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Re: [patch] SymbianOS Arm executables
On Thursday 10 February 2005 10:55, Richard Earnshaw wrote:
> I'm uncomfortable about the way globals->symbian_p is getting scattered
> throughout the entire linking process. I think we really need to try
> and distill that variable into the effects it has on linking (this would
> then make porting the linker to platforms with similar properties much
> less painful).
>
> In this case you've already identified the abstract property: the
> executable is relocated at link time. Most of your used of ->symbian_p
> should therefore be ->exec_reloc_p. There should then be exactly one
> place where symbian_p is tested, and that is then used to set the
> exec_reloc_p property.
Modified patch attached. No functional changes.
Retested on i686-linux, arm-none-elf and arm-none-symbianelf.
Ok?
Paul
2005-02-10 Paul Brook <paul@codesourcery.com>
* elf-bfd.h (struct elf_link_hash_table): Add exec_reloc_p.
* elf.c (_bfd_elf_link_hash_table_init): Initialize it.
* elflink.c (bfd_elf_link_record_dynamic_symbol): Create local dynamic
symbols in relocatable executables.
(bfd_elf_record_link_assignment): Create dynamic section symbols in
relocatable executables.
(_bfd_elf_link_renumber_dynsyms): Ditto.
(bfd_elf_final_link): Ditto.
* elf32-arm.c (elf32_arm_final_link_relocate): Copy absolute
relocations into relocatable executables.
(elf32_arm_check_relocs): Crate dynamic sections for relocatale
executables. Also copy absolute relocations.
(elf32_arm_adjust_dynamic_symbol): Don't create copy relocations
in relocatable executables.
(allocate_dynrelocs): Copy relocations for relocatable executables.
Output dynamic symbols for symbols defined in linker scripts.
Index: bfd/elf-bfd.h
===================================================================
RCS file: /var/cvsroot/src-cvs/src/bfd/elf-bfd.h,v
retrieving revision 1.171
diff -u -p -r1.171 elf-bfd.h
--- bfd/elf-bfd.h 6 Feb 2005 23:21:44 -0000 1.171
+++ bfd/elf-bfd.h 10 Feb 2005 14:57:52 -0000
@@ -398,6 +398,10 @@ struct elf_link_hash_table
/* A linked list of BFD's loaded in the link. */
struct elf_link_loaded_list *loaded;
+
+ /* True if This target has relocatable executables, so needs dynamic
+ section symbols. */
+ bfd_boolean exec_reloc_p;
};
/* Look up an entry in an ELF linker hash table. */
Index: bfd/elf.c
===================================================================
RCS file: /var/cvsroot/src-cvs/src/bfd/elf.c,v
retrieving revision 1.264
diff -u -p -r1.264 elf.c
--- bfd/elf.c 6 Feb 2005 23:21:44 -0000 1.264
+++ bfd/elf.c 10 Feb 2005 15:11:21 -0000
@@ -1496,6 +1496,7 @@ _bfd_elf_link_hash_table_init
table->tls_sec = NULL;
table->tls_size = 0;
table->loaded = NULL;
+ table->exec_reloc_p = FALSE;
ret = _bfd_link_hash_table_init (&table->root, abfd, newfunc);
table->root.type = bfd_link_elf_hash_table;
Index: bfd/elf32-arm.c
===================================================================
RCS file: /var/cvsroot/src-cvs/src/bfd/elf32-arm.c,v
retrieving revision 1.21
diff -u -p -r1.21 elf32-arm.c
--- bfd/elf32-arm.c 10 Feb 2005 14:14:25 -0000 1.21
+++ bfd/elf32-arm.c 10 Feb 2005 14:56:05 -0000
@@ -2352,7 +2352,7 @@ elf32_arm_final_link_relocate (reloc_how
/* When generating a shared object, these relocations are copied
into the output file to be resolved at run time. */
- if (info->shared
+ if ((info->shared || globals->root.exec_reloc_p)
&& (input_section->flags & SEC_ALLOC)
&& (r_type != R_ARM_REL32
|| !SYMBOL_CALLS_LOCAL (info, h))
@@ -3986,6 +3986,14 @@ elf32_arm_check_relocs (bfd *abfd, struc
htab = elf32_arm_hash_table (info);
sreloc = NULL;
+ /* Create dynamic sections for relocatable executables so that we can
+ copy relocations. */
+ if (htab->root.exec_reloc_p && ! htab->root.dynamic_sections_created)
+ {
+ if (! _bfd_elf_link_create_dynamic_sections (abfd, info))
+ return FALSE;
+ }
+
dynobj = elf_hash_table (info)->dynobj;
local_got_offsets = elf_local_got_offsets (abfd);
@@ -4106,11 +4114,11 @@ elf32_arm_check_relocs (bfd *abfd, struc
eh->plt_thumb_refcount += 1;
}
- /* If we are creating a shared library, and this is a reloc
- against a global symbol, or a non PC relative reloc
