Crash in malloc_consolidate (via make_gap_larger, xrealloc).

[Kim F. Storm]

Seems it was trying to insert a 23 byte string in an empty buffer with
a gap of 21 bytes; current command is directory-files, crash
happens during decoding into a (temporary?) buffer.

Anyone seen this before?

Program received signal SIGSEGV, Segmentation fault.
0x4207494e in malloc_consolidate () from /lib/tls/libc.so.6

(gdb) bt
#0  0x4207494e in malloc_consolidate () from /lib/tls/libc.so.6
#1  0x42073f99 in _int_malloc () from /lib/tls/libc.so.6
#2  0x42074b81 in _int_realloc () from /lib/tls/libc.so.6
#3  0x42073614 in realloc () from /lib/tls/libc.so.6
#4  0x08129eae in emacs_blocked_realloc (ptr=0x8fb4918, size=2024)
    at alloc.c:1052
#5  0x4207354c in realloc () from /lib/tls/libc.so.6
#6  0x08129897 in xrealloc (block=0x8e67c70, size=1108546304) at alloc.c:549
#7  0x080ff135 in enlarge_buffer_text (b=0x42131300, delta=2002)
    at buffer.c:4875
#8  0x08101a2b in make_gap_larger (nbytes_added=32) at insdel.c:534
#9  0x08102485 in insert_from_string_1 (string=148682499, pos=0, pos_byte=0,
    nchars=23, nbytes=23, inherit=0, before_markers=0) at insdel.c:1115
#10 0x0810220c in insert_from_string (string=148682499, pos=0, pos_byte=0,
    length=23, length_byte=23, inherit=0) at insdel.c:1060
#11 0x080a20df in run_pre_post_conversion_on_str (str=148682499,
    coding=0xbfffce70, encodep=0) at coding.c:6049
#12 0x080a269a in decode_coding_string (str=148682515, coding=0xbfffce70,
    nocopy=1) at coding.c:6251
#13 0x080a4196 in code_convert_string_norecord (string=148682515,
    coding_system=138270673, encodep=0) at coding.c:7060
#14 0x0811250f in directory_files_internal (directory=148285827,
    full=138214569, match=148285859, nosort=138214521, attrs=0,
    id_format=138214521) at dired.c:293
#15 0x081126db in Fdirectory_files (directory=148285827, full=138214569,
    match=148285859, nosort=138214521) at dired.c:365
---Type <return> to continue, or q <return> to quit---
#16 0x08140397 in Ffuncall (nargs=4, args=0xbfffd270) at eval.c:2726
#17 0x08169f1c in Fbyte_code (bytestr=144541249, vector=3,
    maxdepth=-1073753372) at bytecode.c:689
#18 0x0814066e in funcall_lambda (fun=146521508, nargs=1,
    arg_vector=0xbfffd408) at eval.c:2913
#19 0x08140277 in Ffuncall (nargs=2, args=0xbfffd404) at eval.c:2783
#20 0x08169f1c in Fbyte_code (bytestr=138566177, vector=1,
    maxdepth=-1073753084) at bytecode.c:689
#21 0x0814066e in funcall_lambda (fun=146522444, nargs=1,
    arg_vector=0xbfffd528) at eval.c:2913
#22 0x08140277 in Ffuncall (nargs=2, args=0xbfffd524) at eval.c:2783
#23 0x08169f1c in Fbyte_code (bytestr=138566177, vector=1,
    maxdepth=-1073752796) at bytecode.c:689
#24 0x0814066e in funcall_lambda (fun=146789484, nargs=0,
    arg_vector=0xbfffd644) at eval.c:2913
#25 0x08140277 in Ffuncall (nargs=1, args=0xbfffd640) at eval.c:2783
#26 0x08169f1c in Fbyte_code (bytestr=146778840, vector=0,
