gdb/x86-bsd-nat.c

   1 /* Native-dependent code for X86 BSD's.
   2
   3    Copyright (C) 2003-2018 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
  44 /* Helper macro to access debug register X.  FreeBSD/amd64 and modern
  45    versions of FreeBSD/i386 provide this macro in system headers.  Define
  46    a local version for systems that do not provide it.  */
  47 #ifndef DBREG_DRX
  48 #ifdef __NetBSD__
  49 #define DBREG_DRX(d, x) ((d)->dr[x])
  50 #else
  51 #define DBREG_DRX(d, x) ((&d->dr0)[x])
  52 #endif
  53 #endif
  54
  55 static unsigned long
  56 x86bsd_dr_get (ptid_t ptid, int regnum)
  57 {
  58   struct dbreg dbregs;
  59
  60   if (ptrace (PT_GETDBREGS, get_ptrace_pid (inferior_ptid),
  61               (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  62     perror_with_name (_("Couldn't read debug registers"));
  63
  64   return DBREG_DRX ((&dbregs), regnum);
  65 }
  66
  67 static void
  68 x86bsd_dr_set (int regnum, unsigned long value)
  69 {
  70   struct thread_info *thread;
  71   struct dbreg dbregs;
  72
  73   if (ptrace (PT_GETDBREGS, get_ptrace_pid (inferior_ptid),
  74               (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  75     perror_with_name (_("Couldn't get debug registers"));
  76
  77   /* For some mysterious reason, some of the reserved bits in the
  78      debug control register get set.  Mask these off, otherwise the
  79      ptrace call below will fail.  */
  80   DBREG_DRX ((&dbregs), 7) &= ~(0xffffffff0000fc00);
  81
  82   DBREG_DRX ((&dbregs), regnum) = value;
  83
  84   ALL_NON_EXITED_THREADS (thread)
  85     if (thread->inf == current_inferior ())
  86       {
  87         if (ptrace (PT_SETDBREGS, get_ptrace_pid (thread->ptid),
  88                     (PTRACE_TYPE_ARG3) &dbregs, 0) == -1)
  89           perror_with_name (_("Couldn't write debug registers"));
  90       }
  91 }
  92
  93 static void
  94 x86bsd_dr_set_control (unsigned long control)
  95 {
  96   x86bsd_dr_set (7, control);
  97 }
  98
  99 static void
 100 x86bsd_dr_set_addr (int regnum, CORE_ADDR addr)
 101 {
 102   gdb_assert (regnum >= 0 && regnum <= 4);
 103
 104   x86bsd_dr_set (regnum, addr);
 105 }
 106
 107 static CORE_ADDR
 108 x86bsd_dr_get_addr (int regnum)
 109 {
 110   return x86bsd_dr_get (inferior_ptid, regnum);
 111 }
 112
 113 static unsigned long
 114 x86bsd_dr_get_status (void)
 115 {
 116   return x86bsd_dr_get (inferior_ptid, 6);
 117 }
 118
 119 static unsigned long
 120 x86bsd_dr_get_control (void)
 121 {
 122   return x86bsd_dr_get (inferior_ptid, 7);
 123 }
 124
 125 #endif /* PT_GETDBREGS */
 126
 127 void
 128 _initialize_x86_bsd_nat ()
 129 {
 130 #ifdef HAVE_PT_GETDBREGS
 131   x86_dr_low.set_control = x86bsd_dr_set_control;
 132   x86_dr_low.set_addr = x86bsd_dr_set_addr;
 133   x86_dr_low.get_addr = x86bsd_dr_get_addr;
 134   x86_dr_low.get_status = x86bsd_dr_get_status;
 135   x86_dr_low.get_control = x86bsd_dr_get_control;
 136   x86_set_debug_register_length (sizeof (void *));
 137 #endif /* HAVE_PT_GETDBREGS */
 138 }