1 Date: Tue, 12 Apr 2005 00:00:15 +0930
2 From: Alan Modra <amodra at bigpond dot net dot au>
3 To: binutils at sources dot redhat dot com
4 Cc: Anton Blanchard <anton at samba dot org>,
5 Paul Mackerras <paulus at samba dot org>
6 Subject: AS_NEEDED failure
7 Message-ID: <20050411143015.GB861@bubble.modra.org>
8 Mail-Followup-To: binutils at sources dot redhat dot com,
9 Anton Blanchard <anton at samba dot org>, Paul Mackerras <paulus at samba dot org>
11 Content-Type: text/plain; charset=us-ascii
12 Content-Disposition: inline
15 On powerpc64, I've hit the following during an X11 server build
16 .../libdl.so.2: undefined reference to _rtld_global@GLIBC_PRIVATE
17 This symbol is defined in ld64.so.1, and ld64.so.1 is being searched,
18 but the following conspires to make the link fail:
20 - libc.so contains AS_NEEDED (ld64.so.1)
21 - one or more of the X11 libs has DT_NEEDED libdl.so.2
22 - libdl.so.2 has DT_NEEDED ld64.so.1
24 The libc.so AS_NEEDED() causes symbols from ld64.so.1 to be loaded, but
25 no regular object file needs them so all the ld64.so.1 syms are set back
26 to bfd_link_hash_new, effectively removing them. The X11 lib is loaded,
27 and its DT_NEEDED entry noted. libdl.so.2 is loaded, but ld decides
28 that ld64.so.1 has already been looked at, so doesn't load it again.
29 It should do, because AS_NEEDED lib symbols aren't really loaded.
31 * emultempl/elf32.em (gld${EMULATION_NAME}_stat_needed): Ignore
32 as_needed libs that were not needed.
33 (gld${EMULATION_NAME}_check_needed): Likewise.
35 Applied mainline. I think this should go on 2.16, but after some more
38 Index: ld/emultempl/elf32.em
39 ===================================================================
40 RCS file: /cvs/src/src/ld/emultempl/elf32.em,v
41 retrieving revision 1.138
42 diff -u -p -r1.138 elf32.em
43 --- ld/emultempl/elf32.em 4 Apr 2005 11:27:15 -0000 1.138
44 +++ ld/emultempl/elf32.em 11 Apr 2005 14:23:08 -0000
45 @@ -230,6 +230,9 @@ gld${EMULATION_NAME}_stat_needed (lang_i
47 if (s->the_bfd == NULL)
50 + && (bfd_elf_get_dyn_lib_class (s->the_bfd) & DYN_AS_NEEDED) != 0)
53 if (bfd_stat (s->the_bfd, &st) != 0)
55 @@ -737,6 +740,13 @@ gld${EMULATION_NAME}_check_needed (lang_
59 + /* If this input file was an as-needed entry, and wasn't found to be
60 + needed at the stage it was linked, then don't say we have loaded it. */
62 + && (s->the_bfd == NULL
63 + || (bfd_elf_get_dyn_lib_class (s->the_bfd) & DYN_AS_NEEDED) != 0))
66 if (s->filename != NULL)
72 IBM OzLabs - Linux Technology Centre