libio/vtables.c

   1 /* libio vtable validation.
   2    Copyright (C) 2016-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <dlfcn.h>
  20 #include <libioP.h>
  21 #include <stdio.h>
  22 #include <ldsodefs.h>
  23 #include <pointer_guard.h>
  24 #include <libio-macros.h>
  25
  26 /* Both _IO_str_* and _IO_new_file functions are pulled into every link (from
  27    stdio initialization).  */
  28 #ifndef SHARED
  29 /* NB: the following directives do add pragma weak for _IO_default _* and
  30    _IO_wdefault_* symbols to potentially avoid link failures, since they
  31    are always used when the __io_vtables is used.  */
  32 # pragma weak _IO_wstr_finish
  33 # pragma weak _IO_wstr_overflow
  34 # pragma weak _IO_wstr_pbackfail
  35 # pragma weak _IO_wstr_seekoff
  36 # pragma weak _IO_wstr_underflow
  37
  38 # pragma weak _IO_file_close
  39 # pragma weak _IO_file_close_mmap
  40 # pragma weak _IO_file_doallocate
  41 # pragma weak _IO_file_finish
  42 # pragma weak _IO_file_overflow
  43 # pragma weak _IO_file_read
  44 # pragma weak _IO_file_seek
  45 # pragma weak _IO_file_seekoff_maybe_mmap
  46 # pragma weak _IO_file_seekoff_mmap
  47 # pragma weak _IO_file_setbuf
  48 # pragma weak _IO_file_setbuf_mmap
  49 # pragma weak _IO_file_setbuf_mmap
  50 # pragma weak _IO_file_stat
  51 # pragma weak _IO_file_sync
  52 # pragma weak _IO_file_sync_mmap
  53 # pragma weak _IO_file_underflow
  54 # pragma weak _IO_file_underflow_maybe_mmap
  55 # pragma weak _IO_file_underflow_mmap
  56 # pragma weak _IO_file_xsgetn
  57 # pragma weak _IO_file_xsgetn_maybe_mmap
  58 # pragma weak _IO_file_xsgetn_mmap
  59 # pragma weak _IO_file_xsputn
  60
  61 # pragma weak _IO_wfile_overflow
  62 # pragma weak _IO_wfile_sync
  63 # pragma weak _IO_wfile_underflow
  64 # pragma weak _IO_wfile_underflow_maybe_mmap
  65 # pragma weak _IO_wfile_underflow_mmap
  66 # pragma weak _IO_wfile_doallocate
  67 # pragma weak _IO_wfile_seekoff
  68 # pragma weak _IO_wfile_xsputn
  69
  70 # pragma weak _IO_new_proc_close
  71
  72 # pragma weak _IO_cookie_close
  73 # pragma weak _IO_cookie_read
  74 # pragma weak _IO_cookie_seek
  75 # pragma weak _IO_cookie_seekoff
  76 # pragma weak _IO_cookie_write
  77
  78 # pragma weak _IO_mem_finish
  79 # pragma weak _IO_mem_sync
  80
  81 # pragma weak _IO_wmem_finish
  82 # pragma weak _IO_wmem_sync
  83
  84 # pragma weak __printf_buffer_as_file_overflow
  85 # pragma weak __printf_buffer_as_file_xsputn
  86
  87 # pragma weak __wprintf_buffer_as_file_overflow
  88 # pragma weak __wprintf_buffer_as_file_xsputn
  89 #endif
  90
  91 const struct _IO_jump_t __io_vtables[IO_VTABLES_LEN] attribute_relro =
  92 {
  93   /* _IO_str_jumps  */
  94   [IO_STR_JUMPS] =
  95   {
  96     JUMP_INIT_DUMMY,
  97     JUMP_INIT (finish, _IO_str_finish),
  98     JUMP_INIT (overflow, _IO_str_overflow),
  99     JUMP_INIT (underflow, _IO_str_underflow),
 100     JUMP_INIT (uflow, _IO_default_uflow),
 101     JUMP_INIT (pbackfail, _IO_str_pbackfail),
 102     JUMP_INIT (xsputn, _IO_default_xsputn),
 103     JUMP_INIT (xsgetn, _IO_default_xsgetn),
 104     JUMP_INIT (seekoff, _IO_str_seekoff),
 105     JUMP_INIT (seekpos, _IO_default_seekpos),
 106     JUMP_INIT (setbuf, _IO_default_setbuf),
