[BFD, LD, AArch64, 3/3] Add --pac-plt to enable PLTs protected with PAC.
authorSudakshina Das <sudi.das@arm.com>
Wed, 13 Mar 2019 11:09:10 +0000 (11:09 +0000)
committerSudakshina Das <sudi.das@arm.com>
Wed, 13 Mar 2019 11:47:33 +0000 (11:47 +0000)
commit1dbade7441b9f32d6ba9aa1d44da5f28c44282fa
treedcf3b55249f9b6eafdd883ecf134ccc87dba800b
parent37c18eedffe3926a330149ca93e7407917e2be38
[BFD, LD, AArch64, 3/3] Add --pac-plt to enable PLTs protected with PAC.

This is part of the patch series to add support for BTI and
PAC in AArch64 linker.

1) This patch adds new definitions of PAC enabled PLTs
and both BTI and PAC enabled PLTs.
2) It also defines the new dynamic tag DT_AARCH64_PAC_PLT
for the PAC enabled PLTs.
3) This patch adds a new ld command line option: --pac-plt.
In the presence of this option, the linker uses the PAC
enabled PLTs and marks with DT_AARCH64_PAC_PLT.
4) In case both BTI and PAC are enabled the linker should
pick PLTs enabled with both and also use dynamic tags for both.
All these are made according to the new AArch64 ELF ABI
https://developer.arm.com/docs/ihi0056/latest/elf-for-the-arm-64-bit-architecture-aarch64-abi-2018q4

*** bfd/ChangeLog ***

2019-03-13  Sudakshina Das  <sudi.das@arm.com>

* elfnn-aarch64.c (PLT_PAC_ENTRY_SIZE, PLT_PAC_SMALL_ENTRY_SIZE): New.
(PLT_BTI_PAC_ENTRY_SIZE, PLT_BTI_PAC_SMALL_ENTRY_SIZE): New.
(setup_plt_values): Account for PAC or PAC and BTI enabled PLTs.
(elfNN_aarch64_size_dynamic_sections): Add checks for PLT_BTI_PAC
and PLT_PAC_PLT.
(elfNN_aarch64_finish_dynamic_sections): Account for PLT_BTI_PAC.
(get_plt_type): Add case for DT_AARCH64_PAC_PLT.
(elfNN_aarch64_plt_sym_val): Add cases for PLT_BTI_PAC and PLT_PAC.

*** binutils/ChangeLog ***

2019-03-13  Sudakshina Das  <sudi.das@arm.com>

* readelf.c (get_aarch64_dynamic_type): Add case for
DT_AARCH64_PAC_PLT.
(dynamic_section_aarch64_val): Likewise.

*** include/ChangeLog ***

2019-03-13  Sudakshina Das  <sudi.das@arm.com>

* elf/aarch64.h (DT_AARCH64_PAC_PLT): New.

*** ld/ChangeLog ***

2019-03-13  Sudakshina Das  <sudi.das@arm.com>

* NEWS: Document --pac-plt.
* emultempl/aarch64elf.em (OPTION_PAC_PLT): New.
(PARSE_AND_LIST_LONGOPTS, PARSE_AND_LIST_OPTIONS): Add pac-plt.
(PARSE_AND_LIST_ARGS_CASES): Handle OPTION_PAC_PLT.
* testsuite/ld-aarch64/aarch64-elf.exp: Add the following tests.
* testsuite/ld-aarch64/bti-pac-plt-1.d: New test.
* testsuite/ld-aarch64/bti-pac-plt-2.d: New test.
* testsuite/ld-aarch64/pac-plt-1.d: New test.
* testsuite/ld-aarch64/pac-plt-2.d: New test.
* testsuite/ld-aarch64/bti-plt-1.s: Add .ifndef directive.
15 files changed:
bfd/ChangeLog
bfd/elfnn-aarch64.c
binutils/ChangeLog
binutils/readelf.c
include/ChangeLog
include/elf/aarch64.h
ld/ChangeLog
ld/NEWS
ld/emultempl/aarch64elf.em
ld/testsuite/ld-aarch64/aarch64-elf.exp
ld/testsuite/ld-aarch64/bti-pac-plt-1.d [new file with mode: 0644]
ld/testsuite/ld-aarch64/bti-pac-plt-2.d [new file with mode: 0644]
ld/testsuite/ld-aarch64/bti-plt-1.s
ld/testsuite/ld-aarch64/pac-plt-1.d [new file with mode: 0644]
ld/testsuite/ld-aarch64/pac-plt-2.d [new file with mode: 0644]