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/* Low level Unix child interface to ptrace, for GDB when running under Unix.

   Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,

   1998, 1999, 2000, 2001, 2002

   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 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 "frame.h"

#include "inferior.h"

#include "target.h"

#include "gdb_string.h"

#include "regcache.h"

#include "gdb_wait.h"

#include "command.h"

#ifdef USG

#include <sys/types.h>

#endif

#include <sys/param.h>

#include "gdb_dirent.h"

#include <signal.h>

#include <sys/ioctl.h>

#ifdef HAVE_PTRACE_H

#include <ptrace.h>

#else

#ifdef HAVE_SYS_PTRACE_H

#include <sys/ptrace.h>

#endif

#endif

#if !defined (PT_READ_I)

#define PT_READ_I       1       /* Read word from text space */

#endif

#if !defined (PT_READ_D)

#define PT_READ_D       2       /* Read word from data space */

#endif

#if !defined (PT_READ_U)

#define PT_READ_U       3       /* Read word from kernel user struct */

#endif

#if !defined (PT_WRITE_I)

#define PT_WRITE_I      4       /* Write word to text space */

#endif

#if !defined (PT_WRITE_D)

#define PT_WRITE_D      5       /* Write word to data space */

#endif

#if !defined (PT_WRITE_U)

#define PT_WRITE_U      6       /* Write word to kernel user struct */

#endif

#if !defined (PT_CONTINUE)

#define PT_CONTINUE     7       /* Continue after signal */

#endif

#if !defined (PT_STEP)

#define PT_STEP         9       /* Set flag for single stepping */

#endif

#if !defined (PT_KILL)

#define PT_KILL         8       /* Send child a SIGKILL signal */

#endif

#ifndef PT_ATTACH

#define PT_ATTACH PTRACE_ATTACH

#endif

#ifndef PT_DETACH

#define PT_DETACH PTRACE_DETACH

#endif

#include "gdbcore.h"

#ifndef NO_SYS_FILE

#include <sys/file.h>

#endif

#if 0

/* Don't think this is used anymore.  On the sequent (not sure whether it's

   dynix or ptx or both), it is included unconditionally by sys/user.h and

   not protected against multiple inclusion.  */

#include "gdb_stat.h"

#endif

#if !defined (FETCH_INFERIOR_REGISTERS)

#include <sys/user.h>           /* Probably need to poke the user structure */

#if defined (KERNEL_U_ADDR_BSD)

#include <a.out.h>              /* For struct nlist */

#endif /* KERNEL_U_ADDR_BSD.  */

#endif /* !FETCH_INFERIOR_REGISTERS */

#if !defined (CHILD_XFER_MEMORY)

static void udot_info (char *, int);

#endif

#if !defined (FETCH_INFERIOR_REGISTERS)

static void fetch_register (int);

static void store_register (int);

#endif

void _initialize_kernel_u_addr (void);

void _initialize_infptrace (void);

/* This function simply calls ptrace with the given arguments.

   It exists so that all calls to ptrace are isolated in this

   machine-dependent file. */

int

call_ptrace (int request, int pid, PTRACE_ARG3_TYPE addr, int data)

{

  int pt_status = 0;

#if 0

  int saved_errno;

  printf ("call_ptrace(request=%d, pid=%d, addr=0x%x, data=0x%x)",

          request, pid, addr, data);

#endif

#if defined(PT_SETTRC)

  /* If the parent can be told to attach to us, try to do it.  */

  if (request == PT_SETTRC)

    {

      errno = 0;

#if !defined (FIVE_ARG_PTRACE)

      pt_status = ptrace (PT_SETTRC, pid, addr, data);

#else

      /* Deal with HPUX 8.0 braindamage.  We never use the

         calls which require the fifth argument.  */

      pt_status = ptrace (PT_SETTRC, pid, addr, data, 0);

#endif

      if (errno)

        perror_with_name ("ptrace");

#if 0

      printf (" = %d\n", pt_status);

#endif

      if (pt_status < 0)

        return pt_status;

      else

        return parent_attach_all (pid, addr, data);

    }

#endif

#if defined(PT_CONTIN1)

  /* On HPUX, PT_CONTIN1 is a form of continue that preserves pending

     signals.  If it's available, use it.  */

  if (request == PT_CONTINUE)

    request = PT_CONTIN1;

#endif

#if defined(PT_SINGLE1)

  /* On HPUX, PT_SINGLE1 is a form of step that preserves pending

     signals.  If it's available, use it.  */

  if (request == PT_STEP)

    request = PT_SINGLE1;

