path: root/gdb/linux-tdep.c

/* Target-dependent code for GNU/Linux, architecture independent.

   Copyright (C) 2009-2014 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 "gdbtypes.h"
#include "linux-tdep.h"
#include "auxv.h"
#include "target.h"
#include "gdbthread.h"
#include "gdbcore.h"
#include "regcache.h"
#include "regset.h"
#include "elf/common.h"
#include "elf-bfd.h"            /* for elfcore_write_* */
#include "inferior.h"
#include "cli/cli-utils.h"
#include "arch-utils.h"
#include "gdb_obstack.h"
#include "observer.h"

#include <ctype.h>

/* This enum represents the signals' numbers on a generic architecture
   running the Linux kernel.  The definition of "generic" comes from
   the file <include/uapi/asm-generic/signal.h>, from the Linux kernel
   tree, which is the "de facto" implementation of signal numbers to
   be used by new architecture ports.

   For those architectures which have differences between the generic
   standard (e.g., Alpha), we define the different signals (and *only*
   those) in the specific target-dependent file (e.g.,
   alpha-linux-tdep.c, for Alpha).  Please refer to the architecture's
   tdep file for more information.

   ARM deserves a special mention here.  On the file
   <arch/arm/include/uapi/asm/signal.h>, it defines only one different
   (and ARM-only) signal, which is SIGSWI, with the same number as
   SIGRTMIN.  This signal is used only for a very specific target,
   called ArthurOS (from RISCOS).  Therefore, we do not handle it on
   the ARM-tdep file, and we can safely use the generic signal handler
   here for ARM targets.

   As stated above, this enum is derived from
   <include/uapi/asm-generic/signal.h>, from the Linux kernel
   tree.  */

enum
  {
    LINUX_SIGHUP = 1,
    LINUX_SIGINT = 2,
    LINUX_SIGQUIT = 3,
    LINUX_SIGILL = 4,
    LINUX_SIGTRAP = 5,
    LINUX_SIGABRT = 6,
    LINUX_SIGIOT = 6,
    LINUX_SIGBUS = 7,
    LINUX_SIGFPE = 8,
    LINUX_SIGKILL = 9,
    LINUX_SIGUSR1 = 10,
    LINUX_SIGSEGV = 11,
    LINUX_SIGUSR2 = 12,
    LINUX_SIGPIPE = 13,
    LINUX_SIGALRM = 14,
    LINUX_SIGTERM = 15,
    LINUX_SIGSTKFLT = 16,
    LINUX_SIGCHLD = 17,
    LINUX_SIGCONT = 18,
    LINUX_SIGSTOP = 19,
    LINUX_SIGTSTP = 20,
    LINUX_SIGTTIN = 21,
    LINUX_SIGTTOU = 22,
    LINUX_SIGURG = 23,
    LINUX_SIGXCPU = 24,
    LINUX_SIGXFSZ = 25,
    LINUX_SIGVTALRM = 26,
    LINUX_SIGPROF = 27,
    LINUX_SIGWINCH = 28,
    LINUX_SIGIO = 29,
    LINUX_SIGPOLL = LINUX_SIGIO,
    LINUX_SIGPWR = 30,
    LINUX_SIGSYS = 31,
    LINUX_SIGUNUSED = 31,

    LINUX_SIGRTMIN = 32,
    LINUX_SIGRTMAX = 64,
  };

static struct gdbarch_data *linux_gdbarch_data_handle;

struct linux_gdbarch_data
  {
    struct type *siginfo_type;
  };

static void *
init_linux_gdbarch_data (struct gdbarch *gdbarch)
{
  return GDBARCH_OBSTACK_ZALLOC (gdbarch, struct linux_gdbarch_data);
}

static struct linux_gdbarch_data *
get_linux_gdbarch_data (struct gdbarch *gdbarch)
{
  return gdbarch_data (gdbarch, linux_gdbarch_data_handle);
}

/* Per-inferior data key.  */
static const struct inferior_data *linux_inferior_data;

/* Linux-specific cached data.  This is used by GDB for caching
   purposes for each inferior.  This helps reduce the overhead of
   transfering data from a remote target to the local host.  */
struct linux_info
{
  /* Cache of the inferior's vsyscall/vDSO mapping range.  Only valid
     if VSYSCALL_RANGE_P is positive.  This is cached because getting
     at this info requires an auxv lookup (which is itself cached),
     and looking through the inferior's mappings (which change
     throughout execution and therefore cannot be cached).  */
  struct mem_range vsyscall_range;

  /* Zero if we haven't tried looking up the vsyscall's range before
     yet.  Positive if we tried looking it up, and found it.  Negative
     if we tried looking it up but failed.  */
  int vsyscall_range_p;
};

/* Frees whatever allocated space there is to be freed and sets INF's
   linux cache data pointer to NULL.  */

static void
invalidate_linux_cache_inf (struct inferior *inf)
{
  struct linux_info *info;

  info = inferior_data (inf, linux_inferior_data);
  if (info != NULL)
    {
      xfree (info);
      set_inferior_data (inf, linux_inferior_data, NULL);
    }
}

/* Handles the cleanup of the linux cache for inferior INF.  ARG is
   ignored.  Callback for the inferior_appeared and inferior_exit
   events.  */

static void
linux_inferior_data_cleanup (struct inferior *inf, void *arg)
{
  invalidate_linux_cache_inf (inf);
}

/* Fetch the linux cache info for INF.  This function always returns a
   valid INFO pointer.  */

static struct linux_info *
get_linux_inferior_data (void)
{
  struct linux_info *info;
  struct inferior *inf = current_inferior ();

  info = inferior_data (inf, linux_inferior_data);
  if (info == NULL)
    {
      info = XCNEW (struct linux_info);
      set_inferior_data (inf, linux_inferior_data, info);
    }

  return info;
}

/* This function is suitable for architectures that don't
   extend/override the standard siginfo structure.  */

struct type *
linux_get_siginfo_type (struct gdbarch *gdbarch)
{
  struct linux_gdbarch_data *linux_gdbarch_data;
  struct type *int_type, *uint_type, *long_type, *void_ptr_type;
  struct type *uid_type, *pid_type;
  struct type *sigval_type, *clock_type;
  struct type *siginfo_type, *sifields_type;
  struct type *type;

  linux_gdbarch_data = get_linux_gdbarch_data (gdbarch);
  if (linux_gdbarch_data->siginfo_type != NULL)
    return linux_gdbarch_data->siginfo_type;

  int_type = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch),
			 	0, "int");
  uint_type = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch),
				 1, "unsigned int");
  long_type = arch_integer_type (gdbarch, gdbarch_long_bit (gdbarch),
				 0, "long");
  void_ptr_type = lookup_pointer_type (builtin_type (gdbarch)->builtin_void);

  /* sival_t */
  sigval_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_UNION);
  TYPE_NAME (sigval_type) = xstrdup ("sigval_t");
  append_composite_type_field (sigval_type, "sival_int", int_type);
  append_composite_type_field (sigval_type, "sival_ptr", void_ptr_type);

  /* __pid_t */
  pid_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF,
			TYPE_LENGTH (int_type), "__pid_t");
  TYPE_TARGET_TYPE (pid_type) = int_type;
  TYPE_TARGET_STUB (pid_type) = 1;

  /* __uid_t */
  uid_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF,
			TYPE_LENGTH (uint_type), "__uid_t");
  TYPE_TARGET_TYPE (uid_type) = uint_type;
  TYPE_TARGET_STUB (uid_type) = 1;

