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Re: Add support for STT_GNU_IFUNC?
Hi H.J.
If you check in the initial STT_GNU_IFUNC support and open a bug report,
more people can take a look at it. I never expect any new feature will
be bug free in any software.
OK - I have checked in the attached patch. I am still not happy with
it, but at least it is a starting point.
Cheers
Nick
kc
include/elf
2009-04-30 Nick Clifton <nickc@redhat.com>
* common.h (STT_GNU_IFUNC): Define.
elfcpp
2009-04-30 Nick Clifton <nickc@redhat.com>
* (enum STT): Add STT_GNU_IFUNC.
gas
2009-04-30 Nick Clifton <nickc@redhat.com>
* config/obj-elf.c (obj_elf_type): Add support for a
gnu_indirect_function type.
* config/tc-i386.c (tc_i386_fix_adjustable): Do not adjust fixups
against indirect function symbols.
* doc/as.texinfo (.type): Document the support for the
gnu_indirect_function symbol type.
* NEWS: Mention the new feature.
gas/testsuite
2009-04-30 Nick Clifton <nickc@redhat.com>
* gas/elf/elf.exp: Extend type test to include an ifunc symbol.
Provide an alternative test for targets which do not support ifunc
symbols.
(type.s): Add entry for an ifunc symbol.
(type.e): Add ifunc entry to expected symbol dump.
(section2.e-armelf): Add entry for ifunc symbol.
(type-noifunc.s): New file.
(type-noifunc.e): New file.
bfd/
2009-04-30 Nick Clifton <nickc@redhat.com>
* elf-bfd.h (struct bfd_elf_section_data): Add indirect_relocs
section pointer.
(struct elf_obj_data): Add has_ifunc_symbols boolean.
* elf.c (swap_out_syms): Convert BSF_GNU_INDIRECT_FUNCTION flags
into a STT_GNU_IFUNC symbol type.
(_bfd_elf_is_function_type): Accept STT_GNU_IFUNC as a function
type.
(_bfd_elf_set_osabi): Set the osasbi field to ELFOSABI_LINUX if
the binary contains ifunc symbols.
* elfcode.h (elf_slurp_symbol_table): Translate the STT_GNU_IFUNC
symbol type into a BSF_GNU_INDIRECT_FUNCTION flag.
* elf32-i386.c (is_indirect_function): New function.
(elf_i386_check_relocs): Create an ifunc output section.
(allocate_dynrelocs): Create dynamic relocs in the ifunc output
section if necessary.
(elf_i386_relocate_section): Emit a reloc against an ifunc symbol
if necessary.
(elf_i386_add_symbol_hook): New function. Set the
has_ifunc_symbols field of the elf_obj_data structure if an ifunc
symbol is encountered.
(elf_backend_post_process_headers): Define.
(elf_backend_add_symbol_hook): Define.
(elf_i386_post_process_headers): Rename to
elf_i388_fbsd_post_process_headers.
* elf64-x86_64.c (IS_X86_64_PCREL_TYPE): New macro.
(is_indirect_function): New function.
(elf64_x86_64_check_relocs): Create an ifunc output section.
(allocate_dynrelocs): Create dynamic relocs in the ifunc output
section if necessary.
(elf64_x86_64_relocate_section): Emit a reloc against an ifunc
symbol if necessary.
(elf_i386_add_symbol_hook): Set the has_ifunc_symbols field of the
elf_obj_data structure if an ifunc symbol is encountered.
(elf_backend_post_process_headers): Define.
* elflink.c (_bfd_elf_adjust_dynamic_symbol): Always create a PLT
if we have ifunc symbols to handle.
(get_ifunc_reloc_section_name): New function. Computes the name
for an ifunc section.
(_bfd_elf_make_ifunc_reloc_section): New function. Creates a
section to hold ifunc relocs.
* syms.c (BSF_GNU_INDIRECT_FUNCTION): Define.
(bfd_print_symbol_vandf): Handle ifunc symbols.
(bfd_decode_symclass): Likewise.
* bfd-in2.h: Regenerate.
binutils
2009-04-30 Nick Clifton <nickc@redhat.com>
* readelf.c (dump_relocations): Display a relocation against an
ifunc symbol as if it were a function invocation.
(get_symbol_type): Handle STT_GNU_IFUNC.
ld
2009-04-30 Nick Clifton <nickc@redhat.com>
* NEWS: Mention support for IFUNC symbols.
ld/testsuite
2009-04-30 Nick Clifton <nickc@redhat.com>
* ld-ifunc: New directory.
* ld-ifunc/ifunc.exp: New file: Run the IFUNC tests.
* ld-ifunc/prog.c: New file.
* ld-ifunc/lib.c: New file.
Index: bfd/bfd-in2.h
===================================================================
RCS file: /cvs/src/src/bfd/bfd-in2.h,v
retrieving revision 1.476
diff -c -3 -p -r1.476 bfd-in2.h
*** bfd/bfd-in2.h 27 Apr 2009 14:27:34 -0000 1.476
--- bfd/bfd-in2.h 30 Apr 2009 14:00:16 -0000
*************** typedef struct bfd_symbol
*** 4608,4613 ****
--- 4608,4619 ----
/* This symbol was created by bfd_get_synthetic_symtab. */
#define BSF_SYNTHETIC (1 << 21)
+ /* This symbol is an indirect code object. Unrelated to BSF_INDIRECT.
+ The dynamic linker will compute the value of this symbol by
+ calling the function that it points to. BSF_FUNCTION must
+ also be also set. */
+ #define BSF_GNU_INDIRECT_FUNCTION (1 << 22)
+
flagword flags;
/* A pointer to the section to which this symbol is
Index: bfd/elf-bfd.h
===================================================================
RCS file: /cvs/src/src/bfd/elf-bfd.h,v
retrieving revision 1.281
diff -c -3 -p -r1.281 elf-bfd.h
*** bfd/elf-bfd.h 13 Mar 2009 11:34:42 -0000 1.281
--- bfd/elf-bfd.h 30 Apr 2009 14:00:17 -0000
*************** struct bfd_elf_section_data
*** 1297,1302 ****
--- 1297,1305 ----
/* A pointer to the bfd section used for dynamic relocs. */
asection *sreloc;
+ /* A pointer to the bfd section used for dynamic relocs against ifunc symbols. */
+ asection *indirect_relocs;
+
union {
/* Group name, if this section is a member of a group. */
const char *name;
*************** struct elf_obj_tdata
*** 1559,1564 ****
--- 1562,1572 ----
bfd_size_type build_id_size;
bfd_byte *build_id;
+ /* True if the bfd contains symbols that have the STT_GNU_IFUNC
+ symbol type. Used to set the osabi field in the ELF header
+ structure. */
+ bfd_boolean has_ifunc_symbols;
+
/* An identifier used to distinguish different target
specific extensions to this structure. */
enum elf_object_id object_id;
*************** extern int _bfd_elf_obj_attrs_arg_type (
*** 2139,2144 ****
--- 2147,2155 ----
extern void _bfd_elf_parse_attributes (bfd *, Elf_Internal_Shdr *);
extern bfd_boolean _bfd_elf_merge_object_attributes (bfd *, bfd *);
+ extern asection * _bfd_elf_make_ifunc_reloc_section
+ (bfd *, asection *, bfd *, unsigned int);
+
/* Large common section. */
extern asection _bfd_elf_large_com_section;
Index: bfd/elf.c
===================================================================
RCS file: /cvs/src/src/bfd/elf.c,v
retrieving revision 1.480
diff -c -3 -p -r1.480 elf.c
*** bfd/elf.c 26 Mar 2009 12:23:52 -0000 1.480
--- bfd/elf.c 30 Apr 2009 14:00:20 -0000
*************** Unable to find equivalent output section
*** 6399,6404 ****
--- 6399,6406 ----
if ((flags & BSF_THREAD_LOCAL) != 0)
type = STT_TLS;
+ else if ((flags & BSF_GNU_INDIRECT_FUNCTION) != 0)
+ type = STT_GNU_IFUNC;
else if ((flags & BSF_FUNCTION) != 0)
type = STT_FUNC;
else if ((flags & BSF_OBJECT) != 0)
*************** _bfd_elf_set_osabi (bfd * abfd,
*** 8977,8991 ****
i_ehdrp = elf_elfheader (abfd);
i_ehdrp->e_ident[EI_OSABI] = get_elf_backend_data (abfd)->elf_osabi;
}
/* Return TRUE for ELF symbol types that represent functions.