#endif

#if 0

  saved_errno = errno;

  errno = 0;

#endif

#if !defined (FIVE_ARG_PTRACE)

  pt_status = ptrace (request, pid, addr, data);

#else

  /* Deal with HPUX 8.0 braindamage.  We never use the

     calls which require the fifth argument.  */

  pt_status = ptrace (request, pid, addr, data, 0);

#endif

#if 0

  if (errno)

    printf (" [errno = %d]", errno);

  errno = saved_errno;

  printf (" = 0x%x\n", pt_status);

#endif

  return pt_status;

}

#if defined (DEBUG_PTRACE) || defined (FIVE_ARG_PTRACE)

/* For the rest of the file, use an extra level of indirection */

/* This lets us breakpoint usefully on call_ptrace. */

#define ptrace call_ptrace

#endif

/* Wait for a process to finish, possibly running a target-specific

   hook before returning.  */

int

ptrace_wait (ptid_t ptid, int *status)

{

  int wstate;

  wstate = wait (status);

  target_post_wait (pid_to_ptid (wstate), *status);

  return wstate;

}

void

kill_inferior (void)

{

  int status;

  int pid =  PIDGET (inferior_ptid);

  if (pid == 0)

    return;

  /* This once used to call "kill" to kill the inferior just in case

     the inferior was still running.  As others have noted in the past

     (kingdon) there shouldn't be any way to get here if the inferior

     is still running -- else there's a major problem elsewere in gdb

     and it needs to be fixed.

     The kill call causes problems under hpux10, so it's been removed;

     if this causes problems we'll deal with them as they arise.  */

  ptrace (PT_KILL, pid, (PTRACE_ARG3_TYPE) 0, 0);

  ptrace_wait (null_ptid, &status);

  target_mourn_inferior ();

}

#ifndef CHILD_RESUME

/* Resume execution of the inferior process.

   If STEP is nonzero, single-step it.

   If SIGNAL is nonzero, give it that signal.  */

void

child_resume (ptid_t ptid, int step, enum target_signal signal)

{

  int pid = PIDGET (ptid);

  errno = 0;

  if (pid == -1)

    /* Resume all threads.  */

    /* I think this only gets used in the non-threaded case, where "resume

       all threads" and "resume inferior_ptid" are the same.  */

    pid = PIDGET (inferior_ptid);

  /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where

     it was.  (If GDB wanted it to start some other way, we have already

     written a new PC value to the child.)

     If this system does not support PT_STEP, a higher level function will

     have called single_step() to transmute the step request into a

     continue request (by setting breakpoints on all possible successor

     instructions), so we don't have to worry about that here.  */

  if (step)

    {

      if (SOFTWARE_SINGLE_STEP_P ())

        internal_error (__FILE__, __LINE__, "failed internal consistency check");               /* Make sure this doesn't happen. */

      else

        ptrace (PT_STEP, pid, (PTRACE_ARG3_TYPE) 1,

                target_signal_to_host (signal));

    }

  else

    ptrace (PT_CONTINUE, pid, (PTRACE_ARG3_TYPE) 1,

            target_signal_to_host (signal));

  if (errno)

    {

      perror_with_name ("ptrace");

    }

}

#endif /* CHILD_RESUME */

#ifdef ATTACH_DETACH

/* Start debugging the process whose number is PID.  */

int

attach (int pid)

{

  errno = 0;

  ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0);

  if (errno)

    perror_with_name ("ptrace");

  attach_flag = 1;

  return pid;

}

/* Stop debugging the process whose number is PID

   and continue it with signal number SIGNAL.

   SIGNAL = 0 means just continue it.  */

void

detach (int signal)

{

  errno = 0;

  ptrace (PT_DETACH, PIDGET (inferior_ptid), (PTRACE_ARG3_TYPE) 1,

          signal);

  if (errno)

    perror_with_name ("ptrace");

  attach_flag = 0;

}

#endif /* ATTACH_DETACH */

/* Default the type of the ptrace transfer to int.  */

#ifndef PTRACE_XFER_TYPE

#define PTRACE_XFER_TYPE int

#endif

/* KERNEL_U_ADDR is the amount to subtract from u.u_ar0

   to get the offset in the core file of the register values.  */

#if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)

/* Get kernel_u_addr using BSD-style nlist().  */

CORE_ADDR kernel_u_addr;

#endif /* KERNEL_U_ADDR_BSD.  */

void

_initialize_kernel_u_addr (void)

