From: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date: Wed, 6 Jan 2021 14:28:02 +0000 (+0000)
Subject: csu: Avoid weak ref for __ehdr_start in static PIE
X-Git-Tag: glibc-2.33~38
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=04af1eb3132904519f9bc8fdcca49525bec83fc7;p=thirdparty%2Fglibc.git

csu: Avoid weak ref for __ehdr_start in static PIE

All linkers support __ehdr_start that support static PIE linking,
so there is no need to check for its presence via a weak reference.

This avoids a RELATIVE relocation in static PIE startup code on some
targets.

With non-PIE static linking the weak ref check is kept in case the
linker does not support __ehdr_start.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
---

diff --git a/csu/libc-start.c b/csu/libc-start.c
index db859c3bed1..5b9ce1d158c 100644
--- a/csu/libc-start.c
+++ b/csu/libc-start.c
@@ -175,8 +175,12 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
          information from auxv.  */
 
       extern const ElfW(Ehdr) __ehdr_start
+# if BUILD_PIE_DEFAULT
+	__attribute__ ((visibility ("hidden")));
+# else
 	__attribute__ ((weak, visibility ("hidden")));
       if (&__ehdr_start != NULL)
+# endif
         {
           assert (__ehdr_start.e_phentsize == sizeof *GL(dl_phdr));
           GL(dl_phdr) = (const void *) &__ehdr_start + __ehdr_start.e_phoff;