 107     JUMP_INIT (sync, _IO_default_sync),
 108     JUMP_INIT (doallocate, _IO_default_doallocate),
 109     JUMP_INIT (read, _IO_default_read),
 110     JUMP_INIT (write, _IO_default_write),
 111     JUMP_INIT (seek, _IO_default_seek),
 112     JUMP_INIT (close, _IO_default_close),
 113     JUMP_INIT (stat, _IO_default_stat),
 114     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 115     JUMP_INIT (imbue, _IO_default_imbue)
 116   },
 117   /* _IO_wstr_jumps  */
 118   [IO_WSTR_JUMPS] = {
 119     JUMP_INIT_DUMMY,
 120     JUMP_INIT (finish, _IO_wstr_finish),
 121     JUMP_INIT (overflow, (_IO_overflow_t) _IO_wstr_overflow),
 122     JUMP_INIT (underflow, (_IO_underflow_t) _IO_wstr_underflow),
 123     JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
 124     JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
 125     JUMP_INIT (xsputn, _IO_wdefault_xsputn),
 126     JUMP_INIT (xsgetn, _IO_wdefault_xsgetn),
 127     JUMP_INIT (seekoff, _IO_wstr_seekoff),
 128     JUMP_INIT (seekpos, _IO_default_seekpos),
 129     JUMP_INIT (setbuf, _IO_default_setbuf),
 130     JUMP_INIT (sync, _IO_default_sync),
 131     JUMP_INIT (doallocate, _IO_wdefault_doallocate),
 132     JUMP_INIT (read, _IO_default_read),
 133     JUMP_INIT (write, _IO_default_write),
 134     JUMP_INIT (seek, _IO_default_seek),
 135     JUMP_INIT (close, _IO_default_close),
 136     JUMP_INIT (stat, _IO_default_stat),
 137     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 138     JUMP_INIT (imbue, _IO_default_imbue)
 139   },
 140   /* _IO_file_jumps  */
 141   [IO_FILE_JUMPS] = {
 142     JUMP_INIT_DUMMY,
 143     JUMP_INIT (finish, _IO_file_finish),
 144     JUMP_INIT (overflow, _IO_file_overflow),
 145     JUMP_INIT (underflow, _IO_file_underflow),
 146     JUMP_INIT (uflow, _IO_default_uflow),
 147     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 148     JUMP_INIT (xsputn, _IO_file_xsputn),
 149     JUMP_INIT (xsgetn, _IO_file_xsgetn),
 150     JUMP_INIT (seekoff, _IO_new_file_seekoff),
 151     JUMP_INIT (seekpos, _IO_default_seekpos),
 152     JUMP_INIT (setbuf, _IO_new_file_setbuf),
 153     JUMP_INIT (sync, _IO_new_file_sync),
 154     JUMP_INIT (doallocate, _IO_file_doallocate),
 155     JUMP_INIT (read, _IO_file_read),
 156     JUMP_INIT (write, _IO_new_file_write),
 157     JUMP_INIT (seek, _IO_file_seek),
 158     JUMP_INIT (close, _IO_file_close),
 159     JUMP_INIT (stat, _IO_file_stat),
 160     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 161     JUMP_INIT (imbue, _IO_default_imbue)
 162   },
 163   /* _IO_file_jumps_mmap  */
 164   [IO_FILE_JUMPS_MMAP] = {
 165     JUMP_INIT_DUMMY,
 166     JUMP_INIT (finish, _IO_file_finish),
 167     JUMP_INIT (overflow, _IO_file_overflow),
 168     JUMP_INIT (underflow, _IO_file_underflow_mmap),
 169     JUMP_INIT (uflow, _IO_default_uflow),
 170     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 171     JUMP_INIT (xsputn, _IO_new_file_xsputn),
 172     JUMP_INIT (xsgetn, _IO_file_xsgetn_mmap),
 173     JUMP_INIT (seekoff, _IO_file_seekoff_mmap),
 174     JUMP_INIT (seekpos, _IO_default_seekpos),
 175     JUMP_INIT (setbuf, (_IO_setbuf_t) _IO_file_setbuf_mmap),
 176     JUMP_INIT (sync, _IO_file_sync_mmap),
 177     JUMP_INIT (doallocate, _IO_file_doallocate),
