diff options
author | Nick Clifton <nickc@redhat.com> | 2008-12-03 14:51:00 +0000 |
---|---|---|
committer | Nick Clifton <nickc@redhat.com> | 2008-12-03 14:51:00 +0000 |
commit | e7c3341679431c5ecfc170a984d7196cdc175777 (patch) | |
tree | 5be48e5e73b1b747806d4cc47c80ca9893f3aea4 /bfd | |
parent | 5d73705c26e9cb0108f95c127fc5b87c9a982289 (diff) | |
download | gdb-e7c3341679431c5ecfc170a984d7196cdc175777.zip gdb-e7c3341679431c5ecfc170a984d7196cdc175777.tar.gz gdb-e7c3341679431c5ecfc170a984d7196cdc175777.tar.bz2 |
include/elf/
* common.h (STT_IFUNC): Define.
elfcpp/
* elfcpp.h (enum STT): Add STT_IFUNC.
bfd/
* syms.c (struct bfd_symbol): Add new flag BSF_INDIRECT_FUNCTION.
Remove redundant flag BFD_FORT_COMM_DEFAULT_VALUE. Renumber flags
to remove gaps.
(bfd_print_symbol_vandf): Return 'i' for BSF_INDIRECT_FUNCTION.
(bfd_decode_symclass): Likewise.
* elf.c (swap_out_syms): Translate BSF_INDIRECT_FUNCTION into
STT_IFUNC.
(elf_find_function): Treat STT_IFUNC in the same way as STT_FUNC.
(_bfd_elf_is_function_type): Likewise.
* elf32-arm.c (arm_elf_find_function): Likewise.
(elf32_arm_adjust_dynamic_symbol): Likewise.
(elf32_arm_swap_symbol_in): Likewise.
(elf32_arm_additional_program_headers): Likewise.
* elf32-i386.c (is_indirect_symbol): New function.
(elf_i386_check_relocs): Also generate dynamic relocs for
relocations against STT_IFUNC symbols.
(allocate_dynrelocs): Likewise.
(elf_i386_relocate_section): Likewise.
* elf64-x86-64.c (is_indirect_symbol): New function.
(elf64_x86_64_check_relocs): Also generate dynamic relocs for
relocations against STT_IFUNC symbols.
(allocate_dynrelocs): Likewise.
(elf64_x86_64_relocate_section): Likewise.
* elfcode.h (elf_slurp_symbol_table): Translate STT_IFUNC into
BSF_INDIRECT_FUNCTION.
* elflink.c (_bfd_elf_adjust_dynamic_reloc_section): Add support
for STT_IFUNC symbols.
(get_ifunc_reloc_section_name): New function.
(_bfd_elf_make_ifunc_reloc_section): New function.
* elf-bfd.h (struct bfd_elf_section_data): Add indirect_relocs field.
* bfd-in2.h: Regenerate.
gas/
* config/obj-elf.c (obj_elf_type): Add support for STT_IFUNC type.
* doc/as.texinfo: Document new feature.
* NEWS: Mention new feature.
gas/testsuite/
* gas/elf/type.s: Add test of STT_IFUNC symbol type.
* gas/elf/type.e: Update expected disassembly.
* gas/elf/elf.exp: Update grep of symbol types.
ld/
* NEWS: Mention new feature.
* pe-dll.c (process_def_file): Replace use of redundant
BFD_FORT_COMM_DEFAULT_VALUE with 0.
* scripttempl/elf.sc: Add .rel.ifunc.dyn and .rela.ifunc.dyn
sections.
ld/testsuite/
* ld-mips-elf/reloc-1-n32.d: Updated expected output for reloc
descriptions.
* ld-mips-elf/reloc-1-n64.d: Likewise.
* ld-i386/ifunc.d: New test.
* ld-i386/ifunc.s: Source file for the new test.
* ld-i386/i386.exp: Run the new test.
