i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
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#source: ifunc-2-local-i386.s
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2022-01-05 23:12:03 +08:00
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#ld: -z now -m elf_i386 -shared --hash-style=sysv -z noseparate-code $NO_DT_RELR_LDFLAGS
|
i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
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#as: --32
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#objdump: -dw
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#target: x86_64-*-* i?86-*-*
|
2020-06-30 23:47:02 +08:00
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#notarget: *-*-lynxos *-*-nto*
|
i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
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.*: +file format .*
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Disassembly of section .plt:
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2021-01-07 22:42:00 +08:00
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0+e0 <\*ABS\*@plt-0x10>:
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2020-07-15 14:53:55 +08:00
|
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+[a-f0-9]+: ff b3 04 00 00 00 push 0x4\(%ebx\)
|
i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
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+[a-f0-9]+: ff a3 08 00 00 00 jmp \*0x8\(%ebx\)
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+[a-f0-9]+: 00 00 add %al,\(%eax\)
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...
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|
Define various symbols conditionally in shared libraries
The values of symbols in shared libraries like _end, _edata, and
__bss_start are generally not that useful outside of the shared
library. This patch defines them conditionally with PROVIDE, since a
shared library might need the local value. An example is glibc ld.so
local access to "_begin", "_etext" and "_end". (ld.so gains access to
the local values by making the references using hidden visibility.
That makes the definitions hidden too.)
We can't use PROVIDE_HIDDEN in the linker scripts because the shared
library might need the value of the symbol in the executable. An
example is freebsd libc dynamic access to "_end".
PR ld/23161
* emulparams/aarch64cloudabi.sh: PROVIDE __bss_start__, _bss_end__,
and __end__ in shared libraries.
* emulparams/aarch64fbsd.sh: Likewise.
* emulparams/aarch64linux.sh: Likewise.
* emulparams/aarch64linux32.sh: Likewise.
* emulparams/armelf_fuchsia.sh: Likewise.
* emulparams/armelf_linux.sh: Likewise.
* emulparams/armelf_phoenix.sh: Likewise.
* emulparams/aarch64elf.sh: Likewise, and __data_start
* emulparams/aarch64elf32.sh: Likewise.
* emulparams/armelf.sh: Likewise.
* emulparams/armnto.sh: Likewise.
* emulparams/elf32bmip.sh: Remove duplicate ". = ." from
OTHER_GOT_SYMBOLS. PROVIDE _ftext, _fdata, and _fbss in shared libs.
* emulparams/elf32bmipn32-defs.sh: Likewise.
* emulparams/elf32frv.sh: PROVIDE __end and __data_start in shared libs.
* emulparams/elf32lriscv-defs.sh: Tidy.
* emulparams/elf32mcore.sh: PROVIDE __bss_start and _bss_end in
shared libs
* emulparams/elf32ppccommon.sh: PROVIDE __end in shared libs.
* emulparams/elf32rl78.sh: Tidy.
* emulparams/i386nto.sh: PROVIDE _btext in shared libs.
* emulparams/shelf_nto.sh: Likewise.
* emulparams/shlelf_nto.sh: Likewise.
* emulparams/score3_elf.sh: PROVIDE _gp, _bss_start__, _bss_end__,
__bss_end__, __end__, _fdata, _sdata_begin, and _bss_start in
shared libs.
* scripttempl/elf.sc: Don't use EXECUTABLE_SYMBOLS for shared
libraries. PROVIDE _edata, edata, __bss_start, and _end in shared
libraries.
* testsuite/ld-elf/pr23161.map,
* testsuite/ld-elf/pr23161a.c,
* testsuite/ld-elf/pr23161b.c,
* testsuite/ld-elf/pr23161c.c,
* testsuite/ld-elf/pr23161a.rd,
* testsuite/ld-elf/pr23161b.rd,
* testsuite/ld-elf/pr23161c.rd,
* testsuite/ld-elf/pr23161d.rd: New tests.
* testsuite/ld-elf/shared.exp: Run ld/23161 tests.
* testsuite/ld-elf/pr23162.rd,
* testsuite/ld-aarch64/ifunc-1-local.d,
* testsuite/ld-aarch64/ifunc-1.d,
* testsuite/ld-aarch64/ifunc-2-local.d,
* testsuite/ld-aarch64/ifunc-2.d,
* testsuite/ld-aarch64/ifunc-21.d,
* testsuite/ld-aarch64/ifunc-3a.d,
* testsuite/ld-alpha/tlsbin.rd,
* testsuite/ld-alpha/tlsbin.sd,
* testsuite/ld-alpha/tlsbinr.rd,
* testsuite/ld-alpha/tlspic.rd,
* testsuite/ld-alpha/tlspic.sd,
* testsuite/ld-cris/dso-pltdis1.d,
* testsuite/ld-cris/dso-pltdis2.d,
* testsuite/ld-cris/dso12-pltdis.d,
* testsuite/ld-cris/gotplt1.d,
* testsuite/ld-cris/gotplt2.d,
* testsuite/ld-cris/gotplt3.d,
* testsuite/ld-cris/hiddef1.d,
* testsuite/ld-cris/libdso-1.d,
* testsuite/ld-cris/libdso-10.d,
* testsuite/ld-cris/libdso-11.d,
* testsuite/ld-cris/libdso-12.d,
* testsuite/ld-cris/libdso-12b.d,
* testsuite/ld-cris/libdso-12c.d,
* testsuite/ld-cris/libdso-13.d,
* testsuite/ld-cris/libdso-13b.d,
* testsuite/ld-cris/libdso-14.d,
* testsuite/ld-cris/libdso-15.d,
* testsuite/ld-cris/libdso-15b.d,
* testsuite/ld-cris/libdso-1c.d,
* testsuite/ld-cris/libdso-1d.d,
* testsuite/ld-cris/libdso-2.d,
* testsuite/ld-cris/pic-gc-72.d,
* testsuite/ld-cris/pic-gc-73.d,
* testsuite/ld-cris/pr16044.d,
* testsuite/ld-cris/pv32-1.d,
* testsuite/ld-cris/tls-dso-dtpoffd2.d,
* testsuite/ld-cris/tls-dso-dtpoffd4.d,
* testsuite/ld-cris/tls-dso-tpoffgotcomm1.d,
* testsuite/ld-cris/tls-gc-71.d,
* testsuite/ld-cris/tls-gd-1.d,
* testsuite/ld-cris/tls-gd-1h.d,
* testsuite/ld-cris/tls-gd-2.d,
* testsuite/ld-cris/tls-gd-2h.d,
* testsuite/ld-cris/tls-ie-10.d,
* testsuite/ld-cris/tls-ie-11.d,
* testsuite/ld-cris/tls-ie-78.d,
* testsuite/ld-cris/tls-ie-8.d,
* testsuite/ld-cris/tls-ie-9.d,
* testsuite/ld-cris/tls-js1.d,
* testsuite/ld-cris/tls-ld-4.d,
* testsuite/ld-cris/tls-ld-5.d,
* testsuite/ld-cris/tls-ld-6.d,
* testsuite/ld-cris/tls-ld-7.d,
* testsuite/ld-cris/tls-ldgd-14.d,
* testsuite/ld-cris/tls-ldgd-15.d,
* testsuite/ld-cris/tls-ldgdex-14.d,
* testsuite/ld-cris/tls-ldgdex-15.d,
* testsuite/ld-cris/tls-ldgdx-14.d,
* testsuite/ld-cris/tls-ldgdx-15.d,
* testsuite/ld-cris/tls-legdx-16.d,
* testsuite/ld-cris/tls-legdx-17.d,
* testsuite/ld-cris/tls-local-54.d,
* testsuite/ld-cris/tls-local-60.d,
* testsuite/ld-cris/tls-local-61.d,
* testsuite/ld-cris/tls-local-63.d,
* testsuite/ld-cris/tls-local-64.d,
* testsuite/ld-cris/tls-ok-30.d,
* testsuite/ld-cris/tls-ok-32.d,
* testsuite/ld-cris/tls-ok-34.d,
* testsuite/ld-cris/tls-und-38.d,
* testsuite/ld-cris/tls-und-42.d,
* testsuite/ld-cris/tls-und-46.d,
* testsuite/ld-cris/tls-und-50.d,
* testsuite/ld-cris/weakhiddso.d,
* testsuite/ld-cris/weakref2.d,
* testsuite/ld-frv/fdpic-shared-1.d,
* testsuite/ld-frv/fdpic-shared-2.d,
* testsuite/ld-frv/fdpic-shared-3.d,
* testsuite/ld-frv/fdpic-shared-4.d,
* testsuite/ld-frv/fdpic-shared-5.d,
* testsuite/ld-frv/fdpic-shared-7.d,
* testsuite/ld-frv/fdpic-shared-8.d,
* testsuite/ld-frv/tls-dynamic-2.d,
* testsuite/ld-i386/ibt-plt-1.d,
* testsuite/ld-i386/ibt-plt-2a.d,
* testsuite/ld-i386/ibt-plt-2b.d,
* testsuite/ld-i386/ibt-plt-2c.d,
* testsuite/ld-i386/ibt-plt-2d.d,
* testsuite/ld-i386/ibt-plt-3a.d,
* testsuite/ld-i386/ibt-plt-3b.d,
