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Re: ppc32 broken with cvs head
On Thu, Mar 06, 2003 at 10:02:58PM +1030, Alan Modra wrote:
> On Wed, Mar 05, 2003 at 06:54:45PM +0100, Olaf Hering wrote:
> > unresolvable relocation against symbol `environ@@GLIBC_2.0'
>
> A testcase for this is
>
> cat > env.c <<EOF
> extern char *environ;
> int main (void) { return *environ; }
> EOF
> gcc -o env env.c -fPIC -O
>
> The quick fix is to "#define ELIMINATE_COPY_RELOCS 0" at
> elf32-ppc.c:2458. I'm afraid the ELIMINATE_COPY_RELOCS code is
> broken, and has been broken on x86 for a long time too. In fact,
> it's quite surprising that no one has reported a bug in the x86
> code. Maybe it's just harder to trigger there.
The fix was easy. I've introduced an ELIMINATE_COPY_RELOCS define
for x86 too, mostly just to document the code.
* elf32-ppc.c (ELIMINATE_COPY_RELOCS): Define as one.
(ppc_elf_adjust_dynamic_symbol): For weak symbols, copy
ELF_LINK_NON_GOT_REF from weakdef.
* elf64-ppc.c (ELIMINATE_COPY_RELOCS): Define as one.
(ppc64_elf_adjust_dynamic_symbol): For weak symbols, copy
ELF_LINK_NON_GOT_REF from weakdef.
* elf32-i386.c (ELIMINATE_COPY_RELOCS): Define as one. Use throughout.
(elf_i386_adjust_dynamic_symbol): For weak symbols, copy
ELF_LINK_NON_GOT_REF from weakdef.
Index: bfd/elf32-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-ppc.c,v
retrieving revision 1.69
diff -u -p -r1.69 elf32-ppc.c
--- bfd/elf32-ppc.c 6 Mar 2003 11:32:43 -0000 1.69
+++ bfd/elf32-ppc.c 6 Mar 2003 23:15:56 -0000
@@ -2455,7 +2455,7 @@ ppc_elf_create_dynamic_sections (abfd, i
copying dynamic variables from a shared lib into an app's dynbss
section, and instead use a dynamic relocation to point into the
shared lib. */
-#define ELIMINATE_COPY_RELOCS 0
+#define ELIMINATE_COPY_RELOCS 1
/* Adjust a symbol defined by a dynamic object and referenced by a
regular object. The current definition is in some section of the
@@ -2525,6 +2525,10 @@ ppc_elf_adjust_dynamic_symbol (info, h)
|| h->weakdef->root.type == bfd_link_hash_defweak);
h->root.u.def.section = h->weakdef->root.u.def.section;
h->root.u.def.value = h->weakdef->root.u.def.value;
+ if (ELIMINATE_COPY_RELOCS)
+ h->elf_link_hash_flags
+ = ((h->elf_link_hash_flags & ~ELF_LINK_NON_GOT_REF)
+ | (h->weakdef->elf_link_hash_flags & ELF_LINK_NON_GOT_REF));
return TRUE;
}
Index: bfd/elf64-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-ppc.c,v
retrieving revision 1.90
diff -u -p -r1.90 elf64-ppc.c
--- bfd/elf64-ppc.c 6 Mar 2003 11:32:43 -0000 1.90
+++ bfd/elf64-ppc.c 6 Mar 2003 23:15:59 -0000
@@ -2545,7 +2545,7 @@ struct plt_entry
copying dynamic variables from a shared lib into an app's dynbss
section, and instead use a dynamic relocation to point into the
shared lib. */
-#define ELIMINATE_COPY_RELOCS 0
+#define ELIMINATE_COPY_RELOCS 1
/* Section name for stubs is the associated section name plus this
string. */
@@ -4518,6 +4518,10 @@ ppc64_elf_adjust_dynamic_symbol (info, h
|| h->weakdef->root.type == bfd_link_hash_defweak);
h->root.u.def.section = h->weakdef->root.u.def.section;
h->root.u.def.value = h->weakdef->root.u.def.value;
+ if (ELIMINATE_COPY_RELOCS)
+ h->elf_link_hash_flags
+ = ((h->elf_link_hash_flags & ~ELF_LINK_NON_GOT_REF)
+ | (h->weakdef->elf_link_hash_flags & ELF_LINK_NON_GOT_REF));
return TRUE;
}
Index: bfd/elf32-i386.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-i386.c,v