Diffstat (limited to 'bfd')
-rw-r--r-- | bfd/ChangeLog | 34 | ||||
-rw-r--r-- | bfd/bfd-in2.h | 58 | ||||
-rw-r--r-- | bfd/elf-bfd.h | 5 | ||||
-rw-r--r-- | bfd/elf.c | 7 | ||||
-rw-r--r-- | bfd/elf32-arm.c | 8 | ||||
-rw-r--r-- | bfd/elf32-i386.c | 65 | ||||
-rw-r--r-- | bfd/elf64-x86-64.c | 69 | ||||
-rw-r--r-- | bfd/elfcode.h | 3 | ||||
-rw-r--r-- | bfd/elflink.c | 75 | ||||
-rw-r--r-- | bfd/syms.c | 62 |
10 files changed, 304 insertions, 82 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 27327e7..73615b7 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,37 @@ +2008-12-03 Nick Clifton <nickc@redhat.com> + + * syms.c (struct bfd_symbol): Add new flag BSF_INDIRECT_FUNCTION. + Remove redundant flag BFD_FORT_COMM_DEFAULT_VALUE. Renumber flags + to remove gaps. + (bfd_print_symbol_vandf): Return 'i' for BSF_INDIRECT_FUNCTION. + (bfd_decode_symclass): Likewise. + * elf.c (swap_out_syms): Translate BSF_INDIRECT_FUNCTION into + STT_IFUNC. + (elf_find_function): Treat STT_IFUNC in the same way as STT_FUNC. + (_bfd_elf_is_function_type): Likewise. + * elf32-arm.c (arm_elf_find_function): Likewise. + (elf32_arm_adjust_dynamic_symbol): Likewise. + (elf32_arm_swap_symbol_in): Likewise. + (elf32_arm_additional_program_headers): Likewise. + * elf32-i386.c (is_indirect_symbol): New function. + (elf_i386_check_relocs): Also generate dynamic relocs for + relocations against STT_IFUNC symbols. + (allocate_dynrelocs): Likewise. + (elf_i386_relocate_section): Likewise. + * elf64-x86-64.c (is_indirect_symbol): New function. + (elf64_x86_64_check_relocs): Also generate dynamic relocs for + relocations against STT_IFUNC symbols. + (allocate_dynrelocs): Likewise. + (elf64_x86_64_relocate_section): Likewise. + * elfcode.h (elf_slurp_symbol_table): Translate STT_IFUNC into + BSF_INDIRECT_FUNCTION. + * elflink.c (_bfd_elf_adjust_dynamic_reloc_section): Add support + for STT_IFUNC symbols. + (get_ifunc_reloc_section_name): New function. + (_bfd_elf_make_ifunc_reloc_section): New function. + * elf-bfd.h (struct bfd_elf_section_data): Add indirect_relocs field. + * bfd-in2.h: Regenerate. + 2008-12-02 Tristan Gingold <gingold@adacore.com> * config.bfd: Add x86_64-*-darwin* diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index 917b8bc..b1451c9 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -4445,100 +4445,104 @@ typedef struct bfd_symbol symvalue value; /* Attributes of a symbol. */ -#define BSF_NO_FLAGS 0x00 +#define BSF_NO_FLAGS 0x00 /* The symbol has local scope; <<static>> in <<C>>. The value is the offset into the section of the data. */ -#define BSF_LOCAL 0x01 +#define BSF_LOCAL (1 << 0) /* The symbol has global scope; initialized data in <<C>>. The value is the offset into the section of the data. */ -#define BSF_GLOBAL 0x02 +#define BSF_GLOBAL (1 << 1) /* The symbol has global scope and is exported. The value is the offset into the section of the data. */ #define BSF_EXPORT BSF_GLOBAL /* No real difference. */ /* A normal C symbol would be one of: - <<BSF_LOCAL>>, <<BSF_FORT_COMM>>, <<BSF_UNDEFINED>> or + <<BSF_LOCAL>>, <<BSF_COMMON>>, <<BSF_UNDEFINED>> or <<BSF_GLOBAL>>. */ /* The symbol is a debugging record. The value has an arbitrary meaning, unless BSF_DEBUGGING_RELOC is also set. */ -#define BSF_DEBUGGING 0x08 +#define BSF_DEBUGGING (1 << 2) /* The symbol denotes a function entry point. Used in ELF, perhaps others someday. */ -#define BSF_FUNCTION 0x10 - +#define BSF_FUNCTION (1 << 3) + + /* The symbol is an indirect code object. Unrelated to BSF_INDIRECT. + Relocations against a symbol with this flag have to evaluated at + run-time, where the function pointed to by this symbol is invoked + in order to determine the value to be used in the relocation. + BSF_FUNCTION must also be set for symbols with this flag. */ +#define