Support for dedicated output section for some ARM veneer types

2016-05-23  Thomas Preud'homme  <thomas.preudhomme@arm.com>

bfd/
	* bfd-in.h (bfd_elf32_arm_keep_private_stub_output_sections): Declare
	bfd hook.
	* bfd-in2.h: Regenerate.
	* elf32-arm.c (arm_dedicated_stub_output_section_required): New
	function.
	(arm_dedicated_stub_output_section_required_alignment): Likewise.
	(arm_dedicated_stub_output_section_name): Likewise.
	(arm_dedicated_stub_input_section_ptr): Likewise.
	(elf32_arm_create_or_find_stub_sec): Add stub type parameter and
	function description comment. Add support for dedicated output stub
	section to given stub types.
	(elf32_arm_add_stub): Add a stub type parameter and pass it down to
	elf32_arm_create_or_find_stub_sec.
	(elf32_arm_create_stub): Pass stub type down to elf32_arm_add_stub.
	(elf32_arm_size_stubs): Pass stub type when calling
	elf32_arm_create_or_find_stub_sec for Cortex-A8 erratum veneers.
	(bfd_elf32_arm_keep_private_stub_output_sections): New function.

ld/
	* emultempl/armelf.em (arm_elf_before_allocation): Call
	bfd_elf32_arm_keep_private_stub_output_sections before generic
	before_allocation function.
This commit is contained in:
Thomas Preud'homme 2016-05-23 09:38:32 +01:00
parent 37773e7803
commit daa4adae63
6 changed files with 193 additions and 39 deletions

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@ -1,3 +1,23 @@
2016-05-23 Thomas Preud'homme <thomas.preudhomme@arm.com>
* bfd-in.h (bfd_elf32_arm_keep_private_stub_output_sections): Declare
bfd hook.
* bfd-in2.h: Regenerate.
* elf32-arm.c (arm_dedicated_stub_output_section_required): New
function.
(arm_dedicated_stub_output_section_required_alignment): Likewise.
(arm_dedicated_stub_output_section_name): Likewise.
(arm_dedicated_stub_input_section_ptr): Likewise.
(elf32_arm_create_or_find_stub_sec): Add stub type parameter and
function description comment. Add support for dedicated output stub
section to given stub types.
(elf32_arm_add_stub): Add a stub type parameter and pass it down to
elf32_arm_create_or_find_stub_sec.
(elf32_arm_create_stub): Pass stub type down to elf32_arm_add_stub.
(elf32_arm_size_stubs): Pass stub type when calling
elf32_arm_create_or_find_stub_sec for Cortex-A8 erratum veneers.
(bfd_elf32_arm_keep_private_stub_output_sections): New function.
2016-05-20 H.J. Lu <hongjiu.lu@intel.com>
* elf32-i386.c (elf_i386_check_relocs): Don't check R_386_GOT32

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@ -903,6 +903,9 @@ extern bfd_boolean bfd_elf32_arm_get_bfd_for_interworking
extern bfd_boolean bfd_elf32_arm_add_glue_sections_to_bfd
(bfd *, struct bfd_link_info *);
extern void bfd_elf32_arm_keep_private_stub_output_sections
(struct bfd_link_info *);
/* ELF ARM mapping symbol support. */
#define BFD_ARM_SPECIAL_SYM_TYPE_MAP (1 << 0)
#define BFD_ARM_SPECIAL_SYM_TYPE_TAG (1 << 1)

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@ -910,6 +910,9 @@ extern bfd_boolean bfd_elf32_arm_get_bfd_for_interworking
extern bfd_boolean bfd_elf32_arm_add_glue_sections_to_bfd
(bfd *, struct bfd_link_info *);
extern void bfd_elf32_arm_keep_private_stub_output_sections
(struct bfd_link_info *);
/* ELF ARM mapping symbol support. */
#define BFD_ARM_SPECIAL_SYM_TYPE_MAP (1 << 0)
#define BFD_ARM_SPECIAL_SYM_TYPE_TAG (1 << 1)

