Add "-z undefs" option to the linker.

binutils-z-undefs.patch

@@ -0,0 +1,71 @@
+diff -rup binutils.orig/ld/emultempl/elf32.em binutils-2.29.1/ld/emultempl/elf32.em
+--- binutils.orig/ld/emultempl/elf32.em	2018-01-16 11:34:58.040749108 +0000
++++ binutils-2.29.1/ld/emultempl/elf32.em	2018-01-16 11:35:35.697303875 +0000
+@@ -2666,6 +2666,8 @@ fragment <<EOF
+     case 'z':
+       if (strcmp (optarg, "defs") == 0)
+ 	link_info.unresolved_syms_in_objects = RM_GENERATE_ERROR;
++      else if (strcmp (optarg, "undefs") == 0)
++	link_info.unresolved_syms_in_objects = RM_IGNORE;
+       else if (strcmp (optarg, "muldefs") == 0)
+ 	link_info.allow_multiple_definition = TRUE;
+       else if (CONST_STRNEQ (optarg, "max-page-size="))
+Only in binutils-2.29.1/ld/emultempl: elf32.em.orig
+diff -rup binutils.orig/ld/ld.texinfo binutils-2.29.1/ld/ld.texinfo
+--- binutils.orig/ld/ld.texinfo	2018-01-16 11:34:58.208747127 +0000
++++ binutils-2.29.1/ld/ld.texinfo	2018-01-16 11:35:35.699303851 +0000
+@@ -1125,8 +1125,9 @@ Generate common symbols with the STT_COM
+ link.
+ 
+ @item defs
+-Disallows undefined symbols in object files.  Undefined symbols in
+-shared libraries are still allowed.
++Report unresolved symbol references from regular object files.  This
++is done even if the linker is creating a non-symbolic shared library.
++This option is the inverse of @samp{-z undefs}.
+ 
+ @item execstack
+ Marks the object as requiring executable stack.
+@@ -1279,6 +1280,11 @@ Generate GNU_PROPERTY_X86_FEATURE_1_SHST
+ to indicate compatibility with Intel Shadow Stack.  Supported for
+ Linux/i386 and Linux/x86_64.
+ 
++@item undefs
++Do not report unresolved symbol references from regular object files,
++either when creating an executable, or when creating a shared library.
++This option is the inverse of @samp{-z defs}.
++
+ @end table
+ 
+ Other keywords are ignored for Solaris compatibility.
+@@ -1684,6 +1690,7 @@ while linking a large executable.
+ 
+ @kindex --no-undefined
+ @kindex -z defs
++@kindex -z undefs
+ @item --no-undefined
+ @itemx -z defs
+ Report unresolved symbol references from regular object files.  This
+@@ -1692,6 +1699,8 @@ The switch @option{--[no-]allow-shlib-un
+ behaviour for reporting unresolved references found in shared
+ libraries being linked in.
+ 
++The effects of this option can be reverted by using @code{-z undefs}.
++
+ @kindex --allow-multiple-definition
+ @kindex -z muldefs
+ @item --allow-multiple-definition
+Only in binutils-2.29.1/ld: ld.texinfo.orig
+diff -rup binutils.orig/ld/NEWS binutils-2.29.1/ld/NEWS
+--- binutils.orig/ld/NEWS	2018-01-16 11:34:58.209747115 +0000
++++ binutils-2.29.1/ld/NEWS	2018-01-16 11:35:57.855041557 +0000
+@@ -1,5 +1,7 @@
+ -*- text -*-
+ 
++* Add "-z undefs" command line option as the inverse of the "-z defs" option.
++
+ Changes in 2.29:
+ 
+ * Support for -z shstk in the x86 ELF linker to generate
+Only in binutils-2.29.1/ld: NEWS.orig
+Only in binutils-2.29.1/ld: NEWS.rej

binutils.spec

@@ -54,7 +54,7 @@
 Summary: A GNU collection of binary utilities
 Name: %{?cross}binutils%{?_with_debug:-debug}
 Version: 2.29.1
-Release: 11%{?dist}
+Release: 12%{?dist}
 License: GPLv3+
 Group: Development/Tools
 URL: https://sourceware.org/binutils
@@ -154,6 +154,11 @@ Patch12: binutils-readelf-other-sym-info.patch
 # Lifetime: Fixed in 2.30.
 Patch13: binutils-support-v3-build-notes.patch
 
+# Purpose:  Adds a "-z undefs" option to the linker to compliment the already
+#           present "-z defs" option.
+# Lifetime: Fixed in 2.30.
+Patch14: binutils-z-undefs.patch
+
 #----------------------------------------------------------------------------
 
 Provides: bundled(libiberty)
@@ -289,6 +294,7 @@ using libelf instead of BFD.
 %patch11 -p1
 %patch12 -p1
 %patch13 -p1
+%patch14 -p1
 
 # We cannot run autotools as there is an exact requirement of autoconf-2.59.
 
@@ -693,6 +699,9 @@ exit 0
 
 #----------------------------------------------------------------------------
 %changelog
+* Tue Jan 16 2018 Nick Clifton  <nickc@redhat.com> 2.29.1-12
+- Add "-z undefs" option to the linker.
+
 * Thu Jan 11 2018 Nick Clifton  <nickc@redhat.com> 2.29.1-11
 - *Do* enable relro by default for the PowerPC64 architecture.  (#1523946)