BSF_INDIRECT_FUNCTION (1 << 4) + /* Used by the linker. */ -#define BSF_KEEP 0x20 -#define BSF_KEEP_G 0x40 +#define BSF_KEEP (1 << 5) +#define BSF_KEEP_G (1 << 6) /* A weak global symbol, overridable without warnings by a regular global symbol of the same name. */ -#define BSF_WEAK 0x80 +#define BSF_WEAK (1 << 7) /* This symbol was created to point to a section, e.g. ELF's STT_SECTION symbols. */ -#define BSF_SECTION_SYM 0x100 +#define BSF_SECTION_SYM (1 << 8) /* The symbol used to be a common symbol, but now it is allocated. */ -#define BSF_OLD_COMMON 0x200 - - /* The default value for common data. */ -#define BFD_FORT_COMM_DEFAULT_VALUE 0 +#define BSF_OLD_COMMON (1 << 9) /* In some files the type of a symbol sometimes alters its location in an output file - ie in coff a <<ISFCN>> symbol which is also <<C_EXT>> symbol appears where it was declared and not at the end of a section. This bit is set by the target BFD part to convey this information. */ -#define BSF_NOT_AT_END 0x400 +#define BSF_NOT_AT_END (1 << 10) /* Signal that the symbol is the label of constructor section. */ -#define BSF_CONSTRUCTOR 0x800 +#define BSF_CONSTRUCTOR (1 << 11) /* Signal that the symbol is a warning symbol. The name is a warning. The name of the next symbol is the one to warn about; if a reference is made to a symbol with the same name as the next symbol, a warning is issued by the linker. */ -#define BSF_WARNING 0x1000 +#define BSF_WARNING (1 << 12) /* Signal that the symbol is indirect. This symbol is an indirect pointer to the symbol with the same name as the next symbol. */ -#define BSF_INDIRECT 0x2000 +#define BSF_INDIRECT (1 << 13) /* BSF_FILE marks symbols that contain a file name. This is used for ELF STT_FILE symbols. */ -#define BSF_FILE 0x4000 +#define BSF_FILE (1 << 14) /* Symbol is from dynamic linking information. */ -#define BSF_DYNAMIC 0x8000 +#define BSF_DYNAMIC (1 << 15) /* The symbol denotes a data object. Used in ELF, and perhaps others someday. */ -#define BSF_OBJECT 0x10000 +#define BSF_OBJECT (1 << 16) /* This symbol is a debugging symbol. The value is the offset into the section of the data. BSF_DEBUGGING should be set as well. */ -#define BSF_DEBUGGING_RELOC 0x20000 +#define BSF_DEBUGGING_RELOC (1 << 17) /* This symbol is thread local. Used in ELF. */ -#define BSF_THREAD_LOCAL 0x40000 +#define BSF_THREAD_LOCAL (1 << 18) /* This symbol represents a complex relocation expression, with the expression tree serialized in the symbol name. */ -#define BSF_RELC 0x80000 +#define BSF_RELC (1 << 19) /* This symbol represents a signed complex relocation expression, with the expression tree serialized in the symbol name. */ -#define BSF_SRELC 0x100000 +#define BSF_SRELC (1 << 20) /* This symbol was created by bfd_get_synthetic_symtab. */ -#define BSF_SYNTHETIC 0x200000 +#define BSF_SYNTHETIC (1 << 21) flagword flags; diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h index 5418e7f..effa344 100644 --- a/bfd/elf-bfd.h +++ b/bfd/elf-bfd.h @@ -1287,6 +1287,9 @@ 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; @@ -1768,6 +1771,8 @@ extern asection * _bfd_elf_get_dynamic_reloc_section (bfd *, asection *, bfd_boolean); extern asection * _bfd_elf_make_dynamic_reloc_section (asection *, bfd *, unsigned int, bfd *, bfd_boolean); +extern asection * _bfd_elf_make_ifunc_reloc_section + (bfd *, asection *, bfd *, unsigned int); extern long _bfd_elf_get_dynamic_reloc_upper_bound (bfd *); extern long _bfd_elf_canonicalize_dynamic_reloc @@ -6427,6 +6427,8 @@ 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_INDIRECT_FUNCTION) != 0) + type = STT_IFUNC; else if ((flags & BSF_FUNCTION) != 0) type = STT_FUNC; else if ((flags & BSF_OBJECT) != 0) @@ -7120,6 +7122,7 @@ elf_find_function (bfd *abfd ATTRIBUTE_UNUSED, continue; case STT_NOTYPE: case STT_FUNC: + case