3    Copyright (C) 2003-2017 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 "defs.h"
  21 #include "inferior.h"
  22 #include "gdbthread.h"
  23
  24 /* We include <signal.h> to make sure `struct fxsave64' is defined on
  25    NetBSD, since NetBSD's <machine/reg.h> needs it.  */
  26 #include <signal.h>
  27 #include <sys/types.h>
  28 #include <sys/ptrace.h>
  29 #include <machine/reg.h>
  30
  31 #include "x86-nat.h"
  32 #include "x86-bsd-nat.h"
  33 #include "inf-ptrace.h"
  34 \f
  35
  36 #ifdef PT_GETXSTATE_INFO
  37 size_t x86bsd_xsave_len;
  38 #endif
  39
  40 /* Support for debug registers.  */
  41
  42 #ifdef HAVE_PT_GETDBREGS
  43 static void (*super_mourn_inferior) (struct target_ops *ops);
  44
  45 /* Implement the "to_mourn_inferior" target_ops method.  */
  46
  47 static void
  48 x86bsd_mourn_inferior (struct target_ops *ops)
  49 {
  50   x86_cleanup_dregs ();
  51   super_mourn_inferior (ops);
  52 }
  53
  54 /* Not all versions of FreeBSD/i386 that support the debug registers
  55    have this macro.  */
  56 #ifndef DBREG_DRX
  57 #define DBREG_DRX(d, x) ((&d->dr0)[x])
  58 #endif
  59
  60 static unsigned long
  61 x86bsd_dr_get (ptid_t ptid, int regnum)
  62 {
  63   struct dbreg dbregs;
  64
  65   if (ptrace (PT_GETDBREGS, get_ptrace_pid (inferior_ptid),
  66               (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  67     perror_with_name (_("Couldn't read debug registers"));
  68
  69   return DBREG_DRX ((&dbregs), regnum);
  70 }
  71
  72 static void
  73 x86bsd_dr_set (int regnum, unsigned long value)
  74 {
  75   struct thread_info *thread;
  76   struct dbreg dbregs;
  77
  78   if (ptrace (PT_GETDBREGS, get_ptrace_pid (inferior_ptid),
  79               (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  80     perror_with_name (_("Couldn't get debug registers"));
  81
  82   /* For some mysterious reason, some of the reserved bits in the
  83      debug control register get set.  Mask these off, otherwise the
  84      ptrace call below will fail.  */
  85   DBREG_DRX ((&dbregs), 7) &= ~(0xffffffff0000fc00);
  86
  87   DBREG_DRX ((&dbregs), regnum) = value;
  88
  89   ALL_NON_EXITED_THREADS (thread)
  90     if (thread->inf == current_inferior ())
  91       {
  92         if (ptrace (PT_SETDBREGS, get_ptrace_pid (thread->ptid),
  93                     (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  94           perror_with_name (_("Couldn't write debug registers"));
  95       }
  96 }
  97
  98 static void
  99 x86bsd_dr_set_control (unsigned long control)
 100 {
 101   x86bsd_dr_set (7, control);
 102 }
 103
 104 static void
 105 x86bsd_dr_set_addr (int regnum, CORE_ADDR addr)
 106 {
 107   gdb_assert (regnum >= 0 && regnum <= 4);
 108
 109   x86bsd_dr_set (regnum, addr);
 110 }
 111
 112 static CORE_ADDR
 113 x86bsd_dr_get_addr (int regnum)
 114 {
 115   return x86bsd_dr_get (inferior_ptid, regnum);
 116 }
 117
 118 static unsigned long
 119 x86bsd_dr_get_status (void)
 120 {
 121   return x86bsd_dr_get (inferior_ptid, 6);
 122 }
 123
 124 static unsigned long
 125 x86bsd_dr_get_control (void)
 126 {
 127   return x86bsd_dr_get (inferior_ptid, 7);
 128 }
 129
 130 #endif /* PT_GETDBREGS */
 131
 132 /* Create a prototype *BSD/x86 target.  The client can override it
 133    with local methods.  */
 134
 135 struct target_ops *
 136 x86bsd_target (void)
 137 {
 138   struct target_ops *t;
 139
 140   t = inf_ptrace_target ();
 141
 142 #ifdef HAVE_PT_GETDBREGS
 143   x86_use_watchpoints (t);
 144
 145   x86_dr_low.set_control = x86bsd_dr_set_control;
 146   x86_dr_low.set_addr = x86bsd_dr_set_addr;
 147   x86_dr_low.get_addr = x86bsd_dr_get_addr;
 148   x86_dr_low.get_status = x86bsd_dr_get_status;
 149   x86_dr_low.get_control = x86bsd_dr_get_control;
 150   x86_set_debug_register_length (sizeof (void *));
 151   super_mourn_inferior = t->to_mourn_inferior;
 152   t->to_mourn_inferior = x86bsd_mourn_inferior;
 153 #endif /* HAVE_PT_GETDBREGS */
 154
 155   return t;
 156 }