Go to file
Alan Modra 08be322439 PowerPC PLT16 relocations
The PowerPC64 ELFv2 ABI and the PowerPC SysV ABI support a number of
relocations that can be used to create and access a PLT entry.
However, the relocs are not well defined.  The PLT16 family of relocs
talk about "the section offset or address of the procedure linkage
table entry".  It's plain that we do need a relative address when PIC
as otherwise we'd have dynamic text relocations, but "section offset"
doesn't specify which section.  The most obvious one, ".plt", isn't
that useful because there is no readily available way of addressing
the start of the ".plt" section.  Much more useful would be "the
GOT/TOC-pointer relative offset of the procedure linkage table entry",
and I suppose you could argue that is a "section offset" of sorts.
For PowerPC64 it is better to use the same TOC-pointer relative
addressing even when non-PIC, since ".plt" may be located outside the
range of a 32-bit address.  However, for ppc32 we do want an absolute
address when non-PIC as a GOT pointer may not be set up.  Also, for
ppc32 PIC we have a similar situation to R_PPC_PLTREL24 in that the
GOT pointer is set to a location in the .got2 section and we need to
specify the .got2 offset in the PLT16 reloc addend.

This patch supports PLT16 relocations using these semantics.  This is
not an ABI change for ppc32 since the relocations were not previously
supported by GNU ld, but is for ppc64 where some of the PLT16 relocs
were supported.  I'm not particularly concerned since the old ppc64
PLT16 reloc semantics made them almost completely useless.

bfd/
	* elf32-ppc.c (ppc_elf_check_relocs): Handle PLT16 relocs.
	(ppc_elf_relocate_section): Likewise.
	* elf64-ppc.c (ppc64_elf_check_relocs): Handle PLT16_LO_DS.
	(ppc64_elf_relocate_section): Likewise.  Correct PLT16
	resolution to plt entry relative to toc pointer.
gold/
	* powerpc.cc (Target_powerpc::plt_off): New functions.
	(is_plt16_reloc): New function.
	(Stub_table::plt_off): Use Target_powerpc::plt_off.
	(Stub_table::plt_call_size): Use plt_off.
	(Stub_table::do_write): Likewise.
	(Target_powerpc::Scan::get_reference_flags): Return RELATIVE_REF
	for PLT16 relocations.
	(Target_powerpc::Scan::reloc_needs_plt_for_ifunc): Return true
	for PLT16 relocations.
	(Target_powerpc::Scan::global): Make a PLT entry for PLT16 relocations.
	(Target_powerpc::Relocate::relocate): Support PLT16 relocations.
	(Powerpc_scan_relocatable_reloc::global_strategy): Return RELOC_SPECIAL
	for ppc32 plt16 relocs.
2018-04-09 16:56:35 +09:30
bfd PowerPC PLT16 relocations 2018-04-09 16:56:35 +09:30
binutils Display all DWARF 5 language names 2018-04-06 10:58:34 -06:00
config config: Sync with GCC 2018-04-05 15:22:13 -07:00
cpu
elfcpp Add support for R_AARCH64_TLSLE_LDST8_TPREL_LO12, etc. 2018-03-28 09:10:25 -07:00
etc
gas Use dlsym to check if libdl is needed for plugin 2018-04-05 15:31:53 -07:00
gdb Fix gdb.mi/mi-stack.exp when gcc generates a stack protector 2018-04-07 14:09:14 -04:00
gold PowerPC PLT16 relocations 2018-04-09 16:56:35 +09:30
gprof Use dlsym to check if libdl is needed for plugin 2018-04-05 15:31:53 -07:00
include [1/2][GAS][AARCH64]Add BFD_RELOC_AARCH64_TLSLE_LDST8/16/32/64_TPREL_LO12 support in GAS. 2018-03-28 18:03:55 +01:00
intl
ld Use dlsym to check if libdl is needed for plugin 2018-04-05 15:31:53 -07:00
libdecnumber
libiberty
opcodes i386: Clear vex instead of vex.evex 2018-04-04 04:36:44 -07:00
readline
sim
texinfo
zlib
.cvsignore
.gitattributes
.gitignore
ChangeLog
compile
config-ml.in
config.guess
config.rpath
config.sub
configure
configure.ac
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
README
README-maintainer-mode
setup.com
src-release.sh
symlink-tree
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.