 178     JUMP_INIT (read, _IO_file_read),
 179     JUMP_INIT (write, _IO_new_file_write),
 180     JUMP_INIT (seek, _IO_file_seek),
 181     JUMP_INIT (close, _IO_file_close_mmap),
 182     JUMP_INIT (stat, _IO_file_stat),
 183     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 184     JUMP_INIT (imbue, _IO_default_imbue)
 185   },
 186   /* _IO_file_jumps_maybe_mmap  */
 187   [IO_FILE_JUMPS_MAYBE_MMAP] = {
 188     JUMP_INIT_DUMMY,
 189     JUMP_INIT (finish, _IO_file_finish),
 190     JUMP_INIT (overflow, _IO_file_overflow),
 191     JUMP_INIT (underflow, _IO_file_underflow_maybe_mmap),
 192     JUMP_INIT (uflow, _IO_default_uflow),
 193     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 194     JUMP_INIT (xsputn, _IO_new_file_xsputn),
 195     JUMP_INIT (xsgetn, _IO_file_xsgetn_maybe_mmap),
 196     JUMP_INIT (seekoff, _IO_file_seekoff_maybe_mmap),
 197     JUMP_INIT (seekpos, _IO_default_seekpos),
 198     JUMP_INIT (setbuf, (_IO_setbuf_t) _IO_file_setbuf_mmap),
 199     JUMP_INIT (sync, _IO_new_file_sync),
 200     JUMP_INIT (doallocate, _IO_file_doallocate),
 201     JUMP_INIT (read, _IO_file_read),
 202     JUMP_INIT (write, _IO_new_file_write),
 203     JUMP_INIT (seek, _IO_file_seek),
 204     JUMP_INIT (close, _IO_file_close),
 205     JUMP_INIT (stat, _IO_file_stat),
 206     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 207     JUMP_INIT (imbue, _IO_default_imbue)
 208   },
 209   /* _IO_wfile_jumps  */
 210   [IO_WFILE_JUMPS] = {
 211     JUMP_INIT_DUMMY,
 212     JUMP_INIT (finish, _IO_new_file_finish),
 213     JUMP_INIT (overflow, (_IO_overflow_t) _IO_wfile_overflow),
 214     JUMP_INIT (underflow, (_IO_underflow_t) _IO_wfile_underflow),
 215     JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
 216     JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
 217     JUMP_INIT (xsputn, _IO_wfile_xsputn),
 218     JUMP_INIT (xsgetn, _IO_file_xsgetn),
 219     JUMP_INIT (seekoff, _IO_wfile_seekoff),
 220     JUMP_INIT (seekpos, _IO_default_seekpos),
 221     JUMP_INIT (setbuf, _IO_new_file_setbuf),
 222     JUMP_INIT (sync, (_IO_sync_t) _IO_wfile_sync),
 223     JUMP_INIT (doallocate, _IO_wfile_doallocate),
 224     JUMP_INIT (read, _IO_file_read),
 225     JUMP_INIT (write, _IO_new_file_write),
 226     JUMP_INIT (seek, _IO_file_seek),
 227     JUMP_INIT (close, _IO_file_close),
 228     JUMP_INIT (stat, _IO_file_stat),
 229     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 230     JUMP_INIT (imbue, _IO_default_imbue)
 231   },
 232   /* _IO_wfile_jumps_mmap  */
 233   [IO_WFILE_JUMPS_MMAP] = {
 234     JUMP_INIT_DUMMY,
 235     JUMP_INIT (finish, _IO_new_file_finish),
 236     JUMP_INIT (overflow, (_IO_overflow_t) _IO_wfile_overflow),
 237     JUMP_INIT (underflow, (_IO_underflow_t) _IO_wfile_underflow_mmap),
 238     JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
 239     JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
 240     JUMP_INIT (xsputn, _IO_wfile_xsputn),
 241     JUMP_INIT (xsgetn, _IO_file_xsgetn),
 242     JUMP_INIT (seekoff, _IO_wfile_seekoff),
 243     JUMP_INIT (seekpos, _IO_default_seekpos),
 244     JUMP_INIT (setbuf, _IO_file_setbuf_mmap),
 245     JUMP_INIT (sync, (_IO_sync_t) _IO_wfile_sync),