  /* __clock_t */
  clock_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF,
			  TYPE_LENGTH (long_type), "__clock_t");
  TYPE_TARGET_TYPE (clock_type) = long_type;
  TYPE_TARGET_STUB (clock_type) = 1;

  /* _sifields */
  sifields_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_UNION);

  {
    const int si_max_size = 128;
    int si_pad_size;
    int size_of_int = gdbarch_int_bit (gdbarch) / HOST_CHAR_BIT;

    /* _pad */
    if (gdbarch_ptr_bit (gdbarch) == 64)
      si_pad_size = (si_max_size / size_of_int) - 4;
    else
      si_pad_size = (si_max_size / size_of_int) - 3;
    append_composite_type_field (sifields_type, "_pad",
				 init_vector_type (int_type, si_pad_size));
  }

  /* _kill */
  type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  append_composite_type_field (type, "si_pid", pid_type);
  append_composite_type_field (type, "si_uid", uid_type);
  append_composite_type_field (sifields_type, "_kill", type);

  /* _timer */
  type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  append_composite_type_field (type, "si_tid", int_type);
  append_composite_type_field (type, "si_overrun", int_type);
  append_composite_type_field (type, "si_sigval", sigval_type);
  append_composite_type_field (sifields_type, "_timer", type);

  /* _rt */
  type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  append_composite_type_field (type, "si_pid", pid_type);
  append_composite_type_field (type, "si_uid", uid_type);
  append_composite_type_field (type, "si_sigval", sigval_type);
  append_composite_type_field (sifields_type, "_rt", type);

  /* _sigchld */
  type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  append_composite_type_field (type, "si_pid", pid_type);
  append_composite_type_field (type, "si_uid", uid_type);
  append_composite_type_field (type, "si_status", int_type);
  append_composite_type_field (type, "si_utime", clock_type);
  append_composite_type_field (type, "si_stime", clock_type);
  append_composite_type_field (sifields_type, "_sigchld", type);

  /* _sigfault */
  type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  append_composite_type_field (type, "si_addr", void_ptr_type);
  append_composite_type_field (sifields_type, "_sigfault", type);

  /* _sigpoll */
  type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  append_composite_type_field (type, "si_band", long_type);
  append_composite_type_field (type, "si_fd", int_type);
  append_composite_type_field (sifields_type, "_sigpoll", type);

  /* struct siginfo */
  siginfo_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  TYPE_NAME (siginfo_type) = xstrdup ("siginfo");
  append_composite_type_field (siginfo_type, "si_signo", int_type);
  append_composite_type_field (siginfo_type, "si_errno", int_type);
  append_composite_type_field (siginfo_type, "si_code", int_type);
  append_composite_type_field_aligned (siginfo_type,
				       "_sifields", sifields_type,
				       TYPE_LENGTH (long_type));

  linux_gdbarch_data->siginfo_type = siginfo_type;

  return siginfo_type;
}

/* Return true if the target is running on uClinux instead of normal
   Linux kernel.  */

int
linux_is_uclinux (void)
{
  CORE_ADDR dummy;

  return (target_auxv_search (&current_target, AT_NULL, &dummy) > 0
	  && target_auxv_search (&current_target, AT_PAGESZ, &dummy) == 0);
}

static int
linux_has_shared_address_space (struct gdbarch *gdbarch)
{
  return linux_is_uclinux ();
}

/* This is how we want PTIDs from core files to be printed.  */

static char *
linux_core_pid_to_str (struct gdbarch *gdbarch, ptid_t ptid)
{
  static char buf[80];

  if (ptid_get_lwp (ptid) != 0)
    {
      snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
      return buf;
    }

  return normal_pid_to_str (ptid);
}

/* Service function for corefiles and info proc.  */

static void
read_mapping (const char *line,
	      ULONGEST *addr, ULONGEST *endaddr,
	      const char **permissions, size_t *permissions_len,
	      ULONGEST *offset,
              const char **device, size_t *device_len,
	      ULONGEST *inode,
	      const char **filename)
{
  const char *p = line;

  *addr = strtoulst (p, &p, 16);
  if (*p == '-')
    p++;
  *endaddr = strtoulst (p, &p, 16);

  p = skip_spaces_const (p);
  *permissions = p;
  while (*p && !isspace (*p))
    p++;
  *permissions_len = p - *permissions;

  *offset = strtoulst (p, &p, 16);

  p = skip_spaces_const (p);
  *device = p;
  while (*p && !isspace (*p))
    p++;
  *device_len = p - *device;

  *inode = strtoulst (p, &p, 10);

  p = skip_spaces_const (p);
  *filename = p;
}

/* Implement the "info proc" command.  */

static void
linux_info_proc (struct gdbarch *gdbarch, const char *args,
		 enum info_proc_what what)
{
  /* A long is used for pid instead of an int to avoid a loss of precision
     compiler warning from the output of strtoul.  */
  long pid;
  int cmdline_f = (what == IP_MINIMAL || what == IP_CMDLINE || what == IP_ALL);
  int cwd_f = (what == IP_MINIMAL || what == IP_CWD || what == IP_ALL);
  int exe_f = (what == IP_MINIMAL || what == IP_EXE || what == IP_ALL);
  int mappings_f = (what == IP_MAPPINGS || what == IP_ALL);
  int status_f = (what == IP_STATUS || what == IP_ALL);
  int stat_f = (what == IP_STAT || what == IP_ALL);
  char filename[100];
  char *data;
  int target_errno;

  if (args && isdigit (args[0]))
    {
      char *tem;

      pid = strtoul (args, &tem, 10);
      args = tem;
    }
  else
    {
      if (!target_has_execution)
	error (_("No current process: you must name one."));
      if (current_inferior ()->fake_pid_p)
	error (_("Can't determine the current process's PID: you must name one."));

      pid = current_inferior ()->pid;
    }

  args = skip_spaces_const (args);
  if (args && args[0])
    error (_("Too many parameters: %s"), args);

  printf_filtered (_("process %ld\n"), pid);
  if (cmdline_f)
    {
      xsnprintf (filename, sizeof filename, "/proc/%ld/cmdline", pid);
      data = target_fileio_read_stralloc (filename);
      if (data)
	{
	  struct cleanup *cleanup = make_cleanup (xfree, data);
          printf_filtered ("cmdline = '%s'\n", data);
	  do_cleanups (cleanup);
	}
      else
	warning (_("unable to open /proc file '%s'"), filename);
    }
  if (cwd_f)
    {
      xsnprintf (filename, sizeof filename, "/proc/%ld/cwd", pid);
      data = target_fileio_readlink (filename, &target_errno);
      if (data)
	{
	  struct cleanup *cleanup = make_cleanup (xfree, data);
          printf_filtered ("cwd = '%s'\n", data);
	  do_cleanups (cleanup);
	}
      else
	warning (_("unable to read link '%s'"), filename);
    }
  if (exe_f)
    {
      xsnprintf (filename, sizeof filename, "/proc/%ld/exe", pid);
      data = target_fileio_readlink (filename, &target_errno);
      if (data)
	{
	  struct cleanup *cleanup = make_cleanup (xfree, data);
          printf_filtered ("exe = '%s'\n", data);
	  do_cleanups (cleanup);
	}
      else
	warning (_("unable to read link '%s'"), filename);
    }
  if (mappings_f)
    {
      xsnprintf (filename, sizeof filename, "/proc/%ld/maps", pid);
      data = target_fileio_read_stralloc (filename);
      if (data)
	{
	  struct cleanup *cleanup = make_cleanup (xfree, data);
	  char *line;