retrieving revision 1.95
diff -u -p -r1.95 elf32-i386.c
--- bfd/elf32-i386.c 19 Feb 2003 14:14:16 -0000 1.95
+++ bfd/elf32-i386.c 6 Mar 2003 23:15:52 -0000
@@ -506,6 +506,12 @@ elf_i386_grok_psinfo (abfd, note)
#define ELF_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1"
+/* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
+ copying dynamic variables from a shared lib into an app's dynbss
+ section, and instead use a dynamic relocation to point into the
+ shared lib. */
+#define ELIMINATE_COPY_RELOCS 1
+
/* The size in bytes of an entry in the procedure linkage table. */
#define PLT_ENTRY_SIZE 16
@@ -1106,7 +1112,8 @@ elf_i386_check_relocs (abfd, info, sec,
|| h->root.type == bfd_link_hash_defweak
|| (h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_REGULAR) == 0))))
- || (!info->shared
+ || (ELIMINATE_COPY_RELOCS
+ && !info->shared
&& (sec->flags & SEC_ALLOC) != 0
&& h != NULL
&& (h->root.type == bfd_link_hash_defweak
@@ -1372,8 +1379,6 @@ elf_i386_adjust_dynamic_symbol (info, h)
struct elf_link_hash_entry *h;
{
struct elf_i386_link_hash_table *htab;
- struct elf_i386_link_hash_entry * eh;
- struct elf_i386_dyn_relocs *p;
asection *s;
unsigned int power_of_two;
@@ -1418,6 +1423,10 @@ elf_i386_adjust_dynamic_symbol (info, h)
|| h->weakdef->root.type == bfd_link_hash_defweak);
h->root.u.def.section = h->weakdef->root.u.def.section;
h->root.u.def.value = h->weakdef->root.u.def.value;
+ if (ELIMINATE_COPY_RELOCS || info->nocopyreloc)
+ h->elf_link_hash_flags
+ = ((h->elf_link_hash_flags & ~ELF_LINK_NON_GOT_REF)
+ | (h->weakdef->elf_link_hash_flags & ELF_LINK_NON_GOT_REF));
return TRUE;
}
@@ -1443,20 +1452,26 @@ elf_i386_adjust_dynamic_symbol (info, h)
return TRUE;
}
- eh = (struct elf_i386_link_hash_entry *) h;
- for (p = eh->dyn_relocs; p != NULL; p = p->next)
+ if (ELIMINATE_COPY_RELOCS)
{
- s = p->sec->output_section;
- if (s != NULL && (s->flags & SEC_READONLY) != 0)
- break;
- }
+ struct elf_i386_link_hash_entry * eh;
+ struct elf_i386_dyn_relocs *p;
- /* If we didn't find any dynamic relocs in read-only sections, then
- we'll be keeping the dynamic relocs and avoiding the copy reloc. */
- if (p == NULL)
- {
- h->elf_link_hash_flags &= ~ELF_LINK_NON_GOT_REF;
- return TRUE;
+ eh = (struct elf_i386_link_hash_entry *) h;
+ for (p = eh->dyn_relocs; p != NULL; p = p->next)
+ {
+ s = p->sec->output_section;
+ if (s != NULL && (s->flags & SEC_READONLY) != 0)
+ break;
+ }
+
+ /* If we didn't find any dynamic relocs in read-only sections, then
+ we'll be keeping the dynamic relocs and avoiding the copy reloc. */
+ if (p == NULL)
+ {
+ h->elf_link_hash_flags &= ~ELF_LINK_NON_GOT_REF;
+ return TRUE;
+ }
}
/* We must allocate the symbol in our .dynbss section, which will
@@ -1676,7 +1691,7 @@ allocate_dynrelocs (h, inf)
}
}
}
- else
+ else if (ELIMINATE_COPY_RELOCS)
{
/* For the non-shared case, discard space for relocs against
symbols which turn out to need copy relocs or are not
@@ -2412,7 +2427,8 @@ elf_i386_relocate_section (output_bfd, i
&& (! info->symbolic
|| (h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_REGULAR) == 0))))
- || (!info->shared
+ || (ELIMINATE_COPY_RELOCS
+ && !info->shared
&& h != NULL
&& h->dynindx != -1
&& (h->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0
--
Alan Modra
IBM OzLabs - Linux Technology Centre