This is the default version of this function, which is sufficient for
! most targets. It returns true if TYPE is STT_FUNC. */
bfd_boolean
_bfd_elf_is_function_type (unsigned int type)
{
! return (type == STT_FUNC);
}
--- 8979,9001 ----
i_ehdrp = elf_elfheader (abfd);
i_ehdrp->e_ident[EI_OSABI] = get_elf_backend_data (abfd)->elf_osabi;
+
+ /* To make things simpler for the loader on Linux systems we set the
+ osabi field to ELFOSABI_LINUX if the binary contains symbols of
+ the STT_GNU_IFUNC type. */
+ if (i_ehdrp->e_ident[EI_OSABI] == ELFOSABI_NONE
+ && elf_tdata (abfd)->has_ifunc_symbols)
+ i_ehdrp->e_ident[EI_OSABI] = ELFOSABI_LINUX;
}
/* Return TRUE for ELF symbol types that represent functions.
This is the default version of this function, which is sufficient for
! most targets. It returns true if TYPE is STT_FUNC or STT_GNU_IFUNC. */
bfd_boolean
_bfd_elf_is_function_type (unsigned int type)
{
! return (type == STT_FUNC
! || type == STT_GNU_IFUNC);
}
Index: bfd/elf32-i386.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-i386.c,v
retrieving revision 1.193
diff -c -3 -p -r1.193 elf32-i386.c
*** bfd/elf32-i386.c 12 Mar 2009 17:13:41 -0000 1.193
--- bfd/elf32-i386.c 30 Apr 2009 14:00:21 -0000
*************** elf_i386_tls_transition (struct bfd_link
*** 1196,1201 ****
--- 1196,1220 ----
return TRUE;
}
+ /* Returns true if the hash entry refers to a symbol
+ marked for indirect handling during reloc processing. */
+
+ static bfd_boolean
+ is_indirect_symbol (bfd * abfd, struct elf_link_hash_entry * h)
+ {
+ const struct elf_backend_data * bed;
+
+ if (abfd == NULL || h == NULL)
+ return FALSE;
+
+ bed = get_elf_backend_data (abfd);
+
+ return h->type == STT_GNU_IFUNC
+ && (bed->elf_osabi == ELFOSABI_LINUX
+ /* GNU/Linux is still using the default value 0. */
+ || bed->elf_osabi == ELFOSABI_NONE);
+ }
+
/* Look through the relocs for a section during the first phase, and
calculate needed space in the global offset table, procedure linkage
table, and dynamic reloc sections. */
*************** elf_i386_check_relocs (bfd *abfd,
*** 1473,1478 ****
--- 1492,1503 ----
if (sreloc == NULL)
return FALSE;
+
+ /* Create the ifunc section as well, even if we have not encountered a
+ indirect function symbol yet. We may not even see one in the input
+ object file, but we can still encounter them in libraries. */
+ (void) _bfd_elf_make_ifunc_reloc_section
+ (abfd, sec, htab->elf.dynobj, 2);
}
/* If this is a global symbol, we count the number of
*************** allocate_dynrelocs (struct elf_link_hash
*** 1815,1820 ****
--- 1840,1846 ----
struct elf_i386_link_hash_table *htab;
struct elf_i386_link_hash_entry *eh;
struct elf_i386_dyn_relocs *p;
+ bfd_boolean use_indirect_section = FALSE;
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
*************** allocate_dynrelocs (struct elf_link_hash
*** 2036,2041 ****
--- 2062,2077 ----
}
}
}
+ else if (is_indirect_symbol (info->output_bfd, h)
+ && h->dynindx == -1
+ && ! h->forced_local)
+ {
+ if (bfd_elf_link_record_dynamic_symbol (info, h)
+ && h->dynindx != -1)
+ use_indirect_section = TRUE;
+ else
+ return FALSE;
+ }
else if (ELIMINATE_COPY_RELOCS)
{
/* For the non-shared case, discard space for relocs against
*************** allocate_dynrelocs (struct elf_link_hash
*** 2074,2080 ****
{
asection *sreloc;
! sreloc = elf_section_data (p->sec)->sreloc;
BFD_ASSERT (sreloc != NULL);
sreloc->size += p->count * sizeof (Elf32_External_Rel);
--- 2110,2119 ----
{
asection *sreloc;
! if (use_indirect_section)
! sreloc = elf_section_data (p->sec)->indirect_relocs;
! else
! sreloc = elf_section_data (p->sec)->sreloc;
BFD_ASSERT (sreloc != NULL);
sreloc->size += p->count * sizeof (Elf32_External_Rel);
*************** elf_i386_relocate_section (bfd *output_b
*** 2877,2882 ****
--- 2916,2927 ----
|| h->root.type != bfd_link_hash_undefweak)
&& (r_type != R_386_PC32
|| !SYMBOL_CALLS_LOCAL (info, h)))
+ || (! info->shared
+ && h != NULL
+ && h->dynindx != -1
+ && ! h->forced_local
+ && ((struct elf_i386_link_hash_entry *) h)->dyn_relocs != NULL
+ && is_indirect_symbol (output_bfd, h))
|| (ELIMINATE_COPY_RELOCS
&& !info->shared
&& h != NULL
*************** elf_i386_relocate_section (bfd *output_b
*** 2925,2931 ****
outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
}
! sreloc = elf_section_data (input_section)->sreloc;
BFD_ASSERT (sreloc != NULL && sreloc->contents != NULL);
--- 2970,2985 ----
outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
}
! if (! info->shared
! && h != NULL
! && h->dynindx != -1
! && ! h->forced_local
! && is_indirect_symbol (output_bfd, h)
! && elf_section_data (input_section)->indirect_relocs != NULL
! && elf_section_data (input_section)->indirect_relocs->contents != NULL)
! sreloc = elf_section_data (input_section)->indirect_relocs;
! else
! sreloc = elf_section_data (input_section)->sreloc;
BFD_ASSERT (sreloc != NULL && sreloc->contents != NULL);
*************** elf_i386_hash_symbol (struct elf_link_ha
*** 4045,4050 ****
--- 4099,4122 ----
return _bfd_elf_hash_symbol (h);
}
+ /* Hook called by the linker routine which adds symbols from an object
+ file. */
+
+ static bfd_boolean
+ elf_i386_add_symbol_hook (bfd * abfd ATTRIBUTE_UNUSED,
+ struct bfd_link_info * info ATTRIBUTE_UNUSED,
+ Elf_Internal_Sym * sym,
+ const char ** namep ATTRIBUTE_UNUSED,
+ flagword * flagsp ATTRIBUTE_UNUSED,
+ asection ** secp ATTRIBUTE_UNUSED,
+ bfd_vma * valp ATTRIBUTE_UNUSED)
+ {
+ if (ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC)
+ elf_tdata (info->output_bfd)->has_ifunc_symbols = TRUE;
+
+ return TRUE;
+ }
+
#define TARGET_LITTLE_SYM bfd_elf32_i386_vec
#define TARGET_LITTLE_NAME "elf32-i386"
#define ELF_ARCH bfd_arch_i386
*************** elf_i386_hash_symbol (struct elf_link_ha
*** 4089,4094 ****
--- 4161,4169 ----
((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true)
#define elf_backend_plt_sym_val elf_i386_plt_sym_val
#define elf_backend_hash_symbol elf_i386_hash_symbol
+ #define elf_backend_add_symbol_hook elf_i386_add_symbol_hook
+ #undef elf_backend_post_process_headers
+ #define elf_backend_post_process_headers _bfd_elf_set_osabi
#include "elf32-target.h"
*************** elf_i386_hash_symbol (struct elf_link_ha
*** 4106,4120 ****
executables and (for simplicity) also all other object files. */