	  printf_filtered (_("Mapped address spaces:\n\n"));
	  if (gdbarch_addr_bit (gdbarch) == 32)
	    {
	      printf_filtered ("\t%10s %10s %10s %10s %s\n",
			   "Start Addr",
			   "  End Addr",
			   "      Size", "    Offset", "objfile");
            }
	  else
            {
	      printf_filtered ("  %18s %18s %10s %10s %s\n",
			   "Start Addr",
			   "  End Addr",
			   "      Size", "    Offset", "objfile");
	    }

	  for (line = strtok (data, "\n"); line; line = strtok (NULL, "\n"))
	    {
	      ULONGEST addr, endaddr, offset, inode;
	      const char *permissions, *device, *filename;
	      size_t permissions_len, device_len;

	      read_mapping (line, &addr, &endaddr,
			    &permissions, &permissions_len,
			    &offset, &device, &device_len,
			    &inode, &filename);

	      if (gdbarch_addr_bit (gdbarch) == 32)
	        {
	          printf_filtered ("\t%10s %10s %10s %10s %s\n",
				   paddress (gdbarch, addr),
				   paddress (gdbarch, endaddr),
				   hex_string (endaddr - addr),
				   hex_string (offset),
				   *filename? filename : "");
		}
	      else
	        {
	          printf_filtered ("  %18s %18s %10s %10s %s\n",
				   paddress (gdbarch, addr),
				   paddress (gdbarch, endaddr),
				   hex_string (endaddr - addr),
				   hex_string (offset),
				   *filename? filename : "");
	        }
	    }

	  do_cleanups (cleanup);
	}
      else
	warning (_("unable to open /proc file '%s'"), filename);
    }
  if (status_f)
    {
      xsnprintf (filename, sizeof filename, "/proc/%ld/status", pid);
      data = target_fileio_read_stralloc (filename);
      if (data)
	{
	  struct cleanup *cleanup = make_cleanup (xfree, data);
          puts_filtered (data);
	  do_cleanups (cleanup);
	}
      else
	warning (_("unable to open /proc file '%s'"), filename);
    }
  if (stat_f)
    {
      xsnprintf (filename, sizeof filename, "/proc/%ld/stat", pid);
      data = target_fileio_read_stralloc (filename);
      if (data)
	{
	  struct cleanup *cleanup = make_cleanup (xfree, data);
	  const char *p = data;

	  printf_filtered (_("Process: %s\n"),
			   pulongest (strtoulst (p, &p, 10)));

	  p = skip_spaces_const (p);
	  if (*p == '(')
	    {
	      /* ps command also relies on no trailing fields
		 ever contain ')'.  */
	      const char *ep = strrchr (p, ')');
	      if (ep != NULL)
		{
		  printf_filtered ("Exec file: %.*s\n",
				   (int) (ep - p - 1), p + 1);
		  p = ep + 1;
		}
	    }

	  p = skip_spaces_const (p);
	  if (*p)
	    printf_filtered (_("State: %c\n"), *p++);

	  if (*p)
	    printf_filtered (_("Parent process: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Process group: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Session id: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("TTY: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("TTY owner process group: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));

	  if (*p)
	    printf_filtered (_("Flags: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Minor faults (no memory page): %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Minor faults, children: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Major faults (memory page faults): %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Major faults, children: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("utime: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("stime: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("utime, children: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("stime, children: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("jiffies remaining in current "
			       "time slice: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("'nice' value: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("jiffies until next timeout: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("jiffies until next SIGALRM: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("start time (jiffies since "
			       "system boot): %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Virtual memory size: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Resident set size: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("rlim: %s\n"),
			     pulongest (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Start of text: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("End of text: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Start of stack: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
#if 0	/* Don't know how architecture-dependent the rest is...
	   Anyway the signal bitmap info is available from "status".  */
	  if (*p)
	    printf_filtered (_("Kernel stack pointer: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Kernel instr pointer: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Pending signals bitmap: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Blocked signals bitmap: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Ignored signals bitmap: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("Catched signals bitmap: %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
	  if (*p)
	    printf_filtered (_("wchan (system call): %s\n"),
			     hex_string (strtoulst (p, &p, 10)));
#endif
	  do_cleanups (cleanup);
	}
      else
	warning (_("unable to open /proc file '%s'"), filename);
    }
}

/* Implement "info proc mappings" for a corefile.  */

static void
linux_core_info_proc_mappings (struct gdbarch *gdbarch, const char *args)
{
  asection *section;
  ULONGEST count, page_size;
  unsigned char *descdata, *filenames, *descend, *contents;
  size_t note_size;
  unsigned int addr_size_bits, addr_size;
  struct cleanup *cleanup;
  struct gdbarch *core_gdbarch = gdbarch_from_bfd (core_bfd);
  /* We assume this for reading 64-bit core files.  */
  gdb_static_assert (sizeof (ULONGEST) >= 8);

  section = bfd_get_section_by_name (core_bfd, ".note.linuxcore.file");
  if (section == NULL)
    {
      warning (_("unable to find mappings in core file"));
      return;
    }

  addr_size_bits = gdbarch_addr_bit (core_gdbarch);
  addr_size = addr_size_bits / 8;
  note_size = bfd_get_section_size (section);

  if (note_size < 2 * addr_size)
    error (_("malformed core note - too short for header"));

  contents = xmalloc (note_size);
  cleanup = make_cleanup (xfree, contents);
  if (!bfd_get_section_contents (core_bfd, section, contents, 0, note_size))
    error (_("could not get core note contents"));

  descdata = contents;
  descend = descdata + note_size;

  if (descdata[note_size - 1] != '\0')
    error (_("malformed note - does not end with \\0"));

  count = bfd_get (addr_size_bits, core_bfd, descdata);
  descdata += addr_size;

  page_size = bfd_get (addr_size_bits, core_bfd, descdata);
  descdata += addr_size;

  if (note_size < 2 * addr_size + count * 3 * addr_size)
    error (_("malformed note - too short for supplied file count"));

  printf_filtered (_("Mapped address spaces:\n\n"));
  if (gdbarch_addr_bit (gdbarch) == 32)
    {
      printf_filtered ("\t%10s %10s %10s %10s %s\n",
		       "Start Addr",
		       "  End Addr",
		       "      Size", "    Offset", "objfile");
    }
  else
    {
      printf_filtered ("  %18s %18s %10s %10s %s\n",
		       "Start Addr",
		       "  End Addr",
		       "      Size", "    Offset", "objfile");
    }

  filenames = descdata + count * 3 * addr_size;
  while (--count > 0)
    {
      ULONGEST start, end, file_ofs;

      if (filenames == descend)
	error (_("malformed note - filenames end too early"));

      start = bfd_get (addr_size_bits, core_bfd, descdata);
      descdata += addr_size;
      end = bfd_get (addr_size_bits, core_bfd, descdata);
      descdata += addr_size;
      file_ofs = bfd_get (addr_size_bits, core_bfd, descdata);
      descdata += addr_size;

      file_ofs *= page_size;