    maxdepth=-1073752512) at bytecode.c:689
#27 0x0814066e in funcall_lambda (fun=146789676, nargs=0,
    arg_vector=0xbfffd754) at eval.c:2913
#28 0x08140277 in Ffuncall (nargs=1, args=0xbfffd750) at eval.c:2783
#29 0x08169f1c in Fbyte_code (bytestr=144541513, vector=0,
    maxdepth=-1073752240) at bytecode.c:689
#30 0x0814066e in funcall_lambda (fun=145866172, nargs=6,
    arg_vector=0xbfffd874) at eval.c:2913
#31 0x08140277 in Ffuncall (nargs=7, args=0xbfffd870) at eval.c:2783
---Type <return> to continue, or q <return> to quit---
#32 0x08169f1c in Fbyte_code (bytestr=145695785, vector=6,
    maxdepth=-1073751952) at bytecode.c:689
#33 0x0814066e in funcall_lambda (fun=145865396, nargs=7,
    arg_vector=0xbfffd994) at eval.c:2913
#34 0x08140277 in Ffuncall (nargs=8, args=0xbfffd990) at eval.c:2783
#35 0x08169f1c in Fbyte_code (bytestr=145695785, vector=7,
    maxdepth=-1073751664) at bytecode.c:689
#36 0x0814066e in funcall_lambda (fun=145706364, nargs=3,
    arg_vector=0xbfffdab4) at eval.c:2913
#37 0x08140277 in Ffuncall (nargs=4, args=0xbfffdab0) at eval.c:2783
#38 0x08169f1c in Fbyte_code (bytestr=138566177, vector=3,
    maxdepth=-1073751376) at bytecode.c:689
#39 0x0814066e in funcall_lambda (fun=146598708, nargs=1,
    arg_vector=0xbfffdbf4) at eval.c:2913
#40 0x08140277 in Ffuncall (nargs=2, args=0xbfffdbf0) at eval.c:2783
#41 0x0813c022 in Fcall_interactively (function=146590289,
    record_flag=17276815, keys=138271380) at callint.c:862
#42 0x080ee64b in Fcommand_execute (cmd=146590289, record_flag=138214521,
    keys=138214521, special=0) at keyboard.c:9682
#43 0x080e3798 in command_loop_1 () at keyboard.c:1740
#44 0x0813e836 in internal_condition_case (bfun=0x80e33e8 <command_loop_1>,
    handlers=138275449, hfun=0x80e2f68 <cmd_error>) at eval.c:1333
#45 0x080e325e in command_loop_2 () at keyboard.c:1271
#46 0x0813e3a9 in internal_catch (tag=149322864,
    func=0x80e3240 <command_loop_2>, arg=138214521) at eval.c:1094
#47 0x080e3214 in command_loop () at keyboard.c:1250
---Type <return> to continue, or q <return> to quit---
#48 0x080e2d34 in recursive_edit_1 () at keyboard.c:961
#49 0x080e2e54 in Frecursive_edit () at keyboard.c:1022
#50 0x080e1760 in main (argc=3, argv=0xbfffe3a4) at emacs.c:1693
#51 0x42015574 in __libc_start_main () from /lib/tls/libc.so.6
(gdb) xbacktrace
"directory-files"
"gnus-score-score-files"
"gnus-score-find-bnews"
"gnus-all-score-files"
"gnus-possibly-score-headers"
"gnus-summary-read-group-1"
"gnus-summary-read-group"
"gnus-group-read-group"
"gnus-topic-read-group"
"call-interactively"
(gdb) p current_buffer
$1 = (struct buffer *) 0x869a4a8
(gdb) p *current_buffer
$2 = {
  size = 1073873011,
  next = 0x8690d78,
  own_text = {
    beg = 0x8fb4918 "",
    gpt = 1,
    z = 1,
    gpt_byte = 1,
    z_byte = 1,
    gap_size = 21,
    modiff = 603761,
    save_modiff = 0,
    overlay_modiff = 1,
    beg_unchanged = 0,
    end_unchanged = 0,
