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/* Native-dependent code for SPARC.

   Copyright (C) 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc.

   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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"

#include "inferior.h"

#include "regcache.h"

#include "target.h"

#include "gdb_assert.h"

#include <signal.h>

#include "gdb_string.h"

#include <sys/ptrace.h>

#include "gdb_wait.h"

#ifdef HAVE_MACHINE_REG_H

#include <machine/reg.h>

#endif

#include "sparc-tdep.h"

#include "sparc-nat.h"

#include "inf-ptrace.h"

/* With some trickery we can use the code in this file for most (if

   not all) ptrace(2) based SPARC systems, which includes SunOS 4,

   GNU/Linux and the various SPARC BSD's.

   First, we need a data structure for use with ptrace(2).  SunOS has

   `struct regs' and `struct fp_status' in <machine/reg.h>.  BSD's

   have `struct reg' and `struct fpreg' in <machine/reg.h>.  GNU/Linux

   has the same structures as SunOS 4, but they're in <asm/reg.h>,

   which is a kernel header.  As a general rule we avoid including

   GNU/Linux kernel headers.  Fortunately GNU/Linux has a `gregset_t'

   and a `fpregset_t' that are equivalent to `struct regs' and `struct

   fp_status' in <sys/ucontext.h>, which is automatically included by

   <signal.h>.  Settling on using the `gregset_t' and `fpregset_t'

   typedefs, providing them for the other systems, therefore solves

   the puzzle.  */

#ifdef HAVE_MACHINE_REG_H

#ifdef HAVE_STRUCT_REG

typedef struct reg gregset_t;

typedef struct fpreg fpregset_t;

#else 

typedef struct regs gregset_t;

typedef struct fp_status fpregset_t;

#endif

#endif

/* Second, we need to remap the BSD ptrace(2) requests to their SunOS

   equivalents.  GNU/Linux already follows SunOS here.  */

#ifndef PTRACE_GETREGS

#define PTRACE_GETREGS PT_GETREGS

#endif

#ifndef PTRACE_SETREGS

#define PTRACE_SETREGS PT_SETREGS

#endif

#ifndef PTRACE_GETFPREGS

#define PTRACE_GETFPREGS PT_GETFPREGS

#endif

#ifndef PTRACE_SETFPREGS

#define PTRACE_SETFPREGS PT_SETFPREGS

#endif

/* Register set description.  */

const struct sparc_gregset *sparc_gregset;

void (*sparc_supply_gregset) (const struct sparc_gregset *,

                              struct regcache *, int , const void *);

void (*sparc_collect_gregset) (const struct sparc_gregset *,

                               const struct regcache *, int, void *);

void (*sparc_supply_fpregset) (struct regcache *, int , const void *);

void (*sparc_collect_fpregset) (const struct regcache *, int , void *);

int (*sparc_gregset_supplies_p) (int);

int (*sparc_fpregset_supplies_p) (int);

/* Determine whether `gregset_t' contains register REGNUM.  */

int

sparc32_gregset_supplies_p (int regnum)

{

  /* Integer registers.  */

  if ((regnum >= SPARC_G1_REGNUM && regnum <= SPARC_G7_REGNUM)

      || (regnum >= SPARC_O0_REGNUM && regnum <= SPARC_O7_REGNUM)

      || (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_L7_REGNUM)

      || (regnum >= SPARC_I0_REGNUM && regnum <= SPARC_I7_REGNUM))

    return 1;

  /* Control registers.  */

  if (regnum == SPARC32_PC_REGNUM

      || regnum == SPARC32_NPC_REGNUM

      || regnum == SPARC32_PSR_REGNUM

      || regnum == SPARC32_Y_REGNUM)

    return 1;

  return 0;

}

/* Determine whether `fpregset_t' contains register REGNUM.  */

int

sparc32_fpregset_supplies_p (int regnum)

{

  /* Floating-point registers.  */

  if (regnum >= SPARC_F0_REGNUM && regnum <= SPARC_F31_REGNUM)

    return 1;

