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author | Nick Clifton <nickc@redhat.com> | 2009-04-30 15:47:13 +0000 |
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committer | Nick Clifton <nickc@redhat.com> | 2009-04-30 15:47:13 +0000 |
commit | d8045f234d8865a7a7bfce71e81fcbeaf4098a7e (patch) | |
tree | 31e6bc2d28ac295c02dde51ed85fc561675e29a6 /bfd | |
parent | b22a5a41858f1962abba75900ef9928efca36bcd (diff) | |
download | gdb-d8045f234d8865a7a7bfce71e81fcbeaf4098a7e.zip gdb-d8045f234d8865a7a7bfce71e81fcbeaf4098a7e.tar.gz gdb-d8045f234d8865a7a7bfce71e81fcbeaf4098a7e.tar.bz2 |
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.
Diffstat (limited to 'bfd')
-rw-r--r-- | bfd/ChangeLog | 47 | ||||
-rw-r--r-- | bfd/bfd-in2.h | 6 | ||||
-rw-r--r-- | bfd/elf-bfd.h | 11 | ||||
-rw-r--r-- | bfd/elf.c | 14 | ||||
-rw-r--r-- | bfd/elf32-i386.c | 92 | ||||
-rw-r--r-- | bfd/elf64-x86-64.c | 133 | ||||
-rw-r--r-- | bfd/elfcode.h | 3 | ||||
-rw-r--r-- | bfd/elflink.c | 74 | ||||
-rw-r--r-- | bfd/syms.c | 10 |
9 files changed, 336 insertions, 54 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 25c21ef..d13bda0 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,50 @@ +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 diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index fc6a4a1..18eae4e 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -4608,6 +4608,12 @@ typedef struct bfd_symbol /* 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 diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h index 865388c..5761923 100644 --- a/bfd/elf-bfd.h +++ b/bfd/elf-bfd.h @@ -1297,6 +1297,9 @@ struct bfd_elf_section_data /* 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; @@ -1559,6 +1562,11 @@ struct elf_obj_tdata 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; @@ -2139,6 +2147,9 @@ extern int _bfd_elf_obj_attrs_arg_type (bfd *, int, int); 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; @@ -6399,6 +6399,8 @@ Unable to find equivalent output section for symbol '%s' from section '%s'"), 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) @@ -8977,15 +8979,23 @@ _bfd_elf_set_osabi (bfd * abfd, 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); } diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index 3c56685..c0276c0 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -1196,6 +1196,25 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd, 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. */ @@ -1473,6 +1492,12 @@ elf_i386_check_relocs (bfd *abfd, 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 @@ -1815,6 +1840,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) 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; @@ -2036,6 +2062,16 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) } } } + 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 @@ -2074,7 +2110,10 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) { 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); @@ -2877,6 +2916,12 @@ elf_i386_relocate_section (bfd *output_bfd, || 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 @@ -2925,7 +2970,16 @@ elf_i386_relocate_section (bfd *output_bfd, 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); @@ -4045,6 +4099,24 @@ elf_i386_hash_symbol (struct elf_link_hash_entry *h) 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 @@ -4089,6 +4161,9 @@ elf_i386_hash_symbol (struct elf_link_hash_entry *h) ((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" @@ -4106,15 +4181,10 @@ elf_i386_hash_symbol (struct elf_link_hash_entry *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); @@ -4122,10 +4192,12 @@ elf_i386_post_process_headers (bfd *abfd, } #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. */ diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 58be143..b82bcd1 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -161,6 +161,12 @@ static reloc_howto_type x86_64_elf_howto_table[] = 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 { @@ -977,6 +983,25 @@ elf64_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd, 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. */ @@ -1003,7 +1028,7 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, sym_hashes = elf_sym_hashes (abfd); sreloc = NULL; - + rel_end = relocs + sec->reloc_count; for (rel = relocs; rel < rel_end; rel++) { @@ -1259,13 +1284,9 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, 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 @@ -1293,6 +1314,12 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, 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 @@ -1324,6 +1351,7 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, 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) @@ -1336,10 +1364,7 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, } 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; @@ -1650,6 +1675,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) 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; @@ -1728,7 +1754,9 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) && !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; @@ -1827,13 +1855,21 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* 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 @@ -1850,11 +1886,9 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* 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. */ @@ -1872,7 +1906,10 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) { 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); @@ -2674,11 +2711,14 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, && (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 @@ -2718,13 +2758,10 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, 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; @@ -2773,8 +2810,17 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, } } - 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; @@ -3660,11 +3706,12 @@ elf64_x86_64_section_from_shdr (bfd *abfd, 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; @@ -3687,6 +3734,10 @@ elf64_x86_64_add_symbol_hook (bfd *abfd, *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; } @@ -3914,6 +3965,9 @@ static const struct bfd_elf_special_section #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. */ @@ -3926,9 +3980,6 @@ static const struct bfd_elf_special_section #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 diff --git a/bfd/elfcode.h b/bfd/elfcode.h index b42229f..024ead4 100644 --- a/bfd/elfcode.h +++ b/bfd/elfcode.h @@ -1311,6 +1311,9 @@ elf_slurp_symbol_table (bfd *abfd, asymbol **symptrs, bfd_boolean dynamic) case STT_SRELC: sym->symbol.flags |= BSF_SRELC; break; + case STT_GNU_IFUNC: + sym->symbol.flags |= BSF_GNU_INDIRECT_FUNCTION; + break; } if (dynamic) diff --git a/bfd/elflink.c b/bfd/elflink.c index 3f70d91..54ad2af 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -2749,6 +2749,13 @@ _bfd_elf_adjust_dynamic_symbol (struct elf_link_hash_entry *h, void *data) 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; @@ -12533,3 +12540,70 @@ _bfd_elf_make_dynamic_reloc_section (asection * sec, 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; +} @@ -297,6 +297,12 @@ CODE_FRAGMENT . {* 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 @@ -483,7 +489,7 @@ bfd_print_symbol_vandf (bfd *abfd, void *arg, asymbol *symbol) (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' @@ -669,6 +675,8 @@ bfd_decode_symclass (asymbol *symbol) } 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 |