STT_IFUNC: if (bfd_get_section (&q->symbol) == section && q->symbol.value >= low_func && q->symbol.value <= offset) @@ -8938,10 +8941,10 @@ _bfd_elf_set_osabi (bfd * abfd, /* 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_IFUNC. */ bfd_boolean _bfd_elf_is_function_type (unsigned int type) { - return (type == STT_FUNC); + return (type == STT_FUNC || type == STT_IFUNC); } diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c index cd5a9bf..dacbc16 100644 --- a/bfd/elf32-arm.c +++ b/bfd/elf32-arm.c @@ -9430,6 +9430,7 @@ arm_elf_find_function (bfd * abfd ATTRIBUTE_UNUSED, filename = bfd_asymbol_name (&q->symbol); break; case STT_FUNC: + case STT_IFUNC: case STT_ARM_TFUNC: case STT_NOTYPE: /* Skip mapping symbols. */ @@ -9555,7 +9556,7 @@ elf32_arm_adjust_dynamic_symbol (struct bfd_link_info * info, /* If this is a function, put it in the procedure linkage table. We will fill in the contents of the procedure linkage table later, when we know the address of the .got section. */ - if (h->type == STT_FUNC || h->type == STT_ARM_TFUNC + if (h->type == STT_FUNC || h->type == STT_ARM_TFUNC || h->type == STT_IFUNC || h->needs_plt) { if (h->plt.refcount <= 0 @@ -11729,7 +11730,8 @@ elf32_arm_swap_symbol_in (bfd * abfd, /* New EABI objects mark thumb function symbols by setting the low bit of the address. Turn these into STT_ARM_TFUNC. */ - if (ELF_ST_TYPE (dst->st_info) == STT_FUNC + if ((ELF_ST_TYPE (dst->st_info) == STT_FUNC + || ELF_ST_TYPE (dst->st_info) == STT_IFUNC) && (dst->st_value & 1)) { dst->st_info = ELF_ST_INFO (ELF_ST_BIND (dst->st_info), STT_ARM_TFUNC); @@ -11830,7 +11832,7 @@ elf32_arm_additional_program_headers (bfd *abfd, static bfd_boolean elf32_arm_is_function_type (unsigned int type) { - return (type == STT_FUNC) || (type == STT_ARM_TFUNC); + return (type == STT_FUNC) || (type == STT_ARM_TFUNC) || (type == STT_IFUNC); } /* We use this to override swap_symbol_in and swap_symbol_out. */ diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index 7d14fef..ec0c16f 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -1193,6 +1193,26 @@ 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_IFUNC + && bed != NULL + && (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. */ @@ -1452,7 +1472,8 @@ elf_i386_check_relocs (bfd *abfd, && (sec->flags & SEC_ALLOC) != 0 && h != NULL && (h->root.type == bfd_link_hash_defweak - || !h->def_regular))) + || !h->def_regular)) + || is_indirect_symbol (abfd, h)) { struct elf_i386_dyn_relocs *p; struct elf_i386_dyn_relocs **head; @@ -1472,6 +1493,9 @@ elf_i386_check_relocs (bfd *abfd, return FALSE; } + if (is_indirect_symbol (abfd, h)) + (void) _bfd_elf_make_ifunc_reloc_section (abfd, sec, htab->elf.dynobj, 2); + /* If this is a global symbol, we count the number of relocations we need for this symbol. */ if (h != NULL) @@ -2033,6 +2057,15 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) } } } + else if (is_indirect_symbol (info->output_bfd, h)) + { + 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 @@ -2069,7 +2102,15 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) /* Finally, allocate space. */ for (p = eh->dyn_relocs; p != NULL; p = p->next) { - asection *sreloc = elf_section_data (p->sec)->sreloc; + asection *sreloc; + + if (! info->shared + && is_indirect_symbol (info->output_bfd, h)) + 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); } @@ -2248,7 +2289,7 @@ elf_i386_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, /* Allocate global sym .plt and .got entries, and space for global sym dynamic relocs. */ - elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, (PTR) info); + elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, info); /* For every jump slot reserved in the sgotplt, reloc_count is incremented. However, when we reserve space for TLS descriptors, @@ -2361,8 +2402,7 @@ elf_i386_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, /* If any dynamic relocs apply to a read-only section, then we need a DT_TEXTREL entry. */ if ((info->flags & DF_TEXTREL) == 0) - elf_link_hash_traverse (&htab->elf, readonly_dynrelocs, - (PTR) info); + elf_link_hash_traverse (&htab->elf, readonly_dynrelocs, info); if ((info->flags & DF_TEXTREL) != 0) { @@ -2879,7 +2919,8 @@ elf_i386_relocate_section (bfd *output_bfd, && ((h->def_dynamic && !h->def_regular) || h->root.type == bfd_link_hash_undefweak - || h->root.type == bfd_link_hash_undefined))) + || h->root.type == bfd_link_hash_undefined)) + || is_indirect_symbol (output_bfd, h)) { Elf_Internal_Rela outrel; bfd_byte *loc; @@ -2919,19 +2960,23 @@ 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 (sreloc == NULL) - abort (); + if ((! info->shared) && is_indirect_symbol (output_bfd, h)) + 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; loc += sreloc->reloc_count++ * sizeof (Elf32_External_Rel); + bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); /* If this reloc is against an external symbol, we do not want to fiddle with the addend. Otherwise, we need to include the symbol value so that it becomes an addend for the dynamic reloc. */ - if (! relocate) + if (! relocate || is_indirect_symbol (output_bfd, h)) continue; } break; diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 7eecb22..1ea033b 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -974,6 +974,26 @@ 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_IFUNC + && bed != NULL + && (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. */ @@ -1255,7 +1275,10 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, If on the other hand, we are creating an executable, we may need to keep relocations for symbols satisfied by a dynamic library if we manage to avoid copy relocs for the - symbol. */ + symbol. + + Also we must keep any relocations against IFUNC symbols as + they will be evaluated at load time. */ if ((info->shared && (sec->flags & SEC_ALLOC) != 0 && (((r_type != R_X86_64_PC8) @@ -1271,7 +1294,8 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, && (sec->flags & SEC_ALLOC) != 0 && h != NULL && (h->root.type == bfd_link_hash_defweak - || !h->def_regular))) + || !h->def_regular)) + || is_indirect_symbol (abfd, h)) { struct elf64_x86_64_dyn_relocs *p; struct elf64_x86_64_dyn_relocs **head; @@ -1291,6 +1315,9 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, return FALSE; } + if (is_indirect_symbol (abfd, h)) + (void) _bfd_elf_make_ifunc_reloc_section (abfd, sec, htab->elf.dynobj, 2); + /* If this is a global symbol, we count the number of relocations we need for this symbol. */ if (h != NULL) @@ -1830,6 +1857,13 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) } } } + else if (is_indirect_symbol (info->output_bfd, h)) + { + if (h->dynindx == -1 + && ! h->forced_local + && ! 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 @@ -1866,7 +1900,16 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* Finally, allocate space. */ for (p = eh->dyn_relocs; p != NULL; p = p->next) { - asection *sreloc = elf_section_data (p->sec)->sreloc; + asection * sreloc; + + if (! info->shared + && is_indirect_symbol (info->output_bfd, h)) + 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 (Elf64_External_Rela); } @@ -1970,7 +2013,6 @@ elf64_x86_64_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, srel->size += p->count * sizeof (Elf64_External_Rela); if ((p->sec->output_section->flags & SEC_READONLY) != 0) info->flags |= DF_TEXTREL; - } } } @@ -2039,7 +2081,7 @@ elf64_x86_64_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, /* Allocate global sym .plt and .got entries, and space for global sym dynamic relocs. */ - elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, (PTR) info); + elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, info); /* For every jump slot reserved in the sgotplt, reloc_count is incremented. However, when we reserve space for TLS descriptors, @@ -2170,8 +2212,7 @@ elf64_x86_64_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, /* If any dynamic relocs apply to a read-only section, then we need a DT_TEXTREL entry. */ if ((info->flags & DF_TEXTREL) == 0) - elf_link_hash_traverse (&htab->elf, readonly_dynrelocs, - (PTR) info); + elf_link_hash_traverse (&htab->elf, readonly_dynrelocs, info); if ((info->flags & DF_TEXTREL) != 0) { @@ -2680,7 +2721,8 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, && ((h->def_dynamic && !h->def_regular) || h->root.type == bfd_link_hash_undefweak - || h->root.type == bfd_link_hash_undefined))) + || h->root.type == bfd_link_hash_undefined)) + || is_indirect_symbol (output_bfd, h)) { Elf_Internal_Rela outrel; bfd_byte *loc; @@ -2766,9 +2808,12 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, } } - sreloc = elf_section_data (input_section)->sreloc; - if (sreloc == NULL) - abort (); + if ((! info->shared) && is_indirect_symbol (output_bfd, h)) + 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; loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela); @@ -2778,7 +2823,7 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, not want to fiddle with the addend. Otherwise, we need to include the symbol value so that it becomes an addend for the dynamic reloc. */ - if (! relocate) + if (! relocate || is_indirect_symbol (output_bfd, h)) continue; } diff --git a/bfd/elfcode.h b/bfd/elfcode.h index b42229f..cd8ffe4 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_IFUNC: + sym->symbol.flags |= BSF_INDIRECT_FUNCTION; + break; } if (dynamic) diff --git a/bfd/elflink.c b/bfd/elflink.c index 43379c7..952b4e0 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -2652,6 +2652,13 @@ _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_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; @@ -12400,3 +12407,71 @@ _bfd_elf_make_dynamic_reloc_section (asection * sec, return reloc_sec; } + +#define IFUNC_INFIX ".ifunc" + +/* Returns the name of the ifunc-using-dynamic-reloc section associated with SEC. */ + +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_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; +} @@ -1,6 +1,6 @@ /* Generic symbol-table support for the BFD library. Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, - 2000, 2001, 2002, 2003, 2004, 2007 + 2000, 2001, 2002, 2003, 2004, 2007, 2008 Free Software Foundation, Inc. Written by Cygnus Support. @@ -205,100 +205,104 @@ CODE_FRAGMENT . symvalue value; . . {* Attributes of a symbol. *} -.#define BSF_NO_FLAGS 0x00 +.#define BSF_NO_FLAGS 0x00 . . {* The symbol has local scope; <<static>> in <<C>>. The value . is the offset into the section of the data. *} -.#define BSF_LOCAL 0x01 +.#define BSF_LOCAL (1 << 0) . . {* The symbol has global scope; initialized data in <<C>>. The . value is the offset into the section of the data. *} -.#define BSF_GLOBAL 0x02 +.#define BSF_GLOBAL (1 << 1) . . {* The symbol has global scope and is exported. The value is . the offset into the section of the data. *} .#define BSF_EXPORT BSF_GLOBAL {* No real difference. *} . . {* A normal C symbol would be one of: -. <<BSF_LOCAL>>, <<BSF_FORT_COMM>>, <<BSF_UNDEFINED>> or +. <<BSF_LOCAL>>, <<BSF_COMMON>>, <<BSF_UNDEFINED>> or . <<BSF_GLOBAL>>. *} . . {* The symbol is a debugging record. The value has an arbitrary . meaning, unless BSF_DEBUGGING_RELOC is also set. *} -.#define BSF_DEBUGGING 0x08 +.#define BSF_DEBUGGING (1 << 2) . . {* The symbol denotes a function entry point. Used in ELF, . perhaps others someday. *} -.#define BSF_FUNCTION 0x10 +.