 246     JUMP_INIT (doallocate, _IO_wfile_doallocate),
 247     JUMP_INIT (read, _IO_file_read),
 248     JUMP_INIT (write, _IO_new_file_write),
 249     JUMP_INIT (seek, _IO_file_seek),
 250     JUMP_INIT (close, _IO_file_close_mmap),
 251     JUMP_INIT (stat, _IO_file_stat),
 252     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 253     JUMP_INIT (imbue, _IO_default_imbue)
 254   },
 255   /* _IO_wfile_jumps_maybe_mmap  */
 256   [IO_WFILE_JUMPS_MAYBE_MMAP] = {
 257     JUMP_INIT_DUMMY,
 258     JUMP_INIT (finish, _IO_new_file_finish),
 259     JUMP_INIT (overflow, (_IO_overflow_t) _IO_wfile_overflow),
 260     JUMP_INIT (underflow, (_IO_underflow_t) _IO_wfile_underflow_maybe_mmap),
 261     JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
 262     JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
 263     JUMP_INIT (xsputn, _IO_wfile_xsputn),
 264     JUMP_INIT (xsgetn, _IO_file_xsgetn),
 265     JUMP_INIT (seekoff, _IO_wfile_seekoff),
 266     JUMP_INIT (seekpos, _IO_default_seekpos),
 267     JUMP_INIT (setbuf, _IO_file_setbuf_mmap),
 268     JUMP_INIT (sync, (_IO_sync_t) _IO_wfile_sync),
 269     JUMP_INIT (doallocate, _IO_wfile_doallocate),
 270     JUMP_INIT (read, _IO_file_read),
 271     JUMP_INIT (write, _IO_new_file_write),
 272     JUMP_INIT (seek, _IO_file_seek),
 273     JUMP_INIT (close, _IO_file_close),
 274     JUMP_INIT (stat, _IO_file_stat),
 275     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 276     JUMP_INIT (imbue, _IO_default_imbue)
 277   },
 278   /* _IO_cookie_jumps  */
 279   [IO_COOKIE_JUMPS] = {
 280     JUMP_INIT_DUMMY,
 281     JUMP_INIT (finish, _IO_file_finish),
 282     JUMP_INIT (overflow, _IO_file_overflow),
 283     JUMP_INIT (underflow, _IO_file_underflow),
 284     JUMP_INIT (uflow, _IO_default_uflow),
 285     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 286     JUMP_INIT (xsputn, _IO_file_xsputn),
 287     JUMP_INIT (xsgetn, _IO_default_xsgetn),
 288     JUMP_INIT (seekoff, _IO_cookie_seekoff),
 289     JUMP_INIT (seekpos, _IO_default_seekpos),
 290     JUMP_INIT (setbuf, _IO_file_setbuf),
 291     JUMP_INIT (sync, _IO_file_sync),
 292     JUMP_INIT (doallocate, _IO_file_doallocate),
 293     JUMP_INIT (read, _IO_cookie_read),
 294     JUMP_INIT (write, _IO_cookie_write),
 295     JUMP_INIT (seek, _IO_cookie_seek),
 296     JUMP_INIT (close, _IO_cookie_close),
 297     JUMP_INIT (stat, _IO_default_stat),
 298     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 299     JUMP_INIT (imbue, _IO_default_imbue),
 300   },
 301   /* _IO_proc_jumps  */
 302   [IO_PROC_JUMPS] = {
 303     JUMP_INIT_DUMMY,
 304     JUMP_INIT (finish, _IO_new_file_finish),
 305     JUMP_INIT (overflow, _IO_new_file_overflow),
 306     JUMP_INIT (underflow, _IO_new_file_underflow),
 307     JUMP_INIT (uflow, _IO_default_uflow),
 308     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 309     JUMP_INIT (xsputn, _IO_new_file_xsputn),
 310     JUMP_INIT (xsgetn, _IO_default_xsgetn),
 311     JUMP_INIT (seekoff, _IO_new_file_seekoff),
 312     JUMP_INIT (seekpos, _IO_default_seekpos),
 313     JUMP_INIT (setbuf, _IO_new_file_setbuf),
 314     JUMP_INIT (sync, _IO_new_file_sync),
 315     JUMP_INIT (doallocate, _IO_file_doallocate),
 316     JUMP_INIT (read, _IO_file_read),
