c213164ad2
This patch supports using pcrel instructions in TLS code sequences. A number of new relocations are needed, gas operand modifiers to generate those relocations, and new TLS optimisation. For optimisation it turns out that the new pcrel GD and LD sequences can be distinguished from the non-pcrel GD and LD sequences by there being different relocations on the new sequence. The final "add ra,rb,13" on IE sequences similarly needs a new relocation, or as I chose, a modification of R_PPC64_TLS. On pcrel IE code, the R_PPC64_TLS points one byte into the "add" instruction rather than being on the instruction boundary. GD: pla 3,z@got@tlsgd@pcrel # R_PPC64_GOT_TLSGD34 bl __tls_get_addr@notoc(z@tlsgd) # R_PPC64_TLSGD and R_PPC64_REL24_NOTOC edited to IE pld 3,z@got@tprel@pcrel add 3,3,13 edited to LE paddi 3,13,z@tprel nop LD: pla 3,z@got@tlsld@pcrel # R_PPC64_GOT_TLSLD34 bl __tls_get_addr@notoc(z@tlsld) # R_PPC64_TLSLD and R_PPC64_REL24_NOTOC .. paddi 9,3,z2@dtprel pld 10,z3@got@dtprel@pcrel add 10,10,3 edited to LE paddi 3,13,0x1000 nop IE: pld 9,z@got@tprel@pcrel # R_PPC64_GOT_TPREL34 add 3,9,z@tls@pcrel # R_PPC64_TLS at insn+1 ldx 4,9,z@tls@pcrel lwax 5,9,z@tls@pcrel stdx 5,9,z@tls@pcrel edited to LE paddi 9,13,z@tprel nop ld 4,0(9) lwa 5,0(9) std 5,0(9) LE: paddi 10,13,z@tprel include/ * elf/ppc64.h (R_PPC64_TPREL34, R_PPC64_DTPREL34), (R_PPC64_GOT_TLSGD34, R_PPC64_GOT_TLSLD34), (R_PPC64_GOT_TPREL34, R_PPC64_GOT_DTPREL34): Define. (IS_PPC64_TLS_RELOC): Include new tls relocs. bfd/ * reloc.c (BFD_RELOC_PPC64_TPREL34, BFD_RELOC_PPC64_DTPREL34), (BFD_RELOC_PPC64_GOT_TLSGD34, BFD_RELOC_PPC64_GOT_TLSLD34), (BFD_RELOC_PPC64_GOT_TPREL34, BFD_RELOC_PPC64_GOT_DTPREL34), (BFD_RELOC_PPC64_TLS_PCREL): New pcrel tls relocs. * elf64-ppc.c (ppc64_elf_howto_raw): Add howtos for pcrel tls relocs. (ppc64_elf_reloc_type_lookup): Translate pcrel tls relocs. (must_be_dyn_reloc, dec_dynrel_count): Add R_PPC64_TPREL64. (ppc64_elf_check_relocs): Support pcrel tls relocs. (ppc64_elf_tls_optimize, ppc64_elf_relocate_section): Likewise. * bfd-in2.h: Regenerate. * libbfd.h: Regenerate. gas/ * config/tc-ppc.c (ppc_elf_suffix): Map "tls@pcrel", "got@tlsgd@pcrel", "got@tlsld@pcrel", "got@tprel@pcrel", and "got@dtprel@pcrel". (fixup_size, md_assemble): Handle pcrel tls relocs. (ppc_force_relocation, ppc_fix_adjustable): Likewise. (md_apply_fix, tc_gen_reloc): Likewise. ld/ * testsuite/ld-powerpc/tlsgd.d, * testsuite/ld-powerpc/tlsgd.s, * testsuite/ld-powerpc/tlsie.d, * testsuite/ld-powerpc/tlsie.s, * testsuite/ld-powerpc/tlsld.d, * testsuite/ld-powerpc/tlsld.s: New tests. * testsuite/ld-powerpc/powerpc.exp: Run them. |
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.. | ||
emulparams | ||
emultempl | ||
po | ||
scripttempl | ||
testsuite | ||
.gitignore | ||
aclocal.m4 | ||
ChangeLog | ||
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-2018 | ||
ChangeLog-9197 | ||
ChangeLog-9899 | ||
config.in | ||
configure | ||
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 | ||
h8-doc.texi | ||
ld.h | ||
ld.texi | ||
ldbuildid.c | ||
ldbuildid.h | ||
ldcref.c | ||
ldctor.c | ||
ldctor.h | ||
ldemul.c | ||
ldemul.h | ||
ldexp.c | ||
ldexp.h | ||
ldfile.c | ||
ldfile.h | ||
ldgram.y | ||
ldint.texi | ||
ldlang.c | ||
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 | ||
MAINTAINERS | ||
Makefile.am | ||
Makefile.in | ||
mri.c | ||
mri.h | ||
NEWS | ||
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 |
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.texi), as well as the
beginnings of an internals manual (ldint.texi).
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.texi 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.
Copyright (C) 2012-2019 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.