path: root/gdb/x86-64-linux-nat.c

/* Native-dependent code for GNU/Linux x86-64.

   Copyright 2001, 2002, 2003 Free Software Foundation, Inc.

   Contributed by Jiri Smid, SuSE Labs.

   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 "gdbcore.h"
#include "regcache.h"
#include "linux-nat.h"

#include "gdb_assert.h"
#include "gdb_string.h"
#include <sys/ptrace.h>
#include <sys/debugreg.h>
#include <sys/syscall.h>
#include <sys/procfs.h>
#include <asm/prctl.h>
/* FIXME ezannoni-2003-07-09: we need <sys/reg.h> to be included after
   <asm/ptrace.h> because the latter redefines FS and GS for no apparent
   reason, and those definitions don't match the ones that libpthread_db
   uses, which come from <sys/reg.h>.  */
/* ezannoni-2003-07-09: I think this is fixed. The extraneous defs have
   been removed from ptrace.h in the kernel.  However, better safe than
   sorry.  */
#include <asm/ptrace.h>
#include <sys/reg.h>
#include "gdb_proc_service.h"

/* Prototypes for supply_gregset etc.  */
#include "gregset.h"

#include "x86-64-tdep.h"
#include "x86-64-linux-tdep.h"

/* Which ptrace request retrieves which registers?
   These apply to the corresponding SET requests as well.  */

#define GETFPREGS_SUPPLIES(regno) \
  (FP0_REGNUM <= (regno) && (regno) <= MXCSR_REGNUM)

/* Transfering the general-purpose registers between GDB, inferiors
   and core files.  */

/* Fill GDB's register array with the general-purpose register values
   in *GREGSETP.  */

void
supply_gregset (elf_gregset_t *gregsetp)
{
  x86_64_linux_supply_gregset ((char *) gregsetp);
}

/* Fill register REGNO (if it is a general-purpose register) in
   *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
   do this for all registers.  */

void
fill_gregset (elf_gregset_t *gregsetp, int regno)
{
  x86_64_linux_fill_gregset ((char *) gregsetp, regno);
}

/* Fetch all general-purpose registers from process/thread TID and
   store their values in GDB's register array.  */

static void
fetch_regs (int tid)
{
  elf_gregset_t regs;

  if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
    perror_with_name ("Couldn't get registers");

  supply_gregset (&regs);
}

/* Store all valid general-purpose registers in GDB's register array
   into the process/thread specified by TID.  */

static void
store_regs (int tid, int regno)
{
  elf_gregset_t regs;

  if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
    perror_with_name ("Couldn't get registers");

  fill_gregset (&regs, regno);

  if (ptrace (PTRACE_SETREGS, tid, 0, (long) &regs) < 0)
    perror_with_name ("Couldn't write registers");
}


/* Transfering floating-point registers between GDB, inferiors and cores.  */

/* Fill GDB's register array with the floating-point and SSE register
   values in *FPREGSETP.  */

void
supply_fpregset (elf_fpregset_t *fpregsetp)
{
  x86_64_supply_fxsave ((char *) fpregsetp);
}

/* Fill register REGNUM (if it is a floating-point or SSE register) in
   *FPREGSETP with the value in GDB's register array.  If REGNUM is
   -1, do this for all registers.  */

void
fill_fpregset (elf_fpregset_t *fpregsetp, int regnum)
{
  x86_64_fill_fxsave ((char *) fpregsetp, regnum);
}

/* Fetch all floating-point registers from process/thread TID and store
   thier values in GDB's register array.  */

static void
fetch_fpregs (int tid)
{
  elf_fpregset_t fpregs;

  if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0)
    perror_with_name ("Couldn't get floating point status");

  supply_fpregset (&fpregs);
}

/* Store all valid floating-point registers in GDB's register array
   into the process/thread specified by TID.  */

static void
store_fpregs (int tid, int regno)
{
  elf_fpregset_t fpregs;

  if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0)
    perror_with_name ("Couldn't get floating point status");

  fill_fpregset (&fpregs, regno);

  if (ptrace (PTRACE_SETFPREGS, tid, 0, (long) &fpregs) < 0)
    perror_with_name ("Couldn't write floating point status");
}


/* Transferring arbitrary registers between GDB and inferior.  */

/* Fetch register REGNO from the child process.  If REGNO is -1, do
   this for all registers (including the floating point and SSE
   registers).  */

void
fetch_inferior_registers (int regno)
{
  int tid;

  /* GNU/Linux LWP ID's are process ID's.  */
  tid = TIDGET (inferior_ptid);
  if (tid == 0)
    tid = PIDGET (inferior_ptid); /* Not a threaded program.  */

  if (regno == -1)
    {
      fetch_regs (tid);
      fetch_fpregs (tid);
      return;
    }

  if (x86_64_linux_greg_offset (regno) >= 0)
    {
      fetch_regs (tid);
      return;
    }

  if (GETFPREGS_SUPPLIES (regno))
    {
      fetch_fpregs (tid);
      return;
    }

  internal_error (__FILE__, __LINE__,
		  "Got request for bad register number %d.", regno);
}

/* Store register REGNO back into the child process.  If REGNO is -1,
   do this for all registers (including the floating-point and SSE
   registers).  */

void
store_inferior_registers (int regno)
{
  int tid;