static void
! elf_i386_post_process_headers (bfd *abfd,
! struct bfd_link_info *info ATTRIBUTE_UNUSED)
{
! Elf_Internal_Ehdr *i_ehdrp;
- i_ehdrp = elf_elfheader (abfd);
-
- /* Put an ABI label supported by FreeBSD >= 4.1. */
- i_ehdrp->e_ident[EI_OSABI] = get_elf_backend_data (abfd)->elf_osabi;
#ifdef OLD_FREEBSD_ABI_LABEL
/* The ABI label supported by FreeBSD <= 4.0 is quite nonstandard. */
memcpy (&i_ehdrp->e_ident[EI_ABIVERSION], "FreeBSD", 8);
--- 4181,4190 ----
executables and (for simplicity) also all other object files. */
static void
! elf_i386_fbsd_post_process_headers (bfd *abfd, struct bfd_link_info *info)
{
! _bfd_elf_set_osabi (abfd, info);
#ifdef OLD_FREEBSD_ABI_LABEL
/* The ABI label supported by FreeBSD <= 4.0 is quite nonstandard. */
memcpy (&i_ehdrp->e_ident[EI_ABIVERSION], "FreeBSD", 8);
*************** elf_i386_post_process_headers (bfd *abfd
*** 4122,4131 ****
}
#undef elf_backend_post_process_headers
! #define elf_backend_post_process_headers elf_i386_post_process_headers
#undef elf32_bed
#define elf32_bed elf32_i386_fbsd_bed
#include "elf32-target.h"
/* VxWorks support. */
--- 4192,4203 ----
}
#undef elf_backend_post_process_headers
! #define elf_backend_post_process_headers elf_i386_fbsd_post_process_headers
#undef elf32_bed
#define elf32_bed elf32_i386_fbsd_bed
+ #undef elf_backend_add_symbol_hook
+
#include "elf32-target.h"
/* VxWorks support. */
Index: bfd/elf64-x86-64.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-x86-64.c,v
retrieving revision 1.152
diff -c -3 -p -r1.152 elf64-x86-64.c
*** bfd/elf64-x86-64.c 12 Mar 2009 17:13:41 -0000 1.152
--- bfd/elf64-x86-64.c 30 Apr 2009 14:00:22 -0000
*************** static reloc_howto_type x86_64_elf_howto
*** 161,166 ****
--- 161,172 ----
FALSE)
};
+ #define IS_X86_64_PCREL_TYPE(TYPE) \
+ ( ((TYPE) == R_X86_64_PC8) \
+ || ((TYPE) == R_X86_64_PC16) \
+ || ((TYPE) == R_X86_64_PC32) \
+ || ((TYPE) == R_X86_64_PC64))
+
/* Map BFD relocs to the x86_64 elf relocs. */
struct elf_reloc_map
{
*************** elf64_x86_64_tls_transition (struct bfd_
*** 977,982 ****
--- 983,1007 ----
return TRUE;
}
+ /* Returns true if the hash entry refers to a symbol
+ marked for indirect handling during reloc processing. */
+
+ static bfd_boolean
+ is_indirect_symbol (bfd * abfd, struct elf_link_hash_entry * h)
+ {
+ const struct elf_backend_data * bed;
+
+ if (abfd == NULL || h == NULL)
+ return FALSE;
+
+ bed = get_elf_backend_data (abfd);
+
+ return h->type == STT_GNU_IFUNC
+ && (bed->elf_osabi == ELFOSABI_LINUX
+ /* GNU/Linux is still using the default value 0. */
+ || bed->elf_osabi == ELFOSABI_NONE);
+ }
+
/* Look through the relocs for a section during the first phase, and
calculate needed space in the global offset table, procedure
linkage table, and dynamic reloc sections. */
*************** elf64_x86_64_check_relocs (bfd *abfd, st
*** 1003,1009 ****
sym_hashes = elf_sym_hashes (abfd);
sreloc = NULL;
!
rel_end = relocs + sec->reloc_count;
for (rel = relocs; rel < rel_end; rel++)
{
--- 1028,1034 ----
sym_hashes = elf_sym_hashes (abfd);
sreloc = NULL;
!
rel_end = relocs + sec->reloc_count;
for (rel = relocs; rel < rel_end; rel++)
{
*************** elf64_x86_64_check_relocs (bfd *abfd, st
*** 1259,1271 ****
may need to keep relocations for symbols satisfied by a
dynamic library if we manage to avoid copy relocs for the
symbol. */
-
if ((info->shared
&& (sec->flags & SEC_ALLOC) != 0
! && (((r_type != R_X86_64_PC8)
! && (r_type != R_X86_64_PC16)
! && (r_type != R_X86_64_PC32)
! && (r_type != R_X86_64_PC64))
|| (h != NULL
&& (! SYMBOLIC_BIND (info, h)
|| h->root.type == bfd_link_hash_defweak
--- 1284,1292 ----
may need to keep relocations for symbols satisfied by a
dynamic library if we manage to avoid copy relocs for the
symbol. */
if ((info->shared
&& (sec->flags & SEC_ALLOC) != 0
! && (! IS_X86_64_PCREL_TYPE (r_type)
|| (h != NULL
&& (! SYMBOLIC_BIND (info, h)
|| h->root.type == bfd_link_hash_defweak
*************** elf64_x86_64_check_relocs (bfd *abfd, st
*** 1293,1298 ****
--- 1314,1325 ----
if (sreloc == NULL)
return FALSE;
+
+ /* Create the ifunc section, even if we will not encounter an
+ indirect function symbol. We may not even see one in the input
+ object file, but we can still encounter them in libraries. */
+ (void) _bfd_elf_make_ifunc_reloc_section
+ (abfd, sec, htab->elf.dynobj, 2);
}
/* If this is a global symbol, we count the number of
*************** elf64_x86_64_check_relocs (bfd *abfd, st
*** 1324,1329 ****
--- 1351,1357 ----
if (p == NULL || p->sec != sec)
{
bfd_size_type amt = sizeof *p;
+
p = ((struct elf64_x86_64_dyn_relocs *)
bfd_alloc (htab->elf.dynobj, amt));
if (p == NULL)
*************** elf64_x86_64_check_relocs (bfd *abfd, st
*** 1336,1345 ****
}
p->count += 1;
! if (r_type == R_X86_64_PC8
! || r_type == R_X86_64_PC16
! || r_type == R_X86_64_PC32
! || r_type == R_X86_64_PC64)
p->pc_count += 1;
}
break;
--- 1364,1370 ----
}
p->count += 1;
! if (IS_X86_64_PCREL_TYPE (r_type))
p->pc_count += 1;
}
break;
*************** allocate_dynrelocs (struct elf_link_hash
*** 1650,1655 ****
--- 1675,1681 ----
struct elf64_x86_64_link_hash_table *htab;
struct elf64_x86_64_link_hash_entry *eh;
struct elf64_x86_64_dyn_relocs *p;
+ bfd_boolean use_indirect_section = FALSE;
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
*************** allocate_dynrelocs (struct elf_link_hash
*** 1728,1734 ****
&& !info->shared
&& h->dynindx == -1
&& elf64_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE)
! h->got.offset = (bfd_vma) -1;
else if (h->got.refcount > 0)
{
asection *s;
--- 1754,1762 ----
&& !info->shared
&& h->dynindx == -1
&& elf64_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE)
! {
! h->got.offset = (bfd_vma) -1;
! }
else if (h->got.refcount > 0)
{
asection *s;
*************** allocate_dynrelocs (struct elf_link_hash
*** 1827,1839 ****
/* Make sure undefined weak symbols are output as a dynamic
symbol in PIEs. */
else if (h->dynindx == -1
! && !h->forced_local)
! {
! if (! bfd_elf_link_record_dynamic_symbol (info, h))
! return FALSE;
! }
}
}
else if (ELIMINATE_COPY_RELOCS)
{
/* For the non-shared case, discard space for relocs against
--- 1855,1875 ----
/* Make sure undefined weak symbols are output as a dynamic
