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 --- sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf_chk.c | 1 + 1 file changed, 1 insertion(+) (limited to 'sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf_chk.c') diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf_chk.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf_chk.c index 0039c3b53d..762757a5c7 100644 --- a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf_chk.c +++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf_chk.c @@ -43,4 +43,5 @@ ___ieee128___sprintf_chk (char *s, int flag, size_t slen, return done; } +hidden_def (___ieee128___sprintf_chk) strong_alias (___ieee128___sprintf_chk, __sprintf_chkieee128) -- cgit 1.4.1