* testsuite/ld-i386/ibt-plt-3c.d,
* testsuite/ld-i386/ibt-plt-3d.d,
* testsuite/ld-i386/plt2.dd,
* testsuite/ld-i386/pr20830.d,
* testsuite/ld-i386/tlsbin-nacl.rd,
* testsuite/ld-i386/tlsbin.rd,
* testsuite/ld-i386/tlsbin2-nacl.rd,
* testsuite/ld-i386/tlsbin2.rd,
* testsuite/ld-i386/tlsbindesc-nacl.rd,
* testsuite/ld-i386/tlsbindesc.rd,
* testsuite/ld-i386/tlsdesc-nacl.rd,
* testsuite/ld-i386/tlsdesc.rd,
* testsuite/ld-i386/tlsgdesc-nacl.rd,
* testsuite/ld-i386/tlsgdesc.rd,
* testsuite/ld-i386/tlsnopic-nacl.rd,
* testsuite/ld-i386/tlsnopic.dd,
* testsuite/ld-i386/tlsnopic.rd,
* testsuite/ld-i386/tlsnopic.sd,
* testsuite/ld-i386/tlspic-nacl.rd,
* testsuite/ld-i386/tlspic.rd,
* testsuite/ld-i386/tlspic2-nacl.rd,
* testsuite/ld-i386/tlspic2.rd,
* testsuite/ld-ia64/merge1.d,
* testsuite/ld-ia64/merge2.d,
* testsuite/ld-ia64/merge3.d,
* testsuite/ld-ia64/merge4.d,
* testsuite/ld-ia64/merge5.d,
* testsuite/ld-ia64/tlsbin.rd,
* testsuite/ld-ia64/tlspic.rd,
* testsuite/ld-ifunc/ifunc-2-i386-now.d,
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d,
* testsuite/ld-ifunc/ifunc-2-local-x86-64-now.d,
* testsuite/ld-ifunc/ifunc-2-local-x86-64.d,
* testsuite/ld-ifunc/ifunc-2-x86-64-now.d,
* testsuite/ld-ifunc/ifunc-2-x86-64.d,
* testsuite/ld-ifunc/pr17154-i386-now.d,
* testsuite/ld-ifunc/pr17154-i386.d,
* testsuite/ld-ifunc/pr17154-x86-64-now.d,
* testsuite/ld-ifunc/pr17154-x86-64.d,
* testsuite/ld-m68k/tls-def-1.d,
* testsuite/ld-m68k/tls-gd-1.d2,
* testsuite/ld-metag/shared.d,
* testsuite/ld-metag/stub_pic_app.d,
* testsuite/ld-mips-elf/rel32-n32.d,
* testsuite/ld-mips-elf/rel32-o32.d,
* testsuite/ld-mips-elf/rel64.d,
* testsuite/ld-powerpc/ambiguousv1.d,
* testsuite/ld-powerpc/ambiguousv1b.d,
* testsuite/ld-powerpc/ambiguousv2.d,
* testsuite/ld-powerpc/ambiguousv2b.d,
* testsuite/ld-powerpc/tlsexe.d,
* testsuite/ld-powerpc/tlsexe.r,
* testsuite/ld-powerpc/tlsexe32.d,
* testsuite/ld-powerpc/tlsexe32.g,
* testsuite/ld-powerpc/tlsexe32.r,
* testsuite/ld-powerpc/tlsexetoc.d,
* testsuite/ld-powerpc/tlsexetoc.r,
* testsuite/ld-powerpc/tlsso.d,
* testsuite/ld-powerpc/tlsso.r,
* testsuite/ld-powerpc/tlsso32.g,
* testsuite/ld-powerpc/tlsso32.r,
* testsuite/ld-powerpc/tlstocso.d,
* testsuite/ld-powerpc/tlstocso.g,
* testsuite/ld-powerpc/tlstocso.r,
* testsuite/ld-s390/gotreloc_31-1.dd,
* testsuite/ld-s390/tlsbin.dd,
* testsuite/ld-s390/tlsbin.rd,
* testsuite/ld-s390/tlsbin_64.dd,
* testsuite/ld-s390/tlsbin_64.rd,
* testsuite/ld-s390/tlspic.rd,
* testsuite/ld-s390/tlspic_64.rd,
* testsuite/ld-sh/tlsbin-2.d,
* testsuite/ld-sh/tlspic-2.d,
* testsuite/ld-sparc/gotop32.rd,
* testsuite/ld-sparc/gotop64.rd,
* testsuite/ld-sparc/tlssunbin32.rd,
* testsuite/ld-sparc/tlssunbin64.rd,
* testsuite/ld-sparc/tlssunnopic32.rd,
* testsuite/ld-sparc/tlssunnopic64.rd,
* testsuite/ld-sparc/tlssunpic32.rd,
* testsuite/ld-sparc/tlssunpic64.rd,
* testsuite/ld-x86-64/bnd-branch-1-now.d,
* testsuite/ld-x86-64/bnd-ifunc-1-now.d,
* testsuite/ld-x86-64/bnd-ifunc-2-now.d,
* testsuite/ld-x86-64/bnd-ifunc-2.d,
* testsuite/ld-x86-64/bnd-plt-1-now.d,
* testsuite/ld-x86-64/bnd-plt-1.d,
* testsuite/ld-x86-64/ibt-plt-1-x32.d,
* testsuite/ld-x86-64/ibt-plt-1.d,
* testsuite/ld-x86-64/ibt-plt-2a-x32.d,
* testsuite/ld-x86-64/ibt-plt-2a.d,
* testsuite/ld-x86-64/ibt-plt-2b-x32.d,
* testsuite/ld-x86-64/ibt-plt-2b.d,
* testsuite/ld-x86-64/ibt-plt-2c-x32.d,
* testsuite/ld-x86-64/ibt-plt-2c.d,
* testsuite/ld-x86-64/ibt-plt-2d-x32.d,
* testsuite/ld-x86-64/ibt-plt-2d.d,
* testsuite/ld-x86-64/ibt-plt-3a-x32.d,
* testsuite/ld-x86-64/ibt-plt-3a.d,
* testsuite/ld-x86-64/ibt-plt-3b-x32.d,
* testsuite/ld-x86-64/ibt-plt-3b.d,
* testsuite/ld-x86-64/ibt-plt-3c-x32.d,
* testsuite/ld-x86-64/ibt-plt-3c.d,
* testsuite/ld-x86-64/ibt-plt-3d-x32.d,
* testsuite/ld-x86-64/ibt-plt-3d.d,
* testsuite/ld-x86-64/ilp32-4-nacl.d,
* testsuite/ld-x86-64/ilp32-4.d,
* testsuite/ld-x86-64/load1c-nacl.d,
* testsuite/ld-x86-64/load1c.d,
* testsuite/ld-x86-64/load1d-nacl.d,
* testsuite/ld-x86-64/load1d.d,
* testsuite/ld-x86-64/mpx3n.dd,
* testsuite/ld-x86-64/mpx4.dd,
* testsuite/ld-x86-64/mpx4n.dd,
* testsuite/ld-x86-64/plt2.dd,
* testsuite/ld-x86-64/pr14207.d,
* testsuite/ld-x86-64/pr19162.d,
* testsuite/ld-x86-64/pr20253-1f.d,
* testsuite/ld-x86-64/pr20253-1l.d,
* testsuite/ld-x86-64/pr20830a-now.d,
* testsuite/ld-x86-64/pr20830a.d,
* testsuite/ld-x86-64/pr20830b-now.d,
* testsuite/ld-x86-64/pr20830b.d,
* testsuite/ld-x86-64/pr21038a-now.d,
* testsuite/ld-x86-64/pr21038a.d,
* testsuite/ld-x86-64/pr21038b-now.d,
* testsuite/ld-x86-64/pr21038b.d,
* testsuite/ld-x86-64/pr21038c-now.d,
* testsuite/ld-x86-64/pr21038c.d,
* testsuite/ld-x86-64/tlsbin-nacl.rd,
* testsuite/ld-x86-64/tlsbin.rd,
* testsuite/ld-x86-64/tlsbin2-nacl.rd,
* testsuite/ld-x86-64/tlsbin2.rd,
* testsuite/ld-x86-64/tlsbindesc-nacl.rd,
* testsuite/ld-x86-64/tlsbindesc.rd,
* testsuite/ld-x86-64/tlsdesc-nacl.rd,
* testsuite/ld-x86-64/tlsdesc.rd,
* testsuite/ld-x86-64/tlsgdesc-nacl.rd,
* testsuite/ld-x86-64/tlsgdesc.rd,
* testsuite/ld-x86-64/tlspic-nacl.rd,
* testsuite/ld-x86-64/tlspic.rd,
* testsuite/ld-x86-64/tlspic2-nacl.rd,
* testsuite/ld-x86-64/tlspic2.rd: Update.
2018-06-08 18:47:34 +08:00
|
|
|
0+f0 <\*ABS\*@plt>:
|
i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
|
|
|
+[a-f0-9]+: ff a3 0c 00 00 00 jmp \*0xc\(%ebx\)
|
|
|
|
+[a-f0-9]+: 68 00 00 00 00 push \$0x0
|
2021-01-07 22:42:00 +08:00
|
|
|
+[a-f0-9]+: e9 e0 ff ff ff jmp e0 <\*ABS\*@plt-0x10>
|
i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
|
|
|
|
|
|
|
Disassembly of section .text:
|
|
|
|
|
Define various symbols conditionally in shared libraries
The values of symbols in shared libraries like _end, _edata, and
__bss_start are generally not that useful outside of the shared
library. This patch defines them conditionally with PROVIDE, since a
shared library might need the local value. An example is glibc ld.so
local access to "_begin", "_etext" and "_end". (ld.so gains access to
the local values by making the references using hidden visibility.
That makes the definitions hidden too.)
We can't use PROVIDE_HIDDEN in the linker scripts because the shared
library might need the value of the symbol in the executable. An
example is freebsd libc dynamic access to "_end".
PR ld/23161
* emulparams/aarch64cloudabi.sh: PROVIDE __bss_start__, _bss_end__,
and __end__ in shared libraries.
* emulparams/aarch64fbsd.sh: Likewise.
* emulparams/aarch64linux.sh: Likewise.
* emulparams/aarch64linux32.sh: Likewise.
* emulparams/armelf_fuchsia.sh: Likewise.
* emulparams/armelf_linux.sh: Likewise.
* emulparams/armelf_phoenix.sh: Likewise.
* emulparams/aarch64elf.sh: Likewise, and __data_start
* emulparams/aarch64elf32.sh: Likewise.
* emulparams/armelf.sh: Likewise.
* emulparams/armnto.sh: Likewise.
* emulparams/elf32bmip.sh: Remove duplicate ". = ." from
OTHER_GOT_SYMBOLS. PROVIDE _ftext, _fdata, and _fbss in shared libs.
* emulparams/elf32bmipn32-defs.sh: Likewise.
* emulparams/elf32frv.sh: PROVIDE __end and __data_start in shared libs.
* emulparams/elf32lriscv-defs.sh: Tidy.
* emulparams/elf32mcore.sh: PROVIDE __bss_start and _bss_end in
shared libs
* emulparams/elf32ppccommon.sh: PROVIDE __end in shared libs.
* emulparams/elf32rl78.sh: Tidy.