{

#if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS)

  struct nlist names[2];

  names[0].n_un.n_name = "_u";

  names[1].n_un.n_name = NULL;

  if (nlist ("/vmunix", names) == 0)

    kernel_u_addr = names[0].n_value;

  else

    internal_error (__FILE__, __LINE__,

                    "Unable to get kernel u area address.");

#endif /* KERNEL_U_ADDR_BSD.  */

}

#if !defined (FETCH_INFERIOR_REGISTERS)

#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)

{

  /* This isn't really an address.  But ptrace thinks of it as one.  */

  CORE_ADDR regaddr;

  char mess[128];               /* For messages */

  register int i;

  unsigned int offset;          /* Offset of registers within the u area.  */

  char *buf = alloca (MAX_REGISTER_RAW_SIZE);

  int tid;

  if (CANNOT_FETCH_REGISTER (regno))

    {

      memset (buf, '\0', REGISTER_RAW_SIZE (regno));    /* Supply zeroes */

      supply_register (regno, buf);

      return;

    }

  /* Overload thread id onto process id */

  if ((tid = TIDGET (inferior_ptid)) == 0)

    tid = PIDGET (inferior_ptid);       /* no thread id, just use process id */

  offset = U_REGS_OFFSET;

  regaddr = register_addr (regno, offset);

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

    {

      errno = 0;

      *(PTRACE_XFER_TYPE *) & buf[i] = ptrace (PT_READ_U, tid,

                                               (PTRACE_ARG3_TYPE) regaddr, 0);

      regaddr += sizeof (PTRACE_XFER_TYPE);

      if (errno != 0)

        {

          sprintf (mess, "reading register %s (#%d)",

                   REGISTER_NAME (regno), regno);

          perror_with_name (mess);

        }

    }

  supply_register (regno, buf);

}

/* Fetch register values from the inferior.

   If REGNO is negative, do this for all registers.

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

void

fetch_inferior_registers (int regno)

{

  if (regno >= 0)

    {

      fetch_register (regno);

    }

  else

    {

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

        {

          fetch_register (regno);

        }

    }

}

/* Store one register. */

static void

store_register (int regno)

{

  /* This isn't really an address.  But ptrace thinks of it as one.  */

  CORE_ADDR regaddr;

  char mess[128];               /* For messages */

  register int i;

  unsigned int offset;          /* Offset of registers within the u area.  */

  int tid;

  char *buf = alloca (MAX_REGISTER_RAW_SIZE);

  if (CANNOT_STORE_REGISTER (regno))

    {

      return;

    }

  /* Overload thread id onto process id */

  if ((tid = TIDGET (inferior_ptid)) == 0)

    tid = PIDGET (inferior_ptid);       /* no thread id, just use process id */

  offset = U_REGS_OFFSET;

  regaddr = register_addr (regno, offset);

  /* Put the contents of regno into a local buffer */

  regcache_collect (regno, buf);

  /* Store the local buffer into the inferior a chunk at the time. */

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

    {

      errno = 0;

      ptrace (PT_WRITE_U, tid, (PTRACE_ARG3_TYPE) regaddr,

              *(PTRACE_XFER_TYPE *) (buf + i));

      regaddr += sizeof (PTRACE_XFER_TYPE);

      if (errno != 0)

        {

          sprintf (mess, "writing register %s (#%d)",

                   REGISTER_NAME (regno), regno);

          perror_with_name (mess);

        }

    }

}

/* Store our register values back into the inferior.

   If REGNO is negative, do this for all registers.

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

void

store_inferior_registers (int regno)

{

  if (regno >= 0)

    {

      store_register (regno);

    }

  else

    {

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

        {

          store_register (regno);

        }

    }

}

#endif /* !defined (FETCH_INFERIOR_REGISTERS).  */

/* Set an upper limit on alloca.  */

#ifndef GDB_MAX_ALLOCA

#define GDB_MAX_ALLOCA 0x1000

#endif

#if !defined (CHILD_XFER_MEMORY)

/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory

   in the NEW_SUN_PTRACE case.  It ought to be straightforward.  But

   it appears that writing did not write the data that I specified.  I

   cannot understand where it got the data that it actually did write.  */

/* Copy LEN bytes to or from inferior's memory starting at MEMADDR to

   debugger memory starting at MYADDR.  Copy to inferior if WRITE is

   nonzero.  TARGET is ignored.