symbol in PIEs. */
else if (h->dynindx == -1
! && ! h->forced_local
! && ! bfd_elf_link_record_dynamic_symbol (info, h))
! return FALSE;
}
}
+ else if (is_indirect_symbol (info->output_bfd, h)
+ && h->dynindx == -1
+ && ! h->forced_local)
+ {
+ if (bfd_elf_link_record_dynamic_symbol (info, h)
+ && h->dynindx != -1)
+ use_indirect_section = TRUE;
+ else
+ return FALSE;
+ }
else if (ELIMINATE_COPY_RELOCS)
{
/* For the non-shared case, discard space for relocs against
*************** allocate_dynrelocs (struct elf_link_hash
*** 1850,1860 ****
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
! && !h->forced_local)
! {
! if (! bfd_elf_link_record_dynamic_symbol (info, h))
! return FALSE;
! }
/* If that succeeded, we know we'll be keeping all the
relocs. */
--- 1889,1897 ----
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
! && ! h->forced_local
! && ! bfd_elf_link_record_dynamic_symbol (info, h))
! return FALSE;
/* If that succeeded, we know we'll be keeping all the
relocs. */
*************** allocate_dynrelocs (struct elf_link_hash
*** 1872,1878 ****
{
asection * sreloc;
! sreloc = elf_section_data (p->sec)->sreloc;
BFD_ASSERT (sreloc != NULL);
--- 1909,1918 ----
{
asection * sreloc;
! if (use_indirect_section)
! sreloc = elf_section_data (p->sec)->indirect_relocs;
! else
! sreloc = elf_section_data (p->sec)->sreloc;
BFD_ASSERT (sreloc != NULL);
*************** elf64_x86_64_relocate_section (bfd *outp
*** 2674,2684 ****
&& (h == NULL
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak)
! && ((r_type != R_X86_64_PC8
! && r_type != R_X86_64_PC16
! && r_type != R_X86_64_PC32
! && r_type != R_X86_64_PC64)
! || !SYMBOL_CALLS_LOCAL (info, h)))
|| (ELIMINATE_COPY_RELOCS
&& !info->shared
&& h != NULL
--- 2714,2727 ----
&& (h == NULL
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak)
! && (! IS_X86_64_PCREL_TYPE (r_type)
! || ! SYMBOL_CALLS_LOCAL (info, h)))
! || (! info->shared
! && h != NULL
! && h->dynindx != -1
! && ! h->forced_local
! && ((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs != NULL
! && is_indirect_symbol (output_bfd, h))
|| (ELIMINATE_COPY_RELOCS
&& !info->shared
&& h != NULL
*************** elf64_x86_64_relocate_section (bfd *outp
*** 2718,2730 ****
become local. */
else if (h != NULL
&& h->dynindx != -1
! && (r_type == R_X86_64_PC8
! || r_type == R_X86_64_PC16
! || r_type == R_X86_64_PC32
! || r_type == R_X86_64_PC64
! || !info->shared
! || !SYMBOLIC_BIND (info, h)
! || !h->def_regular))
{
outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
outrel.r_addend = rel->r_addend;
--- 2761,2770 ----
become local. */
else if (h != NULL
&& h->dynindx != -1
! && (IS_X86_64_PCREL_TYPE (r_type)
! || ! info->shared
! || ! SYMBOLIC_BIND (info, h)
! || ! h->def_regular))
{
outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
outrel.r_addend = rel->r_addend;
*************** elf64_x86_64_relocate_section (bfd *outp
*** 2773,2780 ****
}
}
! sreloc = elf_section_data (input_section)->sreloc;
!
BFD_ASSERT (sreloc != NULL && sreloc->contents != NULL);
loc = sreloc->contents;
--- 2813,2830 ----
}
}
! if (! info->shared
! && h != NULL
! && h->dynindx != -1
! && ! h->forced_local
! && is_indirect_symbol (output_bfd, h)
! && elf_section_data (input_section)->indirect_relocs != NULL
! && elf_section_data (input_section)->indirect_relocs->contents != NULL
! )
! sreloc = elf_section_data (input_section)->indirect_relocs;
! else
! sreloc = elf_section_data (input_section)->sreloc;
!
BFD_ASSERT (sreloc != NULL && sreloc->contents != NULL);
loc = sreloc->contents;
*************** elf64_x86_64_section_from_shdr (bfd *abf
*** 3660,3670 ****
static bfd_boolean
elf64_x86_64_add_symbol_hook (bfd *abfd,
! struct bfd_link_info *info ATTRIBUTE_UNUSED,
Elf_Internal_Sym *sym,
const char **namep ATTRIBUTE_UNUSED,
flagword *flagsp ATTRIBUTE_UNUSED,
! asection **secp, bfd_vma *valp)
{
asection *lcomm;
--- 3712,3723 ----
static bfd_boolean
elf64_x86_64_add_symbol_hook (bfd *abfd,
! struct bfd_link_info *info,
Elf_Internal_Sym *sym,
const char **namep ATTRIBUTE_UNUSED,
flagword *flagsp ATTRIBUTE_UNUSED,
! asection **secp,
! bfd_vma *valp)
{
asection *lcomm;
*************** elf64_x86_64_add_symbol_hook (bfd *abfd,
*** 3687,3692 ****
--- 3740,3749 ----
*valp = sym->st_size;
break;
}
+
+ if (ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC)
+ elf_tdata (info->output_bfd)->has_ifunc_symbols = TRUE;
+
return TRUE;
}
*************** static const struct bfd_elf_special_sect
*** 3914,3919 ****
--- 3971,3979 ----
#define elf_backend_hash_symbol \
elf64_x86_64_hash_symbol
+ #undef elf_backend_post_process_headers
+ #define elf_backend_post_process_headers _bfd_elf_set_osabi
+
#include "elf64-target.h"
/* FreeBSD support. */
*************** static const struct bfd_elf_special_sect
*** 3926,3934 ****
#undef ELF_OSABI
#define ELF_OSABI ELFOSABI_FREEBSD
- #undef elf_backend_post_process_headers
- #define elf_backend_post_process_headers _bfd_elf_set_osabi
-
#undef elf64_bed
#define elf64_bed elf64_x86_64_fbsd_bed
--- 3986,3991 ----
Index: bfd/elfcode.h
===================================================================
RCS file: /cvs/src/src/bfd/elfcode.h,v
retrieving revision 1.93
diff -c -3 -p -r1.93 elfcode.h
*** bfd/elfcode.h 23 Dec 2008 09:01:45 -0000 1.93
--- bfd/elfcode.h 30 Apr 2009 14:00:26 -0000
*************** elf_slurp_symbol_table (bfd *abfd, asymb
*** 1311,1316 ****
--- 1311,1319 ----
case STT_SRELC:
sym->symbol.flags |= BSF_SRELC;
break;
+ case STT_GNU_IFUNC:
+ sym->symbol.flags |= BSF_GNU_INDIRECT_FUNCTION;
+ break;
}
if (dynamic)
Index: bfd/elflink.c
===================================================================
RCS file: /cvs/src/src/bfd/elflink.c,v
retrieving revision 1.334
diff -c -3 -p -r1.334 elflink.c
*** bfd/elflink.c 8 Apr 2009 16:04:48 -0000 1.334
--- bfd/elflink.c 30 Apr 2009 14:00:26 -0000
*************** _bfd_elf_adjust_dynamic_symbol (struct e
*** 2749,2754 ****
--- 2749,2761 ----
dynobj = elf_hash_table (eif->info)->dynobj;
bed = get_elf_backend_data (dynobj);
+
+ if (h->type == STT_GNU_IFUNC
+ && (bed->elf_osabi == ELFOSABI_LINUX
+ /* GNU/Linux is still using the default value 0. */
+ || bed->elf_osabi == ELFOSABI_NONE))
+ h->needs_plt = 1;
+
if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