* emulparams/i386nto.sh: PROVIDE _btext in shared libs.
* emulparams/shelf_nto.sh: Likewise.
* emulparams/shlelf_nto.sh: Likewise.
* emulparams/score3_elf.sh: PROVIDE _gp, _bss_start__, _bss_end__,
__bss_end__, __end__, _fdata, _sdata_begin, and _bss_start in
shared libs.
* scripttempl/elf.sc: Don't use EXECUTABLE_SYMBOLS for shared
libraries. PROVIDE _edata, edata, __bss_start, and _end in shared
libraries.
* testsuite/ld-elf/pr23161.map,
* testsuite/ld-elf/pr23161a.c,
* testsuite/ld-elf/pr23161b.c,
* testsuite/ld-elf/pr23161c.c,
* testsuite/ld-elf/pr23161a.rd,
* testsuite/ld-elf/pr23161b.rd,
* testsuite/ld-elf/pr23161c.rd,
* testsuite/ld-elf/pr23161d.rd: New tests.
* testsuite/ld-elf/shared.exp: Run ld/23161 tests.
* testsuite/ld-elf/pr23162.rd,
* testsuite/ld-aarch64/ifunc-1-local.d,
* testsuite/ld-aarch64/ifunc-1.d,
* testsuite/ld-aarch64/ifunc-2-local.d,
* testsuite/ld-aarch64/ifunc-2.d,
* testsuite/ld-aarch64/ifunc-21.d,
* testsuite/ld-aarch64/ifunc-3a.d,
* testsuite/ld-alpha/tlsbin.rd,
* testsuite/ld-alpha/tlsbin.sd,
* testsuite/ld-alpha/tlsbinr.rd,
* testsuite/ld-alpha/tlspic.rd,
* testsuite/ld-alpha/tlspic.sd,
* testsuite/ld-cris/dso-pltdis1.d,
* testsuite/ld-cris/dso-pltdis2.d,
* testsuite/ld-cris/dso12-pltdis.d,
* testsuite/ld-cris/gotplt1.d,
* testsuite/ld-cris/gotplt2.d,
* testsuite/ld-cris/gotplt3.d,
* testsuite/ld-cris/hiddef1.d,
* testsuite/ld-cris/libdso-1.d,
* testsuite/ld-cris/libdso-10.d,
* testsuite/ld-cris/libdso-11.d,
* testsuite/ld-cris/libdso-12.d,
* testsuite/ld-cris/libdso-12b.d,
* testsuite/ld-cris/libdso-12c.d,
* testsuite/ld-cris/libdso-13.d,
* testsuite/ld-cris/libdso-13b.d,
* testsuite/ld-cris/libdso-14.d,
* testsuite/ld-cris/libdso-15.d,
* testsuite/ld-cris/libdso-15b.d,
* testsuite/ld-cris/libdso-1c.d,
* testsuite/ld-cris/libdso-1d.d,
* testsuite/ld-cris/libdso-2.d,
* testsuite/ld-cris/pic-gc-72.d,
* testsuite/ld-cris/pic-gc-73.d,
* testsuite/ld-cris/pr16044.d,
* testsuite/ld-cris/pv32-1.d,
* testsuite/ld-cris/tls-dso-dtpoffd2.d,
* testsuite/ld-cris/tls-dso-dtpoffd4.d,
* testsuite/ld-cris/tls-dso-tpoffgotcomm1.d,
* testsuite/ld-cris/tls-gc-71.d,
* testsuite/ld-cris/tls-gd-1.d,
* testsuite/ld-cris/tls-gd-1h.d,
* testsuite/ld-cris/tls-gd-2.d,
* testsuite/ld-cris/tls-gd-2h.d,
* testsuite/ld-cris/tls-ie-10.d,
* testsuite/ld-cris/tls-ie-11.d,
* testsuite/ld-cris/tls-ie-78.d,
* testsuite/ld-cris/tls-ie-8.d,
* testsuite/ld-cris/tls-ie-9.d,
* testsuite/ld-cris/tls-js1.d,
* testsuite/ld-cris/tls-ld-4.d,
* testsuite/ld-cris/tls-ld-5.d,
* testsuite/ld-cris/tls-ld-6.d,
* testsuite/ld-cris/tls-ld-7.d,
* testsuite/ld-cris/tls-ldgd-14.d,
* testsuite/ld-cris/tls-ldgd-15.d,
* testsuite/ld-cris/tls-ldgdex-14.d,
* testsuite/ld-cris/tls-ldgdex-15.d,
* testsuite/ld-cris/tls-ldgdx-14.d,
* testsuite/ld-cris/tls-ldgdx-15.d,
* testsuite/ld-cris/tls-legdx-16.d,
* testsuite/ld-cris/tls-legdx-17.d,
* testsuite/ld-cris/tls-local-54.d,
* testsuite/ld-cris/tls-local-60.d,
* testsuite/ld-cris/tls-local-61.d,
* testsuite/ld-cris/tls-local-63.d,
* testsuite/ld-cris/tls-local-64.d,
* testsuite/ld-cris/tls-ok-30.d,
* testsuite/ld-cris/tls-ok-32.d,
* testsuite/ld-cris/tls-ok-34.d,
* testsuite/ld-cris/tls-und-38.d,
* testsuite/ld-cris/tls-und-42.d,
* testsuite/ld-cris/tls-und-46.d,
* testsuite/ld-cris/tls-und-50.d,
* testsuite/ld-cris/weakhiddso.d,
* testsuite/ld-cris/weakref2.d,
* testsuite/ld-frv/fdpic-shared-1.d,
* testsuite/ld-frv/fdpic-shared-2.d,
* testsuite/ld-frv/fdpic-shared-3.d,
* testsuite/ld-frv/fdpic-shared-4.d,
* testsuite/ld-frv/fdpic-shared-5.d,
* testsuite/ld-frv/fdpic-shared-7.d,
* testsuite/ld-frv/fdpic-shared-8.d,
* testsuite/ld-frv/tls-dynamic-2.d,
* testsuite/ld-i386/ibt-plt-1.d,
* testsuite/ld-i386/ibt-plt-2a.d,
* testsuite/ld-i386/ibt-plt-2b.d,
* testsuite/ld-i386/ibt-plt-2c.d,
* testsuite/ld-i386/ibt-plt-2d.d,
* testsuite/ld-i386/ibt-plt-3a.d,
* testsuite/ld-i386/ibt-plt-3b.d,
* testsuite/ld-i386/ibt-plt-3c.d,
* testsuite/ld-i386/ibt-plt-3d.d,
* testsuite/ld-i386/plt2.dd,
* testsuite/ld-i386/pr20830.d,
* testsuite/ld-i386/tlsbin-nacl.rd,
* testsuite/ld-i386/tlsbin.rd,
* testsuite/ld-i386/tlsbin2-nacl.rd,
* testsuite/ld-i386/tlsbin2.rd,
* testsuite/ld-i386/tlsbindesc-nacl.rd,
* testsuite/ld-i386/tlsbindesc.rd,
* testsuite/ld-i386/tlsdesc-nacl.rd,
* testsuite/ld-i386/tlsdesc.rd,
* testsuite/ld-i386/tlsgdesc-nacl.rd,
* testsuite/ld-i386/tlsgdesc.rd,
* testsuite/ld-i386/tlsnopic-nacl.rd,
* testsuite/ld-i386/tlsnopic.dd,
* testsuite/ld-i386/tlsnopic.rd,
* testsuite/ld-i386/tlsnopic.sd,
* testsuite/ld-i386/tlspic-nacl.rd,
* testsuite/ld-i386/tlspic.rd,
* testsuite/ld-i386/tlspic2-nacl.rd,
* testsuite/ld-i386/tlspic2.rd,
* testsuite/ld-ia64/merge1.d,
* testsuite/ld-ia64/merge2.d,
* testsuite/ld-ia64/merge3.d,
* testsuite/ld-ia64/merge4.d,
* testsuite/ld-ia64/merge5.d,
* testsuite/ld-ia64/tlsbin.rd,
* testsuite/ld-ia64/tlspic.rd,
* testsuite/ld-ifunc/ifunc-2-i386-now.d,
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d,
* testsuite/ld-ifunc/ifunc-2-local-x86-64-now.d,
* testsuite/ld-ifunc/ifunc-2-local-x86-64.d,
* testsuite/ld-ifunc/ifunc-2-x86-64-now.d,
* testsuite/ld-ifunc/ifunc-2-x86-64.d,
* testsuite/ld-ifunc/pr17154-i386-now.d,
* testsuite/ld-ifunc/pr17154-i386.d,
* testsuite/ld-ifunc/pr17154-x86-64-now.d,
* testsuite/ld-ifunc/pr17154-x86-64.d,
* testsuite/ld-m68k/tls-def-1.d,
* testsuite/ld-m68k/tls-gd-1.d2,
* testsuite/ld-metag/shared.d,
* testsuite/ld-metag/stub_pic_app.d,
* testsuite/ld-mips-elf/rel32-n32.d,
* testsuite/ld-mips-elf/rel32-o32.d,
* testsuite/ld-mips-elf/rel64.d,
* testsuite/ld-powerpc/ambiguousv1.d,
* testsuite/ld-powerpc/ambiguousv1b.d,
* testsuite/ld-powerpc/ambiguousv2.d,
* testsuite/ld-powerpc/ambiguousv2b.d,
* testsuite/ld-powerpc/tlsexe.d,
* testsuite/ld-powerpc/tlsexe.r,
* testsuite/ld-powerpc/tlsexe32.d,
* testsuite/ld-powerpc/tlsexe32.g,
* testsuite/ld-powerpc/tlsexe32.r,
* testsuite/ld-powerpc/tlsexetoc.d,
* testsuite/ld-powerpc/tlsexetoc.r,
* testsuite/ld-powerpc/tlsso.d,
* testsuite/ld-powerpc/tlsso.r,
* testsuite/ld-powerpc/tlsso32.g,
* testsuite/ld-powerpc/tlsso32.r,
* testsuite/ld-powerpc/tlstocso.d,
* testsuite/ld-powerpc/tlstocso.g,
* testsuite/ld-powerpc/tlstocso.r,
* testsuite/ld-s390/gotreloc_31-1.dd,
* testsuite/ld-s390/tlsbin.dd,
* testsuite/ld-s390/tlsbin.rd,
* testsuite/ld-s390/tlsbin_64.dd,
* testsuite/ld-s390/tlsbin_64.rd,
* testsuite/ld-s390/tlspic.rd,
* testsuite/ld-s390/tlspic_64.rd,
* testsuite/ld-sh/tlsbin-2.d,
* testsuite/ld-sh/tlspic-2.d,
* testsuite/ld-sparc/gotop32.rd,
* testsuite/ld-sparc/gotop64.rd,
* testsuite/ld-sparc/tlssunbin32.rd,
* testsuite/ld-sparc/tlssunbin64.rd,
* testsuite/ld-sparc/tlssunnopic32.rd,
* testsuite/ld-sparc/tlssunnopic64.rd,
* testsuite/ld-sparc/tlssunpic32.rd,
* testsuite/ld-sparc/tlssunpic64.rd,
* testsuite/ld-x86-64/bnd-branch-1-now.d,
* testsuite/ld-x86-64/bnd-ifunc-1-now.d,
* testsuite/ld-x86-64/bnd-ifunc-2-now.d,
* testsuite/ld-x86-64/bnd-ifunc-2.d,
* testsuite/ld-x86-64/bnd-plt-1-now.d,
* testsuite/ld-x86-64/bnd-plt-1.d,
* testsuite/ld-x86-64/ibt-plt-1-x32.d,
* testsuite/ld-x86-64/ibt-plt-1.d,
