commit 388b4f1a02f3a801965028bbfcd48d905638b797
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Jun 23 14:38:46 2017 -0700

    Avoid .symver on common symbols [BZ #21666]
    
    The .symver directive on common symbol just creates a new common symbol,
    not an alias and the newer assembler with the bug fix for
    
    https://sourceware.org/bugzilla/show_bug.cgi?id=21661
    
    will issue an error.  Before the fix, we got
    
    $ readelf -sW libc.so | grep "loc[12s]"
      5109: 00000000003a0608     8 OBJECT  LOCAL  DEFAULT   36 loc1
      5188: 00000000003a0610     8 OBJECT  LOCAL  DEFAULT   36 loc2
      5455: 00000000003a0618     8 OBJECT  LOCAL  DEFAULT   36 locs
      6575: 00000000003a05f0     8 OBJECT  GLOBAL DEFAULT   36 locs@GLIBC_2.2.5
      7156: 00000000003a05f8     8 OBJECT  GLOBAL DEFAULT   36 loc1@GLIBC_2.2.5
      7312: 00000000003a0600     8 OBJECT  GLOBAL DEFAULT   36 loc2@GLIBC_2.2.5
    
    in libc.so.  The versioned loc1, loc2 and locs have the wrong addresses.
    After the fix, we got
    
    $ readelf -sW libc.so | grep "loc[12s]"
      6570: 000000000039e3b8     8 OBJECT  GLOBAL DEFAULT   34 locs@GLIBC_2.2.5
      7151: 000000000039e3c8     8 OBJECT  GLOBAL DEFAULT   34 loc1@GLIBC_2.2.5
      7307: 000000000039e3c0     8 OBJECT  GLOBAL DEFAULT   34 loc2@GLIBC_2.2.5
    
            [BZ #21666]
            * misc/regexp.c (loc1): Add __attribute__ ((nocommon));
            (loc2): Likewise.
            (locs): Likewise.

---
 misc/regexp.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/misc/regexp.c
+++ b/misc/regexp.c
@@ -29,14 +29,15 @@
 
 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
 
-/* Define the variables used for the interface.  */
-char *loc1;
-char *loc2;
+/* Define the variables used for the interface.  Avoid .symver on common
+   symbol, which just creates a new common symbol, not an alias.  */
+char *loc1 __attribute__ ((nocommon));
+char *loc2 __attribute__ ((nocommon));
 compat_symbol (libc, loc1, loc1, GLIBC_2_0);
 compat_symbol (libc, loc2, loc2, GLIBC_2_0);
 
 /* Although we do not support the use we define this variable as well.  */
-char *locs;
+char *locs __attribute__ ((nocommon));
 compat_symbol (libc, locs, locs, GLIBC_2_0);
 
 
