binutils-gdb/ld
Alan Modra 1be5d8d3bb PowerPC PLT speculative execution barriers
Spectre variant 2 mitigation for PowerPC and PowerPC64.

bfd/
	* elf32-ppc.c (GLINK_ENTRY_SIZE): Handle speculation barrier.
	(CRSETEQ, BEQCTRM): Define.
	(is_nonpic_glink_stub): Don't check bctr.
	(ppc_elf_link_hash_table_create): Init new ppc_elf_params field.
	(ppc_elf_relax_section): Size speculation barrier.
	(output_bctr): New function.
	(write_glink_stub): Use output_bctr.
	(ppc_elf_relocate_section): Use output_bctr for long branch stub.
	(ppc_elf_finish_dynamic_symbol): Likewise.
	(ppc_elf_finish_dynamic_sections): Use output_bctr.
	* elf32-ppc.h (struct ppc_elf_params): Add speculate_indirect_jumps.
	* elf64-ppc.c (CRSETEQ, BEQCTRM, BEQCTRLM): Define.
	(GLINK_PLTRESOLVE_SIZE): Size speculation barrier.
	(size_global_entry_stubs): Handle speculation barrier sizing.
	(plt_stub_size): Likewise.
	(output_bctr): New function.
	(build_plt_stub, build_tls_get_addr_stub): Output speculation
	barrier.
	(ppc_build_one_stub): Likewise for ppc_stub_plt_branch.
	(ppc_size_one_stub): Size speculation barrier in ppc_stub_plt_branch.
	(build_global_entry_stubs): Output speculation barrier.
	(ppc64_elf_build_stubs): Likewise in __glink_PLTresolve stub.
	* elf64-ppc.h (struct ppc64_elf_params): Add speculate_indirect_jumps.
gold/
	* options.h (speculate_indirect_jumps): New option.
	* powerpc.cc (beqctrm, beqctrlm, crseteq): New insn constants.
	(output_bctr): New function.
	(Stub_table::plt_call_size): Add space for speculation barrier.
	(Stub_table::branch_stub_size): Likewise.
	(Output_data_glink::pltresolve_size): Likewise.
	(Stub_table::do_write): Output speculation barriers.
ld/
	* emultempl/ppc32elf.em (params): Init new field.
	(OPTION_SPECULATE_INDIRECT_JUMPS): Define.
	(OPTION_NO_SPECULATE_INDIRECT_JUMPS): Define.
	(PARSE_AND_LIST_LONGOPTS): Handle new options.
	(PARSE_AND_LIST_ARGS_CASES): Likewise.
	(PARSE_AND_LIST_OPTIONS): Likewise.
	* emultempl/ppc64elf.em (params): Init new field.
	(OPTION_SPECULATE_INDIRECT_JUMPS): Define.
	(OPTION_NO_SPECULATE_INDIRECT_JUMPS): Define.
	(PARSE_AND_LIST_LONGOPTS): Handle --speculate-indirect-jumps.
	(PARSE_AND_LIST_OPTIONS): Likewise.
	(PARSE_AND_LIST_ARGS_CASES): Likewise.
	* ld.texinfo (--no-plt-thread-safe): Correct itemx.
	(--speculate-indirect-jumps): Document.
	* testsuite/ld-powerpc/elfv2exe.d,
	* testsuite/ld-powerpc/elfv2so.d,
	* testsuite/ld-powerpc/relbrlt.d,
	* testsuite/ld-powerpc/powerpc.exp: Disable plt alignment and
	speculation barriers on various tests.
2018-01-17 18:52:57 +10:30
..
emulparams RISC-V: Disable shared library support for embedded elf. 2018-01-05 14:29:49 -08:00
emultempl PowerPC PLT speculative execution barriers 2018-01-17 18:52:57 +10:30
po Update translations for various binutils components. 2018-01-16 12:45:44 +00:00
scripttempl ld: Add "-z separate-code" option to ELF linker 2018-01-11 19:01:52 -08:00
testsuite PowerPC PLT speculative execution barriers 2018-01-17 18:52:57 +10:30
.gitignore
aclocal.m4
ChangeLog PowerPC PLT speculative execution barriers 2018-01-17 18:52:57 +10:30
ChangeLog-0001
ChangeLog-0203
ChangeLog-2004
ChangeLog-2005
ChangeLog-2006
ChangeLog-2007
ChangeLog-2008
ChangeLog-2009
ChangeLog-2010
ChangeLog-2011
ChangeLog-2012
ChangeLog-2013
ChangeLog-2014
ChangeLog-2015
ChangeLog-2016
ChangeLog-2017
ChangeLog-9197
ChangeLog-9899
config.in
configure Bump version number to 2.30.51 2018-01-13 13:31:12 +00:00
configure.ac
configure.host
configure.tgt
deffile.h
deffilep.y
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi
genscrba.sh
genscripts.sh ld: Add "-z separate-code" option to ELF linker 2018-01-11 19:01:52 -08:00
h8-doc.texi
ld.h
ld.texinfo PowerPC PLT speculative execution barriers 2018-01-17 18:52:57 +10:30
ldbuildid.c
ldbuildid.h
ldcref.c
ldctor.c
ldctor.h
ldemul.c
ldemul.h
ldexp.c ld: Remove unused expression state 2018-01-11 17:35:35 +00:00
ldexp.h ld: Remove unused expression state 2018-01-11 17:35:35 +00:00
ldfile.c
ldfile.h
ldgram.y
ldint.texinfo
ldlang.c ld: Fix issue where PROVIDE overrides defined symbol 2018-01-11 17:35:35 +00:00
ldlang.h
ldlex-wrapper.c
ldlex.h
ldlex.l
ldmain.c
ldmain.h
ldmisc.c
ldmisc.h
ldver.c
ldver.h
ldwrite.c
ldwrite.h
lexsup.c ld: Add "-z separate-code" option to ELF linker 2018-01-11 19:01:52 -08:00
MAINTAINERS
Makefile.am
Makefile.in
mri.c
mri.h
NEWS Add 2.30 markers to NEWS files. 2018-01-13 13:20:55 +00:00
pe-dll.c
pe-dll.h
pep-dll.c
pep-dll.h
plugin.c
plugin.h
README
stamp-h.in
sysdep.h
testplug2.c
testplug3.c
testplug4.c
testplug.c
TODO

