From 505c884aeb059ee7741c23d1bfc47956bd9c2a0e Mon Sep 17 00:00:00 2001 From: Frédéric Bérat Date: Wed, 26 Apr 2023 17:26:51 +0200 Subject: 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 --- include/stdio.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'include') 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) -- cgit 1.4.1