+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.
+
2009-04-30 Joseph Myers <joseph@codesourcery.com>
* elf32-arm.c (elf32_arm_check_relocs): Give errors for absolute
/* 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
/* 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;
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 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;
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)
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. */
+ 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);
+ return (type == STT_FUNC
+ || type == STT_GNU_IFUNC);
}
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. */
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
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;
}
}
}
+ 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
{
asection *sreloc;
- sreloc = elf_section_data (p->sec)->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);
|| 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
outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
}
- sreloc = elf_section_data (input_section)->sreloc;
+ 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);
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
((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"
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_i386_fbsd_post_process_headers (bfd *abfd, struct bfd_link_info *info)
{
- Elf_Internal_Ehdr *i_ehdrp;
-
- i_ehdrp = elf_elfheader (abfd);
+ _bfd_elf_set_osabi (abfd, info);
- /* 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);
}
#undef elf_backend_post_process_headers
-#define elf_backend_post_process_headers elf_i386_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. */
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
{
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. */
sym_hashes = elf_sym_hashes (abfd);
sreloc = NULL;
-
+
rel_end = relocs + sec->reloc_count;
for (rel = relocs; rel < rel_end; rel++)
{
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))
+ && (! IS_X86_64_PCREL_TYPE (r_type)
|| (h != NULL
&& (! SYMBOLIC_BIND (info, h)
|| h->root.type == bfd_link_hash_defweak
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
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)
}
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)
+ if (IS_X86_64_PCREL_TYPE (r_type))
p->pc_count += 1;
}
break;
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;
&& !info->shared
&& h->dynindx == -1
&& elf64_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE)
- h->got.offset = (bfd_vma) -1;
+ {
+ h->got.offset = (bfd_vma) -1;
+ }
else if (h->got.refcount > 0)
{
asection *s;
/* 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;
- }
+ && ! 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
/* 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;
- }
+ && ! 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. */
{
asection * sreloc;
- sreloc = elf_section_data (p->sec)->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);
&& (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)))
+ && (! 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
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))
+ && (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;
}
}
- sreloc = elf_section_data (input_section)->sreloc;
-
+ 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;
static bfd_boolean
elf64_x86_64_add_symbol_hook (bfd *abfd,
- struct bfd_link_info *info ATTRIBUTE_UNUSED,
+ struct bfd_link_info *info,
Elf_Internal_Sym *sym,
const char **namep ATTRIBUTE_UNUSED,
flagword *flagsp ATTRIBUTE_UNUSED,
- asection **secp, bfd_vma *valp)
+ asection **secp,
+ bfd_vma *valp)
{
asection *lcomm;
*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;
}
#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. */
#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
case STT_SRELC:
sym->symbol.flags |= BSF_SRELC;
break;
+ case STT_GNU_IFUNC:
+ sym->symbol.flags |= BSF_GNU_INDIRECT_FUNCTION;
+ break;
}
if (dynamic)
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;
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;
+}
. {* 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
(type & BSF_WEAK) ? 'w' : ' ',
(type & BSF_CONSTRUCTOR) ? 'C' : ' ',
(type & BSF_WARNING) ? 'W' : ' ',
- (type & BSF_INDIRECT) ? 'I' : ' ',
+ (type & BSF_INDIRECT) ? 'I' : (type & BSF_GNU_INDIRECT_FUNCTION) ? 'i' : ' ',
(type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ',
((type & BSF_FUNCTION)
? 'F'
}
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
+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.
+
2009-04-29 Anthony Green <green@moxielogic.com>
* NEWS: Tweak verilog support description.
printf (" ");
- print_vma (psym->st_value, LONG_HEX);
+ 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;
- printf (is_32bit_elf ? " " : " ");
+ 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)
{
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
+2009-04-30 Nick Clifton <nickc@redhat.com>
+
+ * (enum STT): Add STT_GNU_IFUNC.
+
2009-03-20 Mikolaj Zalewski <mikolajz@google.com>
* elfcpp.h (SHT_GNU_INCREMENTAL_INPUTS): Define.
STT_COMMON = 5,
STT_TLS = 6,
STT_LOOS = 10,
+ STT_GNU_IFUNC = 10,
STT_HIOS = 12,
STT_LOPROC = 13,
STT_HIPROC = 15,
+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.
+
2009-04-24 Cary Coutant <ccoutant@google.com>
* NEWS: Add item about discriminator support.
* 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:
}
}
}
+ 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)
;
|| 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;
}
@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.
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 "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"
}
-Symbol table '.symtab' contains 6 entries:
+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
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
--- /dev/null
+ .: 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
+ .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
.: 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+2 1 NOTYPE LOCAL DEFAULT . notype
..: 0+1 1 (COMMON|OBJECT) GLOBAL DEFAULT COM common
.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
+2009-04-30 Nick Clifton <nickc@redhat.com>
+
+ * common.h (STT_GNU_IFUNC): Define.
+
2009-04-24 Cary Coutant <ccoutant@google.com>
* dwarf2.h (DW_LNE_set_discriminator): New enum value.
#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 */
+2009-04-30 Nick Clifton <nickc@redhat.com>
+
+ * NEWS: Mention support for IFUNC symbols.
+
2009-04-29 Anthony Green <green@moxielogic.com>
* emulparams/elf32moxie.sh (STACK_ADDR): Move default stack
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
+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.
+
2009-04-30 Joseph Myers <joseph@codesourcery.com>
* ld-arm/movw-shared-1.d, ld-arm/movw-shared-1.s,
# Expect script for LD section checks tests
-# Copyright 1999, 2001, 2003, 2007 Free Software Foundation, Inc.
+# Copyright 1999, 2001, 2003, 2007, 2009 Free Software Foundation, Inc.
#
# This file is part of the GNU Binutils.
#
global ld
global srcdir
global subdir
-
+
# The usage of .lcomm in asm.s is incompatible with ia64 and ppc coff.
if { [istarget ia64-*-*]
- || [istarget powerpc*-*-aix*] || [istarget powerpc-*-beos*]
+ || [istarget powerpc*-*-aix*]
+ || [istarget powerpc-*-beos*]
|| [istarget rs6000-*-*] } {
return
}
set test "check sections 1"
-
- set ldflags "--check-sections"
+
+ set ldflags "--check-sections -e foo"
if { ![ld_assemble $as $srcdir/$subdir/asm.s tmpdir/asm.o]} {
unresolved $test
set ldflags "--check-sections -T $srcdir/$subdir/script -e foo"
# Perform the equivalent of invoking ld_simple_link
- # except that we need to massage the output futher.
-
+ # except that we need to massage the output further.
+
set exec_output [run_host_cmd "$ld" "-o tmpdir/asm.x $ldflags tmpdir/asm.o"]
set exec_output [prune_warnings $exec_output]
# Make sure that we got some output from the linker
if [string match "" $exec_output] then {
fail $test
- }
+ }
# Now remove our expected error message
regsub -all ".*: section .data .* overlaps section .text .*" $exec_output "" exec_output
}
section_check
-
-
--- /dev/null
+# 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
+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
--- /dev/null
+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;
+}
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