- against a local symbol, then we need to copy the reloc
- into the shared library. However, if we are linking with
- -Bsymbolic, we do not need to copy a reloc against a
+ /* If we are creating a shared library or relocatable executable,
+ and this is a reloc against a global symbol, or a non PC
+ relative reloc against a local symbol, then we need to copy
+ the reloc into the shared library. However, if we are linking
+ with -Bsymbolic, we do not need to copy a reloc against a
global symbol which is defined in an object we are
including in the link (i.e., DEF_REGULAR is set). At
this point we have not seen all the input files, so it is
@@ -4118,7 +4126,7 @@ elf32_arm_check_relocs (bfd *abfd, struc
later (it is never cleared). We account for that
possibility below by storing information in the
relocs_copied field of the hash table entry. */
- if (info->shared
+ if ((info->shared || htab->root.exec_reloc_p)
&& (sec->flags & SEC_ALLOC) != 0
&& ((r_type != R_ARM_PC24
&& r_type != R_ARM_PLT32
@@ -4378,7 +4386,9 @@ elf32_arm_adjust_dynamic_symbol (struct
asection * s;
unsigned int power_of_two;
struct elf32_arm_link_hash_entry * eh;
+ struct elf32_arm_link_hash_table *globals;
+ globals = elf32_arm_hash_table (info);
dynobj = elf_hash_table (info)->dynobj;
/* Make sure we know what is going on here. */
@@ -4443,8 +4453,10 @@ elf32_arm_adjust_dynamic_symbol (struct
/* If we are creating a shared library, we must presume that the
only references to the symbol are via the global offset table.
For such cases we need not do anything here; the relocations will
- be handled correctly by relocate_section. */
- if (info->shared)
+ be handled correctly by relocate_section. Relocatable executables
+ can reference data in shared objects directly, so we don't need to
+ do anything here. */
+ if (info->shared || globals->root.exec_reloc_p)
return TRUE;
/* We must allocate the symbol in our .dynbss section, which will
@@ -4637,13 +4649,23 @@ allocate_dynrelocs (struct elf_link_hash
space for pc-relative relocs that have become local due to symbol
visibility changes. */
- if (info->shared)
+ if (info->shared || htab->root.exec_reloc_p)
{
/* Discard relocs on undefined weak syms with non-default
visibility. */
if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
&& h->root.type == bfd_link_hash_undefweak)
eh->relocs_copied = NULL;
+ else if (htab->root.exec_reloc_p && h->dynindx == -1
+ && h->root.type == bfd_link_hash_new)
+ {
+ /* Output absolute symbols so that we can create relocations
+ against them. For normal symbols we output a relocation
+ against the section that contains them. */
+ if (! bfd_elf_link_record_dynamic_symbol (info, h))
+ return FALSE;
+ }
+
}
else
{
@@ -5846,6 +5868,7 @@ elf32_arm_symbian_link_hash_table_create
/* The PLT entries are each three instructions. */
htab->plt_entry_size = 4 * NUM_ELEM (elf32_arm_symbian_plt_entry);
htab->symbian_p = 1;
+ htab->root.exec_reloc_p = 1;
}
return ret;
}
Index: bfd/elflink.c
===================================================================
RCS file: /var/cvsroot/src-cvs/src/bfd/elflink.c,v
retrieving revision 1.133
diff -u -p -r1.133 elflink.c
--- bfd/elflink.c 10 Feb 2005 14:09:40 -0000 1.133
+++ bfd/elflink.c 10 Feb 2005 15:10:45 -0000
@@ -386,7 +386,8 @@ bfd_elf_link_record_dynamic_symbol (stru
&& h->root.type != bfd_link_hash_undefweak)
{
h->forced_local = 1;
- return TRUE;
+ if (!elf_hash_table (info)->exec_reloc_p)
+ return TRUE;
}
default:
@@ -494,7 +495,8 @@ bfd_elf_record_link_assignment (bfd *out
if ((h->def_dynamic
|| h->ref_dynamic
- || info->shared)
+ || info->shared
+ || (info->executable && elf_hash_table (info)->exec_reloc_p))
&& h->dynindx == -1)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
@@ -710,7 +712,7 @@ _bfd_elf_link_renumber_dynsyms (bfd *out
{
unsigned long dynsymcount = 0;
- if (info->shared)
+ if (info->shared || elf_hash_table (info)->exec_reloc_p)
{
const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
asection *p;
@@ -8167,7 +8169,7 @@ bfd_elf_final_link (bfd *abfd, struct bf
long last_local = 0;
/* Write out the section symbols for the output sections. */
- if (info->shared)
+ if (info->shared || elf_hash_table (info)->exec_reloc_p)
{
asection *s;