* testsuite/ld-x86-64/ibt-plt-2a-x32.d,
* testsuite/ld-x86-64/ibt-plt-2a.d,
* testsuite/ld-x86-64/ibt-plt-2b-x32.d,
* testsuite/ld-x86-64/ibt-plt-2b.d,
* testsuite/ld-x86-64/ibt-plt-2c-x32.d,
* testsuite/ld-x86-64/ibt-plt-2c.d,
* testsuite/ld-x86-64/ibt-plt-2d-x32.d,
* testsuite/ld-x86-64/ibt-plt-2d.d,
* testsuite/ld-x86-64/ibt-plt-3a-x32.d,
* testsuite/ld-x86-64/ibt-plt-3a.d,
* testsuite/ld-x86-64/ibt-plt-3b-x32.d,
* testsuite/ld-x86-64/ibt-plt-3b.d,
* testsuite/ld-x86-64/ibt-plt-3c-x32.d,
* testsuite/ld-x86-64/ibt-plt-3c.d,
* testsuite/ld-x86-64/ibt-plt-3d-x32.d,
* testsuite/ld-x86-64/ibt-plt-3d.d,
* testsuite/ld-x86-64/ilp32-4-nacl.d,
* testsuite/ld-x86-64/ilp32-4.d,
* testsuite/ld-x86-64/load1c-nacl.d,
* testsuite/ld-x86-64/load1c.d,
* testsuite/ld-x86-64/load1d-nacl.d,
* testsuite/ld-x86-64/load1d.d,
* testsuite/ld-x86-64/mpx3n.dd,
* testsuite/ld-x86-64/mpx4.dd,
* testsuite/ld-x86-64/mpx4n.dd,
* testsuite/ld-x86-64/plt2.dd,
* testsuite/ld-x86-64/pr14207.d,
* testsuite/ld-x86-64/pr19162.d,
* testsuite/ld-x86-64/pr20253-1f.d,
* testsuite/ld-x86-64/pr20253-1l.d,
* testsuite/ld-x86-64/pr20830a-now.d,
* testsuite/ld-x86-64/pr20830a.d,
* testsuite/ld-x86-64/pr20830b-now.d,
* testsuite/ld-x86-64/pr20830b.d,
* testsuite/ld-x86-64/pr21038a-now.d,
* testsuite/ld-x86-64/pr21038a.d,
* testsuite/ld-x86-64/pr21038b-now.d,
* testsuite/ld-x86-64/pr21038b.d,
* testsuite/ld-x86-64/pr21038c-now.d,
* testsuite/ld-x86-64/pr21038c.d,
* testsuite/ld-x86-64/tlsbin-nacl.rd,
* testsuite/ld-x86-64/tlsbin.rd,
* testsuite/ld-x86-64/tlsbin2-nacl.rd,
* testsuite/ld-x86-64/tlsbin2.rd,
* testsuite/ld-x86-64/tlsbindesc-nacl.rd,
* testsuite/ld-x86-64/tlsbindesc.rd,
* testsuite/ld-x86-64/tlsdesc-nacl.rd,
* testsuite/ld-x86-64/tlsdesc.rd,
* testsuite/ld-x86-64/tlsgdesc-nacl.rd,
* testsuite/ld-x86-64/tlsgdesc.rd,
* testsuite/ld-x86-64/tlspic-nacl.rd,
* testsuite/ld-x86-64/tlspic.rd,
* testsuite/ld-x86-64/tlspic2-nacl.rd,
* testsuite/ld-x86-64/tlspic2.rd: Update.
2018-06-08 18:47:34 +08:00
|
|
|
0+100 <__GI_foo>:
|
opcodes/i386: remove trailing whitespace from insns with zero operands
While working on another patch[1] I had need to touch this code in
i386-dis.c:
ins->obufp = ins->mnemonicendp;
for (i = strlen (ins->obuf) + prefix_length; i < 6; i++)
oappend (ins, " ");
oappend (ins, " ");
(*ins->info->fprintf_styled_func)
(ins->info->stream, dis_style_mnemonic, "%s", ins->obuf);
What this code does is add whitespace after the instruction mnemonic
and before the instruction operands.
The problem I ran into when working on this code can be seen by
assembling this input file:
.text
nop
retq
Now, when I disassemble, here's the output. I've replaced trailing
whitespace with '_' so that the issue is clearer:
Disassembly of section .text:
0000000000000000 <.text>:
0: 90 nop
1: c3 retq___
Notice that there's no trailing whitespace after 'nop', but there are
three spaces after 'retq'!
What happens is that instruction mnemonics are emitted into a buffer
instr_info::obuf, then instr_info::mnemonicendp is setup to point to
the '\0' character at the end of the mnemonic.
When we emit the whitespace, this is then added starting at the
mnemonicendp position. Lets consider 'retq', first the buffer is
setup like this:
'r' 'e' 't' 'q' '\0'
Then we add whitespace characters at the '\0', converting the buffer
to this:
'r' 'e' 't' 'q' ' ' ' ' ' ' '\0'
However, 'nop' is actually an alias for 'xchg %rax,%rax', so,
initially, the buffer is setup like this:
'x' 'c' 'h' 'g' '\0'
Then in NOP_Fixup we spot that we have an instruction that is an alias
for 'nop', and adjust the buffer to this:
'n' 'o' 'p' '\0' '\0'
The second '\0' is left over from the original buffer contents.
However, when we rewrite the buffer, we don't afjust mnemonicendp,
which still points at the second '\0' character.
Now, when we insert whitespace we get:
'n' 'o' 'p' '\0' ' ' ' ' ' ' ' ' '\0'
Notice the whitespace is inserted after the first '\0', so, when we
print the buffer, the whitespace is not printed.
The fix for this is pretty easy, I can change NOP_Fixup to adjust
mnemonicendp, but now a bunch of tests start failing, we now produce
whitespace after the 'nop', which the tests don't expect.
So, I could update the tests to expect the whitespace....
...except I'm not a fan of trailing whitespace, so I'd really rather
not.
Turns out, I can pretty easily update the whitespace emitting code to
spot instructions that have zero operands and just not emit any
whitespace in this case. So this is what I've done.
I've left in the fix for NOP_Fixup, I think updating mnemonicendp is
probably a good thing, though this is not really required any more.
I've then updated all the tests that I saw failing to adjust the
expected patterns to account for the change in whitespace.
[1] https://sourceware.org/pipermail/binutils/2022-April/120610.html
2022-05-26 20:11:11 +08:00
|
|
|
+[a-f0-9]+: c3 ret
|
i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
|
|
|
|
Define various symbols conditionally in shared libraries
The values of symbols in shared libraries like _end, _edata, and
__bss_start are generally not that useful outside of the shared
library. This patch defines them conditionally with PROVIDE, since a
shared library might need the local value. An example is glibc ld.so
local access to "_begin", "_etext" and "_end". (ld.so gains access to
the local values by making the references using hidden visibility.
That makes the definitions hidden too.)
We can't use PROVIDE_HIDDEN in the linker scripts because the shared
library might need the value of the symbol in the executable. An
example is freebsd libc dynamic access to "_end".
PR ld/23161
* emulparams/aarch64cloudabi.sh: PROVIDE __bss_start__, _bss_end__,
and __end__ in shared libraries.
* emulparams/aarch64fbsd.sh: Likewise.
* emulparams/aarch64linux.sh: Likewise.
* emulparams/aarch64linux32.sh: Likewise.
* emulparams/armelf_fuchsia.sh: Likewise.
* emulparams/armelf_linux.sh: Likewise.
* emulparams/armelf_phoenix.sh: Likewise.
* emulparams/aarch64elf.sh: Likewise, and __data_start
* emulparams/aarch64elf32.sh: Likewise.
* emulparams/armelf.sh: Likewise.
* emulparams/armnto.sh: Likewise.
* emulparams/elf32bmip.sh: Remove duplicate ". = ." from
OTHER_GOT_SYMBOLS. PROVIDE _ftext, _fdata, and _fbss in shared libs.
* emulparams/elf32bmipn32-defs.sh: Likewise.
* emulparams/elf32frv.sh: PROVIDE __end and __data_start in shared libs.
* emulparams/elf32lriscv-defs.sh: Tidy.
* emulparams/elf32mcore.sh: PROVIDE __bss_start and _bss_end in
shared libs
* emulparams/elf32ppccommon.sh: PROVIDE __end in shared libs.
* emulparams/elf32rl78.sh: Tidy.
* emulparams/i386nto.sh: PROVIDE _btext in shared libs.
* emulparams/shelf_nto.sh: Likewise.
* emulparams/shlelf_nto.sh: Likewise.
* emulparams/score3_elf.sh: PROVIDE _gp, _bss_start__, _bss_end__,
__bss_end__, __end__, _fdata, _sdata_begin, and _bss_start in
shared libs.
* scripttempl/elf.sc: Don't use EXECUTABLE_SYMBOLS for shared
libraries. PROVIDE _edata, edata, __bss_start, and _end in shared
libraries.
