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authorStefan Liebler <stli@linux.vnet.ibm.com>2016-06-28 12:23:35 +0200
committerStefan Liebler <stli@linux.vnet.ibm.com>2016-06-28 12:28:53 +0200
commit5fa268239b46e127f941c3510ad200ce5ef8df45 (patch)
tree7d1a01839f5eec926509e97fe2d192afd4c46419 /locale/localeinfo.h
parent0cdaef4dac5a885af9848e158e77cc347ee781bb (diff)
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S390: Fix relocation of _nl_current_LC_CATETORY_used in static build. [BZ #19860]
With shared libc, all locale categories are always loaded. For static libc they aren't, but there exist a weak _nl_current_LC_CATEGORY_used symbol for each category. If the category is used, the locale/lc-CATEGORY.o is linked in where _NL_CURRENT_DEFINE (LC_CATEGORY) defines and sets the _nl_current_LC_CATEGORY_used symbol to one. As reported by Marcin "Bug 18960 - s390: _nl_locale_subfreeres uses larl opcode on misaligned symbol" (https://sourceware.org/bugzilla/show_bug.cgi?id=18960) In function _nl_locale_subfreeres (locale/setlocale.c) for each category a check - &_nl_current_LC_CATEGORY_used != 0 - decides whether the category is used or not. There is also a second usage with the same mechanism in function __uselocale (locale/uselocale.c). On s390 a larl instruction with R_390_PC32DBL relocation is used to get the address of _nl_current_LC_CATEGORY_used symbols. As larl loads the address relative in halfwords and the code is always 2-byte aligned, larl can only load even addresses. At the end, the relocated address is always zero and never one. Marcins patch (see bugzilla) uses the following declaration in locale/setlocale.c: extern char _nl_current_##category##_used __attribute__((__aligned__(1))); In function _nl_locale_subfreeres all categories are checked and therefore gcc is now building an array of addresses in rodata section with an R_390_64 relocation for every address. This array is loaded with larl instruction and each address is accessed by index. This fixes only the usage in _nl_locale_subfreeres. Each user has to add the alignment attribute. This patch set the _nl_current_LC_CATEGORY_used symbols to two instead of one. This way gcc can use larl instruction and the check against zero works on every usage. ChangeLog: [BZ #19860] * locale/localeinfo.h (_NL_CURRENT_DEFINE): Set _nl_current_LC_CATEGORY_used to two instead of one.
Diffstat (limited to 'locale/localeinfo.h')
-rw-r--r--locale/localeinfo.h7
1 files changed, 5 insertions, 2 deletions
diff --git a/locale/localeinfo.h b/locale/localeinfo.h
index 94627f3..1f4da92 100644
--- a/locale/localeinfo.h
+++ b/locale/localeinfo.h
@@ -260,12 +260,15 @@ extern __thread struct __locale_data *const *_nl_current_##category \
#define _NL_CURRENT_WORD(category, item) \
((uint32_t) (*_nl_current_##category)->values[_NL_ITEM_INDEX (item)].word)
-/* This is used in lc-CATEGORY.c to define _nl_current_CATEGORY. */
+/* This is used in lc-CATEGORY.c to define _nl_current_CATEGORY. The symbol
+ _nl_current_CATEGORY_used is set to a value unequal to zero to mark this
+ category as used. On S390 the used relocation to load the symbol address
+ can only handle even addresses. */
#define _NL_CURRENT_DEFINE(category) \
__thread struct __locale_data *const *_nl_current_##category \
attribute_hidden = &_nl_global_locale.__locales[category]; \
asm (".globl " __SYMBOL_PREFIX "_nl_current_" #category "_used\n" \
- _NL_CURRENT_DEFINE_ABS (_nl_current_##category##_used, 1));
+ _NL_CURRENT_DEFINE_ABS (_nl_current_##category##_used, 2));
#ifdef HAVE_ASM_SET_DIRECTIVE
# define _NL_CURRENT_DEFINE_ABS(sym, val) ".set " #sym ", " #val
#else