stdio: Ensure *_chk routines have their hidden builtin definition available

If libc_hidden_builtin_{def,proto} isn't properly set for *_chk routines,
there are unwanted PLT entries in libc.so.

There is a special case with __asprintf_chk:
If ldbl_* macros are used for asprintf, ABI gets broken on s390x,
if it isn't, ppc64le isn't building due to multiple asm redirections.

This is due to the inclusion of bits/stdio-lbdl.h for ppc64le whereas it
isn't for s390x. This header creates redirections, which are not
compatible with the ones generated using libc_hidden_def.
Yet, we can't use libc_hidden_ldbl_proto on s390x since it will not
create a simple strong alias (e.g. as done on x86_64), but a versioned
alias, leading to ABI breakage.

This results in errors on s390x:
/usr/bin/ld: glibc/iconv/../libio/bits/stdio2.h:137: undefined reference
to `__asprintf_chk'

Original __asprintf_chk symbols:
00000000001395b0 T __asprintf_chk
0000000000177e90 T __nldbl___asprintf_chk

__asprintf_chk symbols with ldbl_* macros:
000000000012d590 t ___asprintf_chk
000000000012d590 t __asprintf_chk@@GLIBC_2.4
000000000012d590 t __GI___asprintf_chk
000000000012d590 t __GL____asprintf_chk___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk

__asprintf_chk symbols with the patch:
000000000012d590 t ___asprintf_chk
000000000012d590 T __asprintf_chk
000000000012d590 t __GI___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/include/stdio.h b/include/stdio.h
index da47d1ce99..6755877911 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -276,7 +276,18 @@ extern FILE *__open_memstream (char **, size_t *) __THROW __wur;
 libc_hidden_proto (__open_memstream)
 libc_hidden_proto (__libc_fatal)
 rtld_hidden_proto (__libc_fatal)
-libc_hidden_proto (__vsprintf_chk)
+
+libc_hidden_proto (__fgets_unlocked_chk)
+
+#if defined __LDBL_COMPAT || __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
+libc_hidden_ldbl_proto (__asprintf_chk)
+#else
+libc_hidden_proto (__asprintf_chk)
+#endif
+
+libc_hidden_ldbl_proto (__fprintf_chk)
+libc_hidden_ldbl_proto (__sprintf_chk)
+libc_hidden_ldbl_proto (__vsprintf_chk)
 
 extern FILE * __fmemopen (void *buf, size_t len, const char *mode);
 libc_hidden_proto (__fmemopen)