From: Dylan Alex Simon <dylan-sourceware@dylex.net>
Date: Tue, 15 Mar 2016 17:20:01 +0000 (-0400)
Subject: math: don't clobber old libm.so on install [BZ #19822]
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ab98aad2867140c24abaea4c6c7164c490e251f3;p=thirdparty%2Fglibc.git

math: don't clobber old libm.so on install [BZ #19822]

When installing glibc (w/mathvec enabled) in-place on a system with
a glibc w/out mathvec enabled, the install will clobber the existing
libm.so (e.g., /lib64/libm-2.21.so) with a linker script.  This is
because libm.so is a symlink to libm.so.6 which is a symlink to the
final libm-2.21.so file.  When the makefile writes the linker script
directly to libm.so, it gets clobbered.

The simple patch below to math/Makefile fixes this.  It is based on
the nptl Makefile, which does exactly the same thing in a safer way.

(cherry picked from commit f9378ac3773ffe998a2b3406568778ee9f77f759)
(cherry picked from commit 73f158cef52f3968e0b9a7785638cf1737c35306)
---

diff --git a/math/Makefile b/math/Makefile
index 7d573a0074f..6aa87f95283 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -100,7 +100,8 @@ $(inst_libdir)/libm.so: $(common-objpfx)format.lds \
 	 cat $<; \
 	 echo 'GROUP ( $(slibdir)/libm.so$(libm.so-version) ' \
 	      'AS_NEEDED ( $(libdir)/libmvec_nonshared.a $(slibdir)/libmvec.so$(libmvec.so-version) ) )' \
-	) > $@
+	) > $@.new
+	mv -f $@.new $@
 endif
 
 # Rules for the test suite.