  /* Control registers.  */

  if (regnum == SPARC32_FSR_REGNUM)

    return 1;

  return 0;

}

/* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this

   for all registers (including the floating-point registers).  */

void

sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)

{

  int pid;

  /* NOTE: cagney/2002-12-03: This code assumes that the currently

     selected light weight processes' registers can be written

     directly into the selected thread's register cache.  This works

     fine when given an 1:1 LWP:thread model (such as found on

     GNU/Linux) but will, likely, have problems when used on an N:1

     (userland threads) or N:M (userland multiple LWP) model.  In the

     case of the latter two, the LWP's registers do not necessarily

     belong to the selected thread (the LWP could be in the middle of

     executing the thread switch code).

     These functions should instead be paramaterized with an explicit

     object (struct regcache, struct thread_info?) into which the LWPs

     registers can be written.  */

  pid = TIDGET (inferior_ptid);

  if (pid == 0)

    pid = PIDGET (inferior_ptid);

  if (regnum == SPARC_G0_REGNUM)

    {

      regcache_raw_supply (regcache, SPARC_G0_REGNUM, NULL);

      return;

    }

  if (regnum == -1 || sparc_gregset_supplies_p (regnum))

    {

      gregset_t regs;

      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

        perror_with_name (_("Couldn't get registers"));

      sparc_supply_gregset (sparc_gregset, regcache, -1, &regs);

      if (regnum != -1)

        return;

    }

  if (regnum == -1 || sparc_fpregset_supplies_p (regnum))

    {

      fpregset_t fpregs;

      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

        perror_with_name (_("Couldn't get floating point status"));

      sparc_supply_fpregset (regcache, -1, &fpregs);

    }

}

void

sparc_store_inferior_registers (struct regcache *regcache, int regnum)

{

  int pid;

  /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers

     about threaded assumptions.  */

  pid = TIDGET (inferior_ptid);

  if (pid == 0)

    pid = PIDGET (inferior_ptid);

  if (regnum == -1 || sparc_gregset_supplies_p (regnum))

    {

      gregset_t regs;

      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

        perror_with_name (_("Couldn't get registers"));

      sparc_collect_gregset (sparc_gregset, regcache, regnum, &regs);

      if (ptrace (PTRACE_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

        perror_with_name (_("Couldn't write registers"));

      /* Deal with the stack regs.  */

      if (regnum == -1 || regnum == SPARC_SP_REGNUM

          || (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_I7_REGNUM))

        {

          ULONGEST sp;

          regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM, &sp);

          sparc_collect_rwindow (regcache, sp, regnum);

        }

      if (regnum != -1)

        return;

    }

  if (regnum == -1 || sparc_fpregset_supplies_p (regnum))

    {

      fpregset_t fpregs, saved_fpregs;

      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

        perror_with_name (_("Couldn't get floating-point registers"));

      memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));

      sparc_collect_fpregset (regcache, regnum, &fpregs);

      /* Writing the floating-point registers will fail on NetBSD with

         EINVAL if the inferior process doesn't have an FPU state

         (i.e. if it didn't use the FPU yet).  Therefore we don't try

         to write the registers if nothing changed.  */

      if (memcmp (&saved_fpregs, &fpregs, sizeof (fpregs)) != 0)

        {

          if (ptrace (PTRACE_SETFPREGS, pid,

                      (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

            perror_with_name (_("Couldn't write floating-point registers"));

        }

      if (regnum != -1)

        return;

    }

}

/* Fetch StackGhost Per-Process XOR cookie.  */

LONGEST

sparc_xfer_wcookie (struct target_ops *ops, enum target_object object,

                    const char *annex, gdb_byte *readbuf,

                    const gdb_byte *writebuf, ULONGEST offset, LONGEST len)