 317     JUMP_INIT (write, _IO_new_file_write),
 318     JUMP_INIT (seek, _IO_file_seek),
 319     JUMP_INIT (close, _IO_new_proc_close),
 320     JUMP_INIT (stat, _IO_file_stat),
 321     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 322     JUMP_INIT (imbue, _IO_default_imbue)
 323   },
 324   /* _IO_mem_jumps  */
 325   [IO_MEM_JUMPS] = {
 326     JUMP_INIT_DUMMY,
 327     JUMP_INIT (finish, _IO_mem_finish),
 328     JUMP_INIT (overflow, _IO_str_overflow),
 329     JUMP_INIT (underflow, _IO_str_underflow),
 330     JUMP_INIT (uflow, _IO_default_uflow),
 331     JUMP_INIT (pbackfail, _IO_str_pbackfail),
 332     JUMP_INIT (xsputn, _IO_default_xsputn),
 333     JUMP_INIT (xsgetn, _IO_default_xsgetn),
 334     JUMP_INIT (seekoff, _IO_str_seekoff),
 335     JUMP_INIT (seekpos, _IO_default_seekpos),
 336     JUMP_INIT (setbuf, _IO_default_setbuf),
 337     JUMP_INIT (sync, _IO_mem_sync),
 338     JUMP_INIT (doallocate, _IO_default_doallocate),
 339     JUMP_INIT (read, _IO_default_read),
 340     JUMP_INIT (write, _IO_default_write),
 341     JUMP_INIT (seek, _IO_default_seek),
 342     JUMP_INIT (close, _IO_default_close),
 343     JUMP_INIT (stat, _IO_default_stat),
 344     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 345     JUMP_INIT (imbue, _IO_default_imbue)
 346   },
 347   /* _IO_wmem_jumps  */
 348   [IO_WMEM_JUMPS] = {
 349     JUMP_INIT_DUMMY,
 350     JUMP_INIT (finish, _IO_wmem_finish),
 351     JUMP_INIT (overflow, (_IO_overflow_t) _IO_wstr_overflow),
 352     JUMP_INIT (underflow, (_IO_underflow_t) _IO_wstr_underflow),
 353     JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
 354     JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
 355     JUMP_INIT (xsputn, _IO_wdefault_xsputn),
 356     JUMP_INIT (xsgetn, _IO_wdefault_xsgetn),
 357     JUMP_INIT (seekoff, _IO_wstr_seekoff),
 358     JUMP_INIT (seekpos, _IO_default_seekpos),
 359     JUMP_INIT (setbuf, _IO_default_setbuf),
 360     JUMP_INIT (sync, _IO_wmem_sync),
 361     JUMP_INIT (doallocate, _IO_wdefault_doallocate),
 362     JUMP_INIT (read, _IO_default_read),
 363     JUMP_INIT (write, _IO_default_write),
 364     JUMP_INIT (seek, _IO_default_seek),
 365     JUMP_INIT (close, _IO_default_close),
 366     JUMP_INIT (stat, _IO_default_stat),
 367     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 368     JUMP_INIT (imbue, _IO_default_imbue)
 369   },
 370   [IO_PRINTF_BUFFER_AS_FILE_JUMPS] = {
 371     JUMP_INIT_DUMMY,
 372     JUMP_INIT (finish, NULL),
 373     JUMP_INIT (overflow, __printf_buffer_as_file_overflow),
 374     JUMP_INIT (underflow, NULL),
 375     JUMP_INIT (uflow, NULL),
 376     JUMP_INIT (pbackfail, NULL),
 377     JUMP_INIT (xsputn, __printf_buffer_as_file_xsputn),
 378     JUMP_INIT (xsgetn, NULL),
 379     JUMP_INIT (seekoff, NULL),
 380     JUMP_INIT (seekpos, NULL),
 381     JUMP_INIT (setbuf, NULL),
 382     JUMP_INIT (sync, NULL),
 383     JUMP_INIT (doallocate, NULL),
 384     JUMP_INIT (read, NULL),
 385     JUMP_INIT (write, NULL),
 386     JUMP_INIT (seek, NULL),
 387     JUMP_INIT (close, NULL),
 388     JUMP_INIT (stat, NULL),
 389     JUMP_INIT (showmanyc, NULL),
 390     JUMP_INIT (imbue, NULL)
 391   },
 392   [IO_WPRINTF_BUFFER_AS_FILE_JUMPS] = {