{
eif->failed = TRUE;
*************** _bfd_elf_make_dynamic_reloc_section (ase
*** 12533,12535 ****
--- 12540,12609 ----
return reloc_sec;
}
+
+ /* Returns the name of the ifunc using dynamic reloc section associated with SEC. */
+ #define IFUNC_INFIX ".ifunc"
+
+ static const char *
+ get_ifunc_reloc_section_name (bfd * abfd,
+ asection * sec)
+ {
+ const char * dot;
+ char * name;
+ const char * base_name;
+ unsigned int strndx = elf_elfheader (abfd)->e_shstrndx;
+ unsigned int shnam = elf_section_data (sec)->rel_hdr.sh_name;
+
+ base_name = bfd_elf_string_from_elf_section (abfd, strndx, shnam);
+ if (base_name == NULL)
+ return NULL;
+
+ dot = strchr (base_name + 1, '.');
+ name = bfd_alloc (abfd, strlen (base_name) + strlen (IFUNC_INFIX) + 1);
+ sprintf (name, "%.*s%s%s", (int)(dot - base_name), base_name, IFUNC_INFIX, dot);
+
+ return name;
+ }
+
+ /* Like _bfd_elf_make_dynamic_reloc_section but it creates a
+ section for holding relocs against symbols with the STT_GNU_IFUNC
+ type. The section is attached to the OWNER bfd but it is created
+ with a name based on SEC from ABFD. */
+
+ asection *
+ _bfd_elf_make_ifunc_reloc_section (bfd * abfd,
+ asection * sec,
+ bfd * owner,
+ unsigned int align)
+ {
+ asection * reloc_sec = elf_section_data (sec)->indirect_relocs;
+
+ if (reloc_sec == NULL)
+ {
+ const char * name = get_ifunc_reloc_section_name (abfd, sec);
+
+ if (name == NULL)
+ return NULL;
+
+ reloc_sec = bfd_get_section_by_name (owner, name);
+
+ if (reloc_sec == NULL)
+ {
+ flagword flags;
+
+ flags = (SEC_HAS_CONTENTS | SEC_READONLY | SEC_IN_MEMORY | SEC_LINKER_CREATED);
+ if ((sec->flags & SEC_ALLOC) != 0)
+ flags |= SEC_ALLOC | SEC_LOAD;
+
+ reloc_sec = bfd_make_section_with_flags (owner, name, flags);
+
+ if (reloc_sec != NULL
+ && ! bfd_set_section_alignment (owner, reloc_sec, align))
+ reloc_sec = NULL;
+ }
+
+ elf_section_data (sec)->indirect_relocs = reloc_sec;
+ }
+
+ return reloc_sec;
+ }
Index: bfd/syms.c
===================================================================
RCS file: /cvs/src/src/bfd/syms.c,v
retrieving revision 1.50
diff -c -3 -p -r1.50 syms.c
*** bfd/syms.c 13 Jan 2009 23:44:45 -0000 1.50
--- bfd/syms.c 30 Apr 2009 14:00:26 -0000
*************** CODE_FRAGMENT
*** 297,302 ****
--- 297,308 ----
. {* This symbol was created by bfd_get_synthetic_symtab. *}
.#define BSF_SYNTHETIC (1 << 21)
.
+ . {* This symbol is an indirect code object. Unrelated to BSF_INDIRECT.
+ . The dynamic linker will compute the value of this symbol by
+ . calling the function that it points to. BSF_FUNCTION must
+ . also be also set. *}
+ .#define BSF_GNU_INDIRECT_FUNCTION (1 << 22)
+ .
. flagword flags;
.
. {* A pointer to the section to which this symbol is
*************** bfd_print_symbol_vandf (bfd *abfd, void
*** 483,489 ****
(type & BSF_WEAK) ? 'w' : ' ',
(type & BSF_CONSTRUCTOR) ? 'C' : ' ',
(type & BSF_WARNING) ? 'W' : ' ',
! (type & BSF_INDIRECT) ? 'I' : ' ',
(type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ',
((type & BSF_FUNCTION)
? 'F'
--- 489,495 ----
(type & BSF_WEAK) ? 'w' : ' ',
(type & BSF_CONSTRUCTOR) ? 'C' : ' ',
(type & BSF_WARNING) ? 'W' : ' ',
! (type & BSF_INDIRECT) ? 'I' : (type & BSF_GNU_INDIRECT_FUNCTION) ? 'i' : ' ',
(type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ',
((type & BSF_FUNCTION)
? 'F'
*************** bfd_decode_symclass (asymbol *symbol)
*** 669,674 ****
--- 675,682 ----
}
if (bfd_is_ind_section (symbol->section))
return 'I';
+ if (symbol->flags & BSF_GNU_INDIRECT_FUNCTION)
+ return 'i';
if (symbol->flags & BSF_WEAK)
{
/* If weak, determine if it's specifically an object
Index: binutils/readelf.c
===================================================================
RCS file: /cvs/src/src/binutils/readelf.c,v
retrieving revision 1.442
diff -c -3 -p -r1.442 readelf.c
*** binutils/readelf.c 25 Mar 2009 01:37:18 -0000 1.442
--- binutils/readelf.c 30 Apr 2009 14:00:29 -0000
*************** dump_relocations (FILE * file,
*** 1238,1246 ****
printf (" ");
! print_vma (psym->st_value, LONG_HEX);
! printf (is_32bit_elf ? " " : " ");
if (psym->st_name == 0)
{
--- 1238,1275 ----
printf (" ");
! if (ELF_ST_TYPE (psym->st_info) == STT_GNU_IFUNC)
! {
! const char * name;
! unsigned int len;
! unsigned int width = is_32bit_elf ? 8 : 14;
!
! /* Relocations against GNU_IFUNC symbols do not use the value
! of the symbol as the address to relocate against. Instead
! they invoke the function named by the symbol and use its
! result as the address for relocation.
!
! To indicate this to the user, do not display the value of
! the symbol in the "Symbols's Value" field. Instead show
! its name followed by () as a hint that the symbol is
! invoked. */
!
! if (strtab == NULL
! || psym->st_name == 0
! || psym->st_name >= strtablen)
! name = "??";
! else
! name = strtab + psym->st_name;
! len = print_symbol (width, name);
! printf ("()%-*s", len <= width ? (width + 1) - len : 1, " ");
! }
! else
! {
! print_vma (psym->st_value, LONG_HEX);
!
! printf (is_32bit_elf ? " " : " ");
! }
if (psym->st_name == 0)
{
*************** get_symbol_type (unsigned int type)
*** 6922,6927 ****
--- 6951,6962 ----
return "HP_STUB";
}
+ if (type == STT_GNU_IFUNC
+ && (elf_header.e_ident[EI_OSABI] == ELFOSABI_LINUX
+ /* GNU/Linux is still using the default value 0. */
+ || elf_header.e_ident[EI_OSABI] == ELFOSABI_NONE))
+ return "IFUNC";
+
snprintf (buff, sizeof (buff), _("<OS specific>: %d"), type);
}
else
Index: elfcpp/elfcpp.h
===================================================================
RCS file: /cvs/src/src/elfcpp/elfcpp.h,v
retrieving revision 1.21
diff -c -3 -p -r1.21 elfcpp.h
*** elfcpp/elfcpp.h 20 Mar 2009 23:37:51 -0000 1.21
--- elfcpp/elfcpp.h 30 Apr 2009 14:00:29 -0000
*************** enum STT
*** 478,483 ****
--- 478,484 ----
STT_COMMON = 5,
STT_TLS = 6,
STT_LOOS = 10,
+ STT_GNU_IFUNC = 10,
STT_HIOS = 12,
STT_LOPROC = 13,
STT_HIPROC = 15,
Index: gas/NEWS
===================================================================
RCS file: /cvs/src/src/gas/NEWS,v
retrieving revision 1.104
diff -c -3 -p -r1.104 NEWS
*** gas/NEWS 24 Apr 2009 18:31:28 -0000 1.104
--- gas/NEWS 30 Apr 2009 14:00:29 -0000
***************
*** 5,10 ****
--- 5,15 ----
* Add support for Sunplus score architecture.
