gdb/vax-nat.c

   1 /* Native-dependent code for VAX UNIXen (including older BSD's).
   2
   3    Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "inferior.h"
  23
  24 #include "gdb_assert.h"
  25 #include <sys/types.h>
  26 #include <sys/dir.h>
  27 #include <sys/user.h>
  28
  29 #ifdef HAVE_SYS_PTRACE_H
  30 #include <sys/ptrace.h>
  31 #endif
  32
  33 #ifndef PT_READ_U
  34 #define PT_READ_U 3
  35 #endif
  36
  37 #ifdef SYS_REG_H
  38 /* UNIX 32V and derivatives (including 3BSD).  */
  39 #include <sys/reg.h>
  40 #else
  41 /* 4.2BSD and derivatives.  */
  42 #include <machine/reg.h>
  43 #endif
  44
  45 #include "vax-tdep.h"
  46 #include "inf-ptrace.h"
  47
  48 /* Address of the user structure.  This is the the value for 32V; 3BSD
  49    uses a different value, but hey, who's still using those systems?  */
  50 static CORE_ADDR vax_kernel_u_addr = 0x80020000;
  51
  52 /* Location of the user's stored registers; usage is `u.u_ar0[XX]'.
  53    For 4.2BSD and ULTRIX these are negative!  See <machine/reg.h>.  */
  54 static int vax_register_index[] =
  55 {
  56   R0, R1, R2, R3, R4, R5,
  57   R6, R7, R8, R9, R10, R11,
  58   AP, FP, SP, PC, PS
  59 };
  60
  61 static CORE_ADDR
  62 vax_register_u_addr (CORE_ADDR u_ar0, int regnum)
  63 {
  64   gdb_assert (regnum >= 0 && regnum < ARRAY_SIZE (vax_register_index));
  65
  66   /* Type is `int *u_ar0'.  See <sys/user.h>.  */
  67   return u_ar0 + vax_register_index[regnum - VAX_R0_REGNUM] * 4;
  68 }
  69
  70 static CORE_ADDR
  71 vax_register_u_offset (struct gdbarch *gdbarch, int regnum, int store_p)
  72 {
  73   size_t u_ar0_offset = offsetof (struct user, u_ar0);
  74   CORE_ADDR u_ar0;
  75   int pid;
  76
  77   errno = 0;
  78   pid = PIDGET (inferior_ptid);
  79   u_ar0 = ptrace (PT_READ_U, pid, u_ar0_offset, 0);
  80   if (errno)
  81     perror_with_name (_("Unable to determine location of registers"));
  82
  83   return vax_register_u_addr (u_ar0, regnum) - vax_kernel_u_addr;
  84 }
  85 \f
  86
  87 #include <nlist.h>
  88
  89 #ifndef _PATH_UNIX
  90 #define _PATH_UNIX "/vmunix"
  91 #endif
  92
  93 /* Provide a prototype to silence -Wmissing-prototypes.  */
  94 void _initialize_vax_nat (void);
  95
  96 void
  97 _initialize_vax_nat (void)
  98 {
  99   struct nlist names[2];
 100
 101   names[0].n_name = "_u";
 102   names[1].n_name = NULL;
 103   if (nlist (_PATH_UNIX, names) == 0)
 104     vax_kernel_u_addr = names[0].n_value;
 105
 106   add_target (inf_ptrace_trad_target (vax_register_u_offset));
 107 }