  /* GNU/Linux LWP ID's are process ID's.  */
  tid = TIDGET (inferior_ptid);
  if (tid == 0)
    tid = PIDGET (inferior_ptid); /* Not a threaded program.  */

  if (regno == -1)
    {
      store_regs (tid, regno);
      store_fpregs (tid, regno);
      return;
    }

  if (x86_64_linux_greg_offset (regno) >= 0)
    {
      store_regs (tid, regno);
      return;
    }

  if (GETFPREGS_SUPPLIES (regno))
    {
      store_fpregs (tid, regno);
      return;
    }

  internal_error (__FILE__, __LINE__,
		  "Got request to store bad register number %d.", regno);
}


static unsigned long
x86_64_linux_dr_get (int regnum)
{
  int tid;
  unsigned long value;

  /* FIXME: kettenis/2001-01-29: It's not clear what we should do with
     multi-threaded processes here.  For now, pretend there is just
     one thread.  */
  tid = PIDGET (inferior_ptid);

  /* FIXME: kettenis/2001-03-27: Calling perror_with_name if the
     ptrace call fails breaks debugging remote targets.  The correct
     way to fix this is to add the hardware breakpoint and watchpoint
     stuff to the target vectore.  For now, just return zero if the
     ptrace call fails.  */
  errno = 0;
  value = ptrace (PT_READ_U, tid,
		  offsetof (struct user, u_debugreg[regnum]), 0);
  if (errno != 0)
#if 0
    perror_with_name ("Couldn't read debug register");
#else
    return 0;
#endif

  return value;
}

static void
x86_64_linux_dr_set (int regnum, unsigned long value)
{
  int tid;

  /* FIXME: kettenis/2001-01-29: It's not clear what we should do with
     multi-threaded processes here.  For now, pretend there is just
     one thread.  */
  tid = PIDGET (inferior_ptid);

  errno = 0;
  ptrace (PT_WRITE_U, tid, offsetof (struct user, u_debugreg[regnum]), value);
  if (errno != 0)
    perror_with_name ("Couldn't write debug register");
}

void
x86_64_linux_dr_set_control (unsigned long control)
{
  x86_64_linux_dr_set (DR_CONTROL, control);
}

void
x86_64_linux_dr_set_addr (int regnum, CORE_ADDR addr)
{
  gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);

  x86_64_linux_dr_set (DR_FIRSTADDR + regnum, addr);
}

void
x86_64_linux_dr_reset_addr (int regnum)
{
  gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);

  x86_64_linux_dr_set (DR_FIRSTADDR + regnum, 0L);
}

unsigned long
x86_64_linux_dr_get_status (void)
{
  return x86_64_linux_dr_get (DR_STATUS);
}

/* This function is called by libthread_db as part of its handling of
   a request for a thread's local storage address.  */

extern ps_err_e
ps_get_thread_area (const struct ps_prochandle *ph,
                    lwpid_t lwpid, int idx, void **base)
{

  switch (TARGET_ARCHITECTURE->mach)
    {
    case bfd_mach_i386_i386:
    case bfd_mach_i386_i386_intel_syntax:
      {
	/* The full structure is found in <asm-i386/ldt.h>.  The
	   second integer is the LDT's base_address and that is used
	   to locate the thread's local storage.  See i386-linux-nat.c
	   more info.  */
	unsigned int desc[4];

	/* This code assumes that "int" is 32 bits and that
           GET_THREAD_AREA returns no more than 4 int values.  */
	gdb_assert (sizeof (int) == 4);	
#ifndef PTRACE_GET_THREAD_AREA
#define PTRACE_GET_THREAD_AREA 25
#endif
	if  (ptrace (PTRACE_GET_THREAD_AREA, 
		     lwpid, (void *) (long) idx, (unsigned long) &desc) < 0)
	  return PS_ERR;
      
	/* Extend the value to 64 bits.  Here it's assumed that a
           "long" and a "void *" are the same.  */
	(*base) = (void *) (long) desc[1];
	return PS_OK;
      }

    case bfd_mach_x86_64:
    case bfd_mach_x86_64_intel_syntax:

      /* This definition comes from prctl.h, but some kernels may not
         have it.  */
#ifndef PTRACE_ARCH_PRCTL
#define PTRACE_ARCH_PRCTL      30
#endif

      /* FIXME: ezannoni-2003-07-09 see comment above about include
	 file order.  We could be getting bogus values for these two.  */
      gdb_assert (FS < ELF_NGREG);
      gdb_assert (GS < ELF_NGREG);
      switch (idx)
	{
	case FS:
	  if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0)
	    return PS_OK;
	  break;
	case GS:
	  if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_GS) == 0)
	    return PS_OK;
	  break;
	default:                   /* Should not happen.  */
	  return PS_BADADDR;
	}
      return PS_ERR;               /* ptrace failed.  */
      
    case bfd_mach_i386_i8086:
      internal_error (__FILE__, __LINE__, "bad i8086 machine");
    default:
      internal_error (__FILE__, __LINE__, "bad_switch");
    }
}

void
child_post_startup_inferior (ptid_t ptid)
{
  i386_cleanup_dregs ();
  linux_child_post_startup_inferior (ptid);
}