#define BSF_FUNCTION (1 << 3) . +. {* The symbol is an indirect code object. Unrelated to BSF_INDIRECT. +. Relocations against a symbol with this flag have to evaluated at +. run-time, where the function pointed to by this symbol is invoked +. in order to determine the value to be used in the relocation. +. BSF_FUNCTION must also be set for symbols with this flag. *} +.#define BSF_INDIRECT_FUNCTION (1 << 4) +. . {* Used by the linker. *} -.#define BSF_KEEP 0x20 -.#define BSF_KEEP_G 0x40 +.#define BSF_KEEP (1 << 5) +.#define BSF_KEEP_G (1 << 6) . . {* A weak global symbol, overridable without warnings by . a regular global symbol of the same name. *} -.#define BSF_WEAK 0x80 +.#define BSF_WEAK (1 << 7) . . {* This symbol was created to point to a section, e.g. ELF's . STT_SECTION symbols. *} -.#define BSF_SECTION_SYM 0x100 +.#define BSF_SECTION_SYM (1 << 8) . . {* The symbol used to be a common symbol, but now it is . allocated. *} -.#define BSF_OLD_COMMON 0x200 -. -. {* The default value for common data. *} -.#define BFD_FORT_COMM_DEFAULT_VALUE 0 +.#define BSF_OLD_COMMON (1 << 9) . . {* In some files the type of a symbol sometimes alters its . location in an output file - ie in coff a <<ISFCN>> symbol . which is also <<C_EXT>> symbol appears where it was . declared and not at the end of a section. This bit is set . by the target BFD part to convey this information. *} -.#define BSF_NOT_AT_END 0x400 +.#define BSF_NOT_AT_END (1 << 10) . . {* Signal that the symbol is the label of constructor section. *} -.#define BSF_CONSTRUCTOR 0x800 +.#define BSF_CONSTRUCTOR (1 << 11) . . {* Signal that the symbol is a warning symbol. The name is a . warning. The name of the next symbol is the one to warn about; . if a reference is made to a symbol with the same name as the next . symbol, a warning is issued by the linker. *} -.#define BSF_WARNING 0x1000 +.#define BSF_WARNING (1 << 12) . . {* Signal that the symbol is indirect. This symbol is an indirect . pointer to the symbol with the same name as the next symbol. *} -.#define BSF_INDIRECT 0x2000 +.#define BSF_INDIRECT (1 << 13) . . {* BSF_FILE marks symbols that contain a file name. This is used . for ELF STT_FILE symbols. *} -.#define BSF_FILE 0x4000 +.#define BSF_FILE (1 << 14) . . {* Symbol is from dynamic linking information. *} -.#define BSF_DYNAMIC 0x8000 +.#define BSF_DYNAMIC (1 << 15) . . {* The symbol denotes a data object. Used in ELF, and perhaps . others someday. *} -.#define BSF_OBJECT 0x10000 +.#define BSF_OBJECT (1 << 16) . . {* This symbol is a debugging symbol. The value is the offset . into the section of the data. BSF_DEBUGGING should be set . as well. *} -.#define BSF_DEBUGGING_RELOC 0x20000 +.#define BSF_DEBUGGING_RELOC (1 << 17) . . {* This symbol is thread local. Used in ELF. *} -.#define BSF_THREAD_LOCAL 0x40000 +.#define BSF_THREAD_LOCAL (1 << 18) . . {* This symbol represents a complex relocation expression, . with the expression tree serialized in the symbol name. *} -.#define BSF_RELC 0x80000 +.#define BSF_RELC (1 << 19) . . {* This symbol represents a signed complex relocation expression, . with the expression tree serialized in the symbol name. *} -.#define BSF_SRELC 0x100000 +.#define BSF_SRELC (1 << 20) . . {* This symbol was created by bfd_get_synthetic_symtab. *} -.#define BSF_SYNTHETIC 0x200000 +.#define BSF_SYNTHETIC (1 << 21) . . flagword flags; . @@ -486,7 +490,7 @@ 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_INDIRECT_FUNCTION) ? 'i' : ' ', (type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ', ((type & BSF_FUNCTION) ? 'F' @@ -672,6 +676,8 @@ bfd_decode_symclass (asymbol *symbol) } if (bfd_is_ind_section (symbol->section)) return 'I'; + if (symbol->flags & BSF_INDIRECT_FUNCTION) + return 'i'; if (symbol->flags & BSF_WEAK) { /* If weak, determine if it's specifically an object |