* testsuite/ld-elf/pr23161.map,
* testsuite/ld-elf/pr23161a.c,
* testsuite/ld-elf/pr23161b.c,
* testsuite/ld-elf/pr23161c.c,
* testsuite/ld-elf/pr23161a.rd,
* testsuite/ld-elf/pr23161b.rd,
* testsuite/ld-elf/pr23161c.rd,
* testsuite/ld-elf/pr23161d.rd: New tests.
* testsuite/ld-elf/shared.exp: Run ld/23161 tests.
* testsuite/ld-elf/pr23162.rd,
* testsuite/ld-aarch64/ifunc-1-local.d,
* testsuite/ld-aarch64/ifunc-1.d,
* testsuite/ld-aarch64/ifunc-2-local.d,
* testsuite/ld-aarch64/ifunc-2.d,
* testsuite/ld-aarch64/ifunc-21.d,
* testsuite/ld-aarch64/ifunc-3a.d,
* testsuite/ld-alpha/tlsbin.rd,
* testsuite/ld-alpha/tlsbin.sd,
* testsuite/ld-alpha/tlsbinr.rd,
* testsuite/ld-alpha/tlspic.rd,
* testsuite/ld-alpha/tlspic.sd,
* testsuite/ld-cris/dso-pltdis1.d,
* testsuite/ld-cris/dso-pltdis2.d,
* testsuite/ld-cris/dso12-pltdis.d,
* testsuite/ld-cris/gotplt1.d,
* testsuite/ld-cris/gotplt2.d,
* testsuite/ld-cris/gotplt3.d,
* testsuite/ld-cris/hiddef1.d,
* testsuite/ld-cris/libdso-1.d,
* testsuite/ld-cris/libdso-10.d,
* testsuite/ld-cris/libdso-11.d,
* testsuite/ld-cris/libdso-12.d,
* testsuite/ld-cris/libdso-12b.d,
* testsuite/ld-cris/libdso-12c.d,
* testsuite/ld-cris/libdso-13.d,
* testsuite/ld-cris/libdso-13b.d,
* testsuite/ld-cris/libdso-14.d,
* testsuite/ld-cris/libdso-15.d,
* testsuite/ld-cris/libdso-15b.d,
* testsuite/ld-cris/libdso-1c.d,
* testsuite/ld-cris/libdso-1d.d,
* testsuite/ld-cris/libdso-2.d,
* testsuite/ld-cris/pic-gc-72.d,
* testsuite/ld-cris/pic-gc-73.d,
* testsuite/ld-cris/pr16044.d,
* testsuite/ld-cris/pv32-1.d,
* testsuite/ld-cris/tls-dso-dtpoffd2.d,
* testsuite/ld-cris/tls-dso-dtpoffd4.d,
* testsuite/ld-cris/tls-dso-tpoffgotcomm1.d,
* testsuite/ld-cris/tls-gc-71.d,
* testsuite/ld-cris/tls-gd-1.d,
* testsuite/ld-cris/tls-gd-1h.d,
* testsuite/ld-cris/tls-gd-2.d,
* testsuite/ld-cris/tls-gd-2h.d,
* testsuite/ld-cris/tls-ie-10.d,
* testsuite/ld-cris/tls-ie-11.d,
* testsuite/ld-cris/tls-ie-78.d,
* testsuite/ld-cris/tls-ie-8.d,
* testsuite/ld-cris/tls-ie-9.d,
* testsuite/ld-cris/tls-js1.d,
* testsuite/ld-cris/tls-ld-4.d,
* testsuite/ld-cris/tls-ld-5.d,
* testsuite/ld-cris/tls-ld-6.d,
* testsuite/ld-cris/tls-ld-7.d,
* testsuite/ld-cris/tls-ldgd-14.d,
* testsuite/ld-cris/tls-ldgd-15.d,
* testsuite/ld-cris/tls-ldgdex-14.d,
* testsuite/ld-cris/tls-ldgdex-15.d,
* testsuite/ld-cris/tls-ldgdx-14.d,
* testsuite/ld-cris/tls-ldgdx-15.d,
* testsuite/ld-cris/tls-legdx-16.d,
* testsuite/ld-cris/tls-legdx-17.d,
* testsuite/ld-cris/tls-local-54.d,
* testsuite/ld-cris/tls-local-60.d,
* testsuite/ld-cris/tls-local-61.d,
* testsuite/ld-cris/tls-local-63.d,
* testsuite/ld-cris/tls-local-64.d,
* testsuite/ld-cris/tls-ok-30.d,
* testsuite/ld-cris/tls-ok-32.d,
* testsuite/ld-cris/tls-ok-34.d,
* testsuite/ld-cris/tls-und-38.d,
* testsuite/ld-cris/tls-und-42.d,
* testsuite/ld-cris/tls-und-46.d,
* testsuite/ld-cris/tls-und-50.d,
* testsuite/ld-cris/weakhiddso.d,
* testsuite/ld-cris/weakref2.d,
* testsuite/ld-frv/fdpic-shared-1.d,
* testsuite/ld-frv/fdpic-shared-2.d,
* testsuite/ld-frv/fdpic-shared-3.d,
* testsuite/ld-frv/fdpic-shared-4.d,
* testsuite/ld-frv/fdpic-shared-5.d,
* testsuite/ld-frv/fdpic-shared-7.d,
* testsuite/ld-frv/fdpic-shared-8.d,
* testsuite/ld-frv/tls-dynamic-2.d,
* testsuite/ld-i386/ibt-plt-1.d,
* testsuite/ld-i386/ibt-plt-2a.d,
* testsuite/ld-i386/ibt-plt-2b.d,
* testsuite/ld-i386/ibt-plt-2c.d,
* testsuite/ld-i386/ibt-plt-2d.d,
* testsuite/ld-i386/ibt-plt-3a.d,
* testsuite/ld-i386/ibt-plt-3b.d,
* testsuite/ld-i386/ibt-plt-3c.d,
* testsuite/ld-i386/ibt-plt-3d.d,
* testsuite/ld-i386/plt2.dd,
* testsuite/ld-i386/pr20830.d,
* testsuite/ld-i386/tlsbin-nacl.rd,
* testsuite/ld-i386/tlsbin.rd,
* testsuite/ld-i386/tlsbin2-nacl.rd,
* testsuite/ld-i386/tlsbin2.rd,
* testsuite/ld-i386/tlsbindesc-nacl.rd,
* testsuite/ld-i386/tlsbindesc.rd,
* testsuite/ld-i386/tlsdesc-nacl.rd,
* testsuite/ld-i386/tlsdesc.rd,
* testsuite/ld-i386/tlsgdesc-nacl.rd,
* testsuite/ld-i386/tlsgdesc.rd,
* testsuite/ld-i386/tlsnopic-nacl.rd,
* testsuite/ld-i386/tlsnopic.dd,
* testsuite/ld-i386/tlsnopic.rd,
* testsuite/ld-i386/tlsnopic.sd,
* testsuite/ld-i386/tlspic-nacl.rd,
* testsuite/ld-i386/tlspic.rd,
* testsuite/ld-i386/tlspic2-nacl.rd,
* testsuite/ld-i386/tlspic2.rd,
* testsuite/ld-ia64/merge1.d,
* testsuite/ld-ia64/merge2.d,
* testsuite/ld-ia64/merge3.d,
* testsuite/ld-ia64/merge4.d,
* testsuite/ld-ia64/merge5.d,
* testsuite/ld-ia64/tlsbin.rd,
* testsuite/ld-ia64/tlspic.rd,
* testsuite/ld-ifunc/ifunc-2-i386-now.d,
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d,
* testsuite/ld-ifunc/ifunc-2-local-x86-64-now.d,
* testsuite/ld-ifunc/ifunc-2-local-x86-64.d,
* testsuite/ld-ifunc/ifunc-2-x86-64-now.d,
* testsuite/ld-ifunc/ifunc-2-x86-64.d,
* testsuite/ld-ifunc/pr17154-i386-now.d,
* testsuite/ld-ifunc/pr17154-i386.d,
* testsuite/ld-ifunc/pr17154-x86-64-now.d,
* testsuite/ld-ifunc/pr17154-x86-64.d,
* testsuite/ld-m68k/tls-def-1.d,
* testsuite/ld-m68k/tls-gd-1.d2,
* testsuite/ld-metag/shared.d,
* testsuite/ld-metag/stub_pic_app.d,
* testsuite/ld-mips-elf/rel32-n32.d,
* testsuite/ld-mips-elf/rel32-o32.d,
* testsuite/ld-mips-elf/rel64.d,
* testsuite/ld-powerpc/ambiguousv1.d,
* testsuite/ld-powerpc/ambiguousv1b.d,
* testsuite/ld-powerpc/ambiguousv2.d,
* testsuite/ld-powerpc/ambiguousv2b.d,
* testsuite/ld-powerpc/tlsexe.d,
* testsuite/ld-powerpc/tlsexe.r,
* testsuite/ld-powerpc/tlsexe32.d,
* testsuite/ld-powerpc/tlsexe32.g,
* testsuite/ld-powerpc/tlsexe32.r,
* testsuite/ld-powerpc/tlsexetoc.d,
* testsuite/ld-powerpc/tlsexetoc.r,
* testsuite/ld-powerpc/tlsso.d,
* testsuite/ld-powerpc/tlsso.r,
* testsuite/ld-powerpc/tlsso32.g,
* testsuite/ld-powerpc/tlsso32.r,