      if (gdbarch_addr_bit (gdbarch) == 32)
	printf_filtered ("\t%10s %10s %10s %10s %s\n",
			 paddress (gdbarch, start),
			 paddress (gdbarch, end),
			 hex_string (end - start),
			 hex_string (file_ofs),
			 filenames);
      else
	printf_filtered ("  %18s %18s %10s %10s %s\n",
			 paddress (gdbarch, start),
			 paddress (gdbarch, end),
			 hex_string (end - start),
			 hex_string (file_ofs),
			 filenames);

      filenames += 1 + strlen ((char *) filenames);
    }

  do_cleanups (cleanup);
}

/* Implement "info proc" for a corefile.  */

static void
linux_core_info_proc (struct gdbarch *gdbarch, const char *args,
		      enum info_proc_what what)
{
  int exe_f = (what == IP_MINIMAL || what == IP_EXE || what == IP_ALL);
  int mappings_f = (what == IP_MAPPINGS || what == IP_ALL);

  if (exe_f)
    {
      const char *exe;

      exe = bfd_core_file_failing_command (core_bfd);
      if (exe != NULL)
	printf_filtered ("exe = '%s'\n", exe);
      else
	warning (_("unable to find command name in core file"));
    }

  if (mappings_f)
    linux_core_info_proc_mappings (gdbarch, args);

  if (!exe_f && !mappings_f)
    error (_("unable to handle request"));
}

typedef int linux_find_memory_region_ftype (ULONGEST vaddr, ULONGEST size,
					    ULONGEST offset, ULONGEST inode,
					    int read, int write,
					    int exec, int modified,
					    const char *filename,
					    void *data);

/* List memory regions in the inferior for a corefile.  */

static int
linux_find_memory_regions_full (struct gdbarch *gdbarch,
				linux_find_memory_region_ftype *func,
				void *obfd)
{
  char mapsfilename[100];
  char *data;

  /* We need to know the real target PID to access /proc.  */
  if (current_inferior ()->fake_pid_p)
    return 1;

  xsnprintf (mapsfilename, sizeof mapsfilename,
	     "/proc/%d/smaps", current_inferior ()->pid);
  data = target_fileio_read_stralloc (mapsfilename);
  if (data == NULL)
    {
      /* Older Linux kernels did not support /proc/PID/smaps.  */
      xsnprintf (mapsfilename, sizeof mapsfilename,
		 "/proc/%d/maps", current_inferior ()->pid);
      data = target_fileio_read_stralloc (mapsfilename);
    }
  if (data)
    {
      struct cleanup *cleanup = make_cleanup (xfree, data);
      char *line;

      line = strtok (data, "\n");
      while (line)
	{
	  ULONGEST addr, endaddr, offset, inode;
	  const char *permissions, *device, *filename;
	  size_t permissions_len, device_len;
	  int read, write, exec;
	  int modified = 0, has_anonymous = 0;

	  read_mapping (line, &addr, &endaddr, &permissions, &permissions_len,
			&offset, &device, &device_len, &inode, &filename);

	  /* Decode permissions.  */
	  read = (memchr (permissions, 'r', permissions_len) != 0);
	  write = (memchr (permissions, 'w', permissions_len) != 0);
	  exec = (memchr (permissions, 'x', permissions_len) != 0);

	  /* Try to detect if region was modified by parsing smaps counters.  */
	  for (line = strtok (NULL, "\n");
	       line && line[0] >= 'A' && line[0] <= 'Z';
	       line = strtok (NULL, "\n"))
	    {
	      char keyword[64 + 1];

	      if (sscanf (line, "%64s", keyword) != 1)
		{
		  warning (_("Error parsing {s,}maps file '%s'"), mapsfilename);
		  break;
		}
	      if (strcmp (keyword, "Anonymous:") == 0)
		has_anonymous = 1;
	      if (strcmp (keyword, "Shared_Dirty:") == 0
		  || strcmp (keyword, "Private_Dirty:") == 0
		  || strcmp (keyword, "Swap:") == 0
		  || strcmp (keyword, "Anonymous:") == 0)
		{
		  unsigned long number;

		  if (sscanf (line, "%*s%lu", &number) != 1)
		    {
		      warning (_("Error parsing {s,}maps file '%s' number"),
			       mapsfilename);
		      break;
		    }
		  if (number != 0)
		    modified = 1;
		}
	    }

	  /* Older Linux kernels did not support the "Anonymous:" counter.
	     If it is missing, we can't be sure - dump all the pages.  */
	  if (!has_anonymous)
	    modified = 1;

	  /* Invoke the callback function to create the corefile segment.  */
	  func (addr, endaddr - addr, offset, inode,
		read, write, exec, modified, filename, obfd);
	}

      do_cleanups (cleanup);
      return 0;
    }

  return 1;
}

/* A structure for passing information through
   linux_find_memory_regions_full.  */

struct linux_find_memory_regions_data
{
  /* The original callback.  */

  find_memory_region_ftype func;

  /* The original datum.  */

  void *obfd;
};

/* A callback for linux_find_memory_regions that converts between the
   "full"-style callback and find_memory_region_ftype.  */

static int
linux_find_memory_regions_thunk (ULONGEST vaddr, ULONGEST size,
				 ULONGEST offset, ULONGEST inode,
				 int read, int write, int exec, int modified,
				 const char *filename, void *arg)
{
  struct linux_find_memory_regions_data *data = arg;

  return data->func (vaddr, size, read, write, exec, modified, data->obfd);
}

/* A variant of linux_find_memory_regions_full that is suitable as the
   gdbarch find_memory_regions method.  */

static int
linux_find_memory_regions (struct gdbarch *gdbarch,
			   find_memory_region_ftype func, void *obfd)
{
  struct linux_find_memory_regions_data data;

  data.func = func;
  data.obfd = obfd;

  return linux_find_memory_regions_full (gdbarch,
					 linux_find_memory_regions_thunk,
					 &data);
}

/* Determine which signal stopped execution.  */

static int
find_signalled_thread (struct thread_info *info, void *data)
{
  if (info->suspend.stop_signal != GDB_SIGNAL_0
      && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid))
    return 1;

  return 0;
}

static enum gdb_signal
find_stop_signal (void)
{
  struct thread_info *info =
    iterate_over_threads (find_signalled_thread, NULL);

  if (info)
    return info->suspend.stop_signal;
  else
    return GDB_SIGNAL_0;
}

/* Generate corefile notes for SPU contexts.  */

static char *
linux_spu_make_corefile_notes (bfd *obfd, char *note_data, int *note_size)
{
  static const char *spu_files[] =
    {
      "object-id",
      "mem",
      "regs",
      "fpcr",
      "lslr",
      "decr",
      "decr_status",
      "signal1",
      "signal1_type",
      "signal2",
      "signal2_type",
      "event_mask",
      "event_status",
      "mbox_info",
      "ibox_info",
      "wbox_info",
      "dma_info",
      "proxydma_info",
   };

  enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
  gdb_byte *spu_ids;
  LONGEST i, j, size;

  /* Determine list of SPU ids.  */
  size = target_read_alloc (&current_target, TARGET_OBJECT_SPU,
			    NULL, &spu_ids);