 393     JUMP_INIT_DUMMY,
 394     JUMP_INIT (finish, NULL),
 395     JUMP_INIT (overflow, (_IO_overflow_t) __wprintf_buffer_as_file_overflow),
 396     JUMP_INIT (underflow, NULL),
 397     JUMP_INIT (uflow, NULL),
 398     JUMP_INIT (pbackfail, NULL),
 399     JUMP_INIT (xsputn, __wprintf_buffer_as_file_xsputn),
 400     JUMP_INIT (xsgetn, NULL),
 401     JUMP_INIT (seekoff, NULL),
 402     JUMP_INIT (seekpos, NULL),
 403     JUMP_INIT (setbuf, NULL),
 404     JUMP_INIT (sync, NULL),
 405     JUMP_INIT (doallocate, NULL),
 406     JUMP_INIT (read, NULL),
 407     JUMP_INIT (write, NULL),
 408     JUMP_INIT (seek, NULL),
 409     JUMP_INIT (close, NULL),
 410     JUMP_INIT (stat, NULL),
 411     JUMP_INIT (showmanyc, NULL),
 412     JUMP_INIT (imbue, NULL)
 413   },
 414
 415 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
 416   /* _IO_old_file_jumps  */
 417   [IO_OLD_FILE_JUMPS] = {
 418     JUMP_INIT_DUMMY,
 419     JUMP_INIT (finish, _IO_old_file_finish),
 420     JUMP_INIT (overflow, _IO_old_file_overflow),
 421     JUMP_INIT (underflow, _IO_old_file_underflow),
 422     JUMP_INIT (uflow, _IO_default_uflow),
 423     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 424     JUMP_INIT (xsputn, _IO_old_file_xsputn),
 425     JUMP_INIT (xsgetn, _IO_default_xsgetn),
 426     JUMP_INIT (seekoff, _IO_old_file_seekoff),
 427     JUMP_INIT (seekpos, _IO_default_seekpos),
 428     JUMP_INIT (setbuf, _IO_old_file_setbuf),
 429     JUMP_INIT (sync, _IO_old_file_sync),
 430     JUMP_INIT (doallocate, _IO_file_doallocate),
 431     JUMP_INIT (read, _IO_file_read),
 432     JUMP_INIT (write, _IO_old_file_write),
 433     JUMP_INIT (seek, _IO_file_seek),
 434     JUMP_INIT (close, _IO_file_close),
 435     JUMP_INIT (stat, _IO_file_stat)
 436   },
 437   /*  _IO_old_proc_jumps  */
 438   [IO_OLD_PROC_JUMPS] = {
 439     JUMP_INIT_DUMMY,
 440     JUMP_INIT (finish, _IO_old_file_finish),
 441     JUMP_INIT (overflow, _IO_old_file_overflow),
 442     JUMP_INIT (underflow, _IO_old_file_underflow),
 443     JUMP_INIT (uflow, _IO_default_uflow),
 444     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 445     JUMP_INIT (xsputn, _IO_old_file_xsputn),
 446     JUMP_INIT (xsgetn, _IO_default_xsgetn),
 447     JUMP_INIT (seekoff, _IO_old_file_seekoff),
 448     JUMP_INIT (seekpos, _IO_default_seekpos),
 449     JUMP_INIT (setbuf, _IO_old_file_setbuf),
 450     JUMP_INIT (sync, _IO_old_file_sync),
 451     JUMP_INIT (doallocate, _IO_file_doallocate),
 452     JUMP_INIT (read, _IO_file_read),
 453     JUMP_INIT (write, _IO_old_file_write),
 454     JUMP_INIT (seek, _IO_file_seek),
 455     JUMP_INIT (close, _IO_old_proc_close),
 456     JUMP_INIT (stat, _IO_file_stat),
 457     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 458     JUMP_INIT (imbue, _IO_default_imbue)
 459   },
 460 #endif
 461
 462 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
 463   /* _IO_old_cookie_jumps  */
 464   [IO_OLD_COOKIED_JUMPS] = {
 465     JUMP_INIT_DUMMY,
 466     JUMP_INIT (finish, _IO_file_finish),
 467     JUMP_INIT (overflow, _IO_file_overflow),
 468     JUMP_INIT (underflow, _IO_file_underflow),
 469     JUMP_INIT (uflow, _IO_default_uflow),
 470     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 471     JUMP_INIT (xsputn, _IO_file_xsputn),
