Go to file
Sudakshina Das 37c18eedff [BFD, LD, AArch64, 2/3] Add --force-bti to enable BTI and to select BTI enabled PLTs
This is part of the patch series to add support for BTI and
PAC in AArch64 linker.

1) This patch adds a new ld command line option: --force-bti.
In the presence of this option, the linker enables BTI with the
GNU_PROPERTY_AARCH64_FEATURE_1_BTI feature. This gives out warning
in case of missing gnu notes for BTI in inputs.
2) It also defines a new set of BTI enabled PLTs. These are used either
when all the inputs are marked with GNU_PROPERTY_AARCH64_FEATURE_1_BTI
or when the new --force-bti option is used. This required adding new
fields in elf_aarch64_link_hash_table so that we could make the PLT
related information more generic.
3) It also defines a dynamic tag DT_AARCH64_BTI_PLT. The linker uses
this whenever it picks BTI enabled PLTs.
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>
	    Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* bfd-in.h (aarch64_plt_type, aarch64_enable_bti_type): New.
	(aarch64_bti_pac_info): New.
	(bfd_elf64_aarch64_set_options): Add aarch64_bti_pac_info argument.
	(bfd_elf32_aarch64_set_options): Likewise.
	* bfd-in2.h: Regenerate
	* elfnn-aarch64.c (PLT_BTI_ENTRY_SIZE): New.
	(PLT_BTI_SMALL_ENTRY_SIZE, PLT_BTI_TLSDESC_ENTRY_SIZE): New.
	(elfNN_aarch64_small_plt0_bti_entry): New.
	(elfNN_aarch64_small_plt_bti_entry): New.
	(elfNN_aarch64_tlsdesc_small_plt_bti_entry): New.
	(elf_aarch64_obj_tdata): Add no_bti_warn and plt_type fields.
	(elf_aarch64_link_hash_table): Add plt0_entry, plt_entry and
	tlsdesc_plt_entry_size fields.
	(elfNN_aarch64_link_hash_table_create): Initialise the new fields.
	(setup_plt_values): New helper function.
	(bfd_elfNN_aarch64_set_options): Use new bp_info to set plt sizes and
	bti enable type.
	(elfNN_aarch64_allocate_dynrelocs): Use new size members instead of
	fixed macros.
	(elfNN_aarch64_size_dynamic_sections): Likewise and add checks.
	(elfNN_aarch64_create_small_pltn_entry): Use new generic pointers
	to plt stubs instead of fixed ones and update filling them according
	to the need for bti.
	(elfNN_aarch64_init_small_plt0_entry): Likewise.
	(elfNN_aarch64_finish_dynamic_sections): Likewise.
	(get_plt_type, elfNN_aarch64_get_synthetic_symtab): New.
	(elfNN_aarch64_plt_sym_val): Update size accordingly.
	(elfNN_aarch64_link_setup_gnu_properties): Set up plts if BTI GNU NOTE
	is set.
	(bfd_elfNN_get_synthetic_symtab): Define.
	(elfNN_aarch64_merge_gnu_properties): Give out warning with --force-bti
	and mising BTI NOTE SECTION.

*** binutils/ChangeLog ***

2019-03-13  Sudakshina Das  <sudi.das@arm.com>
	    Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* readelf.c (get_aarch64_dynamic_type): New.
	(get_dynamic_type): Use above for EM_AARCH64.
	(dynamic_section_aarch64_val): New.
	(process_dynamic_section): Use above for EM_AARCH64.

*** include/ChangeLog ***

2019-03-13  Sudakshina Das  <sudi.das@arm.com>
	    Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* elf/aarch64.h (DT_AARCH64_BTI_PLT): New.

