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.

(cherry picked from commit 388b4f1a02)
This commit is contained in:
H.J. Lu 2017-07-26 10:08:46 -07:00
parent 7cdbe5b6f9
commit 0edeadc0d3
2 changed files with 12 additions and 4 deletions

View File

@ -1,3 +1,10 @@
2017-07-26 H.J. Lu <hongjiu.lu@intel.com>
[BZ #21666]
* misc/regexp.c (loc1): Add __attribute__ ((nocommon));
(loc2): Likewise.
(locs): Likewise.
2017-07-12 Szabolcs Nagy <szabolcs.nagy@arm.com>
* sysdeps/aarch64/dl-machine.h (RTLD_START_1): Change _dl_argv to the

View File

@ -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);