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 /* Helper macro to access debug register X.  FreeBSD/amd64 and modern
  55    versions of FreeBSD/i386 provide this macro in system headers.  Define
  56    a local version for systems that do not provide it.  */
  57 #ifndef DBREG_DRX
  58 #ifdef __NetBSD__
  59 #define DBREG_DRX(d, x) ((d)->dr[x])
  60 #else
  61 #define DBREG_DRX(d, x) ((&d->dr0)[x])
  62 #endif
  63 #endif
  64
  65 static unsigned long
  66 x86bsd_dr_get (ptid_t ptid, int regnum)
  67 {
  68   struct dbreg dbregs;
  69
  70   if (ptrace (PT_GETDBREGS, get_ptrace_pid (inferior_ptid),
  71               (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  72     perror_with_name (_("Couldn't read debug registers"));
  73
  74   return DBREG_DRX ((&dbregs), regnum);
  75 }
  76
  77 static void
  78 x86bsd_dr_set (int regnum, unsigned long value)
  79 {
  80   struct thread_info *thread;
  81   struct dbreg dbregs;
  82
  83   if (ptrace (PT_GETDBREGS, get_ptrace_pid (inferior_ptid),
  84               (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  85     perror_with_name (_("Couldn't get debug registers"));
  86
  87   /* For some mysterious reason, some of the reserved bits in the
  88      debug control register get set.  Mask these off, otherwise the
  89      ptrace call below will fail.  */
  90   DBREG_DRX ((&dbregs), 7) &= ~(0xffffffff0000fc00);
  91
  92   DBREG_DRX ((&dbregs), regnum) = value;
  93
  94   ALL_NON_EXITED_THREADS (thread)
  95     if (thread->inf == current_inferior ())
  96       {
  97         if (ptrace (PT_SETDBREGS, get_ptrace_pid (thread->ptid),
  98                     (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  99           perror_with_name (_("Couldn't write debug registers"));
 100       }
 101 }
 102
 103 static void
 104 x86bsd_dr_set_control (unsigned long control)
 105 {
 106   x86bsd_dr_set (7, control);
 107 }
 108
 109 static void
 110 x86bsd_dr_set_addr (int regnum, CORE_ADDR addr)
 111 {
 112   gdb_assert (regnum >= 0 && regnum <= 4);
 113
 114   x86bsd_dr_set (regnum, addr);
 115 }
 116
 117 static CORE_ADDR
 118 x86bsd_dr_get_addr (int regnum)
 119 {
 120   return x86bsd_dr_get (inferior_ptid, regnum);
 121 }
 122
 123 static unsigned long
 124 x86bsd_dr_get_status (void)
 125 {
 126   return x86bsd_dr_get (inferior_ptid, 6);
 127 }
 128
 129 static unsigned long
 130 x86bsd_dr_get_control (void)
 131 {
 132   return x86bsd_dr_get (inferior_ptid, 7);
 133 }
 134
 135 #endif /* PT_GETDBREGS */
 136
 137 /* Create a prototype *BSD/x86 target.  The client can override it
 138    with local methods.  */
 139
 140 struct target_ops *
 141 x86bsd_target (void)
 142 {
 143   struct target_ops *t;
 144
 145   t = inf_ptrace_target ();
 146
 147 #ifdef HAVE_PT_GETDBREGS
 148   x86_use_watchpoints (t);
 149
 150   x86_dr_low.set_control = x86bsd_dr_set_control;
 151   x86_dr_low.set_addr = x86bsd_dr_set_addr;
 152   x86_dr_low.get_addr = x86bsd_dr_get_addr;
 153   x86_dr_low.get_status = x86bsd_dr_get_status;
 154   x86_dr_low.get_control = x86bsd_dr_get_control;
 155   x86_set_debug_register_length (sizeof (void *));
 156   super_mourn_inferior = t->to_mourn_inferior;
 157   t->to_mourn_inferior = x86bsd_mourn_inferior;
 158 #endif /* HAVE_PT_GETDBREGS */
 159
 160   return t;
 161 }