gdb/vax-nat.c

   1 /* Native-dependent code for VAX UNIXen (including older BSD's).
   2
   3    Copyright (C) 2004-2013 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
  23 #include "gdb_assert.h"
  24 #include <sys/types.h>
  25 #include <sys/dir.h>
  26 #include <sys/user.h>
  27
  28 #ifdef HAVE_SYS_PTRACE_H
  29 #include <sys/ptrace.h>
  30 #endif
  31
  32 #ifndef PT_READ_U
  33 #define PT_READ_U 3
  34 #endif
  35
  36 #ifdef SYS_REG_H
  37 /* UNIX 32V and derivatives (including 3BSD).  */
  38 #include <sys/reg.h>
  39 #else
  40 /* 4.2BSD and derivatives.  */
  41 #include <machine/reg.h>
  42 #endif
  43
  44 #include "vax-tdep.h"
  45 #include "inf-ptrace.h"
  46
  47 /* Address of the user structure.  This is the value for 32V; 3BSD
  48    uses a different value, but hey, who's still using those systems?  */
  49 static CORE_ADDR vax_kernel_u_addr = 0x80020000;
  50
  51 /* Location of the user's stored registers; usage is `u.u_ar0[XX]'.
  52    For 4.2BSD and ULTRIX these are negative!  See <machine/reg.h>.  */
  53 static int vax_register_index[] =
  54 {
  55   R0, R1, R2, R3, R4, R5,
  56   R6, R7, R8, R9, R10, R11,
  57   AP, FP, SP, PC, PS
  58 };
  59
  60 static CORE_ADDR
  61 vax_register_u_addr (CORE_ADDR u_ar0, int regnum)
  62 {
  63   gdb_assert (regnum >= 0 && regnum < ARRAY_SIZE (vax_register_index));
  64
  65   /* Type is `int *u_ar0'.  See <sys/user.h>.  */
  66   return u_ar0 + vax_register_index[regnum - VAX_R0_REGNUM] * 4;
  67 }
  68
  69 static CORE_ADDR
  70 vax_register_u_offset (struct gdbarch *gdbarch, int regnum, int store_p)
  71 {
  72   size_t u_ar0_offset = offsetof (struct user, u_ar0);
  73   CORE_ADDR u_ar0;
  74   int pid;
  75
  76   errno = 0;
  77   pid = PIDGET (inferior_ptid);
  78   u_ar0 = ptrace (PT_READ_U, pid, u_ar0_offset, 0);
  79   if (errno)
  80     perror_with_name (_("Unable to determine location of registers"));
  81
  82   return vax_register_u_addr (u_ar0, regnum) - vax_kernel_u_addr;
  83 }
  84 \f
  85
  86 #include <nlist.h>
  87
  88 #ifndef _PATH_UNIX
  89 #define _PATH_UNIX "/vmunix"
  90 #endif
  91
  92 /* Provide a prototype to silence -Wmissing-prototypes.  */
  93 void _initialize_vax_nat (void);
  94
  95 void
  96 _initialize_vax_nat (void)
  97 {
  98   struct nlist names[2];
  99
 100   names[0].n_name = "_u";
 101   names[1].n_name = NULL;
 102   if (nlist (_PATH_UNIX, names) == 0)
 103     vax_kernel_u_addr = names[0].n_value;
 104
 105   add_target (inf_ptrace_trad_target (vax_register_u_offset));
 106 }