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@ -4136,68 +4136,155 @@ elf32_arm_get_stub_entry (const asection *input_section,
return stub_entry;
}
/* Find or create a stub section. Returns a pointer to the stub section, and
the section to which the stub section will be attached (in *LINK_SEC_P).
/* Whether veneers of type STUB_TYPE require to be in a dedicated output
section. */
static bfd_boolean
arm_dedicated_stub_output_section_required (enum elf32_arm_stub_type stub_type)
{
if (stub_type >= max_stub_type)
abort (); /* Should be unreachable. */
return FALSE;
}
/* Required alignment (as a power of 2) for the dedicated section holding
veneers of type STUB_TYPE, or 0 if veneers of this type are interspersed
with input sections. */
static int
arm_dedicated_stub_output_section_required_alignment
(enum elf32_arm_stub_type stub_type)
{
if (stub_type >= max_stub_type)
abort (); /* Should be unreachable. */
BFD_ASSERT (!arm_dedicated_stub_output_section_required (stub_type));
return 0;
}
/* Name of the dedicated output section to put veneers of type STUB_TYPE, or
NULL if veneers of this type are interspersed with input sections. */
static const char *
arm_dedicated_stub_output_section_name (enum elf32_arm_stub_type stub_type)
{
if (stub_type >= max_stub_type)
abort (); /* Should be unreachable. */
BFD_ASSERT (!arm_dedicated_stub_output_section_required (stub_type));
return NULL;
}
/* If veneers of type STUB_TYPE should go in a dedicated output section,
returns the address of the hash table field in HTAB holding a pointer to the
corresponding input section. Otherwise, returns NULL. */
static asection **
arm_dedicated_stub_input_section_ptr
(struct elf32_arm_link_hash_table *htab ATTRIBUTE_UNUSED,
enum elf32_arm_stub_type stub_type)
{
if (stub_type >= max_stub_type)
abort (); /* Should be unreachable. */
BFD_ASSERT (!arm_dedicated_stub_output_section_required (stub_type));
return NULL;
}
/* Find or create a stub section to contain a stub of type STUB_TYPE. SECTION
is the section that branch into veneer and can be NULL if stub should go in
a dedicated output section. Returns a pointer to the stub section, and the
section to which the stub section will be attached (in *LINK_SEC_P).
LINK_SEC_P may be NULL. */
static asection *
elf32_arm_create_or_find_stub_sec (asection **link_sec_p, asection *section,
struct elf32_arm_link_hash_table *htab)
struct elf32_arm_link_hash_table *htab,
enum elf32_arm_stub_type stub_type)
{
asection *link_sec;
asection *stub_sec;
asection *out_sec;
asection *link_sec, *out_sec, **stub_sec_p;
const char *stub_sec_prefix;
bfd_boolean dedicated_output_section =
arm_dedicated_stub_output_section_required (stub_type);
int align;
link_sec = htab->stub_group[section->id].link_sec;
BFD_ASSERT (link_sec != NULL);
stub_sec = htab->stub_group[section->id].stub_sec;
if (stub_sec == NULL)
if (dedicated_output_section)
{
stub_sec = htab->stub_group[link_sec->id].stub_sec;
if (stub_sec == NULL)
bfd *output_bfd = htab->obfd;
const char *out_sec_name =
arm_dedicated_stub_output_section_name (stub_type);
link_sec = NULL;
stub_sec_p = arm_dedicated_stub_input_section_ptr (htab, stub_type);
stub_sec_prefix = out_sec_name;
align = arm_dedicated_stub_output_section_required_alignment (stub_type);
out_sec = bfd_get_section_by_name (output_bfd, out_sec_name);
if (out_sec == NULL)
{
size_t namelen;
bfd_size_type len;
char *s_name;
namelen = strlen (link_sec->name);
len = namelen + sizeof (STUB_SUFFIX);
s_name = (char *) bfd_alloc (htab->stub_bfd, len);
if (s_name == NULL)
return NULL;
memcpy (s_name, link_sec->name, namelen);
memcpy (s_name + namelen, STUB_SUFFIX, sizeof (STUB_SUFFIX));
out_sec = link_sec->output_section;
stub_sec = (*htab->add_stub_section) (s_name, out_sec, link_sec,
htab->nacl_p ? 4 : 3);
if (stub_sec == NULL)
return NULL;
htab->stub_group[link_sec->id].stub_sec = stub_sec;
(*_bfd_error_handler) (_("No address assigned to the veneers output "
"section %s"), out_sec_name);
return NULL;
}
htab->stub_group[section->id].stub_sec = stub_sec;
}
else
{
link_sec = htab->stub_group[section->id].link_sec;
BFD_ASSERT (link_sec != NULL);
stub_sec_p = &htab->stub_group[section->id].stub_sec;
if (*stub_sec_p == NULL)
stub_sec_p = &htab->stub_group[link_sec->id].stub_sec;
