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/* Machine-dependent hooks for the unix child process stratum.  This

   code is for the HP PA-RISC cpu.

   Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1998,

   1999, 2000, 2001 Free Software Foundation, Inc.

   Contributed by the Center for Software Science at the

   University of Utah (pa-gdb-bugs@cs.utah.edu).

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 2 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, write to the Free Software

   Foundation, Inc., 59 Temple Place - Suite 330,

   Boston, MA 02111-1307, USA.  */

#include "defs.h"

#include "inferior.h"

#include "target.h"

#include "regcache.h"

#include <sys/ptrace.h>

/* Use an extra level of indirection for ptrace calls.

   This lets us breakpoint usefully on call_ptrace.   It also

   allows us to pass an extra argument to ptrace without

   using an ANSI-C specific macro.  */

#define ptrace call_ptrace

#if !defined (offsetof)

#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)

#endif

/* U_REGS_OFFSET is the offset of the registers within the u area.  */

#if !defined (U_REGS_OFFSET)

#define U_REGS_OFFSET \

  ptrace (PT_READ_U, PIDGET (inferior_ptid), \

          (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \

    - KERNEL_U_ADDR

#endif

/* Fetch one register.  */

static void

fetch_register (int regno)

{

  register unsigned int regaddr;

  char buf[MAX_REGISTER_RAW_SIZE];

  register int i;

  /* Offset of registers within the u area.  */

  unsigned int offset;

  offset = U_REGS_OFFSET;

  regaddr = register_addr (regno, offset);

  for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))

    {

      errno = 0;

      *(int *) &buf[i] = ptrace (PT_RUREGS, PIDGET (inferior_ptid),

                                 (PTRACE_ARG3_TYPE) regaddr, 0);

      regaddr += sizeof (int);

      if (errno != 0)

        {

          /* Warning, not error, in case we are attached; sometimes the

             kernel doesn't let us at the registers.  */

          char *err = safe_strerror (errno);

          char *msg = alloca (strlen (err) + 128);

          sprintf (msg, "reading register %s: %s", REGISTER_NAME (regno), err);

          warning (msg);

          goto error_exit;

        }

    }

  supply_register (regno, buf);

error_exit:;

}

/* Fetch all registers, or just one, from the child process.  */

void

fetch_inferior_registers (int regno)

{

  if (regno == -1)

    for (regno = 0; regno < NUM_REGS; regno++)

      fetch_register (regno);

  else

    fetch_register (regno);

}

/* Store our register values back into the inferior.

   If REGNO is -1, do this for all registers.

   Otherwise, REGNO specifies which register (so we can save time).  */

void

store_inferior_registers (int regno)

{

  register unsigned int regaddr;

  char buf[80];

  register int i;

  unsigned int offset = U_REGS_OFFSET;

  int scratch;

  if (regno >= 0)

    {

      if (CANNOT_STORE_REGISTER (regno))

        return;

      regaddr = register_addr (regno, offset);

      errno = 0;

      if (regno == PCOQ_HEAD_REGNUM || regno == PCOQ_TAIL_REGNUM)

        {

          scratch = *(int *) &registers[REGISTER_BYTE (regno)] | 0x3;

          ptrace (PT_WUREGS, PIDGET (inferior_ptid), (PTRACE_ARG3_TYPE) regaddr,

                  scratch);

          if (errno != 0)

            {

              /* Error, even if attached.  Failing to write these two

                 registers is pretty serious.  */

              sprintf (buf, "writing register number %d", regno);

              perror_with_name (buf);

            }

        }

      else

        for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))

          {

            errno = 0;

            ptrace (PT_WUREGS, PIDGET (inferior_ptid),

                    (PTRACE_ARG3_TYPE) regaddr,

                    *(int *) &registers[REGISTER_BYTE (regno) + i]);

            if (errno != 0)

              {

                /* Warning, not error, in case we are attached; sometimes the

                   kernel doesn't let us at the registers.  */

                char *err = safe_strerror (errno);

                char *msg = alloca (strlen (err) + 128);

                sprintf (msg, "writing register %s: %s",

                         REGISTER_NAME (regno), err);

                warning (msg);

                return;

              }

            regaddr += sizeof (int);

          }

    }

  else

    for (regno = 0; regno < NUM_REGS; regno++)

      store_inferior_registers (regno);

}

/* PT_PROT is specific to the PA BSD kernel and isn't documented

   anywhere (except here).

   PT_PROT allows one to enable/disable the data memory break bit

   for pages of memory in an inferior process.  This bit is used

   to cause "Data memory break traps" to occur when the appropriate

   page is written to.

   The arguments are as follows:

   PT_PROT -- The ptrace action to perform.

   INFERIOR_PID -- The pid of the process who's page table entries

   will be modified.

   PT_ARGS -- The *address* of a 3 word block of memory which has

   additional information:

   word 0 -- The start address to watch.  This should be a page-aligned

   address.

   word 1 -- The ending address to watch.  Again, this should be a

   page aligned address.

   word 2 -- Nonzero to enable the data memory break bit on the

   given address range or zero to disable the data memory break

   bit on the given address range.

   This call may fail if the given addresses are not valid in the inferior

   process.  This most often happens when restarting a program which

   has watchpoints inserted on heap or stack memory.  */

#define PT_PROT 21

int

hppa_set_watchpoint (int addr, int len, int flag)

{

  int pt_args[3];

  pt_args[0] = addr;

  pt_args[1] = addr + len;

  pt_args[2] = flag;

  /* Mask off the lower 12 bits since we want to work on a page basis.  */

  pt_args[0] >>= 12;

  pt_args[1] >>= 12;

  /* Rounding adjustments.  */

  pt_args[1] -= pt_args[0];

  pt_args[1]++;

  /* Put the lower 12 bits back as zero.  */

  pt_args[0] <<= 12;

  pt_args[1] <<= 12;

  /* Do it.  */

  return ptrace (PT_PROT, PIDGET (inferior_ptid), (PTRACE_ARG3_TYPE) pt_args, 0);

}