* testsuite/ld-powerpc/tlstocso.d,
* testsuite/ld-powerpc/tlstocso.g,
* testsuite/ld-powerpc/tlstocso.r,
* testsuite/ld-s390/gotreloc_31-1.dd,
* testsuite/ld-s390/tlsbin.dd,
* testsuite/ld-s390/tlsbin.rd,
* testsuite/ld-s390/tlsbin_64.dd,
* testsuite/ld-s390/tlsbin_64.rd,
* testsuite/ld-s390/tlspic.rd,
* testsuite/ld-s390/tlspic_64.rd,
* testsuite/ld-sh/tlsbin-2.d,
* testsuite/ld-sh/tlspic-2.d,
* testsuite/ld-sparc/gotop32.rd,
* testsuite/ld-sparc/gotop64.rd,
* testsuite/ld-sparc/tlssunbin32.rd,
* testsuite/ld-sparc/tlssunbin64.rd,
* testsuite/ld-sparc/tlssunnopic32.rd,
* testsuite/ld-sparc/tlssunnopic64.rd,
* testsuite/ld-sparc/tlssunpic32.rd,
* testsuite/ld-sparc/tlssunpic64.rd,
* testsuite/ld-x86-64/bnd-branch-1-now.d,
* testsuite/ld-x86-64/bnd-ifunc-1-now.d,
* testsuite/ld-x86-64/bnd-ifunc-2-now.d,
* testsuite/ld-x86-64/bnd-ifunc-2.d,
* testsuite/ld-x86-64/bnd-plt-1-now.d,
* testsuite/ld-x86-64/bnd-plt-1.d,
* testsuite/ld-x86-64/ibt-plt-1-x32.d,
* testsuite/ld-x86-64/ibt-plt-1.d,
* testsuite/ld-x86-64/ibt-plt-2a-x32.d,
* testsuite/ld-x86-64/ibt-plt-2a.d,
* testsuite/ld-x86-64/ibt-plt-2b-x32.d,
* testsuite/ld-x86-64/ibt-plt-2b.d,
* testsuite/ld-x86-64/ibt-plt-2c-x32.d,
* testsuite/ld-x86-64/ibt-plt-2c.d,
* testsuite/ld-x86-64/ibt-plt-2d-x32.d,
* testsuite/ld-x86-64/ibt-plt-2d.d,
* testsuite/ld-x86-64/ibt-plt-3a-x32.d,
* testsuite/ld-x86-64/ibt-plt-3a.d,
* testsuite/ld-x86-64/ibt-plt-3b-x32.d,
* testsuite/ld-x86-64/ibt-plt-3b.d,
* testsuite/ld-x86-64/ibt-plt-3c-x32.d,
* testsuite/ld-x86-64/ibt-plt-3c.d,
* testsuite/ld-x86-64/ibt-plt-3d-x32.d,
* testsuite/ld-x86-64/ibt-plt-3d.d,
* testsuite/ld-x86-64/ilp32-4-nacl.d,
* testsuite/ld-x86-64/ilp32-4.d,
* testsuite/ld-x86-64/load1c-nacl.d,
* testsuite/ld-x86-64/load1c.d,
* testsuite/ld-x86-64/load1d-nacl.d,
* testsuite/ld-x86-64/load1d.d,
* testsuite/ld-x86-64/mpx3n.dd,
* testsuite/ld-x86-64/mpx4.dd,
* testsuite/ld-x86-64/mpx4n.dd,
* testsuite/ld-x86-64/plt2.dd,
* testsuite/ld-x86-64/pr14207.d,
* testsuite/ld-x86-64/pr19162.d,
* testsuite/ld-x86-64/pr20253-1f.d,
* testsuite/ld-x86-64/pr20253-1l.d,
* testsuite/ld-x86-64/pr20830a-now.d,
* testsuite/ld-x86-64/pr20830a.d,
* testsuite/ld-x86-64/pr20830b-now.d,
* testsuite/ld-x86-64/pr20830b.d,
* testsuite/ld-x86-64/pr21038a-now.d,
* testsuite/ld-x86-64/pr21038a.d,
* testsuite/ld-x86-64/pr21038b-now.d,
* testsuite/ld-x86-64/pr21038b.d,
* testsuite/ld-x86-64/pr21038c-now.d,
* testsuite/ld-x86-64/pr21038c.d,
* testsuite/ld-x86-64/tlsbin-nacl.rd,
* testsuite/ld-x86-64/tlsbin.rd,
* testsuite/ld-x86-64/tlsbin2-nacl.rd,
* testsuite/ld-x86-64/tlsbin2.rd,
* testsuite/ld-x86-64/tlsbindesc-nacl.rd,
* testsuite/ld-x86-64/tlsbindesc.rd,
* testsuite/ld-x86-64/tlsdesc-nacl.rd,
* testsuite/ld-x86-64/tlsdesc.rd,
* testsuite/ld-x86-64/tlsgdesc-nacl.rd,
* testsuite/ld-x86-64/tlsgdesc.rd,
* testsuite/ld-x86-64/tlspic-nacl.rd,
* testsuite/ld-x86-64/tlspic.rd,
* testsuite/ld-x86-64/tlspic2-nacl.rd,
* testsuite/ld-x86-64/tlspic2.rd: Update.
2018-06-08 18:47:34 +08:00
|
|
|
0+101 <bar>:
|
|
|
|
+[a-f0-9]+: e8 00 00 00 00 call 106 <bar\+0x5>
|
i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
|
|
|
+[a-f0-9]+: 5b pop %ebx
|
|
|
|
+[a-f0-9]+: 81 c3 9e 10 00 00 add \$0x109e,%ebx
|
Define various symbols conditionally in shared libraries
The values of symbols in shared libraries like _end, _edata, and
__bss_start are generally not that useful outside of the shared
library. This patch defines them conditionally with PROVIDE, since a
shared library might need the local value. An example is glibc ld.so
local access to "_begin", "_etext" and "_end". (ld.so gains access to
the local values by making the references using hidden visibility.
That makes the definitions hidden too.)
We can't use PROVIDE_HIDDEN in the linker scripts because the shared
library might need the value of the symbol in the executable. An
example is freebsd libc dynamic access to "_end".
PR ld/23161
* emulparams/aarch64cloudabi.sh: PROVIDE __bss_start__, _bss_end__,
and __end__ in shared libraries.
* emulparams/aarch64fbsd.sh: Likewise.
* emulparams/aarch64linux.sh: Likewise.
* emulparams/aarch64linux32.sh: Likewise.
* emulparams/armelf_fuchsia.sh: Likewise.
* emulparams/armelf_linux.sh: Likewise.
* emulparams/armelf_phoenix.sh: Likewise.
* emulparams/aarch64elf.sh: Likewise, and __data_start
* emulparams/aarch64elf32.sh: Likewise.
* emulparams/armelf.sh: Likewise.
* emulparams/armnto.sh: Likewise.
* emulparams/elf32bmip.sh: Remove duplicate ". = ." from
OTHER_GOT_SYMBOLS. PROVIDE _ftext, _fdata, and _fbss in shared libs.
* emulparams/elf32bmipn32-defs.sh: Likewise.
* emulparams/elf32frv.sh: PROVIDE __end and __data_start in shared libs.
* emulparams/elf32lriscv-defs.sh: Tidy.
* emulparams/elf32mcore.sh: PROVIDE __bss_start and _bss_end in
shared libs
* emulparams/elf32ppccommon.sh: PROVIDE __end in shared libs.
* emulparams/elf32rl78.sh: Tidy.
* emulparams/i386nto.sh: PROVIDE _btext in shared libs.
* emulparams/shelf_nto.sh: Likewise.
* emulparams/shlelf_nto.sh: Likewise.
* emulparams/score3_elf.sh: PROVIDE _gp, _bss_start__, _bss_end__,
__bss_end__, __end__, _fdata, _sdata_begin, and _bss_start in
shared libs.
* scripttempl/elf.sc: Don't use EXECUTABLE_SYMBOLS for shared
libraries. PROVIDE _edata, edata, __bss_start, and _end in shared
libraries.
* testsuite/ld-elf/pr23161.map,
* testsuite/ld-elf/pr23161a.c,
* testsuite/ld-elf/pr23161b.c,
* testsuite/ld-elf/pr23161c.c,
* testsuite/ld-elf/pr23161a.rd,
* testsuite/ld-elf/pr23161b.rd,
* testsuite/ld-elf/pr23161c.rd,
* testsuite/ld-elf/pr23161d.rd: New tests.
* testsuite/ld-elf/shared.exp: Run ld/23161 tests.
