commit 388b4f1a02f3a801965028bbfcd48d905638b797 Author: H.J. Lu 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);