* Re: ld bug?
[not found] <1060095548.9686.69.camel@brick.watson.ibm.com>
@ 2003-08-06 1:26 ` Alan Modra
0 siblings, 0 replies; 6+ messages in thread
From: Alan Modra @ 2003-08-06 1:26 UTC (permalink / raw)
To: Michal Ostrowski, binutils
On Tue, Aug 05, 2003 at 10:59:09AM -0400, Michal Ostrowski wrote:
> Hi,
>
> I have a bunch of object files that when linked together (to build
> "troff") result in certain symbols being assigned the same location in
> memory.
>
> This was achieved with gcc-3.2.3 (c++) and,
>
> powerpc64-linux-ld -v
> GNU ld version 2.14.90 20030805
>
> The problem is that we have a couple of symbols as follow:
>
> 84: 0000000020015c10 8 NOTYPE LOCAL DEFAULT 26 soft_hyphen_char
> 2986: 0000000020015c18 8 NOTYPE GLOBAL DEFAULT 26 global_special_fonts
>
>
> However, we also have (from .rela.dyn):
> 000020015c10 004700000013 R_PPC_COPY 0000000020015c10 _ZTVN10__cxxabiv117__c + 0
>
> This causes ld.so to copy 88 bytes of data to the location of
> soft_hyphen_char (and the symbols that follow it).
[snip]
Hmm, yes. A ld map shows
.bss 0x0000000010085b30 0x4248
*(.dynbss)
*fill* 0x0000000010085b30 0x0 00
*(.bss .bss.* .gnu.linkonce.b.*)
.bss 0x0000000010085b30 0x1 ./crtbegin.o
*fill* 0x0000000010085b31 0x7 00
.bss 0x0000000010085b38 0xc8 ./env.o
Note the zero .dynbss allocation. It should be 312 bytes in this case.
The problem was uncoverd by this patch:
2003-07-10 Alan Modra <amodra@bigpond.net.au>
(ppc64_elf_build_stubs): Check for stub sections in stub bfd by
testing section flags.
Fixed like this.
* elflink.c (_bfd_elf_create_dynamic_sections): Mark .dynbss with
SEC_LINKER_CREATED.
Index: bfd/elflink.c
===================================================================
RCS file: /cvs/src/src/bfd/elflink.c,v
retrieving revision 1.42
diff -u -p -r1.42 elflink.c
--- bfd/elflink.c 4 Aug 2003 09:39:46 -0000 1.42
+++ bfd/elflink.c 6 Aug 2003 01:22:35 -0000
@@ -309,7 +309,7 @@ _bfd_elf_create_dynamic_sections (bfd *a
section into the .bss section of the final image. */
s = bfd_make_section (abfd, ".dynbss");
if (s == NULL
- || ! bfd_set_section_flags (abfd, s, SEC_ALLOC))
+ || ! bfd_set_section_flags (abfd, s, SEC_ALLOC | SEC_LINKER_CREATED))
return FALSE;
/* The .rel[a].bss section holds copy relocs. This section is not
--
Alan Modra
IBM OzLabs - Linux Technology Centre
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: ld bug?
2001-10-30 23:42 ` H . J . Lu
@ 2001-10-31 6:27 ` Nick Clifton
0 siblings, 0 replies; 6+ messages in thread
From: Nick Clifton @ 2001-10-31 6:27 UTC (permalink / raw)
To: H . J . Lu; +Cc: Vassili Karpov, binutils
Hi H.J.
> 2001-10-30 H.J. Lu <hjl@gnu.org>
>
> * elflink.h (elf_link_output_extsym): Don't clear the visibility
> field for relocateable.
Approved.
Cheers
Nick
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: ld bug?
2001-10-30 23:33 ` H . J . Lu
@ 2001-10-30 23:42 ` H . J . Lu
2001-10-31 6:27 ` Nick Clifton
0 siblings, 1 reply; 6+ messages in thread
From: H . J . Lu @ 2001-10-30 23:42 UTC (permalink / raw)
To: Vassili Karpov; +Cc: binutils
On Tue, Oct 30, 2001 at 11:33:09PM -0800, H . J . Lu wrote:
> On Tue, Oct 30, 2001 at 11:30:13PM -0800, H . J . Lu wrote:
> > On Tue, Oct 30, 2001 at 01:36:04AM +0300, Vassili Karpov wrote:
> > > LD discards ELF visibility attributes when making relocateable objects.
> > >
> > > Example:
> > > a.s
> > > ==
> > > .protected symbol
> > >
> > > b.s
> > > ==
> > > dummy:
> > > ---
> > > as -o a.o a.s
> > > as -o b.o b.s
> > > ld -r -o c.o a.o b.o
> > >
> > > a.o: 4: 00000000 0 NOTYPE GLOBAL PROTECTED UND symbol
> > > c.o: 8: 00000000 0 NOTYPE GLOBAL DEFAULT UND symbol
> > > --
> >
> > It is ok since symbol is undefined. There is no such a thing as
> > protected, undefined symbol.