   Returns the length copied, which is either the LEN argument or

   zero.  This xfer function does not do partial moves, since

   child_ops doesn't allow memory operations to cross below us in the

   target stack anyway.  */

int

child_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,

                   struct mem_attrib *attrib, struct target_ops *target)

{

  int i;

  /* Round starting address down to longword boundary.  */

  CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);

  /* Round ending address up; get number of longwords that makes.  */

  int count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)

               / sizeof (PTRACE_XFER_TYPE));

  int alloc = count * sizeof (PTRACE_XFER_TYPE);

  PTRACE_XFER_TYPE *buffer;

  struct cleanup *old_chain = NULL;

  /* Allocate buffer of that many longwords.  */

  if (len < GDB_MAX_ALLOCA)

    {

      buffer = (PTRACE_XFER_TYPE *) alloca (alloc);

    }

  else

    {

      buffer = (PTRACE_XFER_TYPE *) xmalloc (alloc);

      old_chain = make_cleanup (xfree, buffer);

    }

  if (write)

    {

      /* Fill start and end extra bytes of buffer with existing memory

         data.  */

      if (addr != memaddr || len < (int) sizeof (PTRACE_XFER_TYPE))

        {

          /* Need part of initial word -- fetch it.  */

          buffer[0] = ptrace (PT_READ_I, PIDGET (inferior_ptid),

                              (PTRACE_ARG3_TYPE) addr, 0);

        }

      if (count > 1)            /* FIXME, avoid if even boundary.  */

        {

          buffer[count - 1] =

            ptrace (PT_READ_I, PIDGET (inferior_ptid),

                    ((PTRACE_ARG3_TYPE)

                     (addr + (count - 1) * sizeof (PTRACE_XFER_TYPE))), 0);

        }

      /* Copy data to be written over corresponding part of buffer.  */

      memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),

              myaddr, len);

      /* Write the entire buffer.  */

      for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))

        {

          errno = 0;

          ptrace (PT_WRITE_D, PIDGET (inferior_ptid),

                  (PTRACE_ARG3_TYPE) addr, buffer[i]);

          if (errno)

            {

              /* Using the appropriate one (I or D) is necessary for

                 Gould NP1, at least.  */

              errno = 0;

              ptrace (PT_WRITE_I, PIDGET (inferior_ptid),

                      (PTRACE_ARG3_TYPE) addr, buffer[i]);

            }

          if (errno)

            return 0;

        }

#ifdef CLEAR_INSN_CACHE

      CLEAR_INSN_CACHE ();

#endif

    }

  else

    {

      /* Read all the longwords.  */

      for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))

        {

          errno = 0;

          buffer[i] = ptrace (PT_READ_I, PIDGET (inferior_ptid),

                              (PTRACE_ARG3_TYPE) addr, 0);

          if (errno)

            return 0;

          QUIT;

        }

      /* Copy appropriate bytes out of the buffer.  */

      memcpy (myaddr,

              (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),

              len);

    }

  if (old_chain != NULL)

    do_cleanups (old_chain);

  return len;

}

static void

udot_info (char *dummy1, int dummy2)

{

#if defined (KERNEL_U_SIZE)

  int udot_off;                 /* Offset into user struct */

  int udot_val;                 /* Value from user struct at udot_off */

  char mess[128];               /* For messages */

#endif

  if (!target_has_execution)

    {

      error ("The program is not being run.");

    }

#if !defined (KERNEL_U_SIZE)

  /* Adding support for this command is easy.  Typically you just add a

     routine, called "kernel_u_size" that returns the size of the user

     struct, to the appropriate *-nat.c file and then add to the native

     config file "#define KERNEL_U_SIZE kernel_u_size()" */

  error ("Don't know how large ``struct user'' is in this version of gdb.");

#else

  for (udot_off = 0; udot_off < KERNEL_U_SIZE; udot_off += sizeof (udot_val))

    {

      if ((udot_off % 24) == 0)

        {

          if (udot_off > 0)

            {

              printf_filtered ("\n");

            }

          printf_filtered ("%04x:", udot_off);

        }

      udot_val = ptrace (PT_READ_U, PIDGET (inferior_ptid), (PTRACE_ARG3_TYPE) udot_off, 0);

      if (errno != 0)

        {

          sprintf (mess, "\nreading user struct at offset 0x%x", udot_off);

          perror_with_name (mess);

        }

      /* Avoid using nonportable (?) "*" in print specs */

      printf_filtered (sizeof (int) == 4 ? " 0x%08x" : " 0x%16x", udot_val);

    }

  printf_filtered ("\n");

#endif

}

#endif /* !defined (CHILD_XFER_MEMORY).  */

void

_initialize_infptrace (void)

{

#if !defined (CHILD_XFER_MEMORY)

  add_info ("udot", udot_info,

            "Print contents of kernel ``struct user'' for current child.");

#endif

}