    unchanged_modified = 1,
    overlay_unchanged_modified = 1,
    intervals = 0x0,
    markers = 0x0
  },
  text = 0x869a4b0,
  pt = 1,
  pt_byte = 1,
  begv = 1,
  begv_byte = 1,
  zv = 1,
---Type <return> to continue, or q <return> to quit---
  zv_byte = 1,
  base_buffer = 0x0,
  local_flags = '\0' <repeats 34 times>, "j\b uj\b`\200j\b`\200j\b\000",
  modtime = 0,
  auto_save_modified = 0,
  display_error_modiff = 0,
  auto_save_failure_time = -1,
  last_window_start = 1,
  clip_changed = 0,
  newline_cache = 0x0,
  width_run_cache = 0x0,
  prevent_redisplay_optimizations_p = 1,
  overlays_before = 0x0,
  overlays_after = 0x0,
  overlay_center = 1,
  name = 141136379,
  filename = 138214521,
  directory = 152117907,
  backed_up = 138214521,
  save_length = 0,
  auto_save_file_name = 138214521,
  read_only = 138214521,
  mark = 139716594,
  local_var_alist = 143885701,
  major_mode = 138214761,
  mode_name = 138221803,
---Type <return> to continue, or q <return> to quit---
  mode_line_format = 138614301,
  undo_list = 138214569,
  header_line_format = 138214521,
  keymap = 138214521,
  abbrev_table = 138307132,
  syntax_table = 138251828,
  category_table = 138253396,
  case_fold_search = 138214569,
  tab_width = 64,
  fill_column = 560,
  left_margin = 0,
  auto_fill_function = 138214521,
  buffer_file_type = 138214521,
  downcase_table = 138254972,
  upcase_table = 139802972,
  case_canon_table = 139889652,
  case_eqv_table = 139911140,
  truncate_lines = 138214521,
  ctl_arrow = 138214569,
  direction_reversed = 138214521,
  selective_display = 138214521,
  selective_display_ellipses = 138214569,
  minor_modes = 138214521,
  overwrite_mode = 138214521,
  abbrev_mode = 138214521,
  display_table = 138214521,
---Type <return> to continue, or q <return> to quit---
  mark_active = 138214521,
  enable_multibyte_characters = 138214569,
  buffer_file_coding_system = 138270673,
  file_format = 138214521,
  cache_long_line_scans = 138214521,
  width_table = 138214521,
  pt_marker = 138214521,
  begv_marker = 138214521,
  zv_marker = 138214521,
  point_before_scroll = 138214521,
  file_truename = 138214521,
  invisibility_spec = 138214569,
  last_selected_window = 138214521,
  display_count = 0,
  left_margin_cols = 0,
  right_margin_cols = 0,
  left_fringe_width = 138214521,
  right_fringe_width = 138214521,
  fringes_outside_margins = 138214521,
  scroll_bar_width = 138214521,
  vertical_scroll_bar_type = 138214569,
  indicate_empty_lines = 138214521,
  indicate_buffer_boundaries = 143820453,
  display_time = 138214521,
  scroll_up_aggressively = 138214521,
  scroll_down_aggressively = 138214521,
---Type <return> to continue, or q <return> to quit---
  cursor_type = 138413425,
  extra_line_spacing = 138214521
}
(gdb) up
#9  0x08102485 in insert_from_string_1 (string=148682499, pos=0, pos_byte=0,
    nchars=23, nbytes=23, inherit=0, before_markers=0) at insdel.c:1115