+ * The .type pseudo-op now accepts a type of STT_GNU_IFUNC which can be used to
+ indicate that if the symbol is the target of a relocation, its value should
+ not be use. Instead the function should be invoked and its result used as
+ the value.
+
* Add support for Lattice Mico32 (lm32) architecture.
Changes in 2.19:
Index: gas/config/obj-elf.c
===================================================================
RCS file: /cvs/src/src/gas/config/obj-elf.c,v
retrieving revision 1.112
diff -c -3 -p -r1.112 obj-elf.c
*** gas/config/obj-elf.c 15 Jan 2009 12:42:52 -0000 1.112
--- gas/config/obj-elf.c 30 Apr 2009 14:00:30 -0000
*************** obj_elf_type (int ignore ATTRIBUTE_UNUSE
*** 1664,1669 ****
--- 1664,1683 ----
}
}
}
+ else if (strcmp (typename, "gnu_indirect_function") == 0
+ || strcmp (typename, "10") == 0
+ || strcmp (typename, "STT_GNU_IFUNC") == 0)
+ {
+ const struct elf_backend_data *bed;
+
+ bed = get_elf_backend_data (stdoutput);
+ if (!(bed->elf_osabi == ELFOSABI_LINUX
+ /* GNU/Linux is still using the default value 0. */
+ || bed->elf_osabi == ELFOSABI_NONE))
+ as_bad (_("symbol type \"%s\" is supported only by GNU targets"),
+ typename);
+ type = BSF_FUNCTION | BSF_GNU_INDIRECT_FUNCTION;
+ }
#ifdef md_elf_symbol_type
else if ((type = md_elf_symbol_type (typename, sym, elfsym)) != -1)
;
Index: gas/config/tc-i386.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-i386.c,v
retrieving revision 1.372
diff -c -3 -p -r1.372 tc-i386.c
*** gas/config/tc-i386.c 20 Apr 2009 06:31:49 -0000 1.372
--- gas/config/tc-i386.c 30 Apr 2009 14:00:32 -0000
*************** tc_i386_fix_adjustable (fixS *fixP ATTRI
*** 2499,2504 ****
--- 2499,2508 ----
|| fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT
|| fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
return 0;
+
+ if (fixP->fx_addsy != NULL
+ && symbol_get_bfdsym (fixP->fx_addsy)->flags & BSF_GNU_INDIRECT_FUNCTION)
+ return 0;
#endif
return 1;
}
Index: gas/doc/as.texinfo
===================================================================
RCS file: /cvs/src/src/gas/doc/as.texinfo,v
retrieving revision 1.200
diff -c -3 -p -r1.200 as.texinfo
*** gas/doc/as.texinfo 24 Apr 2009 18:31:28 -0000 1.200
--- gas/doc/as.texinfo 30 Apr 2009 14:00:35 -0000
*************** The types supported are:
*** 6327,6332 ****
--- 6327,6337 ----
@itemx function
Mark the symbol as being a function name.
+ @item STT_GNU_IFUNC
+ @itemx gnu_indirect_function
+ Mark the symbol as an indirect function when evaluated during reloc
+ processing. (This is only supported on Linux targeted assemblers).
+
@item STT_OBJECT
@itemx object
Mark the symbol as being a data object.
Index: gas/testsuite/gas/elf/elf.exp
===================================================================
RCS file: /cvs/src/src/gas/testsuite/gas/elf/elf.exp,v
retrieving revision 1.49
diff -c -3 -p -r1.49 elf.exp
*** gas/testsuite/gas/elf/elf.exp 5 Feb 2009 21:58:41 -0000 1.49
--- gas/testsuite/gas/elf/elf.exp 30 Apr 2009 14:00:35 -0000
*************** if { ([istarget "*-*-*elf*"]
*** 114,121 ****
run_elf_list_test "section5" "" "-al" "-SW" "| grep \" \\\\.test\\\[0-9\\\]\""
run_dump_test "struct"
run_dump_test "symtab"
! run_dump_test "symver"
! run_elf_list_test "type" "" "" "-s" "| grep \"1 \\\[FIONTC\\\]\""
run_dump_test "section6"
run_dump_test "section7"
}
--- 114,133 ----
run_elf_list_test "section5" "" "-al" "-SW" "| grep \" \\\\.test\\\[0-9\\\]\""
run_dump_test "struct"
run_dump_test "symtab"
! run_dump_test "symver"
!
! # The MSP port sets the ELF header's OSABI field to ELFOSABI_STANDALONE.
! # The non-eabi ARM ports sets it to ELFOSABI_ARM.
! # So for these targets we cannot include an IFUNC symbol type
! # in the symbol type test.
! if { [istarget "msp*-*-*"]
! || [istarget "arm*-*-*"]
! || [istarget "xscale*-*-*"]} then {
! run_elf_list_test "type-noifunc" "" "" "-s" "| grep \"1 \\\[FONTC\\\]\""
! } else {
! run_elf_list_test "type" "" "" "-s" "| grep \"1 \\\[FIONTC\\\]\""
! }
!
run_dump_test "section6"
run_dump_test "section7"
}
Index: gas/testsuite/gas/elf/section2.e-armelf
===================================================================
RCS file: /cvs/src/src/gas/testsuite/gas/elf/section2.e-armelf,v
retrieving revision 1.1
diff -c -3 -p -r1.1 section2.e-armelf
*** gas/testsuite/gas/elf/section2.e-armelf 22 Nov 2006 17:45:56 -0000 1.1
--- gas/testsuite/gas/elf/section2.e-armelf 30 Apr 2009 14:00:35 -0000
***************
*** 1,5 ****
! Symbol table '.symtab' contains 6 entries:
Num: Value[ ]* Size Type Bind Vis Ndx Name
0: 0+0 0 NOTYPE LOCAL DEFAULT UND
1: 0+0 0 SECTION LOCAL DEFAULT 1
--- 1,5 ----
! Symbol table '.symtab' contains 7 entries:
Num: Value[ ]* Size Type Bind Vis Ndx Name
0: 0+0 0 NOTYPE LOCAL DEFAULT UND
1: 0+0 0 SECTION LOCAL DEFAULT 1
*************** Symbol table '.symtab' contains 6 entrie
*** 7,9 ****
--- 7,10 ----
3: 0+0 0 SECTION LOCAL DEFAULT 3
4: 0+0 0 SECTION LOCAL DEFAULT 4
5: 0+0 0 NOTYPE LOCAL DEFAULT 4 \$d
+ 6: 0+0 0 SECTION LOCAL DEFAULT 5
Index: gas/testsuite/gas/elf/type.e
===================================================================
RCS file: /cvs/src/src/gas/testsuite/gas/elf/type.e,v
retrieving revision 1.5
diff -c -3 -p -r1.5 type.e
*** gas/testsuite/gas/elf/type.e 23 Dec 2008 09:01:49 -0000 1.5
--- gas/testsuite/gas/elf/type.e 30 Apr 2009 14:00:35 -0000
***************
*** 1,5 ****
.: 0+0 1 FUNC LOCAL DEFAULT . function
.: 0+0 1 OBJECT LOCAL DEFAULT . object
.: 0+1 1 TLS LOCAL DEFAULT . tls_object
! .: 0+2 1 NOTYPE LOCAL DEFAULT . notype
..: 0+1 1 (COMMON|OBJECT) GLOBAL DEFAULT COM common
--- 1,6 ----
.: 0+0 1 FUNC LOCAL DEFAULT . function
+ .: 0+1 1 IFUNC LOCAL DEFAULT . indirect_function
.: 0+0 1 OBJECT LOCAL DEFAULT . object
.: 0+1 1 TLS LOCAL DEFAULT . tls_object
! ..: 0+2 1 NOTYPE LOCAL DEFAULT . notype
..: 0+1 1 (COMMON|OBJECT) GLOBAL DEFAULT COM common
Index: gas/testsuite/gas/elf/type.s
===================================================================
RCS file: /cvs/src/src/gas/testsuite/gas/elf/type.s,v
retrieving revision 1.5
diff -c -3 -p -r1.5 type.s
*** gas/testsuite/gas/elf/type.s 23 Dec 2008 09:01:49 -0000 1.5
--- gas/testsuite/gas/elf/type.s 30 Apr 2009 14:00:35 -0000
***************
*** 3,8 ****
--- 3,12 ----
.type function,%function
function:
.byte 0x0
+ .size indirect_function,1
+ .type indirect_function,%gnu_indirect_function
+ indirect_function:
+ .byte 0x0
.data
.type object,%object
.size object,1
Index: include/elf/common.h
===================================================================
RCS file: /cvs/src/src/include/elf/common.h,v
retrieving revision 1.110
diff -c -3 -p -r1.110 common.h
*** include/elf/common.h 16 Apr 2009 15:39:45 -0000 1.110
--- include/elf/common.h 30 Apr 2009 14:00:40 -0000
***************
*** 569,574 ****
--- 569,575 ----
#define STT_RELC 8 /* Complex relocation expression */
#define STT_SRELC 9 /* Signed Complex relocation expression */
#define STT_LOOS 10 /* OS-specific semantics */
+ #define STT_GNU_IFUNC 10 /* Symbol is an indirect code object */
#define STT_HIOS 12 /* OS-specific semantics */
#define STT_LOPROC 13 /* Processor-specific semantics */
#define STT_HIPROC 15 /* Processor-specific semantics */
Index: ld/NEWS
===================================================================
RCS file: /cvs/src/src/ld/NEWS,v
retrieving revision 1.101
diff -c -3 -p -r1.101 NEWS
*** ld/NEWS 8 Apr 2009 16:04:50 -0000 1.101
--- ld/NEWS 30 Apr 2009 14:00:41 -0000
***************
*** 12,17 ****
--- 12,21 ----
automatically in the presence of un-stripped debug information, as GDB
needs to be able to find the debug info sections by their full names.
