gdb/

[deliverable/binutils-gdb.git] / gdb / linux-tdep.c

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

   Copyright (C) 2009-2013 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 "cli/cli-utils.h"

#include <ctype.h>

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);
}

/* 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;
}

static int
linux_has_shared_address_space (struct gdbarch *gdbarch)
{
  /* Determine whether we are running on uClinux or normal Linux
     kernel.  */
  CORE_ADDR dummy;
  int target_is_uclinux;

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

  return target_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, 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];
  gdb_byte *data;
  int target_errno;

  if (args && isdigit (args[0]))
    pid = strtoul (args, &args, 10);
  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 (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 == '(')
            {
              const char *ep = strchr (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, 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, 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];
  gdb_byte *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 (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;
}

/* 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 core_regset_section *sect_list;
  unsigned long lwp;

  sect_list = gdbarch_core_regset_sections (gdbarch);
  gdb_assert (sect_list);

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

  while (sect_list->sect_name != NULL)
    {
      const struct regset *regset;
      char *buf;

      regset = gdbarch_regset_from_core_section (gdbarch,
                                                 sect_list->sect_name,
                                                 sect_list->size);
      gdb_assert (regset && regset->collect_regset);

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

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

      if (!note_data)
        return NULL;
    }

  return 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;
  int num_notes;
  enum gdb_signal stop_signal;
  linux_collect_thread_registers_ftype collect;
};

/* 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;

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

      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 = args->collect (regcache, info->ptid, args->obfd,
                                       args->note_data, args->note_size,
                                       args->stop_signal);
      args->num_notes++;

      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);
          args->num_notes++;
        }

      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);

  /* Getting rid of the executable name, since we already have it.  We
     know that this name will be in parentheses, so we can safely look
     for the close-paren.  */
  while (*proc_stat != ')')
    ++proc_stat;
  ++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;
}

/* Fills the "to_make_corefile_note" target vector.  Builds the note
   section for a corefile, and returns it in a malloc buffer.  */

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

  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.  */
  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.num_notes = 0;
  thread_args.stop_signal = find_stop_signal ();
  thread_args.collect = collect;
  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);

  make_cleanup (xfree, note_data);
  return note_data;
}

static char *
linux_make_corefile_notes_1 (struct gdbarch *gdbarch, bfd *obfd, int *note_size)
{
  /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been
     converted to gdbarch_core_regset_sections, we no longer need to fall back
     to the target method at this point.  */

  if (!gdbarch_core_regset_sections (gdbarch))
    return target_make_corefile_notes (obfd, note_size);
  else
    return linux_make_corefile_notes (gdbarch, obfd, note_size,
                                      linux_collect_thread_registers);
}

/* 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_1);
  set_gdbarch_has_shared_address_space (gdbarch,
                                        linux_has_shared_address_space);
}

/* 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);
}