1115        make_gap (outgoing_nbytes - GAP_SIZE);
(gdb) p string
$3 = 148682499
(gdb) pr
"gnu.emacs.sources.SCORE"
(gdb) p outgoing_nbytes
$4 = 23


(gdb) up
#10 0x0810220c in insert_from_string (string=148682499, pos=0, pos_byte=0,
    length=23, length_byte=23, inherit=0) at insdel.c:1060
1060      insert_from_string_1 (string, pos, pos_byte, length, length_byte,
(gdb) up
#11 0x080a20df in run_pre_post_conversion_on_str (str=148682499,
    coding=0xbfffce70, encodep=0) at coding.c:6049
6049      insert_from_string (str, 0, 0,
(gdb) p str
$5 = 148682499
(gdb) pr
"gnu.emacs.sources.SCORE"
(gdb) p coding
$6 = (struct coding_system *) 0xbfffce70
(gdb) p *coding
$7 = {
  type = coding_type_ccl,
  eol_type = 3,
  common_flags = 15,
  flags = 0,
  mode = 3,
  composing = 0,
  composition_rule_follows = 0,
  cmp_data = 0x0,
  cmp_data_start = 0,
  cmp_data_index = 0,
  spec = {
    iso2022 = {
      current_invocation = {420, 139159312},
      current_designation = {419, 363, -1, 0},
      initial_designation = {0, 0, 0, 158},
      last_invalid_designation_register = 128,
      requested_designation = 
"\000\000\000\000\000\000\000\000\002\000\000\000\000\000\000\000\002", '\0' 
<repeats 27 times>, "\363\000\000\000\bnK\b\002\000\000\000\350", '\0' <repeats 
47 times>, "\001", '\0' <repeats 27 times>, '\001' <repeats 123 times>,
      charset_revision_number = '\001' <repeats 133 times>, '\0' <repeats 121 
times>,
      single_shifting = 0,
      bol = 0
    },
---Type <return> to continue, or q <return> to quit---
    ccl = {
      decoder = {
        size = 420,
        prog = 0x84b6710,
        ic = 419,
        eof_ic = 363,
        reg = {-1, 0, 0, 0, 0, 158, 128, 0},
        private_state = 0,
        last_block = 2,
        status = 0,
        buf_magnification = 2,
        stack_idx = 0,
        eol_type = 0,
        multibyte = 0,
        cr_consumed = 0,
        suppress_error = 0,
        eight_bit_control = 0
      },
      encoder = {
        size = 243,
        prog = 0x84b6e08,
        ic = 2,
        eof_ic = 232,
        reg = {0, 0, 0, 0, 0, 0, 0, 0},
        private_state = 0,
        last_block = 0,
---Type <return> to continue, or q <return> to quit---
        status = 0,
        buf_magnification = 1,
        stack_idx = 0,
        eol_type = 0,
        multibyte = 0,
        cr_consumed = 0,
        suppress_error = 0,
        eight_bit_control = 0
      },
      valid_codes = '\001' <repeats 256 times>,
      cr_carryover = 0,
      eight_bit_carryover = "\000\000\000"
    }
  },
  category_idx = 10,
  src_multibyte = 0,
  dst_multibyte = 1,
  heading_ascii = -1,
  produced = 23,
  produced_char = 23,
  consumed = 23,
  consumed_char = 0,
  errors = 0,
  result = 0,
  suppress_error = 0,
  symbol = 138270673,
---Type <return> to continue, or q <return> to quit---
  post_read_conversion = 139140513,
  pre_write_conversion = 138214521,
  translation_table_for_decode = 138214521,
  translation_table_for_encode = 138214521
}
(gdb)

void
make_gap_larger (nbytes_added)
     int nbytes_added;
{
  Lisp_Object tem;
  int real_gap_loc;
  int real_gap_loc_byte;
  int old_gap_size;

  /* If we have to get more space, get enough to last a while.  */
  nbytes_added += 2000;

  /* Don't allow a buffer size that won't fit in an int
     even if it will fit in a Lisp integer.
     That won't work because so many places use `int'.