  /* Generate corefile notes for each SPU file.  */
  for (i = 0; i < size; i += 4)
    {
      int fd = extract_unsigned_integer (spu_ids + i, 4, byte_order);

      for (j = 0; j < sizeof (spu_files) / sizeof (spu_files[0]); j++)
	{
	  char annex[32], note_name[32];
	  gdb_byte *spu_data;
	  LONGEST spu_len;

	  xsnprintf (annex, sizeof annex, "%d/%s", fd, spu_files[j]);
	  spu_len = target_read_alloc (&current_target, TARGET_OBJECT_SPU,
				       annex, &spu_data);
	  if (spu_len > 0)
	    {
	      xsnprintf (note_name, sizeof note_name, "SPU/%s", annex);
	      note_data = elfcore_write_note (obfd, note_data, note_size,
					      note_name, NT_SPU,
					      spu_data, spu_len);
	      xfree (spu_data);

	      if (!note_data)
		{
		  xfree (spu_ids);
		  return NULL;
		}
	    }
	}
    }

  if (size > 0)
    xfree (spu_ids);

  return note_data;
}

/* This is used to pass information from
   linux_make_mappings_corefile_notes through
   linux_find_memory_regions_full.  */

struct linux_make_mappings_data
{
  /* Number of files mapped.  */
  ULONGEST file_count;

  /* The obstack for the main part of the data.  */
  struct obstack *data_obstack;

  /* The filename obstack.  */
  struct obstack *filename_obstack;

  /* The architecture's "long" type.  */
  struct type *long_type;
};

static linux_find_memory_region_ftype linux_make_mappings_callback;

/* A callback for linux_find_memory_regions_full that updates the
   mappings data for linux_make_mappings_corefile_notes.  */

static int
linux_make_mappings_callback (ULONGEST vaddr, ULONGEST size,
			      ULONGEST offset, ULONGEST inode,
			      int read, int write, int exec, int modified,
			      const char *filename, void *data)
{
  struct linux_make_mappings_data *map_data = data;
  gdb_byte buf[sizeof (ULONGEST)];

  if (*filename == '\0' || inode == 0)
    return 0;

  ++map_data->file_count;

  pack_long (buf, map_data->long_type, vaddr);
  obstack_grow (map_data->data_obstack, buf, TYPE_LENGTH (map_data->long_type));
  pack_long (buf, map_data->long_type, vaddr + size);
  obstack_grow (map_data->data_obstack, buf, TYPE_LENGTH (map_data->long_type));
  pack_long (buf, map_data->long_type, offset);
  obstack_grow (map_data->data_obstack, buf, TYPE_LENGTH (map_data->long_type));

  obstack_grow_str0 (map_data->filename_obstack, filename);

  return 0;
}

/* Write the file mapping data to the core file, if possible.  OBFD is
   the output BFD.  NOTE_DATA is the current note data, and NOTE_SIZE
   is a pointer to the note size.  Returns the new NOTE_DATA and
   updates NOTE_SIZE.  */

static char *
linux_make_mappings_corefile_notes (struct gdbarch *gdbarch, bfd *obfd,
				    char *note_data, int *note_size)
{
  struct cleanup *cleanup;
  struct obstack data_obstack, filename_obstack;
  struct linux_make_mappings_data mapping_data;
  struct type *long_type
    = arch_integer_type (gdbarch, gdbarch_long_bit (gdbarch), 0, "long");
  gdb_byte buf[sizeof (ULONGEST)];

  obstack_init (&data_obstack);
  cleanup = make_cleanup_obstack_free (&data_obstack);
  obstack_init (&filename_obstack);
  make_cleanup_obstack_free (&filename_obstack);

  mapping_data.file_count = 0;
  mapping_data.data_obstack = &data_obstack;
  mapping_data.filename_obstack = &filename_obstack;
  mapping_data.long_type = long_type;

  /* Reserve space for the count.  */
  obstack_blank (&data_obstack, TYPE_LENGTH (long_type));
  /* We always write the page size as 1 since we have no good way to
     determine the correct value.  */
  pack_long (buf, long_type, 1);
  obstack_grow (&data_obstack, buf, TYPE_LENGTH (long_type));

  linux_find_memory_regions_full (gdbarch, linux_make_mappings_callback,
				  &mapping_data);

  if (mapping_data.file_count != 0)
    {
      /* Write the count to the obstack.  */
      pack_long ((gdb_byte *) obstack_base (&data_obstack),
		 long_type, mapping_data.file_count);

      /* Copy the filenames to the data obstack.  */
      obstack_grow (&data_obstack, obstack_base (&filename_obstack),
		    obstack_object_size (&filename_obstack));

      note_data = elfcore_write_note (obfd, note_data, note_size,
				      "CORE", NT_FILE,
				      obstack_base (&data_obstack),
				      obstack_object_size (&data_obstack));
    }

  do_cleanups (cleanup);
  return note_data;
}

/* Structure for passing information from
   linux_collect_thread_registers via an iterator to
   linux_collect_regset_section_cb. */

struct linux_collect_regset_section_cb_data
{
  struct gdbarch *gdbarch;
  const struct regcache *regcache;
  bfd *obfd;
  char *note_data;
  int *note_size;
  unsigned long lwp;
  enum gdb_signal stop_signal;
  int abort_iteration;
};

/* Callback for iterate_over_regset_sections that records a single
   regset in the corefile note section.  */

static void
linux_collect_regset_section_cb (const char *sect_name, int size,
				 const struct regset *regset,
				 const char *human_name, void *cb_data)
{
  char *buf;
  struct linux_collect_regset_section_cb_data *data = cb_data;

  if (data->abort_iteration)
    return;

  gdb_assert (regset && regset->collect_regset);

  buf = xmalloc (size);
  regset->collect_regset (regset, data->regcache, -1, buf, size);

  /* PRSTATUS still needs to be treated specially.  */
  if (strcmp (sect_name, ".reg") == 0)
    data->note_data = (char *) elfcore_write_prstatus
      (data->obfd, data->note_data, data->note_size, data->lwp,
       gdb_signal_to_host (data->stop_signal), buf);
  else
    data->note_data = (char *) elfcore_write_register_note
      (data->obfd, data->note_data, data->note_size,
       sect_name, buf, size);
  xfree (buf);

  if (data->note_data == NULL)
    data->abort_iteration = 1;
}

/* Records the thread's register state for the corefile note
   section.  */

static char *
linux_collect_thread_registers (const struct regcache *regcache,
				ptid_t ptid, bfd *obfd,
				char *note_data, int *note_size,
				enum gdb_signal stop_signal)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  struct linux_collect_regset_section_cb_data data;

  data.gdbarch = gdbarch;
  data.regcache = regcache;
  data.obfd = obfd;
  data.note_data = note_data;
  data.note_size = note_size;
  data.stop_signal = stop_signal;
  data.abort_iteration = 0;

  /* For remote targets the LWP may not be available, so use the TID.  */
  data.lwp = ptid_get_lwp (ptid);
  if (!data.lwp)
    data.lwp = ptid_get_tid (ptid);

  gdbarch_iterate_over_regset_sections (gdbarch,
					linux_collect_regset_section_cb,
					&data, regcache);
  return data.note_data;
}