{

  unsigned long wcookie = 0;

  char *buf = (char *)&wcookie;

  gdb_assert (object == TARGET_OBJECT_WCOOKIE);

  gdb_assert (readbuf && writebuf == NULL);

  if (offset == sizeof (unsigned long))

    return 0;                    /* Signal EOF.  */

  if (offset > sizeof (unsigned long))

    return -1;

#ifdef PT_WCOOKIE

  /* If PT_WCOOKIE is defined (by <sys/ptrace.h>), assume we're

     running on an OpenBSD release that uses StackGhost (3.1 or

     later).  Since release 3.6, OpenBSD uses a fully randomized

     cookie.  */

  {

    int pid;

    pid = TIDGET (inferior_ptid);

    if (pid == 0)

      pid = PIDGET (inferior_ptid);

    /* Sanity check.  The proper type for a cookie is register_t, but

       we can't assume that this type exists on all systems supported

       by the code in this file.  */

    gdb_assert (sizeof (wcookie) == sizeof (register_t));

    /* Fetch the cookie.  */

    if (ptrace (PT_WCOOKIE, pid, (PTRACE_TYPE_ARG3) &wcookie, 0) == -1)

      {

        if (errno != EINVAL)

          perror_with_name (_("Couldn't get StackGhost cookie"));

        /* Although PT_WCOOKIE is defined on OpenBSD 3.1 and later,

           the request wasn't implemented until after OpenBSD 3.4.  If

           the kernel doesn't support the PT_WCOOKIE request, assume

           we're running on a kernel that uses non-randomized cookies.  */

        wcookie = 0x3;

      }

  }

#endif /* PT_WCOOKIE */

  if (len > sizeof (unsigned long) - offset)

    len = sizeof (unsigned long) - offset;

  memcpy (readbuf, buf + offset, len);

  return len;

}

LONGEST (*inf_ptrace_xfer_partial) (struct target_ops *, enum target_object,

                                    const char *, gdb_byte *, const gdb_byte *,

                                    ULONGEST, LONGEST);

static LONGEST

sparc_xfer_partial (struct target_ops *ops, enum target_object object,

                    const char *annex, gdb_byte *readbuf,

                    const gdb_byte *writebuf, ULONGEST offset, LONGEST len)

{

  if (object == TARGET_OBJECT_WCOOKIE)

    return sparc_xfer_wcookie (ops, object, annex, readbuf, writebuf,

                               offset, len);

  return inf_ptrace_xfer_partial (ops, object, annex, readbuf, writebuf,

                                  offset, len);

}

/* Create a prototype generic SPARC target.  The client can override

   it with local methods.  */

struct target_ops *

sparc_target (void)

{

  struct target_ops *t;

  t = inf_ptrace_target ();

  t->to_fetch_registers = sparc_fetch_inferior_registers;

  t->to_store_registers = sparc_store_inferior_registers;

  inf_ptrace_xfer_partial = t->to_xfer_partial;

  t->to_xfer_partial = sparc_xfer_partial;

  return t;

}

/* Provide a prototype to silence -Wmissing-prototypes.  */

void _initialize_sparc_nat (void);

void

_initialize_sparc_nat (void)

{

  /* Deafult to using SunOS 4 register sets.  */

  if (sparc_gregset == NULL)

    sparc_gregset = &sparc32_sunos4_gregset;

  if (sparc_supply_gregset == NULL)

    sparc_supply_gregset = sparc32_supply_gregset;

  if (sparc_collect_gregset == NULL)

    sparc_collect_gregset = sparc32_collect_gregset;

  if (sparc_supply_fpregset == NULL)

    sparc_supply_fpregset = sparc32_supply_fpregset;

  if (sparc_collect_fpregset == NULL)

    sparc_collect_fpregset = sparc32_collect_fpregset;

  if (sparc_gregset_supplies_p == NULL)

    sparc_gregset_supplies_p = sparc32_gregset_supplies_p;

  if (sparc_fpregset_supplies_p == NULL)

    sparc_fpregset_supplies_p = sparc32_fpregset_supplies_p;

}