+ * For GNU/Linux systems the linker will now avoid processing any relocations
+ made against symbols of the STT_GNU_IFUNC type and instead emit them into
+ the resulting binary for processing by the loader.
+
* --as-needed now links in a dynamic library if it satisfies undefined
symbols in regular objects, or in other dynamic libraries. In the
latter case the library is not linked if it is found in a DT_NEEDED
*** /dev/null 2009-04-30 11:28:48.565250861 +0100
--- gas/testsuite/gas/elf/type-noifunc.s 2009-04-24 13:35:53.000000000 +0100
***************
*** 0 ****
--- 1,20 ----
+ .text
+ .size function,1
+ .type function,%function
+ function:
+ .byte 0x0
+ .data
+ .type object,%object
+ .size object,1
+ object:
+ .byte 0x0
+ .type tls_object,%tls_object
+ .size tls_object,1
+ tls_object:
+ .byte 0x0
+ .type notype,%notype
+ .size notype,1
+ notype:
+ .byte 0x0
+ .comm common, 1
+ .type common,STT_COMMON
*** /dev/null 2009-04-30 11:28:48.565250861 +0100
--- gas/testsuite/gas/elf/type-noifunc.e 2009-04-24 13:36:08.000000000 +0100
***************
*** 0 ****
--- 1,5 ----
+ .: 0+0 1 FUNC LOCAL DEFAULT . function
+ .: 0+0 1 OBJECT LOCAL DEFAULT . object
+ .: 0+1 1 TLS LOCAL DEFAULT . tls_object
+ ..: 0+2 1 NOTYPE LOCAL DEFAULT . notype
+ ..: 0+1 1 (COMMON|OBJECT) GLOBAL DEFAULT COM common
*** /dev/null 2009-04-30 11:28:48.565250861 +0100
--- ld/testsuite/ld-ifunc/ifunc.exp 2009-04-30 14:57:22.000000000 +0100
***************
*** 0 ****
--- 1,254 ----
+ # Expect script for linker support of IFUNC symbols and relocations.
+ #
+ # Copyright 2009 Free Software Foundation, Inc.
+ # Contributed by Red Hat.
+ #
+ # This file is part of the GNU Binutils.
+ #
+ # This program is free software; you can redistribute it and/or modify
+ # it under the terms of the GNU General Public License as published by
+ # the Free Software Foundation; either version 3 of the License, or
+ # (at your option) any later version.
+ #
+ # This program is distributed in the hope that it will be useful,
+ # but WITHOUT ANY WARRANTY; without even the implied warranty of
+ # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ # GNU General Public License for more details.
+ #
+ # You should have received a copy of the GNU General Public License
+ # along with this program; if not, write to the Free Software
+ # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+ # MA 02110-1301, USA.
+ #
+ # Written by Nick Clifton <nickc@redhat.com>
+
+
+ # IFUNC support has only been implemented for the x86_64 and ix86 so far.
+ if {! ( [istarget "x86_64-*-elf*"]
+ || [istarget "x86_64-*-linux*"]
+ || [istarget "i?86-*-elf*"]
+ || [istarget "i?86-*-linux*"]) } {
+ verbose "IFUNC tests not run - target does not support IFUNC"
+ return
+ }
+
+ # We need a native system. FIXME: Strictly speaking this
+ # is not true, we just need to know how to create a fully
+ # linked executable, including the C and Z libraries, using
+ # the linker that is under test.
+ if ![isnative] {
+ verbose "IFUNC tests not run - not a native toolchain"
+ return
+ }
+
+ # We need a working compiler. (Strictly speaking this is
+ # not true, we could use target specific assembler files).
+ if { [which $CC] == 0 } {
+ verbose "IFUNC tests not run - no compiler available"
+ return
+ }
+
+ # A procedure to check the OS/ABI field in the ELF header of a binary file.
+ proc check_osabi { binary_file expected_osabi } {
+ global READELF
+ global READELFFLAGS
+
+ catch "exec $READELF $READELFFLAGS --file-header $binary_file > readelf.out" got
+
+ if ![string match "" $got] then {
+ verbose "proc check_osabi: Readelf produced unexpected out processing $binary_file: $got"
+ return 0
+ }
+
+ if { ![regexp "\n\[ \]*OS/ABI:\[ \]*(.+)\n\[ \]*ABI" \
+ [file_contents readelf.out] nil osabi] } {
+ verbose "proc check_osabi: Readelf failed to extract an ELF header from $binary_file"
+ return 0
+ }
+
+ if { $osabi == $expected_osabi } {
+ return 1
+ }
+
+ verbose "Expected OSABI: $expected_osabi, Obtained osabi: $osabi"
+
+ return 0
+ }
+
+ # A procedure to confirm that a file contains the IFUNC symbol.
+ # Returns -1 upon error, 0 if the symbol was not found and 1 if it was found.
+ proc contains_ifunc_symbol { binary_file } {
+ global READELF
+ global READELFFLAGS
+
+ catch "exec $READELF $READELFFLAGS --symbols $binary_file > readelf.out" got
+
+ if ![string match "" $got] then {
+ verbose "proc contains_ifunc_symbol: Readelf produced unexpected out processing $binary_file: $got"
+ return -1
+ }
+
+ # Look for a line like this:
+ # 58: 0000000000400600 30 IFUNC GLOBAL DEFAULT 12 library_func2
+
+ if { ![regexp ".*\[ \]*IFUNC\[ \]+GLOBAL\[ \]+DEFAULT\[ \]+\[UND0-9\]+\[ \]+library_func2\n" [file_contents readelf.out]] } {
+ return 0
+ }
+
+ return 1
+ }
+
+ # A procedure to confirm that a file contains a relocation that references an IFUNC symbol.
+ # Returns -1 upon error, 0 if the reloc was not found and 1 if it was found.