     Make sure we don't introduce overflows in the calculation.  */

  if (Z_BYTE - BEG_BYTE + GAP_SIZE
      >= (((EMACS_INT) 1 << (min (VALBITS, BITS_PER_INT) - 1)) - 1
          - nbytes_added))
    error ("Buffer exceeds maximum size");

  enlarge_buffer_text (current_buffer, nbytes_added);




void
enlarge_buffer_text (b, delta)
     struct buffer *b;
     int delta;
{
  POINTER_TYPE *p;
  size_t nbytes = (BUF_Z_BYTE (b) - BUF_BEG_BYTE (b) + BUF_GAP_SIZE (b) + 1
                   + delta);
  BLOCK_INPUT;
  p = xrealloc (b->text->beg, nbytes);

(gdb) p current_buffer->text
$27 = (struct buffer_text *) 0x869a4b0
(gdb) p *current_buffer->text
$28 = {
  beg = 0x8fb4918 "",
  gpt = 1,
  z = 1,
  gpt_byte = 1,
  z_byte = 1,
  gap_size = 21,
  modiff = 603761,
  save_modiff = 0,
  overlay_modiff = 1,
  beg_unchanged = 0,
  end_unchanged = 0,
  unchanged_modified = 1,
  overlay_unchanged_modified = 1,
  intervals = 0x0,
  markers = 0x0
}
(gdb) p current_buffer->text->beg
$29 = (unsigned char *) 0x8fb4918 ""
(gdb) x/20 current_buffer->text->beg
0x8fb4918:      0x706d6f00      0x616d652e      0x532e7363      0x45524f43
0x8fb4928:      0x00000000      0x00000000      0x406e0000      0x000003f9
0x8fb4938:      0x00000036      0x0000c5ee      0x08fb43b0      0x08fb43cc
0x8fb4948:      0x08fb4244      0x08d0b8c0      0x09403fdd      0x00000043
0x8fb4958:      0x0000c571      0x08fb4970      0x08fb49a8      0x08fb498c
(gdb) x/20c current_buffer->text->beg
0x8fb4918:      0 '\0'  111 'o' 109 'm' 112 'p' 46 '.'  101 'e' 109 'm' 97 'a'
0x8fb4920:      99 'c'  115 's' 46 '.'  83 'S'  67 'C'  79 'O'  82 'R'  69 'E'
0x8fb4928:      0 '\0'  0 '\0'  0 '\0'  0 '\0'
(gdb) up
#8  0x08101a2b in make_gap_larger (nbytes_added=32) at insdel.c:534
534       enlarge_buffer_text (current_buffer, nbytes_added);
(gdb) up
#9  0x08102485 in insert_from_string_1 (string=148682499, pos=0, pos_byte=0,
    nchars=23, nbytes=23, inherit=0, before_markers=0) at insdel.c:1115
1115        make_gap (outgoing_nbytes - GAP_SIZE);
(gdb) up
#10 0x0810220c in insert_from_string (string=148682499, pos=0, pos_byte=0,
    length=23, length_byte=23, inherit=0) at insdel.c:1060
1060      insert_from_string_1 (string, pos, pos_byte, length, length_byte,
(gdb) p string
$30 = 148682499
(gdb) xtype
Lisp_String
(gdb) xstring
$31 = (struct Lisp_String *) 0x8dcb700
"gnu.emacs.sources.SCORE"
(gdb) x/40c current_buffer->text->beg
0x8fb4918:      0 '\0'  111 'o' 109 'm' 112 'p' 46 '.'  101 'e' 109 'm' 97 'a'
0x8fb4920:      99 'c'  115 's' 46 '.'  83 'S'  67 'C'  79 'O'  82 'R'  69 'E'
0x8fb4928:      0 '\0'  0 '\0'  0 '\0'  0 '\0'  0 '\0'  0 '\0'  0 '\0'  0 '\0'
0x8fb4930:      0 '\0'  0 '\0'  110 'n' 64 '@'  -7 '\371'       3 '\003'        
0 '\0'  0 '\0'
0x8fb4938:      54 '6'  0 '\0'  0 '\0'  0 '\0'  -18 '\356'      -59 '\305'      
0 '\0'  0 '\0'

-- 
Kim F. Storm <address@hidden> http://www.cua.dk