stub_sec_prefix = link_sec->name;
out_sec = link_sec->output_section;
align = htab->nacl_p ? 4 : 3;
}
if (*stub_sec_p == NULL)
{
size_t namelen;
bfd_size_type len;
char *s_name;
namelen = strlen (stub_sec_prefix);
len = namelen + sizeof (STUB_SUFFIX);
s_name = (char *) bfd_alloc (htab->stub_bfd, len);
if (s_name == NULL)
return NULL;
memcpy (s_name, stub_sec_prefix, namelen);
memcpy (s_name + namelen, STUB_SUFFIX, sizeof (STUB_SUFFIX));
*stub_sec_p = (*htab->add_stub_section) (s_name, out_sec, link_sec,
align);
if (*stub_sec_p == NULL)
return NULL;
out_sec->flags |= SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
| SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY
| SEC_KEEP;
}
if (!dedicated_output_section)
htab->stub_group[section->id].stub_sec = *stub_sec_p;
if (link_sec_p)
*link_sec_p = link_sec;
return stub_sec;
return *stub_sec_p;
}
/* Add a new stub entry to the stub hash. Not all fields of the new
stub entry are initialised. */
static struct elf32_arm_stub_hash_entry *
elf32_arm_add_stub (const char *stub_name,
asection *section,
struct elf32_arm_link_hash_table *htab)
elf32_arm_add_stub (const char *stub_name, asection *section,
struct elf32_arm_link_hash_table *htab,
enum elf32_arm_stub_type stub_type)
{
asection *link_sec;
asection *stub_sec;
struct elf32_arm_stub_hash_entry *stub_entry;
stub_sec = elf32_arm_create_or_find_stub_sec (&link_sec, section, htab);
stub_sec = elf32_arm_create_or_find_stub_sec (&link_sec, section, htab,
stub_type);
if (stub_sec == NULL)
return NULL;
@ -5187,7 +5274,7 @@ elf32_arm_create_stub (struct elf32_arm_link_hash_table *htab,
return TRUE;
}
stub_entry = elf32_arm_add_stub (stub_name, section, htab);
stub_entry = elf32_arm_add_stub (stub_name, section, htab, stub_type);
if (stub_entry == NULL)
{
if (!sym_claimed)
@ -5700,7 +5787,7 @@ elf32_arm_size_stubs (bfd *output_bfd,
for (i = 0; i < num_a8_fixes; i++)
{
stub_sec = elf32_arm_create_or_find_stub_sec (NULL,
a8_fixes[i].section, htab);
a8_fixes[i].section, htab, a8_fixes[i].stub_type);
if (stub_sec == NULL)
return FALSE;
@ -6491,6 +6578,37 @@ bfd_elf32_arm_add_glue_sections_to_bfd (bfd *abfd,
&& arm_make_glue_section (abfd, STM32L4XX_ERRATUM_VENEER_SECTION_NAME);
}
/* Mark output sections of veneers needing a dedicated one with SEC_KEEP. This
ensures they are not marked for deletion by
strip_excluded_output_sections () when veneers are going to be created
later. Not doing so would trigger assert on empty section size in
lang_size_sections_1 (). */
void
bfd_elf32_arm_keep_private_stub_output_sections (struct bfd_link_info *info)
{
enum elf32_arm_stub_type stub_type;
/* If we are only performing a partial
link do not bother adding the glue. */
if (bfd_link_relocatable (info))
return;
for (stub_type = arm_stub_none + 1; stub_type < max_stub_type; stub_type++)
{
asection *out_sec;
const char *out_sec_name;
if (!arm_dedicated_stub_output_section_required (stub_type))
continue;
out_sec_name = arm_dedicated_stub_output_section_name (stub_type);
out_sec = bfd_get_section_by_name (info->output_bfd, out_sec_name);
if (out_sec != NULL)
out_sec->flags |= SEC_KEEP;
}
}
/* Select a BFD to be used to hold the sections used by the glue code.
This function is called from the linker scripts in ld/emultempl/
{armelf/pe}.em. */

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@ -1,3 +1,9 @@
2016-05-23 Thomas Preud'homme <thomas.preudhomme@arm.com>
* emultempl/armelf.em (arm_elf_before_allocation): Call
bfd_elf32_arm_keep_private_stub_output_sections before generic
before_allocation function.
2016-05-20 Maciej W. Rozycki <macro@imgtec.com>
* testsuite/ld-mips-elf/jalx-addend.d: New test.

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@ -83,6 +83,10 @@ arm_elf_before_allocation (void)
/* Auto-select Cortex-A8 erratum fix if it wasn't explicitly specified. */
bfd_elf32_arm_set_cortex_a8_fix (link_info.output_bfd, &link_info);
/* Ensure the output sections of veneers needing a dedicated one is not
removed. */
bfd_elf32_arm_keep_private_stub_output_sections (&link_info);
/* We should be able to set the size of the interworking stub section. We
can't do it until later if we have dynamic sections, though. */
if (elf_hash_table (&link_info)->dynobj == NULL)