/* Fetch the siginfo data for the current thread, if it exists.  If
   there is no data, or we could not read it, return NULL.  Otherwise,
   return a newly malloc'd buffer holding the data and fill in *SIZE
   with the size of the data.  The caller is responsible for freeing
   the data.  */

static gdb_byte *
linux_get_siginfo_data (struct gdbarch *gdbarch, LONGEST *size)
{
  struct type *siginfo_type;
  gdb_byte *buf;
  LONGEST bytes_read;
  struct cleanup *cleanups;

  if (!gdbarch_get_siginfo_type_p (gdbarch))
    return NULL;
  
  siginfo_type = gdbarch_get_siginfo_type (gdbarch);

  buf = xmalloc (TYPE_LENGTH (siginfo_type));
  cleanups = make_cleanup (xfree, buf);

  bytes_read = target_read (&current_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
			    buf, 0, TYPE_LENGTH (siginfo_type));
  if (bytes_read == TYPE_LENGTH (siginfo_type))
    {
      discard_cleanups (cleanups);
      *size = bytes_read;
    }
  else
    {
      do_cleanups (cleanups);
      buf = NULL;
    }

  return buf;
}

struct linux_corefile_thread_data
{
  struct gdbarch *gdbarch;
  int pid;
  bfd *obfd;
  char *note_data;
  int *note_size;
  enum gdb_signal stop_signal;
};

/* Called by gdbthread.c once per thread.  Records the thread's
   register state for the corefile note section.  */

static int
linux_corefile_thread_callback (struct thread_info *info, void *data)
{
  struct linux_corefile_thread_data *args = data;

  /* It can be current thread
     which cannot be removed by update_thread_list.  */
  if (info->state == THREAD_EXITED)
    return 0;

  if (ptid_get_pid (info->ptid) == args->pid)
    {
      struct cleanup *old_chain;
      struct regcache *regcache;
      gdb_byte *siginfo_data;
      LONGEST siginfo_size = 0;

      regcache = get_thread_arch_regcache (info->ptid, args->gdbarch);

      old_chain = save_inferior_ptid ();
      inferior_ptid = info->ptid;
      target_fetch_registers (regcache, -1);
      siginfo_data = linux_get_siginfo_data (args->gdbarch, &siginfo_size);
      do_cleanups (old_chain);

      old_chain = make_cleanup (xfree, siginfo_data);

      args->note_data = linux_collect_thread_registers
	(regcache, info->ptid, args->obfd, args->note_data,
	 args->note_size, args->stop_signal);

      /* Don't return anything if we got no register information above,
         such a core file is useless.  */
      if (args->note_data != NULL)
	if (siginfo_data != NULL)
	  args->note_data = elfcore_write_note (args->obfd,
						args->note_data,
						args->note_size,
						"CORE", NT_SIGINFO,
						siginfo_data, siginfo_size);

      do_cleanups (old_chain);
    }

  return !args->note_data;
}

/* Fill the PRPSINFO structure with information about the process being
   debugged.  Returns 1 in case of success, 0 for failures.  Please note that
   even if the structure cannot be entirely filled (e.g., GDB was unable to
   gather information about the process UID/GID), this function will still
   return 1 since some information was already recorded.  It will only return
   0 iff nothing can be gathered.  */

static int
linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p)
{
  /* The filename which we will use to obtain some info about the process.
     We will basically use this to store the `/proc/PID/FILENAME' file.  */
  char filename[100];
  /* The full name of the program which generated the corefile.  */
  char *fname;
  /* The basename of the executable.  */
  const char *basename;
  /* The arguments of the program.  */
  char *psargs;
  char *infargs;
  /* The contents of `/proc/PID/stat' and `/proc/PID/status' files.  */
  char *proc_stat, *proc_status;
  /* Temporary buffer.  */
  char *tmpstr;
  /* The valid states of a process, according to the Linux kernel.  */
  const char valid_states[] = "RSDTZW";
  /* The program state.  */
  const char *prog_state;
  /* The state of the process.  */
  char pr_sname;
  /* The PID of the program which generated the corefile.  */
  pid_t pid;
  /* Process flags.  */
  unsigned int pr_flag;
  /* Process nice value.  */
  long pr_nice;
  /* The number of fields read by `sscanf'.  */
  int n_fields = 0;
  /* Cleanups.  */
  struct cleanup *c;
  int i;

  gdb_assert (p != NULL);

  /* Obtaining PID and filename.  */
  pid = ptid_get_pid (inferior_ptid);
  xsnprintf (filename, sizeof (filename), "/proc/%d/cmdline", (int) pid);
  fname = target_fileio_read_stralloc (filename);

  if (fname == NULL || *fname == '\0')
    {
      /* No program name was read, so we won't be able to retrieve more
	 information about the process.  */
      xfree (fname);
      return 0;
    }

  c = make_cleanup (xfree, fname);
  memset (p, 0, sizeof (*p));

  /* Defining the PID.  */
  p->pr_pid = pid;

  /* Copying the program name.  Only the basename matters.  */
  basename = lbasename (fname);
  strncpy (p->pr_fname, basename, sizeof (p->pr_fname));
  p->pr_fname[sizeof (p->pr_fname) - 1] = '\0';

  infargs = get_inferior_args ();

  psargs = xstrdup (fname);
  if (infargs != NULL)
    psargs = reconcat (psargs, psargs, " ", infargs, NULL);

  make_cleanup (xfree, psargs);

  strncpy (p->pr_psargs, psargs, sizeof (p->pr_psargs));
  p->pr_psargs[sizeof (p->pr_psargs) - 1] = '\0';

  xsnprintf (filename, sizeof (filename), "/proc/%d/stat", (int) pid);
  proc_stat = target_fileio_read_stralloc (filename);
  make_cleanup (xfree, proc_stat);

  if (proc_stat == NULL || *proc_stat == '\0')
    {
      /* Despite being unable to read more information about the
	 process, we return 1 here because at least we have its
	 command line, PID and arguments.  */
      do_cleanups (c);
      return 1;
    }

  /* Ok, we have the stats.  It's time to do a little parsing of the
     contents of the buffer, so that we end up reading what we want.

     The following parsing mechanism is strongly based on the
     information generated by the `fs/proc/array.c' file, present in
     the Linux kernel tree.  More details about how the information is
     displayed can be obtained by seeing the manpage of proc(5),
     specifically under the entry of `/proc/[pid]/stat'.  */

  /* Getting rid of the PID, since we already have it.  */
  while (isdigit (*proc_stat))
    ++proc_stat;

  proc_stat = skip_spaces (proc_stat);

  /* ps command also relies on no trailing fields ever contain ')'.  */
  proc_stat = strrchr (proc_stat, ')');
  if (proc_stat == NULL)
    {
      do_cleanups (c);
      return 1;
    }
  proc_stat++;

  proc_stat = skip_spaces (proc_stat);

  n_fields = sscanf (proc_stat,
		     "%c"		/* Process state.  */
		     "%d%d%d"		/* Parent PID, group ID, session ID.  */
		     "%*d%*d"		/* tty_nr, tpgid (not used).  */
		     "%u"		/* Flags.  */
		     "%*s%*s%*s%*s"	/* minflt, cminflt, majflt,
					   cmajflt (not used).  */
		     "%*s%*s%*s%*s"	/* utime, stime, cutime,
					   cstime (not used).  */
		     "%*s"		/* Priority (not used).  */
		     "%ld",		/* Nice.  */
		     &pr_sname,
		     &p->pr_ppid, &p->pr_pgrp, &p->pr_sid,
		     &pr_flag,
		     &pr_nice);

  if (n_fields != 6)
    {
      /* Again, we couldn't read the complementary information about
	 the process state.  However, we already have minimal
	 information, so we just return 1 here.  */
      do_cleanups (c);
      return 1;
    }

