newlib-cygwin/newlib/libc/locale/duplocale.c

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/*
FUNCTION
<<duplocale>>---duplicate a locale object
INDEX
duplocale
INDEX
_duplocale_r
ANSI_SYNOPSIS
#include <locale.h>
locale_t duplocale(locale_t <[locobj]>);
locale_t _duplocale_r(void *<[reent]>, locale_t <[locobj]>);
DESCRIPTION
The <<duplocale>> function shall create a duplicate copy of the locale
object referenced by the <[locobj]> argument.
If the <[locobj]> argument is LC_GLOBAL_LOCALE, duplocale() shall create
a new locale object containing a copy of the global locale determined by
the setlocale() function.
The behavior is undefined if the <[locobj]> argument is not a valid locale
object handle.
RETURNS
Upon successful completion, the <<duplocale>> function shall return a
handle for a new locale object. Otherwise <<duplocale>> shall return
(locale_t) <<0>> and set errno to indicate the error.
PORTABILITY
<<duplocale>> is POSIX-1.2008.
*/
#include <newlib.h>
#include <reent.h>
#include <stdlib.h>
#include "setlocale.h"
struct __locale_t *
_duplocale_r (struct _reent *p, struct __locale_t *locobj)
{
struct __locale_t tmp_locale, *new_locale;
int i;
#ifndef _MB_CAPABLE
return __get_C_locale ();
#else /* _MB_CAPABLE */
/* LC_GLOBAL_LOCALE denotes the global locale. */
if (locobj == LC_GLOBAL_LOCALE)
locobj = __get_global_locale ();
/* The "C" locale is used statically, never copied. */
else if (locobj == __get_C_locale ())
return __get_C_locale ();
/* Copy locale content. */
tmp_locale = *locobj;
#ifdef __HAVE_LOCALE_INFO__
for (i = 1; i < _LC_LAST; ++i)
if (locobj->lc_cat[i].buf)
{
/* 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;
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>
2017-03-12 00:27:26 +08:00
tmp_locale.categories[i][0] = '\0'; /* __loadlocale tests this! */
if (!__loadlocale (&tmp_locale, i, locobj->categories[i]))
goto error;
}
#endif /* __HAVE_LOCALE_INFO__ */
/* Allocate new locale_t. */
new_locale = (struct __locale_t *) _calloc_r (p, 1, sizeof *new_locale);
if (!new_locale)
goto error;
*new_locale = tmp_locale;
return new_locale;
error:
/* An error occured while we had already (potentially) allocated memory.
Free memory and return NULL. errno is supposed to be set already. */
#ifdef __HAVE_LOCALE_INFO__
while (--i > 0)
if (tmp_locale.lc_cat[i].buf)
{
_free_r (p, (void *) tmp_locale.lc_cat[i].ptr);
_free_r (p, tmp_locale.lc_cat[i].buf);
}
#endif /* __HAVE_LOCALE_INFO__ */
return NULL;
#endif /* _MB_CAPABLE */
}
#ifndef _REENT_ONLY
struct __locale_t *
duplocale (struct __locale_t *locobj)
{
return _duplocale_r (_REENT, locobj);
}
#endif