*** ld/ChangeLog ***

2019-03-13  Sudakshina Das  <sudi.das@arm.com>
	    Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* NEWS: Document --force-bti.
	* emultempl/aarch64elf.em (plt_type, bti_type, OPTION_FORCE_BTI): New.
	(PARSE_AND_LIST_SHORTOPTS, PARSE_AND_LIST_OPTIONS): Add force-bti.
	(PARSE_AND_LIST_ARGS_CASES): Handle OPTION_FORCE_BTI.
	* testsuite/ld-aarch64/aarch64-elf.exp: Add all the tests below.
	* testsuite/ld-aarch64/bti-plt-1.d: New test.
	* testsuite/ld-aarch64/bti-plt-1.s: New test.
	* testsuite/ld-aarch64/bti-plt-2.s: New test.
	* testsuite/ld-aarch64/bti-plt-2.d: New test.
	* testsuite/ld-aarch64/bti-plt-3.d: New test.
	* testsuite/ld-aarch64/bti-plt-4.d: New test.
	* testsuite/ld-aarch64/bti-plt-5.d: New test.
	* testsuite/ld-aarch64/bti-plt-6.d: New test.
	* testsuite/ld-aarch64/bti-plt-7.d: New test.
	* testsuite/ld-aarch64/bti-plt-so.s: New test.
	* testsuite/ld-aarch64/bti-plt.ld: New test.
2019-03-13 11:47:07 +00:00
bfd [BFD, LD, AArch64, 2/3] Add --force-bti to enable BTI and to select BTI enabled PLTs 2019-03-13 11:47:07 +00:00
binutils [BFD, LD, AArch64, 2/3] Add --force-bti to enable BTI and to select BTI enabled PLTs 2019-03-13 11:47:07 +00:00
config Add markers for 2.32 branch to NEWS and ChangeLog files. 2019-01-19 15:55:50 +00:00
contrib
cpu Add markers for 2.32 branch to NEWS and ChangeLog files. 2019-01-19 15:55:50 +00:00
elfcpp Add markers for 2.32 branch to NEWS and ChangeLog files. 2019-01-19 15:55:50 +00:00
etc
gas dwarf2: Align relocation within .debug_line section 2019-03-13 13:29:35 +10:30
gdb The NEWS file had two "New targets" sections for 8.3. 2019-03-12 13:56:53 -07:00
gold Check whether symbols with MOVW_.ABS relocations require PLT entries (aarch64). 2019-02-19 16:13:24 -08:00
gprof Updated translations for various binutils subdirectories. 2019-01-21 12:59:20 +00:00
include [BFD, LD, AArch64, 2/3] Add --force-bti to enable BTI and to select BTI enabled PLTs 2019-03-13 11:47:07 +00:00
intl Change version to 2.32.51 and regenerate configure and pot files. 2019-01-19 16:51:42 +00:00
ld [BFD, LD, AArch64, 2/3] Add --force-bti to enable BTI and to select BTI enabled PLTs 2019-03-13 11:47:07 +00:00
libdecnumber
libiberty Fix splay tree KEY leak detected in GDB test gdb.base/macscp.exp 2019-02-12 06:06:19 -07:00
opcodes Add missing changelogs for previous commits. 2019-03-12 14:23:21 +01:00
readline Readline: Cleanup some warnings 2019-01-31 17:25:06 +00:00
sim (gdb/sim) Move Mike Frysinger to past maintainers section 2019-02-28 11:20:29 +04:00
texinfo
zlib
.cvsignore
.gitattributes
.gitignore
ar-lib
ChangeLog Add markers for 2.32 branch to NEWS and ChangeLog files. 2019-01-19 15:55:50 +00:00
compile
config-ml.in
config.guess Sync config.guess, config.sub from GCC 2019-01-14 15:47:35 +01:00
config.rpath
config.sub Sync config.guess, config.sub from GCC 2019-01-14 15:47:35 +01:00
configure Don't build readline/libreadline.a, when --with-system-readline is supplied 2019-01-03 00:03:34 -05:00
configure.ac Don't build readline/libreadline.a, when --with-system-readline is supplied 2019-01-03 00:03:34 -05:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4
lt~obsolete.m4
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS
Makefile.def
Makefile.in
Makefile.tpl
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
multilib.am
README
README-maintainer-mode
setup.com
src-release.sh Move potentially obsolete BFD targets into the definitely obsolete section. Add a note to the README-how-to-make-a-release document about doing this. 2019-02-07 14:30:02 +00:00
symlink-tree
test-driver
ylwrap

		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.