* testsuite/ld-elf/pr23162.rd,
* testsuite/ld-aarch64/ifunc-1-local.d,
* testsuite/ld-aarch64/ifunc-1.d,
* testsuite/ld-aarch64/ifunc-2-local.d,
* testsuite/ld-aarch64/ifunc-2.d,
* testsuite/ld-aarch64/ifunc-21.d,
* testsuite/ld-aarch64/ifunc-3a.d,
* testsuite/ld-alpha/tlsbin.rd,
* testsuite/ld-alpha/tlsbin.sd,
* testsuite/ld-alpha/tlsbinr.rd,
* testsuite/ld-alpha/tlspic.rd,
* testsuite/ld-alpha/tlspic.sd,
* testsuite/ld-cris/dso-pltdis1.d,
* testsuite/ld-cris/dso-pltdis2.d,
* testsuite/ld-cris/dso12-pltdis.d,
* testsuite/ld-cris/gotplt1.d,
* testsuite/ld-cris/gotplt2.d,
* testsuite/ld-cris/gotplt3.d,
* testsuite/ld-cris/hiddef1.d,
* testsuite/ld-cris/libdso-1.d,
* testsuite/ld-cris/libdso-10.d,
* testsuite/ld-cris/libdso-11.d,
* testsuite/ld-cris/libdso-12.d,
* testsuite/ld-cris/libdso-12b.d,
* testsuite/ld-cris/libdso-12c.d,
* testsuite/ld-cris/libdso-13.d,
* testsuite/ld-cris/libdso-13b.d,
* testsuite/ld-cris/libdso-14.d,
* testsuite/ld-cris/libdso-15.d,
* testsuite/ld-cris/libdso-15b.d,
* testsuite/ld-cris/libdso-1c.d,
* testsuite/ld-cris/libdso-1d.d,
* testsuite/ld-cris/libdso-2.d,
* testsuite/ld-cris/pic-gc-72.d,
* testsuite/ld-cris/pic-gc-73.d,
* testsuite/ld-cris/pr16044.d,
* testsuite/ld-cris/pv32-1.d,
* testsuite/ld-cris/tls-dso-dtpoffd2.d,
* testsuite/ld-cris/tls-dso-dtpoffd4.d,
* testsuite/ld-cris/tls-dso-tpoffgotcomm1.d,
* testsuite/ld-cris/tls-gc-71.d,
* testsuite/ld-cris/tls-gd-1.d,
* testsuite/ld-cris/tls-gd-1h.d,
* testsuite/ld-cris/tls-gd-2.d,
* testsuite/ld-cris/tls-gd-2h.d,
* testsuite/ld-cris/tls-ie-10.d,
* testsuite/ld-cris/tls-ie-11.d,
* testsuite/ld-cris/tls-ie-78.d,
* testsuite/ld-cris/tls-ie-8.d,
* testsuite/ld-cris/tls-ie-9.d,
* testsuite/ld-cris/tls-js1.d,
* testsuite/ld-cris/tls-ld-4.d,
* testsuite/ld-cris/tls-ld-5.d,
* testsuite/ld-cris/tls-ld-6.d,
* testsuite/ld-cris/tls-ld-7.d,
* testsuite/ld-cris/tls-ldgd-14.d,
* testsuite/ld-cris/tls-ldgd-15.d,
* testsuite/ld-cris/tls-ldgdex-14.d,
* testsuite/ld-cris/tls-ldgdex-15.d,
* testsuite/ld-cris/tls-ldgdx-14.d,
* testsuite/ld-cris/tls-ldgdx-15.d,
* testsuite/ld-cris/tls-legdx-16.d,
* testsuite/ld-cris/tls-legdx-17.d,
* testsuite/ld-cris/tls-local-54.d,
* testsuite/ld-cris/tls-local-60.d,
* testsuite/ld-cris/tls-local-61.d,
* testsuite/ld-cris/tls-local-63.d,
* testsuite/ld-cris/tls-local-64.d,
* testsuite/ld-cris/tls-ok-30.d,
* testsuite/ld-cris/tls-ok-32.d,
* testsuite/ld-cris/tls-ok-34.d,
* testsuite/ld-cris/tls-und-38.d,
* testsuite/ld-cris/tls-und-42.d,
* testsuite/ld-cris/tls-und-46.d,
* testsuite/ld-cris/tls-und-50.d,
* testsuite/ld-cris/weakhiddso.d,
* testsuite/ld-cris/weakref2.d,
* testsuite/ld-frv/fdpic-shared-1.d,
* testsuite/ld-frv/fdpic-shared-2.d,
* testsuite/ld-frv/fdpic-shared-3.d,
* testsuite/ld-frv/fdpic-shared-4.d,
* testsuite/ld-frv/fdpic-shared-5.d,
* testsuite/ld-frv/fdpic-shared-7.d,
* testsuite/ld-frv/fdpic-shared-8.d,
* testsuite/ld-frv/tls-dynamic-2.d,
* testsuite/ld-i386/ibt-plt-1.d,
* testsuite/ld-i386/ibt-plt-2a.d,
* testsuite/ld-i386/ibt-plt-2b.d,
* testsuite/ld-i386/ibt-plt-2c.d,
* testsuite/ld-i386/ibt-plt-2d.d,
* testsuite/ld-i386/ibt-plt-3a.d,
* testsuite/ld-i386/ibt-plt-3b.d,
* testsuite/ld-i386/ibt-plt-3c.d,
* testsuite/ld-i386/ibt-plt-3d.d,
* testsuite/ld-i386/plt2.dd,
* testsuite/ld-i386/pr20830.d,
* testsuite/ld-i386/tlsbin-nacl.rd,
* testsuite/ld-i386/tlsbin.rd,
* testsuite/ld-i386/tlsbin2-nacl.rd,
* testsuite/ld-i386/tlsbin2.rd,
* testsuite/ld-i386/tlsbindesc-nacl.rd,
* testsuite/ld-i386/tlsbindesc.rd,
* testsuite/ld-i386/tlsdesc-nacl.rd,
* testsuite/ld-i386/tlsdesc.rd,
* testsuite/ld-i386/tlsgdesc-nacl.rd,
* testsuite/ld-i386/tlsgdesc.rd,
* testsuite/ld-i386/tlsnopic-nacl.rd,
* testsuite/ld-i386/tlsnopic.dd,
* testsuite/ld-i386/tlsnopic.rd,
* testsuite/ld-i386/tlsnopic.sd,
* testsuite/ld-i386/tlspic-nacl.rd,
* testsuite/ld-i386/tlspic.rd,
* testsuite/ld-i386/tlspic2-nacl.rd,
* testsuite/ld-i386/tlspic2.rd,
* testsuite/ld-ia64/merge1.d,
* testsuite/ld-ia64/merge2.d,
* testsuite/ld-ia64/merge3.d,
* testsuite/ld-ia64/merge4.d,
* testsuite/ld-ia64/merge5.d,
* testsuite/ld-ia64/tlsbin.rd,
* testsuite/ld-ia64/tlspic.rd,
* testsuite/ld-ifunc/ifunc-2-i386-now.d,
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d,
* testsuite/ld-ifunc/ifunc-2-local-x86-64-now.d,
* testsuite/ld-ifunc/ifunc-2-local-x86-64.d,
* testsuite/ld-ifunc/ifunc-2-x86-64-now.d,
* testsuite/ld-ifunc/ifunc-2-x86-64.d,
* testsuite/ld-ifunc/pr17154-i386-now.d,
* testsuite/ld-ifunc/pr17154-i386.d,
* testsuite/ld-ifunc/pr17154-x86-64-now.d,
* testsuite/ld-ifunc/pr17154-x86-64.d,
* testsuite/ld-m68k/tls-def-1.d,
* testsuite/ld-m68k/tls-gd-1.d2,
* testsuite/ld-metag/shared.d,
* testsuite/ld-metag/stub_pic_app.d,
* testsuite/ld-mips-elf/rel32-n32.d,
* testsuite/ld-mips-elf/rel32-o32.d,
* testsuite/ld-mips-elf/rel64.d,
* testsuite/ld-powerpc/ambiguousv1.d,
* testsuite/ld-powerpc/ambiguousv1b.d,
* testsuite/ld-powerpc/ambiguousv2.d,
* testsuite/ld-powerpc/ambiguousv2b.d,
* testsuite/ld-powerpc/tlsexe.d,
* testsuite/ld-powerpc/tlsexe.r,
* testsuite/ld-powerpc/tlsexe32.d,
* testsuite/ld-powerpc/tlsexe32.g,
* testsuite/ld-powerpc/tlsexe32.r,
* testsuite/ld-powerpc/tlsexetoc.d,
* testsuite/ld-powerpc/tlsexetoc.r,
* testsuite/ld-powerpc/tlsso.d,
* testsuite/ld-powerpc/tlsso.r,
* testsuite/ld-powerpc/tlsso32.g,
* testsuite/ld-powerpc/tlsso32.r,
* testsuite/ld-powerpc/tlstocso.d,
* testsuite/ld-powerpc/tlstocso.g,
* testsuite/ld-powerpc/tlstocso.r,
* testsuite/ld-s390/gotreloc_31-1.dd,
* testsuite/ld-s390/tlsbin.dd,
* testsuite/ld-s390/tlsbin.rd,
* testsuite/ld-s390/tlsbin_64.dd,
* testsuite/ld-s390/tlsbin_64.rd,
* testsuite/ld-s390/tlspic.rd,
* testsuite/ld-s390/tlspic_64.rd,
* testsuite/ld-sh/tlsbin-2.d,
* testsuite/ld-sh/tlspic-2.d,
* testsuite/ld-sparc/gotop32.rd,
* testsuite/ld-sparc/gotop64.rd,
* testsuite/ld-sparc/tlssunbin32.rd,
* testsuite/ld-sparc/tlssunbin64.rd,
* testsuite/ld-sparc/tlssunnopic32.rd,
* testsuite/ld-sparc/tlssunnopic64.rd,
* testsuite/ld-sparc/tlssunpic32.rd,
* testsuite/ld-sparc/tlssunpic64.rd,
* testsuite/ld-x86-64/bnd-branch-1-now.d,
* testsuite/ld-x86-64/bnd-ifunc-1-now.d,
* testsuite/ld-x86-64/bnd-ifunc-2-now.d,
* testsuite/ld-x86-64/bnd-ifunc-2.d,
* testsuite/ld-x86-64/bnd-plt-1-now.d,
* testsuite/ld-x86-64/bnd-plt-1.d,
* testsuite/ld-x86-64/ibt-plt-1-x32.d,
* testsuite/ld-x86-64/ibt-plt-1.d,
* testsuite/ld-x86-64/ibt-plt-2a-x32.d,
* testsuite/ld-x86-64/ibt-plt-2a.d,
* testsuite/ld-x86-64/ibt-plt-2b-x32.d,
* testsuite/ld-x86-64/ibt-plt-2b.d,
* testsuite/ld-x86-64/ibt-plt-2c-x32.d,
* testsuite/ld-x86-64/ibt-plt-2c.d,
* testsuite/ld-x86-64/ibt-plt-2d-x32.d,
* testsuite/ld-x86-64/ibt-plt-2d.d,
* testsuite/ld-x86-64/ibt-plt-3a-x32.d,
* testsuite/ld-x86-64/ibt-plt-3a.d,
* testsuite/ld-x86-64/ibt-plt-3b-x32.d,
* testsuite/ld-x86-64/ibt-plt-3b.d,
* testsuite/ld-x86-64/ibt-plt-3c-x32.d,
* testsuite/ld-x86-64/ibt-plt-3c.d,
* testsuite/ld-x86-64/ibt-plt-3d-x32.d,
* testsuite/ld-x86-64/ibt-plt-3d.d,
* testsuite/ld-x86-64/ilp32-4-nacl.d,
* testsuite/ld-x86-64/ilp32-4.d,
* testsuite/ld-x86-64/load1c-nacl.d,
* testsuite/ld-x86-64/load1c.d,
* testsuite/ld-x86-64/load1d-nacl.d,
* testsuite/ld-x86-64/load1d.d,
* testsuite/ld-x86-64/mpx3n.dd,
* testsuite/ld-x86-64/mpx4.dd,
* testsuite/ld-x86-64/mpx4n.dd,
* testsuite/ld-x86-64/plt2.dd,
* testsuite/ld-x86-64/pr14207.d,
* testsuite/ld-x86-64/pr19162.d,
* testsuite/ld-x86-64/pr20253-1f.d,
* testsuite/ld-x86-64/pr20253-1l.d,
* testsuite/ld-x86-64/pr20830a-now.d,
* testsuite/ld-x86-64/pr20830a.d,
* testsuite/ld-x86-64/pr20830b-now.d,
* testsuite/ld-x86-64/pr20830b.d,
* testsuite/ld-x86-64/pr21038a-now.d,
* testsuite/ld-x86-64/pr21038a.d,
* testsuite/ld-x86-64/pr21038b-now.d,
* testsuite/ld-x86-64/pr21038b.d,
* testsuite/ld-x86-64/pr21038c-now.d,
* testsuite/ld-x86-64/pr21038c.d,
* testsuite/ld-x86-64/tlsbin-nacl.rd,
* testsuite/ld-x86-64/tlsbin.rd,
* testsuite/ld-x86-64/tlsbin2-nacl.rd,
* testsuite/ld-x86-64/tlsbin2.rd,
* testsuite/ld-x86-64/tlsbindesc-nacl.rd,
* testsuite/ld-x86-64/tlsbindesc.rd,
* testsuite/ld-x86-64/tlsdesc-nacl.rd,
* testsuite/ld-x86-64/tlsdesc.rd,
* testsuite/ld-x86-64/tlsgdesc-nacl.rd,
* testsuite/ld-x86-64/tlsgdesc.rd,
* testsuite/ld-x86-64/tlspic-nacl.rd,
* testsuite/ld-x86-64/tlspic.rd,
* testsuite/ld-x86-64/tlspic2-nacl.rd,
* testsuite/ld-x86-64/tlspic2.rd: Update.