+ proc contains_ifunc_reloc { binary_file } {
+ global READELF
+ global READELFFLAGS
+
+ catch "exec $READELF $READELFFLAGS --relocs $binary_file > readelf.out" got
+
+ if ![string match "" $got] then {
+ verbose "proc contains_ifunc_reloc: Readelf produced unexpected out processing $binary_file: $got"
+ return -1
+ }
+
+ if [string match "" [file_contents readelf.out]] then {
+ verbose "No relocs found in $binary_file"
+ return 0
+ }
+
+ if { ![regexp "\\(\\)" [file_contents readelf.out]] } {
+ return 0
+ }
+
+ return 1
+ }
+
+ set fails 0
+
+ # Create the object files, libraries and executables.
+ if ![ld_compile "$CC -c -shared -fPIC" "$srcdir/$subdir/prog.c" "tmpdir/shared_prog.o"] {
+ fail "Could not create a shared object file"
+ set fails [expr $fails + 1]
+ }
+ if ![ld_compile "$CC -c -static" "$srcdir/$subdir/prog.c" "tmpdir/static_prog.o"] {
+ fail "Could not create a static object file"
+ set fails [expr $fails + 1]
+ }
+ if ![ld_compile "$CC -c -shared -fPIC -DWITH_IFUNC" "$srcdir/$subdir/lib.c" "tmpdir/shared_ifunc.o"] {
+ fail "Could not create an object file containing an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+ if ![ld_compile "$CC -c -static -DWITH_IFUNC" "$srcdir/$subdir/lib.c" "tmpdir/static_ifunc.o"] {
+ fail "Could not create a static object file containing an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+ if ![ld_compile "$CC -c -static -DWITHOUT_IFUNC" "$srcdir/$subdir/lib.c" "tmpdir/static_noifunc.o"] {
+ fail "Could not create an ordinary static object file"
+ set fails [expr $fails + 1]
+ }
+
+ if { $fails != 0 } {
+ return
+ }
+
+ if ![ld_simple_link $ld "tmpdir/libshared_ifunc.so" "-shared tmpdir/shared_ifunc.o"] {
+ fail "Could not create a shared library containing an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+ if ![ar_simple_create $ar "" "tmpdir/libifunc.a" "tmpdir/static_ifunc.o"] {
+ fail "Could not create a static library containing an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+
+ if { $fails != 0 } {
+ return
+ }
+
+ if ![default_ld_link $ld "tmpdir/dynamic_prog" "-Ltmpdir tmpdir/shared_prog.o -Bdynamic -lshared_ifunc -rpath ./tmpdir"] {
+ fail "Could not link a dynamic executable"
+ set fails [expr $fails + 1]
+ }
+ if ![default_ld_link $ld "tmpdir/static_prog" "-Ltmpdir tmpdir/static_prog.o -lifunc"] {
+ fail "Could not link a static executable"
+ set fails [expr $fails + 1]
+ }
+ if ![default_ld_link $ld "tmpdir/static_nonifunc_prog" "-Ltmpdir tmpdir/static_prog.o tmpdir/static_noifunc.o"] {
+ fail "Could not link a non-ifunc using static executable"
+ set fails [expr $fails + 1]
+ }
+
+ if { $fails == 0 } {
+ pass "Building ifunc binaries"
+ set fails 0
+ } else {
+ return
+ }
+
+ # Check the executables.
+ #
+ # The linked ifunc using executables should have an OSABI field of LINUX
+ # The linked non-ifunc using executable should have an OSABI field of NONE (aka System V).
+
+ if {! [check_osabi tmpdir/static_prog {UNIX - Linux}]} {
+ fail "Static ifunc-using executable does not have an OS/ABI field of LINUX"
+ set fails [expr $fails + 1]
+ }
+ if {! [check_osabi tmpdir/dynamic_prog {UNIX - Linux}]} {
+ fail "Dynamic ifunc-using executable does not have an OS/ABI field of LINUX"
+ set fails [expr $fails + 1]
+ }
+ if {! [check_osabi tmpdir/static_nonifunc_prog {UNIX - System V}]} {
+ fail "Static non-ifunc-using executable does not have an OS/ABI field of System V"
+ set fails [expr $fails + 1]
+ }
+
+ # The linked ifunc using executables should contain an IFUNC symbol,
+ # The non-ifunc using executable should not.
+
+ if {[contains_ifunc_symbol tmpdir/static_prog] != 1} {
+ fail "Static ifunc-using executable does not contain an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+ if {[contains_ifunc_symbol tmpdir/dynamic_prog] != 1} {
+ fail "Dynamic ifunc-using executable does not contain an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+ if {[contains_ifunc_symbol tmpdir/static_nonifunc_prog] != 0} {
+ fail "Static non-ifunc-using executable contains an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+
+ # The linked ifunc using executablea should contain a dynamic reloc referencing the IFUNC symbol.
+ # (Even the static executable which should have a dynamic section created for it).
+ # The non-ifunc using executable should not.
+
+ if {[contains_ifunc_reloc tmpdir/static_prog] != 1} {
+ fail "Static ifunc-using executable does not contain a reloc against an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+ if {[contains_ifunc_reloc tmpdir/dynamic_prog] != 1} {
+ fail "Dynamic ifunc-using executable does not contain a reloc against an IFUNC symbol"
+ set fails [expr $fails + 1]
+ }
+ if {[contains_ifunc_reloc tmpdir/static_nonifunc_prog] == 1} {
+ fail "Static non-ifunc-using executable contains a reloc against an IFUNC symbol!"
+ set fails [expr $fails + 1]
+ }
+
+ if { $fails == 0 } {
+ pass "Checking ifunc binaries"
+ }
+
+ # Clean up, unless we are being verbose, in which case we leave the files available.
+ if { $verbose < 1 } {
+ remote_file host delete "tmpdir/shared_prog.o"
+ remote_file host delete "tmpdir/static_prog.o"
+ remote_file host delete "tmpdir/shared_ifunc.o"
+ remote_file host delete "tmpdir/static_ifunc.o"
+ remote_file host delete "tmpdir/static_noifunc.o"
+ remote_file host delete "tmpdir/libshared_ifunc.so"
+ remote_file host delete "tmpdir/libifunc.a"
+ remote_file host delete "tmpdir/dynamic_prog"
+ remote_file host delete "tmpdir/static_prog"
+ remote_file host delete "tmpdir/static_nonifunc_prog"
+ }
*** /dev/null 2009-04-30 11:28:48.565250861 +0100
--- ld/testsuite/ld-ifunc/prog.c 2009-04-30 14:48:14.000000000 +0100
***************
*** 0 ****
--- 1,46 ----
+ extern int printf (const char *, ...);
+
+ extern int library_func1 (void);
+ extern int library_func2 (void);
+ extern int global;
+
+ int
+ main (void)
+ {
+ int res = -1;
+
+ res += library_func1 ();
+ res += library_func2 ();
+
+ switch (res)
+ {
+ case 0:
+ if (global)
+ printf ("ifunc working correctly\n");
+ else
+ {
+ printf ("wrong value returned by library_func2\n");
+ res = -1;
+ }
+ break;
+
+ case 1:
+ if (global)
+ printf ("wrong value returned by library_func2\n");
+ else
+ {
+ printf ("ifunc working correctly\n");
+ res = 0;
+ }
+ break;
+
+ case 4:
+ printf ("non-ifunc testcase\n");
+ break;
+
+ default:
+ printf ("ifunc function not evaluated at run-time, res = %x\n", res);
+ break;
+ }
+ return res;
+ }
*** /dev/null 2009-04-30 11:28:48.565250861 +0100
--- ld/testsuite/ld-ifunc/lib.c 2009-04-30 14:50:23.000000000 +0100
***************
*** 0 ****
--- 1,26 ----
+ int
+ library_func1 (void)
+ {
+ return 2;
+ }
+
+ int global = 1;
+
+ #ifdef WITH_IFUNC
+
+ static int minus_one (void) { return -1; }
+ static int zero (void) { return 0; }
+
+ void * library_func2_ifunc (void) __asm__ ("library_func2");
+ void * library_func2_ifunc (void) { return global ? minus_one : zero ; }
+ __asm__(".type library_func2, %gnu_indirect_function");
+
+ #else /* WITHOUT_IFUNC */
+
+ int
+ library_func2 (void)
+ {
+ return 3;
+ }
+
+ #endif