Commit Graph

5 Commits

Author SHA1 Message Date
Koichi Murase 973f766f6e Fix duplocale (libc/locale/duplocale.c) which fails to properly call __loadlocale
Problem:

  After  passing  locales  created  by  'duplocale'   to   'uselocale',
  referencing   'MB_CUR_MAX',   which   is   actually   expanded    to
  '__locale_mb_cur_max()' by preprocessors, causes segmentation faults.
  Direct use of locales from 'newlocale' does not  cause  the  problem.
  This is the problem of 'duplocale'.

  $ echo $LANG
  ja_JP.UTF-8
  $ cat test.c
  #include <stdlib.h>
  #include <locale.h>

  volatile int var;

  int main(void) {
    locale_t const loc = newlocale(LC_ALL_MASK, "", NULL);
    locale_t const dup = duplocale(loc);
    locale_t const old = uselocale(dup);
    var = MB_CUR_MAX; /* <-- crashes here */
    uselocale(old);
    freelocale(dup);
    freelocale(loc);
    return 0;
  }
  $ gcc test.c
  $ ./a
  Segmentation fault (core dumped)

  # Note: "core dumped" in the above message was  actually written  in
  # Japanese, but I translated the part to post a mail in English.

Bug:

  In the beginning of '__loadlocale' (newlib/libc/locale/locale.c:501),
  there is a code which checks if the operations can be skipped:

  > /* Avoid doing everything twice if nothing has changed. */
  > if (!strcmp (new_locale, loc->categories[category]))
  >   return loc->categories[category];

  While,   in   the   function   '_duplocale_r'    (newlib/libc/locale/
  duplocale.c), '__loadlocale'  is  called  as  in  the  quoted  codes:

  > /* If the object is not a "C" locale category, copy it.  Just call
  >    __loadlocale.  It knows what to do to replicate the category. */
  > tmp_locale.lc_cat[i].ptr = NULL;
  > tmp_locale.lc_cat[i].buf = NULL;
  > if (!__loadlocale (&tmp_locale, i, tmp_locale.categories[i]))
  >   goto error;

  This call of '__loadlocale' results in the skip check being

    !strcmp(tmp_locale.categories[i], tmp_locale.categories[i]),

  which is always true. This  means  that  the  actual  operations  of
  '__loadLocale' will never be performed for 'duplocale'.

Fix:

  The call of '__loadlocale' in '_duplocale_r' is modified.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2017-03-13 11:12:01 +01:00
Corinna Vinschen 3f36c6fa62 Add __get_C_locale inline function and fix new locale code for !_MB_CAPABLE targets
Only access "C" locale using the new __get_C_locale inline function.
Enable __global_locale for !_MB_CAPABLE targets.  Accommodate !_MB_CAPABLE
targets in new locale code.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-08-23 17:57:06 +02:00
Corinna Vinschen f4fb06ce17 Add/change a few #ifdef comments in locale code for clearness
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-08-23 12:43:40 +02:00
Corinna Vinschen 5ef60b7e6a Add documentation for duplocale, freelocale, newlocale, and uselocale.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-08-15 17:34:40 +02:00
Corinna Vinschen 956565be70 Move localeconv, duplocale, freelocale, newlocale, uselocale into separate files
Signed-off by: Corinna Vinschen <corinna@vinschen.de>
2016-08-15 10:56:57 +02:00