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Remove attribute_hidden for wchar ifunc symbols.

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On s390 (31bit) various debug/tst-*chk* testcases are failing as the tests
are ending with a segmentation fault.

One test is e.g. calling wcsnrtombs in debug/tst-chk1.c:1549.
The function wcsnrtombs itself calls __wcsnlen. This function is called via
PLT! The PLT-stub itself loads the address from GOT (r12 is assumed to be
the GOT-pointer). In this case the loaded address is zero and the following
branch leads to the segmentation fault.

Due to the attribute_hidden in commit 44af8a32c3
"Mark internal wchar functions with attribute_hidden [BZ #18822]"
for e.g. the __wcsnlen function, r12 is not loaded with the GOT-pointer
in wcsnrtombs.

On s390x (64bit), this __wcsnlen call is also using the PLT-stub. But it is
not failing as the GOT-pointer is setup with larl-instruction by the PLT-stub
itself.
Note: On s390x/s390, __wcsnlen is an IFUNC symbol.

On x86_64, __wcsnlen is also an IFUNC symbol and is called via PLT, too.

Further IFUNC symbols on s390 which were marked as hidden by the mentioned
commit are: __wcscat, __wcsncpy, __wcpncpy, __wcschrnul.

This patch removes the attribute_hidden in wchar.h.
Then the compiler setups e.g. r12 on s390 in order to call __wcsnlen via PLT.

ChangeLog:

	* include/wchar.h (__wcsnlen, __wcscat, __wcsncpy, __wcpncpy,
	__wcschrnul): Remove attribute_hidden.
This commit is contained in:
Stefan Liebler 2017-11-21 08:39:53 +01:00
parent 567d8c1f68
commit 80eb52e3a9
2 changed files with 10 additions and 7 deletions
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5
ChangeLog
View File

@ -1,3 +1,8 @@
2017-11-21 Stefan Liebler <stli@linux.vnet.ibm.com>
* include/wchar.h (__wcsnlen, __wcscat, __wcsncpy, __wcpncpy,
__wcschrnul): Remove attribute_hidden.
2017-11-20 Paul Eggert <eggert@cs.ucla.edu>
regex: don't assume uint64_t or uint32_t

12
include/wchar.h
View File

@ -152,9 +152,8 @@ extern int __wcsncasecmp (const wchar_t *__s1, const wchar_t *__s2,
__attribute_pure__;
extern size_t __wcslen (const wchar_t *__s) __attribute_pure__;
extern size_t __wcsnlen (const wchar_t *__s, size_t __maxlen)
attribute_hidden __attribute_pure__;
extern wchar_t *__wcscat (wchar_t *dest, const wchar_t *src)
attribute_hidden;
__attribute_pure__;
extern wchar_t *__wcscat (wchar_t *dest, const wchar_t *src);
extern wint_t __btowc (int __c) attribute_hidden;
extern int __mbsinit (const __mbstate_t *__ps);
extern size_t __mbrtowc (wchar_t *__restrict __pwc,
@ -182,11 +181,10 @@ extern size_t __wcsnrtombs (char *__restrict __dst,
__mbstate_t *__restrict __ps)
attribute_hidden;
extern wchar_t *__wcsncpy (wchar_t *__restrict __dest,
const wchar_t *__restrict __src, size_t __n)
attribute_hidden;
const wchar_t *__restrict __src, size_t __n);
extern wchar_t *__wcpcpy (wchar_t *__dest, const wchar_t *__src);
extern wchar_t *__wcpncpy (wchar_t *__dest, const wchar_t *__src,
size_t __n) attribute_hidden;
size_t __n);
extern wchar_t *__wmemcpy (wchar_t *__s1, const wchar_t *s2,
size_t __n) attribute_hidden;
extern wchar_t *__wmempcpy (wchar_t *__restrict __s1,
@ -195,7 +193,7 @@ extern wchar_t *__wmempcpy (wchar_t *__restrict __s1,
extern wchar_t *__wmemmove (wchar_t *__s1, const wchar_t *__s2,
size_t __n) attribute_hidden;
extern wchar_t *__wcschrnul (const wchar_t *__s, wchar_t __wc)
attribute_hidden __attribute_pure__;
__attribute_pure__;
extern wchar_t *__wmemset_chk (wchar_t *__s, wchar_t __c, size_t __n,
size_t __ns) __THROW;