2018-06-08 18:47:34 +08:00
|
|
|
+[a-f0-9]+: e8 de ff ff ff call f0 <\*ABS\*@plt>
|
i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
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+[a-f0-9]+: 8d 83 4c ef ff ff lea -0x10b4\(%ebx\),%eax
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opcodes/i386: remove trailing whitespace from insns with zero operands
While working on another patch[1] I had need to touch this code in
i386-dis.c:
ins->obufp = ins->mnemonicendp;
for (i = strlen (ins->obuf) + prefix_length; i < 6; i++)
oappend (ins, " ");
oappend (ins, " ");
(*ins->info->fprintf_styled_func)
(ins->info->stream, dis_style_mnemonic, "%s", ins->obuf);
What this code does is add whitespace after the instruction mnemonic
and before the instruction operands.
The problem I ran into when working on this code can be seen by
assembling this input file:
.text
nop
retq
Now, when I disassemble, here's the output. I've replaced trailing
whitespace with '_' so that the issue is clearer:
Disassembly of section .text:
0000000000000000 <.text>:
0: 90 nop
1: c3 retq___
Notice that there's no trailing whitespace after 'nop', but there are
three spaces after 'retq'!
What happens is that instruction mnemonics are emitted into a buffer
instr_info::obuf, then instr_info::mnemonicendp is setup to point to
the '\0' character at the end of the mnemonic.
When we emit the whitespace, this is then added starting at the
mnemonicendp position. Lets consider 'retq', first the buffer is
setup like this:
'r' 'e' 't' 'q' '\0'
Then we add whitespace characters at the '\0', converting the buffer
to this:
'r' 'e' 't' 'q' ' ' ' ' ' ' '\0'
However, 'nop' is actually an alias for 'xchg %rax,%rax', so,
initially, the buffer is setup like this:
'x' 'c' 'h' 'g' '\0'
Then in NOP_Fixup we spot that we have an instruction that is an alias
for 'nop', and adjust the buffer to this:
'n' 'o' 'p' '\0' '\0'
The second '\0' is left over from the original buffer contents.
However, when we rewrite the buffer, we don't afjust mnemonicendp,
which still points at the second '\0' character.
Now, when we insert whitespace we get:
'n' 'o' 'p' '\0' ' ' ' ' ' ' ' ' '\0'
Notice the whitespace is inserted after the first '\0', so, when we
print the buffer, the whitespace is not printed.
The fix for this is pretty easy, I can change NOP_Fixup to adjust
mnemonicendp, but now a bunch of tests start failing, we now produce
whitespace after the 'nop', which the tests don't expect.
So, I could update the tests to expect the whitespace....
...except I'm not a fan of trailing whitespace, so I'd really rather
not.
Turns out, I can pretty easily update the whitespace emitting code to
spot instructions that have zero operands and just not emit any
whitespace in this case. So this is what I've done.
I've left in the fix for NOP_Fixup, I think updating mnemonicendp is
probably a good thing, though this is not really required any more.
I've then updated all the tests that I saw failing to adjust the
expected patterns to account for the change in whitespace.
[1] https://sourceware.org/pipermail/binutils/2022-April/120610.html
2022-05-26 20:11:11 +08:00
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+[a-f0-9]+: c3 ret
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i386: Improve PLT generation and synthetic PLT symbols
On i386, the procedure linkage table (PLT) is used to
1. Call external function.
2. Call internal IFUNC function. The best implementation is selected
for the target processor at run-time.
3. Act as the canonical function address.
4. Support LD_AUDIT to audit external function calls.
5. Support LD_PROFILE to profile external function calls.
PLT looks like:
PLT0: push GOT[1]
jmp *GOT[2]
nop
PLT1: jmp *GOT[name1_index]
push name1_reloc_index
jmp PLT0
GOT is an array of addresses. Initially the GOT entry of name1 is
filled with the address of the "push name1_reloc_index" instruction.
The function, name1, is called via "jmp *GOT[name1]" in the PLT entry.
Even when lazy binding is disabled by "-z now", the PLT0 entry may
still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
canonical function address.
1. With lazy binding, when the external function, name1, is called the
first time, dynamic linker is called via PLT0 to update GOT[name1_index]
with the actual address of name1 and transfers control to name1
afterwards.
2. PLT is also used to call a local IFUNC function, name1, run-time
loader updates GOT[name1_index] when loading the module.
This patch
1. Remove PLT layout configurations from i386 backend_data.
2. Add generic, lay and non-lazy PLT layout configurations to i386
link_hash_table. Generic PLT layout includes the PLT entry templates,
information how to update the first instruction in PLT and PLT eh_frame
informaton, which are initialized in i386 setup_gnu_properties, based
on PIC and target selection. PLT section alignment is also set to PLT
entry size for non-NaCl/VxWorks target.
3. Remove elf_i386_create_dynamic_sections. create_dynamic_sections
isn't always called, but GOT relocations need GOT relocations. Instead,
create all i386 specific dynamic sections in i386 setup_gnu_properties,
which initializes elf.dynobj, so that i386 check_relocs can be simplified.
4. Rewrite elf_i386_get_synthetic_symtab to check PLT sections against
all dynamic relocations to support both lazy and non-lazy PLTs.
bfd/
* elf32-i386.c (PLT_ENTRY_SIZE): Renamed to ...
(LAZY_PLT_ENTRY_SIZE): This.
(NON_LAZY_PLT_ENTRY_SIZE): New.
(elf_i386_plt0_entry): Renamed to ...
(elf_i386_lazy_plt0_entry): This.
(elf_i386_plt_entry): Renamed to ...
(elf_i386_lazy_plt_entry): This.
(elf_i386_pic_plt0_entry): Renamed to ...
(elf_i386_pic_lazy_plt0_entry): This.
(elf_i386_pic_plt_entry): Renamed to ...
(elf_i386_pic_lazy_plt_entry): This.
(elf_i386_got_plt_entry): Renamed to ...
(elf_i386_non_lazy_plt_entry): This.
(elf_i386_pic_got_plt_entry): Renamed to ...
(elf_i386_pic_non_lazy_plt_entry): This.
(elf_i386_eh_frame_plt): Renamed to ...
(elf_i386_eh_frame_lazy_plt): This.
(elf_i386_eh_frame_plt_got): Renamed to ...
(elf_i386_eh_frame_non_lazy_plt): This.
(elf_i386_plt_layout): Renamed to ...
(elf_i386_lazy_plt_layout): This. Remove eh_frame_plt_got and
eh_frame_plt_got_size.
(elf_i386_non_lazy_plt_layout): New.
(elf_i386_plt_layout): Likewise.
(elf_i386_non_lazy_plt): Likewise.
(GET_PLT_ENTRY_SIZE): Removed.
(elf_i386_plt): Renamed to ...
(elf_i386_lazy_plt): This.
(elf_i386_backend_data): Remove plt. Rename is_vxworks to os.
(elf_i386_arch_bed): Updated.
(elf_i386_link_hash_table): Add plt, lazy_plt and non_lazy_plt.
(elf_i386_create_dynamic_sections): Removed.
(elf_i386_check_relocs): Don't check elf.dynobj. Don't call
_bfd_elf_create_ifunc_sections nor _bfd_elf_create_got_section.
(elf_i386_adjust_dynamic_symbol): Updated.
(elf_i386_allocate_dynrelocs): Updated. Pass 0 as PLT header
size to _bfd_elf_allocate_ifunc_dyn_relocs and don't allocate
size for PLT0 if there is no PLT0.
(elf_i386_size_dynamic_sections): Updated. Check whether GOT
output section is discarded only if GOT isn't empty.
(elf_i386_relocate_section): Updated. Properly get PLT index
if there is no PLT0.
(elf_i386_finish_dynamic_symbol): Updated. Don't fill the
second and third slots in the PLT entry if there is no PLT0.
(elf_i386_finish_dynamic_sections): Updated. Don't fill PLT0
if there is no PLT0. Set sh_entsize on the .plt.got section.
(elf_i386_nacl_plt): Forward declaration.
(elf_i386_get_plt_sym_val): Removed.
(elf_i386_get_synthetic_symtab): Rewrite to check PLT sections
against all dynamic relocations.
(elf_i386_link_setup_gnu_properties): New function.
(elf_backend_create_dynamic_sections): Updated.
(elf_backend_setup_gnu_properties): New.
(elf_i386_nacl_plt): Updated.
(elf_i386_nacl_arch_bed): Likewise.
(elf_i386_vxworks_arch_bed): Likewise.
ld/
* testsuite/ld-i386/i386.exp: Add some -z now tests.
* testsuite/ld-i386/plt-pic2.dd: New file.
* testsuite/ld-i386/plt2.dd: Likewise.
* testsuite/ld-i386/plt2.rd: Likewise.
* testsuite/ld-i386/plt2.s: Likewise.
* testsuite/ld-ifunc/ifunc-16-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
* testsuite/ld-i386/pr20830.d: Update the .plt.got section
with func@plt.
2017-05-09 01:10:22 +08:00
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#pass
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