>
> I take it back. It is a bug. I will fix it.
>
>
Here it is.
H.J.
---
2001-10-30 H.J. Lu <hjl@gnu.org>
* elflink.h (elf_link_output_extsym): Don't clear the visibility
field for relocateable.
Index: elflink.h
===================================================================
RCS file: /work/cvs/gnu/binutils/bfd/elflink.h,v
retrieving revision 1.87
diff -u -p -r1.87 elflink.h
--- elflink.h 2001/10/28 17:38:27 1.87
+++ elflink.h 2001/10/31 07:40:35
@@ -5877,7 +5877,8 @@ elf_link_output_extsym (h, data)
/* If a symbol is not defined locally, we clear the visibility
field. */
- if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
+ if (! finfo->info->relocateable
+ && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
sym.st_other ^= ELF_ST_VISIBILITY (sym.st_other);
/* If this symbol should be put in the .dynsym section, then put it
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: ld bug?
2001-10-30 23:30 ` H . J . Lu
@ 2001-10-30 23:33 ` H . J . Lu
2001-10-30 23:42 ` H . J . Lu
0 siblings, 1 reply; 6+ messages in thread
From: H . J . Lu @ 2001-10-30 23:33 UTC (permalink / raw)
To: Vassili Karpov; +Cc: binutils
On Tue, Oct 30, 2001 at 11:30:13PM -0800, H . J . Lu wrote:
> On Tue, Oct 30, 2001 at 01:36:04AM +0300, Vassili Karpov wrote:
> > LD discards ELF visibility attributes when making relocateable objects.
> >
> > Example:
> > a.s
> > ==
> > .protected symbol
> >
> > b.s
> > ==
> > dummy:
> > ---
> > as -o a.o a.s
> > as -o b.o b.s
> > ld -r -o c.o a.o b.o
> >
> > a.o: 4: 00000000 0 NOTYPE GLOBAL PROTECTED UND symbol
> > c.o: 8: 00000000 0 NOTYPE GLOBAL DEFAULT UND symbol
> > --
>
> It is ok since symbol is undefined. There is no such a thing as
> protected, undefined symbol.
I take it back. It is a bug. I will fix it.
H.J.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: ld bug?
2001-10-29 14:35 Vassili Karpov
@ 2001-10-30 23:30 ` H . J . Lu
2001-10-30 23:33 ` H . J . Lu
0 siblings, 1 reply; 6+ messages in thread
From: H . J . Lu @ 2001-10-30 23:30 UTC (permalink / raw)
To: Vassili Karpov; +Cc: binutils
On Tue, Oct 30, 2001 at 01:36:04AM +0300, Vassili Karpov wrote:
> LD discards ELF visibility attributes when making relocateable objects.
>
> Example:
> a.s
> ==
> .protected symbol
>
> b.s
> ==
> dummy:
> ---
> as -o a.o a.s
> as -o b.o b.s
> ld -r -o c.o a.o b.o
>
> a.o: 4: 00000000 0 NOTYPE GLOBAL PROTECTED UND symbol
> c.o: 8: 00000000 0 NOTYPE GLOBAL DEFAULT UND symbol
> --
It is ok since symbol is undefined. There is no such a thing as
protected, undefined symbol.
H.J.
^ permalink raw reply [flat|nested] 6+ messages in thread
* ld bug?
@ 2001-10-29 14:35 Vassili Karpov
2001-10-30 23:30 ` H . J . Lu
0 siblings, 1 reply; 6+ messages in thread
From: Vassili Karpov @ 2001-10-29 14:35 UTC (permalink / raw)
To: binutils
LD discards ELF visibility attributes when making relocateable objects.
Example:
a.s
==
.protected symbol
b.s
==
dummy:
---
as -o a.o a.s
as -o b.o b.s
ld -r -o c.o a.o b.o
a.o: 4: 00000000 0 NOTYPE GLOBAL PROTECTED UND symbol
c.o: 8: 00000000 0 NOTYPE GLOBAL DEFAULT UND symbol
--
mailto:malc@pulsesoft.com
^ permalink raw reply [flat|nested] 6+ messages in thread
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[not found] <1060095548.9686.69.camel@brick.watson.ibm.com>
2003-08-06 1:26 ` ld bug? Alan Modra
2001-10-29 14:35 Vassili Karpov
2001-10-30 23:30 ` H . J . Lu
2001-10-30 23:33 ` H . J . Lu
2001-10-30 23:42 ` H . J . Lu
2001-10-31 6:27 ` Nick Clifton
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