gdb/hppah-nat.c

   1 /* Machine-dependent hooks for the unix child process stratum, for HPUX PA-RISC.
   2
   3    Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993
   4    Free Software Foundation, Inc.
   5
   6    Contributed by the Center for Software Science at the
   7    University of Utah (pa-gdb-bugs@cs.utah.edu).
   8
   9 This file is part of GDB.
  10
  11 This program is free software; you can redistribute it and/or modify
  12 it under the terms of the GNU General Public License as published by
  13 the Free Software Foundation; either version 2 of the License, or
  14 (at your option) any later version.
  15
  16 This program is distributed in the hope that it will be useful,
  17 but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 GNU General Public License for more details.
  20
  21 You should have received a copy of the GNU General Public License
  22 along with this program; if not, write to the Free Software
  23 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  24
  25
  26 #include "defs.h"
  27 #include "inferior.h"
  28 #include "target.h"
  29 #include <sys/ptrace.h>
  30
  31 extern CORE_ADDR text_end;
  32
  33 static void fetch_register ();
  34
  35 void
  36 fetch_inferior_registers (regno)
  37      int regno;
  38 {
  39   if (regno == -1)
  40     for (regno = 0; regno < NUM_REGS; regno++)
  41       fetch_register (regno);
  42   else
  43     fetch_register (regno);
  44 }
  45
  46 /* Store our register values back into the inferior.
  47    If REGNO is -1, do this for all registers.
  48    Otherwise, REGNO specifies which register (so we can save time).  */
  49
  50 void
  51 store_inferior_registers (regno)
  52      int regno;
  53 {
  54   register unsigned int regaddr;
  55   char buf[80];
  56   extern char registers[];
  57   register int i;
  58   unsigned int offset = U_REGS_OFFSET;
  59   int scratch;
  60
  61   if (regno >= 0)
  62     {
  63       if (CANNOT_STORE_REGISTER (regno))
  64         return;
  65       regaddr = register_addr (regno, offset);
  66       errno = 0;
  67       if (regno == PCOQ_HEAD_REGNUM || regno == PCOQ_TAIL_REGNUM)
  68         {
  69           scratch = *(int *) &registers[REGISTER_BYTE (regno)] | 0x3;
  70           ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
  71                   scratch, 0);
  72           if (errno != 0)
  73             {
  74               /* Error, even if attached.  Failing to write these two
  75                  registers is pretty serious.  */
  76               sprintf (buf, "writing register number %d", regno);
  77               perror_with_name (buf);
  78             }
  79         }
  80       else
  81         for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int))
  82           {
  83             errno = 0;
  84             ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
  85                     *(int *) &registers[REGISTER_BYTE (regno) + i], 0);
  86             if (errno != 0)
  87               {
  88                 /* Warning, not error, in case we are attached; sometimes the
  89                    kernel doesn't let us at the registers.  */
  90                 char *err = safe_strerror (errno);
  91                 char *msg = alloca (strlen (err) + 128);
  92                 sprintf (msg, "writing register %s: %s",
  93                          reg_names[regno], err);
  94                 warning (msg);
  95                 return;
  96               }
  97             regaddr += sizeof(int);
  98           }
  99     }
 100   else
 101     for (regno = 0; regno < NUM_REGS; regno++)
 102       store_inferior_registers (regno);
 103 }
 104
 105 /* Fetch one register.  */
 106
 107 static void
 108 fetch_register (regno)
 109      int regno;
 110 {
 111   register unsigned int regaddr;
 112   char buf[MAX_REGISTER_RAW_SIZE];
 113   char mess[128];                               /* For messages */
 114   register int i;
 115
 116   /* Offset of registers within the u area.  */
 117   unsigned int offset;
 118
 119   offset = U_REGS_OFFSET;
 120
 121   regaddr = register_addr (regno, offset);
 122   for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
 123     {
 124       errno = 0;
 125       *(int *) &buf[i] = ptrace (PT_RUREGS, inferior_pid,
 126                                  (PTRACE_ARG3_TYPE) regaddr, 0, 0);
 127       regaddr += sizeof (int);
 128       if (errno != 0)
 129         {
 130           /* Warning, not error, in case we are attached; sometimes the
 131              kernel doesn't let us at the registers.  */
 132           char *err = safe_strerror (errno);
 133           char *msg = alloca (strlen (err) + 128);
 134           sprintf (msg, "reading register %s: %s", reg_names[regno], err);
 135           warning (msg);
 136           goto error_exit;
 137         }
 138     }
 139   if (regno == PCOQ_HEAD_REGNUM || regno == PCOQ_TAIL_REGNUM)
 140     buf[3] &= ~0x3;
 141   supply_register (regno, buf);
 142  error_exit:;
