From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <libc-hacker-return-9027-listarch-libc-hacker=sources.redhat.com@sourceware.org>
Received: (qmail 377 invoked by alias); 31 Aug 2006 15:38:15 -0000
Received: (qmail 360 invoked by uid 22791); 31 Aug 2006 15:38:15 -0000
X-Spam-Check-By: sourceware.org
Received: from sunsite.ms.mff.cuni.cz (HELO sunsite.mff.cuni.cz) (195.113.15.26)
    by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 31 Aug 2006 15:38:11 +0000
Received: from sunsite.mff.cuni.cz (sunsite.mff.cuni.cz [127.0.0.1])
	by sunsite.mff.cuni.cz (8.13.1/8.13.1) with ESMTP id k7VFc16W026198;
	Thu, 31 Aug 2006 17:38:01 +0200
Received: (from jj@localhost)
	by sunsite.mff.cuni.cz (8.13.1/8.13.1/Submit) id k7VFc184026197;
	Thu, 31 Aug 2006 17:38:01 +0200
Date: Thu, 31 Aug 2006 15:38:00 -0000
From: Jakub Jelinek <jakub@redhat.com>
To: Ulrich Drepper <drepper@redhat.com>
Cc: Glibc hackers <libc-hacker@sources.redhat.com>
Subject: [PATCH] Fix tst-addr1 on ppc64 and ia64
Message-ID: <20060831153800.GQ4556@sunsite.mff.cuni.cz>
Reply-To: Jakub Jelinek <jakub@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.4.1i
Mailing-List: contact libc-hacker-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Subscribe: <mailto:libc-hacker-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/libc-hacker/>
List-Post: <mailto:libc-hacker@sourceware.org>
List-Help: <mailto:libc-hacker-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: libc-hacker-owner@sourceware.org
X-SW-Source: 2006-08/txt/msg00037.txt.bz2

Hi!

On ppc64 and ia64 &printf is put into GOT, so the SHN_UNDEF printf
symbol has zero st_value and thus dladdr (&printf, ...) returns
a symbol in libc.so.  But, unfortunately, in libc.so _IO_printf
is an alias to printf, both are global symbols and have the same
address and size.  Which one comes first in the hash table depends
on the linker.

2006-08-31  Jakub Jelinek  <jakub@redhat.com>

	* elf/tst-addr1.c (do_test): Allow i.dli_sname "_IO_printf".

--- libc/elf/tst-addr1.c.jj	2006-08-24 22:18:59.000000000 +0200
+++ libc/elf/tst-addr1.c	2006-08-31 17:27:20.000000000 +0200
@@ -12,7 +12,14 @@ do_test (void)
       return 1;
     }
   printf ("found symbol %s in %s\n", i.dli_sname, i.dli_fname);
-  return i.dli_sname == NULL || strcmp (i.dli_sname, "printf") != 0;
+  return i.dli_sname == NULL
+	 || (strcmp (i.dli_sname, "printf") != 0
+	     /* On architectures which create PIC code by default
+		&printf may resolve to an address in libc.so
+		rather than in the binary.  printf and _IO_printf
+		are aliased and which one comes first in the
+		hash table is up to the linker.  */
+	     && strcmp (i.dli_sname, "_IO_printf") != 0);
 }
 
 #define TEST_FUNCTION do_test ()

	Jakub