 472     JUMP_INIT (xsgetn, _IO_default_xsgetn),
 473     JUMP_INIT (seekoff, _IO_cookie_seekoff),
 474     JUMP_INIT (seekpos, _IO_default_seekpos),
 475     JUMP_INIT (setbuf, _IO_file_setbuf),
 476     JUMP_INIT (sync, _IO_file_sync),
 477     JUMP_INIT (doallocate, _IO_file_doallocate),
 478     JUMP_INIT (read, _IO_cookie_read),
 479     JUMP_INIT (write, _IO_cookie_write),
 480     JUMP_INIT (seek, _IO_old_cookie_seek),
 481     JUMP_INIT (close, _IO_cookie_close),
 482     JUMP_INIT (stat, _IO_default_stat),
 483     JUMP_INIT (showmanyc, _IO_default_showmanyc),
 484     JUMP_INIT (imbue, _IO_default_imbue),
 485   },
 486 #endif
 487 };
 488
 489 #ifdef SHARED
 490
 491 void (*IO_accept_foreign_vtables) (void) attribute_hidden;
 492
 493 #else  /* !SHARED */
 494
 495 /* Used to check whether static dlopen support is needed.  */
 496 # pragma weak __dlopen
 497
 498 #endif
 499
 500 void attribute_hidden
 501 _IO_vtable_check (void)
 502 {
 503 #ifdef SHARED
 504   /* Honor the compatibility flag.  */
 505   void (*flag) (void) = atomic_load_relaxed (&IO_accept_foreign_vtables);
 506   PTR_DEMANGLE (flag);
 507   if (flag == &_IO_vtable_check)
 508     return;
 509
 510   /* In case this libc copy is in a non-default namespace, we always
 511      need to accept foreign vtables because there is always a
 512      possibility that FILE * objects are passed across the linking
 513      boundary.  */
 514   {
 515     Dl_info di;
 516     struct link_map *l;
 517     if (!rtld_active ()
 518         || (_dl_addr (_IO_vtable_check, &di, &l, NULL) != 0
 519             && l->l_ns != LM_ID_BASE))
 520       return;
 521   }
 522
 523 #else /* !SHARED */
 524   /* We cannot perform vtable validation in the static dlopen case
 525      because FILE * handles might be passed back and forth across the
 526      boundary.  Therefore, we disable checking in this case.  */
 527   if (__dlopen != NULL)
 528     return;
 529 #endif
 530
 531   __libc_fatal ("Fatal error: glibc detected an invalid stdio handle\n");
 532 }
 533
 534 /* Some variants of libstdc++ interpose _IO_2_1_stdin_ etc. and
 535    install their own vtables directly, without calling _IO_init or
 536    other functions.  Detect this by looking at the vtables values
 537    during startup, and disable vtable validation in this case.  */
 538 #ifdef SHARED
 539 __attribute__ ((constructor))
 540 static void
 541 check_stdfiles_vtables (void)
 542 {
 543   if (_IO_2_1_stdin_.vtable != &_IO_file_jumps
 544       || _IO_2_1_stdout_.vtable != &_IO_file_jumps
 545       || _IO_2_1_stderr_.vtable != &_IO_file_jumps)
 546     IO_set_accept_foreign_vtables (&_IO_vtable_check);
 547 }
 548 #endif
 549
 550 #define STR(s)  XSTR(s)
 551 #define XSTR(s) #s
 552
 553 #undef _IO_file_jumps
 554 #define _IO_file_jumps_alias  "__io_vtables + " STR(IO_FILE_JUMPS_OFFSET)
 555 declare_object_symbol_alias (_IO_file_jumps, _IO_file_jumps_alias,
 556                              IO_JUMP_T_SIZE)
 557 #undef _IO_wfile_jumps
 558 #define _IO_wfile_jumps_alias  "__io_vtables + " STR(IO_WFILE_JUMPS_OFFSET)
 559 declare_object_symbol_alias (_IO_wfile_jumps, _IO_wfile_jumps_alias,
 560                              IO_JUMP_T_SIZE)