 143 }
 144
 145 /* Copy LEN bytes to or from inferior's memory starting at MEMADDR
 146    to debugger memory starting at MYADDR.   Copy to inferior if
 147    WRITE is nonzero.
 148
 149    Returns the length copied, which is either the LEN argument or zero.
 150    This xfer function does not do partial moves, since child_ops
 151    doesn't allow memory operations to cross below us in the target stack
 152    anyway.  */
 153
 154 int
 155 child_xfer_memory (memaddr, myaddr, len, write, target)
 156      CORE_ADDR memaddr;
 157      char *myaddr;
 158      int len;
 159      int write;
 160      struct target_ops *target;         /* ignored */
 161 {
 162   register int i;
 163   /* Round starting address down to longword boundary.  */
 164   register CORE_ADDR addr = memaddr & - sizeof (int);
 165   /* Round ending address up; get number of longwords that makes.  */
 166   register int count
 167     = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 168   /* Allocate buffer of that many longwords.  */
 169   register int *buffer = (int *) alloca (count * sizeof (int));
 170
 171   if (write)
 172     {
 173       /* Fill start and end extra bytes of buffer with existing memory data.  */
 174
 175       if (addr != memaddr || len < (int)sizeof (int)) {
 176         /* Need part of initial word -- fetch it.  */
 177         buffer[0] = ptrace (addr < text_end ? PT_RIUSER : PT_RDUSER,
 178                             inferior_pid, (PTRACE_ARG3_TYPE) addr, 0, 0);
 179       }
 180
 181       if (count > 1)            /* FIXME, avoid if even boundary */
 182         {
 183           buffer[count - 1]
 184             = ptrace (addr < text_end ? PT_RIUSER : PT_RDUSER, inferior_pid,
 185                       (PTRACE_ARG3_TYPE) (addr + (count - 1) * sizeof (int)),
 186                       0, 0);
 187         }
 188
 189       /* Copy data to be written over corresponding part of buffer */
 190
 191       memcpy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);
 192
 193       /* Write the entire buffer.  */
 194
 195       for (i = 0; i < count; i++, addr += sizeof (int))
 196         {
 197 /* The HP-UX kernel crashes if you use PT_WDUSER to write into the text
 198    segment.  FIXME -- does it work to write into the data segment using
 199    WIUSER, or do these idiots really expect us to figure out which segment
 200    the address is in, so we can use a separate system call for it??!  */
 201           errno = 0;
 202           ptrace (addr < text_end ? PT_WIUSER : PT_WDUSER, inferior_pid,
 203                   (PTRACE_ARG3_TYPE) addr,
 204                   buffer[i], 0);
 205           if (errno)
 206             return 0;
 207         }
 208     }
 209   else
 210     {
 211       /* Read all the longwords */
 212       for (i = 0; i < count; i++, addr += sizeof (int))
 213         {
 214           errno = 0;
 215           buffer[i] = ptrace (addr < text_end ? PT_RIUSER : PT_RDUSER,
 216                               inferior_pid, (PTRACE_ARG3_TYPE) addr, 0, 0);
 217           if (errno)
 218             return 0;
 219           QUIT;
 220         }
 221
 222       /* Copy appropriate bytes out of the buffer.  */
 223       memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 224     }
 225   return len;
 226 }