  /* Filling the structure fields.  */
  prog_state = strchr (valid_states, pr_sname);
  if (prog_state != NULL)
    p->pr_state = prog_state - valid_states;
  else
    {
      /* Zero means "Running".  */
      p->pr_state = 0;
    }

  p->pr_sname = p->pr_state > 5 ? '.' : pr_sname;
  p->pr_zomb = p->pr_sname == 'Z';
  p->pr_nice = pr_nice;
  p->pr_flag = pr_flag;

  /* Finally, obtaining the UID and GID.  For that, we read and parse the
     contents of the `/proc/PID/status' file.  */
  xsnprintf (filename, sizeof (filename), "/proc/%d/status", (int) pid);
  proc_status = target_fileio_read_stralloc (filename);
  make_cleanup (xfree, proc_status);

  if (proc_status == NULL || *proc_status == '\0')
    {
      /* Returning 1 since we already have a bunch of information.  */
      do_cleanups (c);
      return 1;
    }

  /* Extracting the UID.  */
  tmpstr = strstr (proc_status, "Uid:");
  if (tmpstr != NULL)
    {
      /* Advancing the pointer to the beginning of the UID.  */
      tmpstr += sizeof ("Uid:");
      while (*tmpstr != '\0' && !isdigit (*tmpstr))
	++tmpstr;

      if (isdigit (*tmpstr))
	p->pr_uid = strtol (tmpstr, &tmpstr, 10);
    }

  /* Extracting the GID.  */
  tmpstr = strstr (proc_status, "Gid:");
  if (tmpstr != NULL)
    {
      /* Advancing the pointer to the beginning of the GID.  */
      tmpstr += sizeof ("Gid:");
      while (*tmpstr != '\0' && !isdigit (*tmpstr))
	++tmpstr;

      if (isdigit (*tmpstr))
	p->pr_gid = strtol (tmpstr, &tmpstr, 10);
    }

  do_cleanups (c);

  return 1;
}

/* Build the note section for a corefile, and return it in a malloc
   buffer.  */

static char *
linux_make_corefile_notes (struct gdbarch *gdbarch, bfd *obfd, int *note_size)
{
  struct linux_corefile_thread_data thread_args;
  struct elf_internal_linux_prpsinfo prpsinfo;
  char *note_data = NULL;
  gdb_byte *auxv;
  int auxv_len;
  volatile struct gdb_exception e;

  if (! gdbarch_iterate_over_regset_sections_p (gdbarch))
    return NULL;

  if (linux_fill_prpsinfo (&prpsinfo))
    {
      if (gdbarch_elfcore_write_linux_prpsinfo_p (gdbarch))
	{
	  note_data = gdbarch_elfcore_write_linux_prpsinfo (gdbarch, obfd,
							    note_data, note_size,
							    &prpsinfo);
	}
      else
	{
	  if (gdbarch_ptr_bit (gdbarch) == 64)
	    note_data = elfcore_write_linux_prpsinfo64 (obfd,
							note_data, note_size,
							&prpsinfo);
	  else
	    note_data = elfcore_write_linux_prpsinfo32 (obfd,
							note_data, note_size,
							&prpsinfo);
	}
    }

  /* Thread register information.  */
  TRY_CATCH (e, RETURN_MASK_ERROR)
    {
      update_thread_list ();
    }
  if (e.reason < 0)
    exception_print (gdb_stderr, e);
  thread_args.gdbarch = gdbarch;
  thread_args.pid = ptid_get_pid (inferior_ptid);
  thread_args.obfd = obfd;
  thread_args.note_data = note_data;
  thread_args.note_size = note_size;
  thread_args.stop_signal = find_stop_signal ();
  iterate_over_threads (linux_corefile_thread_callback, &thread_args);
  note_data = thread_args.note_data;
  if (!note_data)
    return NULL;

  /* Auxillary vector.  */
  auxv_len = target_read_alloc (&current_target, TARGET_OBJECT_AUXV,
				NULL, &auxv);
  if (auxv_len > 0)
    {
      note_data = elfcore_write_note (obfd, note_data, note_size,
				      "CORE", NT_AUXV, auxv, auxv_len);
      xfree (auxv);

      if (!note_data)
	return NULL;
    }

  /* SPU information.  */
  note_data = linux_spu_make_corefile_notes (obfd, note_data, note_size);
  if (!note_data)
    return NULL;

  /* File mappings.  */
  note_data = linux_make_mappings_corefile_notes (gdbarch, obfd,
						  note_data, note_size);

  return note_data;
}

/* Implementation of `gdbarch_gdb_signal_from_target', as defined in
   gdbarch.h.  This function is not static because it is exported to
   other -tdep files.  */

enum gdb_signal
linux_gdb_signal_from_target (struct gdbarch *gdbarch, int signal)
{
  switch (signal)
    {
    case 0:
      return GDB_SIGNAL_0;

    case LINUX_SIGHUP:
      return GDB_SIGNAL_HUP;

    case LINUX_SIGINT:
      return GDB_SIGNAL_INT;

    case LINUX_SIGQUIT:
      return GDB_SIGNAL_QUIT;

    case LINUX_SIGILL:
      return GDB_SIGNAL_ILL;

    case LINUX_SIGTRAP:
      return GDB_SIGNAL_TRAP;

    case LINUX_SIGABRT:
      return GDB_SIGNAL_ABRT;

    case LINUX_SIGBUS:
      return GDB_SIGNAL_BUS;

    case LINUX_SIGFPE:
      return GDB_SIGNAL_FPE;

    case LINUX_SIGKILL:
      return GDB_SIGNAL_KILL;

    case LINUX_SIGUSR1:
      return GDB_SIGNAL_USR1;

    case LINUX_SIGSEGV:
      return GDB_SIGNAL_SEGV;

    case LINUX_SIGUSR2:
      return GDB_SIGNAL_USR2;

    case LINUX_SIGPIPE:
      return GDB_SIGNAL_PIPE;

    case LINUX_SIGALRM:
      return GDB_SIGNAL_ALRM;

    case LINUX_SIGTERM:
      return GDB_SIGNAL_TERM;

    case LINUX_SIGCHLD:
      return GDB_SIGNAL_CHLD;

    case LINUX_SIGCONT:
      return GDB_SIGNAL_CONT;

    case LINUX_SIGSTOP:
      return GDB_SIGNAL_STOP;

    case LINUX_SIGTSTP:
      return GDB_SIGNAL_TSTP;

    case LINUX_SIGTTIN:
      return GDB_SIGNAL_TTIN;

    case LINUX_SIGTTOU:
      return GDB_SIGNAL_TTOU;

    case LINUX_SIGURG:
      return GDB_SIGNAL_URG;

    case LINUX_SIGXCPU:
      return GDB_SIGNAL_XCPU;

    case LINUX_SIGXFSZ:
      return GDB_SIGNAL_XFSZ;

    case LINUX_SIGVTALRM:
      return GDB_SIGNAL_VTALRM;

    case LINUX_SIGPROF:
      return GDB_SIGNAL_PROF;

    case LINUX_SIGWINCH:
      return GDB_SIGNAL_WINCH;

    /* No way to differentiate between SIGIO and SIGPOLL.
       Therefore, we just handle the first one.  */
    case LINUX_SIGIO:
      return GDB_SIGNAL_IO;

    case LINUX_SIGPWR:
      return GDB_SIGNAL_PWR;

    case LINUX_SIGSYS:
      return GDB_SIGNAL_SYS;