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		README for LD

This is the GNU linker.  It is distributed with other "binary
utilities" which should be in ../binutils.  See ../binutils/README for
more general notes, including where to send bug reports.

There are many features of the linker:

* The linker uses a Binary File Descriptor library (../bfd)
  that it uses to read and write object files.  This helps
  insulate the linker itself from the format of object files.

* The linker supports a number of different object file
  formats.  It can even handle multiple formats at once:
  Read two input formats and write a third.

* The linker can be configured for cross-linking.

* The linker supports a control language.

* There is a user manual (ld.texinfo), as well as the
  beginnings of an internals manual (ldint.texinfo).

Installation
============

See ../binutils/README.

If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile
or using the --with-lib-path configure switch.

To build just the linker, make the target all-ld from the top level
directory (one directory above this one).

Porting to a new target
=======================

See the ldint.texinfo manual.

Reporting bugs etc
===========================

See ../binutils/README.

Known problems
==============

The Solaris linker normally exports all dynamic symbols from an
executable.  The GNU linker does not do this by default.  This is
because the GNU linker tries to present the same interface for all
similar targets (in this case, all native ELF targets).  This does not
matter for normal programs, but it can make a difference for programs
which try to dlopen an executable, such as PERL or Tcl.  You can make
the GNU linker export all dynamic symbols with the -E or
--export-dynamic command line option.

HP/UX 9.01 has a shell bug that causes the linker scripts to be
generated incorrectly.  The symptom of this appears to be "fatal error
- scanner input buffer overflow" error messages.  There are various
workarounds to this:
  * Build and install bash, and build with "make SHELL=bash".
  * Update to a version of HP/UX with a working shell (e.g., 9.05).
  * Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
    genscripts.sh with "sh ${srcdir}..." (no parens) and make sure the
    emulparams script used exports any shell variables it sets.

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