    /* SIGRTMIN and SIGRTMAX are not continuous in <gdb/signals.def>,
       therefore we have to handle them here.  */
    case LINUX_SIGRTMIN:
      return GDB_SIGNAL_REALTIME_32;

    case LINUX_SIGRTMAX:
      return GDB_SIGNAL_REALTIME_64;
    }

  if (signal >= LINUX_SIGRTMIN + 1 && signal <= LINUX_SIGRTMAX - 1)
    {
      int offset = signal - LINUX_SIGRTMIN + 1;

      return (enum gdb_signal) ((int) GDB_SIGNAL_REALTIME_33 + offset);
    }

  return GDB_SIGNAL_UNKNOWN;
}

/* Implementation of `gdbarch_gdb_signal_to_target', as defined in
   gdbarch.h.  This function is not static because it is exported to
   other -tdep files.  */

int
linux_gdb_signal_to_target (struct gdbarch *gdbarch,
			    enum gdb_signal signal)
{
  switch (signal)
    {
    case GDB_SIGNAL_0:
      return 0;

    case GDB_SIGNAL_HUP:
      return LINUX_SIGHUP;

    case GDB_SIGNAL_INT:
      return LINUX_SIGINT;

    case GDB_SIGNAL_QUIT:
      return LINUX_SIGQUIT;

    case GDB_SIGNAL_ILL:
      return LINUX_SIGILL;

    case GDB_SIGNAL_TRAP:
      return LINUX_SIGTRAP;

    case GDB_SIGNAL_ABRT:
      return LINUX_SIGABRT;

    case GDB_SIGNAL_FPE:
      return LINUX_SIGFPE;

    case GDB_SIGNAL_KILL:
      return LINUX_SIGKILL;

    case GDB_SIGNAL_BUS:
      return LINUX_SIGBUS;

    case GDB_SIGNAL_SEGV:
      return LINUX_SIGSEGV;

    case GDB_SIGNAL_SYS:
      return LINUX_SIGSYS;

    case GDB_SIGNAL_PIPE:
      return LINUX_SIGPIPE;

    case GDB_SIGNAL_ALRM:
      return LINUX_SIGALRM;

    case GDB_SIGNAL_TERM:
      return LINUX_SIGTERM;

    case GDB_SIGNAL_URG:
      return LINUX_SIGURG;

    case GDB_SIGNAL_STOP:
      return LINUX_SIGSTOP;

    case GDB_SIGNAL_TSTP:
      return LINUX_SIGTSTP;

    case GDB_SIGNAL_CONT:
      return LINUX_SIGCONT;

    case GDB_SIGNAL_CHLD:
      return LINUX_SIGCHLD;

    case GDB_SIGNAL_TTIN:
      return LINUX_SIGTTIN;

    case GDB_SIGNAL_TTOU:
      return LINUX_SIGTTOU;

    case GDB_SIGNAL_IO:
      return LINUX_SIGIO;

    case GDB_SIGNAL_XCPU:
      return LINUX_SIGXCPU;

    case GDB_SIGNAL_XFSZ:
      return LINUX_SIGXFSZ;

    case GDB_SIGNAL_VTALRM:
      return LINUX_SIGVTALRM;

    case GDB_SIGNAL_PROF:
      return LINUX_SIGPROF;

    case GDB_SIGNAL_WINCH:
      return LINUX_SIGWINCH;

    case GDB_SIGNAL_USR1:
      return LINUX_SIGUSR1;

    case GDB_SIGNAL_USR2:
      return LINUX_SIGUSR2;

    case GDB_SIGNAL_PWR:
      return LINUX_SIGPWR;

    case GDB_SIGNAL_POLL:
      return LINUX_SIGPOLL;

    /* GDB_SIGNAL_REALTIME_32 is not continuous in <gdb/signals.def>,
       therefore we have to handle it here.  */
    case GDB_SIGNAL_REALTIME_32:
      return LINUX_SIGRTMIN;

    /* Same comment applies to _64.  */
    case GDB_SIGNAL_REALTIME_64:
      return LINUX_SIGRTMAX;
    }

  /* GDB_SIGNAL_REALTIME_33 to _64 are continuous.  */
  if (signal >= GDB_SIGNAL_REALTIME_33
      && signal <= GDB_SIGNAL_REALTIME_63)
    {
      int offset = signal - GDB_SIGNAL_REALTIME_33;

      return LINUX_SIGRTMIN + 1 + offset;
    }

  return -1;
}

/* Rummage through mappings to find a mapping's size.  */

static int
find_mapping_size (CORE_ADDR vaddr, unsigned long size,
		   int read, int write, int exec, int modified,
		   void *data)
{
  struct mem_range *range = data;

  if (vaddr == range->start)
    {
      range->length = size;
      return 1;
    }
  return 0;
}

/* Helper for linux_vsyscall_range that does the real work of finding
   the vsyscall's address range.  */

static int
linux_vsyscall_range_raw (struct gdbarch *gdbarch, struct mem_range *range)
{
  if (target_auxv_search (&current_target, AT_SYSINFO_EHDR, &range->start) <= 0)
    return 0;

  /* This is installed by linux_init_abi below, so should always be
     available.  */
  gdb_assert (gdbarch_find_memory_regions_p (target_gdbarch ()));

  range->length = 0;
  gdbarch_find_memory_regions (gdbarch, find_mapping_size, range);
  return 1;
}

/* Implementation of the "vsyscall_range" gdbarch hook.  Handles
   caching, and defers the real work to linux_vsyscall_range_raw.  */

static int
linux_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range)
{
  struct linux_info *info = get_linux_inferior_data ();

  if (info->vsyscall_range_p == 0)
    {
      if (linux_vsyscall_range_raw (gdbarch, &info->vsyscall_range))
	info->vsyscall_range_p = 1;
      else
	info->vsyscall_range_p = -1;
    }

  if (info->vsyscall_range_p < 0)
    return 0;

  *range = info->vsyscall_range;
  return 1;
}

/* To be called from the various GDB_OSABI_LINUX handlers for the
   various GNU/Linux architectures and machine types.  */

void
linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  set_gdbarch_core_pid_to_str (gdbarch, linux_core_pid_to_str);
  set_gdbarch_info_proc (gdbarch, linux_info_proc);
  set_gdbarch_core_info_proc (gdbarch, linux_core_info_proc);
  set_gdbarch_find_memory_regions (gdbarch, linux_find_memory_regions);
  set_gdbarch_make_corefile_notes (gdbarch, linux_make_corefile_notes);
  set_gdbarch_has_shared_address_space (gdbarch,
					linux_has_shared_address_space);
  set_gdbarch_gdb_signal_from_target (gdbarch,
				      linux_gdb_signal_from_target);
  set_gdbarch_gdb_signal_to_target (gdbarch,
				    linux_gdb_signal_to_target);
  set_gdbarch_vsyscall_range (gdbarch, linux_vsyscall_range);
}

/* Provide a prototype to silence -Wmissing-prototypes.  */
extern initialize_file_ftype _initialize_linux_tdep;

void
_initialize_linux_tdep (void)
{
  linux_gdbarch_data_handle =
    gdbarch_data_register_post_init (init_linux_gdbarch_data);

  /* Set a cache per-inferior.  */
  linux_inferior_data
    = register_inferior_data_with_cleanup (NULL, linux_inferior_data_cleanup);
  /* Observers used to invalidate the cache when needed.  */
  observer_attach_inferior_exit (invalidate_linux_cache_inf);
  observer_attach_inferior_appeared (invalidate_linux_cache_inf);
}